[Three dimensional finite element analysis of maxillary anterior teeth retraction with micro-implant anchorage and sliding mechanics].

Science.gov (United States)

Zhang, Yi; Zhang, Lei; Fan, Yu-bo; Song, Jin-lin; Deng, Feng

2009-10-01

To investigate the biomechanical effects of micro-implant anchorage technique with sliding mechanics on maxillary anterior teeth retraction under different implant insertion heights and different retraction hook heights. The three dimensional finite element model of maxillary anterior teeth retraction force system was constructed with CT scanning and MIMICS software and the relationships between brackets, teeth, wire and micro-implant were simulating the clinical factions. Then the initial tooth displacement was calculated when the insertion heights were 4 mm and 8 mm and the retraction hook heights were 1, 4, 7, 10 mm respectively. With retraction hook height added, the anterior teeth movement changed from lingual crown tipping to labial crown tipping and the intrusion movement was more apparent when the micro-implant was inserted in a higher location. The ideal teeth movement control could be achieved by different insertion heights of micro-implant and different retraction hook heights in straight wire retraction force system.

Gingival Retraction Methods: A Systematic Review.

Science.gov (United States)

Tabassum, Sadia; Adnan, Samira; Khan, Farhan Raza

2017-12-01

The aim of this systematic review was to assess the gingival retraction methods in terms of the amount of gingival retraction achieved and changes observed in various clinical parameters: gingival index (GI), plaque index (PI), probing depth (PD), and attachment loss (AL). Data sources included three major databases, PubMed, CINAHL plus (Ebsco), and Cochrane, along with hand search. Search was made using the key terms in different permutations of gingival retraction* AND displacement method* OR technique* OR agents OR material* OR medicament*. The initial search results yielded 145 articles which were narrowed down to 10 articles using a strict eligibility criteria of including clinical trials or experimental studies on gingival retraction methods with the amount of tooth structure gained and assessment of clinical parameters as the outcomes conducted on human permanent teeth only. Gingival retraction was measured in 6/10 studies whereas the clinical parameters were assessed in 5/10 studies. The total number of teeth assessed in the 10 included studies was 400. The most common method used for gingival retraction was chemomechanical. The results were heterogeneous with regards to the outcome variables. No method seemed to be significantly superior to the other in terms of gingival retraction achieved. Clinical parameters were not significantly affected by the gingival retraction method. © 2016 by the American College of Prosthodontists.

RETRACTED: A novel membrane-based anti-diabetic action of atorvastatin

Energy Technology Data Exchange (ETDEWEB)

Horvath, Emily M.; Tackett, Lixuan [Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Center for Diabetes Research, VanNuys Medical Science, Building Rm 308A, Indianapolis, IN 46202 (United States); Elmendorf, Jeffrey S., E-mail: jelmendo@iupui.edu [Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Center for Diabetes Research, VanNuys Medical Science, Building Rm 308A, Indianapolis, IN 46202 (United States); Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Center for Diabetes Research, Indianapolis, IN 46202 (United States)

2008-08-08

This article has been retracted. Please see Elsevier Policy on Article Withdrawal ((http://www.elsevier.com/locate/withdrawalpolicy)). Reason: The editors would like to confirm the retraction of this paper at the request of the authors. One of the authors, Emily M. Horvath, admitted to altering data in two of the figures. Specifically in Figures 2, and 4A, some of the values were incorrectly reported for the radioactive glucose uptake assays. None of the other authors associated with this publication were aware of the data manipulation. The authors sincerely regret if this has caused problems with investigators that have used this information experimentally.

RETRACTED: A novel membrane-based anti-diabetic action of atorvastatin

International Nuclear Information System (INIS)

Horvath, Emily M.; Tackett, Lixuan; Elmendorf, Jeffrey S.

2008-01-01

This article has been retracted. Please see Elsevier Policy on Article Withdrawal ((http://www.elsevier.com/locate/withdrawalpolicy)). Reason: The editors would like to confirm the retraction of this paper at the request of the authors. One of the authors, Emily M. Horvath, admitted to altering data in two of the figures. Specifically in Figures 2, and 4A, some of the values were incorrectly reported for the radioactive glucose uptake assays. None of the other authors associated with this publication were aware of the data manipulation. The authors sincerely regret if this has caused problems with investigators that have used this information experimentally.

Corticotomy-assisted retraction: An outcome assessment

Directory of Open Access Journals (Sweden)

S Vijayashri Sakthi

2014-01-01

Conclusion: The rate of retraction with study group was twice as faster when compared to the control group, accelerating during the first 2 months of retraction. There was better anchorage control with the undecorticated molar segment during the retraction period but was found to increase as time advanced.

The (lack of) impact of retraction on citation networks.

Science.gov (United States)

Madlock-Brown, Charisse R; Eichmann, David

2015-02-01

Article retraction in research is rising, yet retracted articles continue to be cited at a disturbing rate. This paper presents an analysis of recent retraction patterns, with a unique emphasis on the role author self-cites play, to assist the scientific community in creating counter-strategies. This was accomplished by examining the following: (1) A categorization of retracted articles more complete than previously published work. (2) The relationship between citation counts and after-retraction self-cites from the authors of the work, and the distribution of self-cites across our retraction categories. (3) The distribution of retractions written by both the author and the editor across our retraction categories. (4) The trends for seven of our nine defined retraction categories over a 6-year period. (5) The average journal impact factor by category, and the relationship between impact factor, author self-cites, and overall citations. Our findings indicate new reasons for retractions have emerged in recent years, and more editors are penning retractions. The rates of increase for retraction varies by category, and there is statistically significant difference of average impact factor between many categories. 18 % of authors self-cite retracted work post retraction with only 10 % of those authors also citing the retraction notice. Further, there is a positive correlation between self-cites and after retraction citations.

The level’s changing of transforming growth factor β2 during canine retraction in non-growing age patient

Directory of Open Access Journals (Sweden)

Adianti Adianti

2015-06-01

Full Text Available Background: Orthodontic tooth movement occurred as a result of alveolar bone remodeling and collagen due to mechanical load. This mechanical load applied to the tooth will exert a number of cytokine and growth factors. One of the growth factors that are often associated with orthodontic tooth movement is transforming growth factor-β(TGF-β. It has 3 isoforms, TGF-β1, TGF-β2, and TGF-β3. It has been known that in adult patient, tooth movement rate was slower. Purpose: The aim of this study was to investigate the changing level of TGF-β2 in non-growing patient due to mechanical load in canine retraction. Method: Gingival crevicular fluid from 6 subjects who undergo canine retraction was taken to investigate changing level of TGF-β2. Distal site of each upper canine served as an experimental tooth. The gingival crevicular fluid from experimental tooth was taken just prior to mechanical load, at 24h and 72h after mechanical load. Result: ELISA reader showed that level of TGF-β2 was decreasing during experiment time. Conclusion: It can be concluded that in non-growing patient, TGF-β2 has less role in alveolar bone resorption in orthodontic tooth movement.

CT features of malignant hepatic tumors : the significance of capsular retraction

International Nuclear Information System (INIS)

Seo, Bo Kyoung; Rhee, Ji Yong; Seol, Hae Young; Lee, Ki Yeol; Park, Cheol Min; Chung, Kyoo Byung

1998-01-01

To evaluate the prevalence of capsular retraction in malignant hepatic tumors and the factors involved. Between January 1994 and December 1996, we retrospectively reviewed the CT scans of 152 patients with pathologically-proven, peripherally-located, malignant hepatic tumors. We evaluated size, site, portal and hepatic venous obstruction, bile duct dilatation, and liver atrophy in 18 cases involving capsular retraction. The overall prevalence of capsular retraction among malignant hepatic tumors was 18/152 (12 %); the prevalence was 9/129 (7%) in hepatocellular carcinoma, 6/14 (43 %) in cholangiocarcinoma and 3/9 (33 %) in metastatic cancer; among cases of cholangiocarcinoma and metastatic cancer, the prevalence was high (p<0.05). Portal venous obstruction was seen in six patients with hepatocellular carcinoma ( a high incidence; p=0.04) and one with cholangiocarcinoma. Hepatic venous obstruction was demonstrated in one patient with hepatocellular carcinoma and one with cholangiocarcinoma. Among cholangiocarcinoma patients, bile duct obstruction was seen in four and liver atrophy in three, but among metastatic cancer cases there were no similar findings. The main factors causing capsular retraction were portal venous obstruction in hepatocellular carcinoma and bile duct obstruction and liver atrophy in cholangiocarcinoma. (author). 16 refs., 3 figs

Thermal transport in oblique finned microminichannels

CERN Document Server

Fan, Yan; Singh, Pawan Kumar; Lee, Yong Jiun

2015-01-01

The main aim of this book is to introduce and give an overview of a novel, easy, and highly effective heat transfer augmentation technique for single-phase micro/minichannel heat sink. The specific objectives of the volume are to: Introduce a novel planar oblique fin microchannel and cylindrical oblique fin minichannel heat sink design using passive heat transfer enhancement techniques  Investigate the thermal transport in both planar and cylindrical oblique fin structures through numerical simulation and systematic experimental studies. Evaluate the feasibility of employing the proposed solution in cooling non-uniform heat fluxes and hotspot suppression Conduct the similarity analysis and parametric study to obtain empirical correlations to evaluate the total heat transfer rate of the oblique fin heat sink Investigate the flow mechanism and optimize the dimensions of cylindrical oblique fin heat sink Investigate the influence of edge effect on flow and temperature uniformity in these oblique fin chan...

Fully-Implicit Navier-Stokes (FIN-S)

Science.gov (United States)

Kirk, Benjamin S.

2010-01-01

FIN-S is a SUPG finite element code for flow problems under active development at NASA Lyndon B. Johnson Space Center and within PECOS: a) The code is built on top of the libMesh parallel, adaptive finite element library. b) The initial implementation of the code targeted supersonic/hypersonic laminar calorically perfect gas flows & conjugate heat transfer. c) Initial extension to thermochemical nonequilibrium about 9 months ago. d) The technologies in FIN-S have been enhanced through a strongly collaborative research effort with Sandia National Labs.

Advanced microchannel heat exchanger with S-shaped fins

International Nuclear Information System (INIS)

Tsuzuki, Nobuyoshi; Ishizuka, Takao; Kato, Yasuyoshi; Nikitin, Konstantin

2009-01-01

Fin shape effects on thermal-hydraulic characteristics were studied for a Microchannel Heat Exchanger (MCHE) with S-shaped fins using 3D-CFD and changing the fin parameters: fin angle, overlapping length, fin width, fin length, and edge roundness. The fin angle effect on the pressure drop is consistent with the equation obtained experimentally by Weisbach for a circular bent tube: the pressure drop in the S-shaped fin configuration results from bent flow. The overlap of fins with those located immediately downstream at the offset position provides a guide wing effect that reduces the pressure drop remarkably. The overlap was changed by changing the fin radial position and arc length. The pressure drop was minimized when the downstream fins are placed in the middle of the bent flow channels formed by the fins upstream, which differs from Ito's configuration obtained from experiments with a single bent duct. Regarding arc length, the pressure drop is minimized at the standard overlapping length, which was formed to have the longest arc without a change in channel width. Shorter arc lengths from the optimum value by 30 and 50%, respectively, give 2.4 and 4.6% decreases in the heat transfer rate and 17 and 13% increases in the pressure drop. Thinner fins show better thermal-hydraulic performance for fin widths of 0.2-0.8 mm. However, the pressure drop reduced by the longer fin and heat transfer rate was also reduced. Rounded fins with 0.1 mm radius increased the pressure drop by about 30% compared with that of the fin designed with no roundness. (author)

Topological stability through extremely tame retractions

DEFF Research Database (Denmark)

Feragen, Aasa

2012-01-01

not know whether f will be topologically stable if we can find a pair of continuous retractions r and s. The class of extremely tame (E-tame) retractions, introduced by du Plessis and Wall, are defined by their nice geometric properties, which are sufficient to ensure that f is topologically stable....... In this article, we present the E-tame retractions and their relation with topological stability, survey recent results by the author concerning their construction, and illustrate the use of our techniques by constructing E-tame retractions for certain germs belonging to the E- and Z-series of singularities....

Endogenous fibrinolysis facilitates clot retraction in vivo.

Science.gov (United States)

Samson, Andre L; Alwis, Imala; Maclean, Jessica A A; Priyananda, Pramith; Hawkett, Brian; Schoenwaelder, Simone M; Jackson, Shaun P

2017-12-07

Clot retraction refers to the process whereby activated platelets transduce contractile forces onto the fibrin network of a thrombus, which over time increases clot density and decreases clot size. This process is considered important for promoting clot stability and maintaining blood vessel patency. Insights into the mechanisms regulating clot retraction at sites of vascular injury have been hampered by a paucity of in vivo experimental models. By pairing localized vascular injury with thrombin microinjection in the mesenteric circulation of mice, we have demonstrated that the fibrin network of thrombi progressively compacts over a 2-hour period. This was a genuine retraction process, as treating thrombi with blebbistatin to inhibit myosin IIa-mediated platelet contractility prevented shrinkage of the fibrin network. Real-time confocal analysis of fibrinolysis after recombinant tissue-type plasminogen activator (tPA) administration revealed that incomplete proteolysis of fibrin polymers markedly facilitated clot retraction. Similarly, inhibiting endogenous fibrinolysis with tranexamic acid reduced retraction of fibrin polymers in vivo. In vitro clot retraction experiments indicated that subthreshold doses of tPA facilitated clot retraction through a plasmin-dependent mechanism. These effects correlated with changes in the elastic modulus of fibrin clots. These findings define the endogenous fibrinolytic system as an important regulator of clot retraction, and show that promoting clot retraction is a novel and complementary means by which fibrinolytic enzymes can reduce thrombus size. © 2017 by The American Society of Hematology.

High performance flexible CMOS SOI FinFETs

KAUST Repository

Fahad, Hossain M.; Sevilla, Galo T.; Ghoneim, Mohamed T.; Hussain, Muhammad Mustafa

2014-01-01

We demonstrate the first ever CMOS compatible soft etch back based high performance flexible CMOS SOI FinFETs. The move from planar to non-planar FinFETs has enabled continued scaling down to the 14 nm technology node. This has been possible due

Retractions in cancer research: a systematic survey

OpenAIRE

Bozzo, Anthony; Bali, Kamal; Evaniew, Nathan; Ghert, Michelle

2017-01-01

Background The annual number of retracted publications in the scientific literature is rapidly increasing. The objective of this study was to determine the frequency and reason for retraction of cancer publications and to determine how journals in the cancer field handle retracted articles. Methods We searched three online databases (MEDLINE, Embase, The Cochrane Library) from database inception until 2015 for retracted journal publications related to cancer research. For each article, the re...

A Biologically Derived Pectoral Fin for Yaw Turn Manoeuvres

Directory of Open Access Journals (Sweden)

Jonah R. Gottlieb

2010-01-01

Full Text Available A bio-robotic fin has been developed that models the pectoral fin of the bluegill sunfish as the fish turned to avoid an obstacle. This work involved biological studies of the sunfish fin, the development of kinematic models of the motions of the fin's rays, CFD based predictions of the 3D forces and flows created by the fin, and the implementation of simplified models of the fin's kinematics and mechanical properties in a physical model. The resulting robotic fin produced the forces and flows that drove the manoeuvre and had a sufficiently high number of degrees of freedom to create a variety of non-biologically derived motions. The results indicate that for robotic fins to produce a level of performance on par with biological fins, both the kinematics and the mechanical properties of the biological fin must be modelled well.

Heat transfer and pressure drop characteristics of the tube bank fin heat exchanger with fin punched with flow redistributors and curved triangular vortex generators

Science.gov (United States)

Liu, Song; Jin, Hua; Song, KeWei; Wang, LiangChen; Wu, Xiang; Wang, LiangBi

2017-10-01

The heat transfer performance of the tube bank fin heat exchanger is limited by the air-side thermal resistance. Thus, enhancing the air-side heat transfer is an effective method to improve the performance of the heat exchanger. A new fin pattern with flow redistributors and curved triangular vortex generators is experimentally studied in this paper. The effects of the flow redistributors located in front of the tube stagnation point and the curved vortex generators located around the tube on the characteristics of heat transfer and pressure drop are discussed in detail. A performance comparison is also carried out between the fins with and without flow redistributors. The experimental results show that the flow redistributors stamped out from the fin in front of the tube stagnation points can decrease the friction factor at the cost of decreasing the heat transfer performance. Whether the combination of the flow redistributors and the curved vortex generators will present a better heat transfer performance depends on the size of the curved vortex generators. As for the studied two sizes of vortex generators, the heat transfer performance is promoted by the flow redistributors for the fin with larger size of vortex generators and the performance is suppressed by the flow redistributors for the fin with smaller vortex generators.

Retraction RETRACTION of "Association between polymorphisms in the XRCC1 gene and the risk of non-small cell lung cancer", by Han JC, Zhang YJ and Li XD - Genet. Mol. Res. 14 (4): 12888-12893 (2015).

Science.gov (United States)

Han, J C; Zhang, Y J; Li, X D

2016-10-07

The retracted article is: Han JC, Zhang YJ and Li XD (2015). Association between polymorphisms in the XRCC1 gene and the risk of non-small cell lung cancer. Genet. Mol. Res. 14: 12888-12893. The GMR editorial staff was alerted about this article (received on May 3, 2015; accepted on August 18, 2015) published on October 21, 2015 (DOI: 10.4238/2015.October.21.9) that was found to be substantially similar to the publication of "Association of XRCC1 gene polymorphisms with risk of non-small cell lung cancer" (received on January 25, 2015; accepted on March 23, 2015; e-published on April 1, 2015) by Kang et al., published in the International Journal of Clinical Experimental Pathology 8 (4): 4171-4176. The authors were aware of the Kang et al.'s paper, since they cite it several times in the manuscript published in GMR. Some of the language is similar between the two manuscripts, but what is the most concerning is that several of the tables in the papers are nearly identical. Tables 2 and 3 are exactly identical between the two articles, suggesting that the publication in GMR was plagiarized from the publication in the International Journal of Clinical Experimental Pathology. The Publisher and Editor decided to retract these articles in accordance with the recommendations of the Committee on Publication Ethics (COPE). After a thorough investigation, we have strong reason to believe that the peer review process was failure and, after review and contacting the authors, the editors of Genetics and Molecular Research decided to retract the article. The authors and their institutions were advised of this serious breach of ethics.

Fin Ray Stiffness and Fin Morphology Control Ribbon-Fin-Based Propulsion.

Science.gov (United States)

Liu, Hanlin; Taylor, Bevan; Curet, Oscar M

2017-06-01

Ribbon-fin-based propulsion has rich locomotor capabilities that can enhance the mobility and performance of underwater vehicles navigating in complex environments. Bony fishes using this type of propulsion send one or multiple traveling waves along an elongated fin with the actuation of highly flexible rays that are interconnected by an elastic membrane. In this work, we study how the use of flexible rays and different morphology can affect the performance of ribbon-fin propulsion. We developed a physical model composed of 15 rays that are interconnected with an elastic membrane. We tested four different ray flexural stiffness and four aspect ratios. The robotic model was tested in a low-turbulence flume under two flow conditions ([Formula: see text] wavelength/s). In two experimental sets, we measured fin kinematics, net surge forces, and power consumption. Using these data, we perform a thrust and power analysis of the undulating fin. We present the thrust coefficient, power coefficient, and propulsive efficiency. We find that the thrust generation was linear with the enclosed area swept by the fin, and square of the relative velocity between the incoming flow and traveling wave. The thrust coefficient levels off around 0.5. In addition, for our parameter range, we find that the power consumption scales by the cube of the effective tangential velocity of the rays [Formula: see text] (A is the amplitude of the ray oscillating motion, and [Formula: see text] is the angular velocity). We show that a decay in stiffness decreases both thrust production and power consumption. However, for rays with high flexural stiffness, the difference in thrust compared with rigid rays is minimal. Moreover, our results show that flexible rays can improve the propulsive efficiency compared with a rigid counterpart. Finally, we find that the morphology of ribbon fin affects its propulsive efficiency. For the aspect ratio considered in our experiments, [Formula: see text] was the most

RETRACTED: Early Cretaceous origin of the Woyla Arc (Sumatra, Indonesia) on the Australian plate

Science.gov (United States)

Advokaat, Eldert L.; Bongers, Mayke L. M.; Rudyawan, Alfend; BouDagher-Fadel, Marcelle K.; Langereis, Cor G.; van Hinsbergen, Douwe J. J.

2018-04-01

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy) The authors contacted the Editor shortly after publication stating that they have been made aware of errors in their data files and the paleomagnetic directions, site averages, and paleolatitudes that lie at the basis of their interpretations are incorrect. Because this error concerns the heart of the paper, the authors have decided to retract. A revised version of the article will be submitted for peer review.

Retracted Publications in the Biomedical Literature from Open Access Journals.

Science.gov (United States)

Wang, Tao; Xing, Qin-Rui; Wang, Hui; Chen, Wei

2018-03-07

The number of articles published in open access journals (OAJs) has increased dramatically in recent years. Simultaneously, the quality of publications in these journals has been called into question. Few studies have explored the retraction rate from OAJs. The purpose of the current study was to determine the reasons for retractions of articles from OAJs in biomedical research. The Medline database was searched through PubMed to identify retracted publications in OAJs. The journals were identified by the Directory of Open Access Journals. Data were extracted from each retracted article, including the time from publication to retraction, causes, journal impact factor, and country of origin. Trends in the characteristics related to retraction were determined. Data from 621 retracted studies were included in the analysis. The number and rate of retractions have increased since 2010. The most common reasons for retraction are errors (148), plagiarism (142), duplicate publication (101), fraud/suspected fraud (98) and invalid peer review (93). The number of retracted articles from OAJs has been steadily increasing. Misconduct was the primary reason for retraction. The majority of retracted articles were from journals with low impact factors and authored by researchers from China, India, Iran, and the USA.

Retracted articles in surgery journals. What are surgeons doing wrong?

Science.gov (United States)

Cassão, Bruna Dell'Acqua; Herbella, Fernando A M; Schlottmann, Francisco; Patti, Marco G

2018-03-08

Retraction of previously published scientific articles is an important mechanism to preserve the integrity of scientific work. This study analyzed retractions of previously published articles from surgery journals. We searched for retracted articles in the 100 surgery journals with the highest SJR2 indicator grades. We found 130 retracted articles in 49 journals (49%). Five or more retracted articles were published in 8 journals (8%). The mean time between publication and retraction was 26 months (range 1 to 158 months). The United States, China, Germany, Japan, and the United Kingdom accounted for more than 3 out of 4 of the retracted articles. The greatest number of retractions came from manuscripts about orthopedics and traumatology, general surgery, anesthesiology, cardiothoracic surgery, and plastic surgery. Nonsurgeons were responsible for 16% of retractions in these surgery journals. The main reasons for retraction were duplicate publication (42%), plagiarism (16%), absence of proven integrity of the study (14%), incorrect data (13%), data published without authorization (12%), violation of research ethics (11%), documented fraud (11%), request of an author(s) (5%), and unknown (3%). In 25% of the retracted articles, other publications by the same authors also had been retracted. Retraction of published articles does not occur frequently in surgery journals. Some form of scientific misconduct was present in the majority of retractions, especially duplication of publication and plagiarism. Retractions of previously published articles were most frequent from countries with the greatest number of publications; some authors showed recidivism. Copyright © 2018 Elsevier Inc. All rights reserved.

Retraction of Neurosurgical Publications: A Systematic Review.

Science.gov (United States)

Wang, Justin; Ku, Jerry C; Alotaibi, Naif M; Rutka, James T

2017-07-01

Despite the increasing awareness of scientific fraud, no attempt has been made to assess its prevalence in neurosurgery. The aim of our review was to assess the chronologic trend, reasons, research type/design, and country of origin of retracted neurosurgical publications. Three independent reviewers searched the EMBASE and MEDLINE databases using neurosurgical keywords for retracted articles from 1995 to 2016. Archives of retracted articles (retractionwatch.com) and the independent Web sites of neurosurgical journals were also searched. Data including the journal, impact factor, reason for retraction, country of origin, and citations were extracted. A total of 97 studies were included for data extraction. Journal impact factor ranged from 0.57 to 35.03. Most studies (61) were retracted within the last 5 years. The most common reason for retraction was because of a duplicated publication found elsewhere (26), followed closely by plagiarism (22), or presenting fraudulent data (14). Other reasons included scientific errors/mistakes, author misattribution, and compromised peer review. Articles originated from several countries and some were widely cited. Retractions of neurosurgical publications are increasing significantly, mostly because of issues of academic integrity, including duplicate publishing and plagiarism. Implementation of more transparent data-sharing repositories and thorough screening of data before manuscript submission, as well as additional educational programs for new researchers, may help mitigate these issues in the future. Copyright © 2017 Elsevier Inc. All rights reserved.

THE PLACE OF RETRACTION CORDS AMONG THE TISSUE DISPLACEMENT METHODS

Directory of Open Access Journals (Sweden)

Stoyan Yankov

2017-12-01

Full Text Available Gingival displacement is performed to create sufficient space between the finishing line and the gingival tissue, to allow the injection of the adequate bulk of the impression material into the expanded crevice. Control of moisture in the sulcus is also necessary. The variety of methods for tissue management can be broadly classified into surgical and non-surgical. Objective: To analyse the properties of tissue displacement methods, described in the literature for the last 4 years and display the prefered choices of the practitioners. Material and method: A time range from the last 4 years was set. Using the keywords “retraction cord” and “survey,” we found 64 from 115 articles in total, relevant to our topic. Patents, citations and books weren’t included in this review. Results from the overview of the properties of the different tissue management methods indicate that retraction cords take a significant place among them and can be recognised as a classical and well known method. Conclusions: The studies from the articles show adequate sulcal width right after retraction with most methods, sufficient haemostasis can also be obtained. Every each method, however, is accompanied by several drawbacks. Concidering all the quallities of the different tissue dispalcent methods, there is no specific evidence to promote the use of a single technique over any other. The selection of the method for gingival retraction primarily depends on each clinical case. However, the retraction cord technique remains to be the prefered method for gingival management due to its many advantages.

Characteristics of retractions related to faked peer reviews: an overview.

Science.gov (United States)

Qi, Xingshun; Deng, Han; Guo, Xiaozhong

2017-08-01

A faked peer review is a novel cause for retraction. We reviewed the characteristics of papers retracted due to a faked peer review. All papers retracted due to faked peer reviews were identified by searching the Retraction Watch website and by conducting a manual search. All identified papers were confirmed in published journals. The information of retracted papers was collected, which primarily included publisher, journal, journal impact factor, country, as well as publication and retraction year. Overall, 250 retracted papers were identified. They were published in 48 journals by six publishers. The top 5 journals included the Journal of Vibration and Control (24.8%), Molecular Biology Reports (11.6%), Immunopharmacology and Immunotoxicology (8.0%), Tumour Biology (6.8%) and European Journal of Medical Research (6.4%). The publishers included SAGE (31%), Springer (26%), BioMed Central (18%), Elsevier (13%), Informa (11%) and LWW (1%). A minority (4%) of retracted papers were published in Science Citation Index (SCI) journals with an impact factor of >5. A majority (74.8%) of retracted papers were written by Chinese researchers. In terms of the publication year, the retracted papers were published since 2010, and the number of retracted papers peaked in 2014 (40.8%). In terms of the retraction year, the retractions started in 2012, and the number of retractions peaked in 2015 (59.6%). The number of papers retracted due to faked peer reviews differs largely among journals and countries. With the improvement of the peer review mechanism and increased education about publishing ethics, such academic misconduct may gradually disappear in future. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Publication misconduct and plagiarism retractions: a systematic, retrospective study.

Science.gov (United States)

Stretton, Serina; Bramich, Narelle J; Keys, Janelle R; Monk, Julie A; Ely, Julie A; Haley, Cassandra; Woolley, Mark J; Woolley, Karen L

2012-10-01

To investigate whether plagiarism is more prevalent in publications retracted from the medical literature when first authors are affiliated with lower-income countries versus higher-income countries. Secondary objectives included investigating other factors associated with plagiarism (e.g., national language of the first author's country affiliation, publication type, journal ranking). Systematic, controlled, retrospective, bibliometric study. Retracted publications dataset in MEDLINE (search filters: English, human, January 1966-February 2008). Retracted misconduct publications were classified according to the first author's country affiliation, country income level, and country national language, publication type, and ranking of the publishing journal. Standardised definitions and data collection tools were used; data were analysed (odds ratio [OR], 95% confidence limits [CL], chi-squared tests) by an independent academic statistician. Of the 213 retracted misconduct publications, 41.8% (89/213) were retracted for plagiarism, 52.1% (111/213) for falsification/fabrication, 2.3% (5/213) for author disputes, 2.3% (5/213) for ethical issues, and 1.4% (3/213) for unknown reasons. The OR (95% CL) of plagiarism retractions (other misconduct retractions as reference) were higher (P 1 retraction) with publications retracted for plagiarism (11.5%, 9/78) than other types of misconduct (28.9%, 24/83). This is the first study to demonstrate that publications retracted for plagiarism are significantly associated with first authors affiliated with lower-income countries. These findings have implications for developing appropriate evidence-based strategies and allocation of resources to help mitigate plagiarism misconduct.

What time-lag for a retraction search on PubMed?

Science.gov (United States)

Decullier, Evelyne; Huot, Laure; Maisonneuve, Hervé

2014-06-25

To investigate fraud and errors, scientists have studied cohorts of retraction notices. These researches have been performed using a PubMed search on publication type "retraction of publication" which retrieves the notices of the retractions. We assessed the stability of the indexation of retraction notices over a 15-month period and what was the time-lag to get stability. A search on notices of retraction issued in 2008 was repeated every 3 months during 15 months from February 2011. The first search resulted in 237 notices of retraction. Throughout the study period, 14 discrepancies with the initial search were observed (6%). We found that the number of retraction notices became stable 35 months after the retraction. The time-lag observed in this study has to be taken into account when performing a PubMed search.

Promoting Ethics and Integrity in Management Academic Research: Retraction Initiative.

Science.gov (United States)

Ayodele, Freida Ozavize; Yao, Liu; Haron, Hasnah

2018-02-13

In the management academic research, academic advancement, job security, and the securing of research funds at one's university are judged mainly by one's output of publications in high impact journals. With bogus resumes filled with published journal articles, universities and other allied institutions are keen to recruit or sustain the appointment of such academics. This often places undue pressure on aspiring academics and on those already recruited to engage in research misconduct which often leads to research integrity. This structured review focuses on the ethics and integrity of management research through an analysis of retracted articles published from 2005 to 2016. The study employs a structured literature review methodology whereby retracted articles published between 2005 and 2016 in the field of management science were found using Crossref and Google Scholar. The searched articles were then streamlined by selecting articles based on their relevance and content in accordance with the inclusion criteria. Based on the analysed retracted articles, the study shows evidence of ethical misconduct among researchers of management science. Such misconduct includes data falsification, the duplication of submitted articles, plagiarism, data irregularity and incomplete citation practices. Interestingly, the analysed results indicate that the field of knowledge management includes the highest number of retracted articles, with plagiarism constituting the most significant ethical issue. Furthermore, the findings of this study show that ethical misconduct is not restricted to a particular geographic location; it occurs in numerous countries. In turn, avenues of further study on research misconduct in management research are proposed.

Maxillary incisor retraction: evaluation of different mechanisms

Directory of Open Access Journals (Sweden)

Antônio Carlos de Oliveira Ruellas

2013-04-01

Full Text Available OBJECTIVE: To mechanically evaluate different systems used for incisors retraction. METHODS: Three different methods for incisors retraction using 0.019 x 0.025-in stainless steel wire were evaluated. The samples were divided into three groups: Group A (retraction arch with 7-mm high vertical hooks; Group G3 (elastic chain attached to the miniimplant and to the 3-mm stainless steel hook soldered to the retraction arch; Group G6 (elastic chain attached to the mini-implant and to the 6-mm stainless steel hook soldered to the retraction arch. A dental mannequin was used for evaluation in order to simulate the desired movements when the device was exposed to a heat source. The analysis of variance (ANOVA and the Tukey test were used (p < 0.05. RESULTS: The results demonstrated that Groups G3 and G6 exhibited less extrusion and less incisor inclination during the retraction phase (p < 0.05. With regard to incisor extrusion, statistically significant differences were observed between Groups A and G3, and between Groups A and G6 (p < 0.05. Regarding incisor inclination, statistically significant differences were observed between the three systems evaluated (p < 0.05. CONCLUSIONS: Arches with 6-mm vertical hooks allow the force to be applied on the center of resistance of the incisors, thus improving mechanical control when compared with the other two systems.

The Tie retraction syndrome.

Science.gov (United States)

Geerling, Gerd; Neppert, Birte; Hemmant, Bridget

2012-12-01

Tissue retraction is implicated in the pathogenesis of various ophthalmic disorders. Here we describe the clinical characteristics, epidemiology and pathophysiology of a form of retraction syndrome which - to the best of our knowledge - has not been reported in the ophthalmic literature so far. We have termed this condition - consisting of a slowly progressive pseudovertical shortening of tie length due to a horizontal extension of girth length - the "Tie retraction syndrome" (TRS). Other pathognomonic features include an increased tie tip to belt buckle distance and a prolapse of the subumbilical fat pad (SUFP). The syndrome has a clear male to female preponderance and shows an increasing incidence with age and income before tax. Based on a newly proposed grading scheme we discuss and illustrate the diagnosis as well as the medical and surgical management options of this abundant, but often undiagnosed condition. The authors have no explanation for the apparent lack of awareness for this widely preponderant syndrome and its severe cosmetically disfiguring potential. We thus would like to invite all fellow colleagues with expertise in the field to comment or present their views.

Rate of retraction of anterior teeth after canine distraction

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Litesh Singla

2017-01-01

Full Text Available Background and Objectives: Orthodontists have always strived to develop a new technique to reduce the treatment time with minimal patient cooperation. Canine distraction was introduced as an alternative technique for canine retraction in a minimum possible period of 3 weeks, thus avoiding taxing the anchorage by molars since the canines are retracted within the lag phase of molars. It has been proved by numerous studies that the bone mesial to canine after rapid canine distraction through the extraction socket is a new and immature. The objectives of this study were to evaluate the rate of retraction of anterior teeth, the time taken, and anchorage loss during the retraction of anterior teeth into this newly organized bone. Methods: Six orthodontic patients who required first premolar extractions were selected. Undermining of the interseptal bone distal to the canine was done, and canines were retracted into the extraction space of the first premolar, using a custom-made tooth borne intraoral distraction screw, following which the incisors were retracted into the newly formed bone using closing loops. The patients were called at weekly intervals to measure the amount of space left between canine and lateral incisor, and the rate of retraction was calculated after space was closed. Results: The present study showed that the rate of retraction of mandibular and maxillary teeth was 0.74 ± 0.39 mm and 0.73 ± 0.15 mm/week, respectively. The anchorage loss was found to be 1.83 ± 0.29 mm and 2.08 ± 0.38 mm in mandibular and maxillary arches, respectively. The time taken to retract the incisors was found to be 40.3 ± 1.5 and 41.7 ± 0.6 days for mandibular and maxillary arches, respectively. Interpretation and Conclusion: Retraction of incisors is faster in both maxillary and mandibular arches when the incisors are retracted immediately into the immature bone created after canine distraction.

Evaluating the effects of consolidation on intrusion and retraction using temporary anchorage devices—a FEM study

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Monica Namburi

2017-01-01

Full Text Available Abstract Background Extraction of premolars and retracting the anterior teeth using mini-implants and anterior retraction hooks became advent now a day. In such treatments, consolidation of arches is not done in regular practice. So, the present study is concentrated on effects of consolidation in two implant and three implant combinations of retraction and intrusion. Methods A three-dimensional FEM model of maxillary teeth and periodontal ligament housed in the alveolar bone with the first premolars extracted is generated with appropriate number of elements and nodes. The models were broadly divided into two groups according to the no. of implants. Mini-implants were placed bilaterally between the second premolar and molar at varying heights (7, 10, 13 mm in group I, and along with bilateral implants, an additional mid-implant is placed between the central incisors as group II. Brackets with 0.022 slot were placed on the teeth, 19 × 25 SS wire is placed in the brackets, an anterior retraction hook was placed at 9 mm height, and analysis was done to evaluate the stresses and displacement patterns in consolidation and non-consolidation models. Results The results showed that consolidation of the anterior teeth during intrusion and retraction shows various advantages such as less stresses on the bone, PDL, implant, teeth, and no labial flaring of the anterior teeth and three implant system, i.e., two bilateral implant at 10 mm and a mid-implant at 12 mm between the centrals has shown to be better than other models as bodily movement is observed. Conclusion Consolidation is better than non consolidation during enmasse retraction and intrusion.

RETRACTED: Hydrological

Directory of Open Access Journals (Sweden)

S.S. Panhalkar

2014-12-01

This paper has been retracted upon the request of the author and the editor as the paper requires major revision. The author did not have the permission to publish part of the discharge information presented in Figures 10–13. The Publisher apologizes for any inconvenience this may cause.

Retraction of publications in nursing and midwifery research: A systematic review.

Science.gov (United States)

Al-Ghareeb, Amal; Hillel, Stav; McKenna, Lisa; Cleary, Michelle; Visentin, Denis; Jones, Martin; Bressington, Daniel; Gray, Richard

2018-05-01

Rates of manuscript retraction in academic journals are increasing. Papers are retracted because of scientific misconduct or serious error. To date there have been no studies that have examined rates of retraction in nursing and midwifery journals. A systematic review of Journal Citation Report listed nursing science journals. The Medline database was searched systematically from January 1980 through July 2017, and www.retractionwatch.com was manually searched for relevant studies that met the inclusion criteria. Two researchers undertook title and abstract and full text screening. Data were extracted on the country of the corresponding author, journal title, impact factor, study design, year of retraction, number of citations after retraction, and reason for retraction. Journals retraction index was also calculated. Twenty-nine retracted papers published in nursing science journals were identified, the first in 2007. This represents 0.029% of all papers published in these journals since 2007. We observed a significant increase in the retraction rate of 0.44 per 10,000 publications per year (95% CI; 0.03-0.84, p = .037). There was a negative association between a journal's retraction index and impact factor with a significant reduction in retraction index of -0.57 for a one-point increase in impact factor (95% CI; -1.05 to -0.09, p = .022). Duplicate publication was the most common reason for retraction (n = 18, 58%). The mean number of citations manuscripts received after retraction was seven, the highest was 52. Most (n = 27, 93.1%) of the retracted papers are still available online (with a watermark indicating they are retracted). Compared to more established academic disciplines, rates of retraction in nursing and midwifery are low. Findings suggest that unsound research is not being identified and that the checks and balances incumbent in the scientific method are not working. In a clinical discipline, this is concerning and may indicate that

Effect of the Curved Fin Top Edge on the Electrical Characteristics of FinFETs.

Science.gov (United States)

Ahn, Joonsung; Kim, Tae Whan

2018-03-01

The effect of the curved fin top edge on the electrical characteristics of FinFETs was investigated. The curvature radius of the fin top edge for the FinFETs was changed from 0 to 5 nm in order to determine the optimum condition of the electrical characteristics for the devices. The on-current level of the FinFETs with a curvature radius of 5 nm of fin top edge was 24.45% larger than that of the FinFETs with a cuboid fin. The electron current density and the electron mobility of the fin top edge for the FinFETs were larger than those for the FinFETs with a cuboid fin. The electrical characteristics of the FinFETs with a curvature radius of 5 nm for the fin top edge showed the best performance due to the largest expansion of the effective channel region.

Origin of fin-clipped salmonids collected at two thermal discharges on Lake Michigan

International Nuclear Information System (INIS)

Romberg, G.P.; Thommes, M.M.; Spigarelli, S.A.

1974-01-01

Fin clips observed on fish collected during tagging studies at the Point Beach and Waukegan thermal discharges were recorded and the data were tabulated by species. Using fin clip and fish size, attempts were made to identify probable stocking locations and dates from agency records. Data are presented for lake trout, rainbow trout, brown trout, and Coho salmon. Tables are presented to show probable stocking locations and dates

Model-based identification of motion sensor placement for tracking retraction and elongation of the tongue.

Science.gov (United States)

Wang, Yikun K; Nash, Martyn P; Pullan, Andrew J; Kieser, Jules A; Röhrle, Oliver

2013-04-01

Electromagnetic articulography (EMA) is designed to track facial and tongue movements. In practice, the EMA sensors for tracking the movement of the tongue's surface are placed heuristically. No recommendation exists. Within this paper, a model-based approach providing a mathematical analysis and a computational-based recommendation for the placement of sensors, which is based on the tongue's envelope of movement, is proposed. For this purpose, an anatomically detailed Finite Element (FE) model of the tongue has been employed to determine the envelope of motion for retraction and elongation using a forward simulation. Two optimality criteria have been proposed to identify a set of optimal sensor locations based on the pre-computed envelope of motion. The first one is based on the assumption that locations exhibiting large displacements contain the most information regarding the tongue's movement and are less susceptible to measurement errors. The second one selects sensors exhibiting each the largest displacements in the anterior-posterior, superior-inferior, medial-lateral and overall direction. The quality of the two optimality criteria is analysed based on their ability to deduce from the respective sensor locations the corresponding muscle activation parameters of the relevant muscle fibre groups during retraction and elongation by solving the corresponding inverse problem. For this purpose, a statistical analysis has been carried out, in which sensor locations for two different modes of deformation have been subjected to typical measurement errors. Then, for tongue retraction and elongation, the expectation value, the standard deviation, the averaged bias and the averaged coefficient of variation have been computed based on 41 different error-afflicted sensor locations. The results show that the first optimality criteria is superior to the second one and that the averaged bias and averaged coefficient of variation decrease when the number of sensors is

Age estimation of burbot using pectoral fin rays, brachiostegal rays, and otoliths

Science.gov (United States)

Klein, Zachary B.; Terrazas, Marc M.; Quist, Michael C.

2014-01-01

Throughout much of its native distribution, burbot (Lota lota) is a species of conservation concern. Understanding dynamic rate functions is critical for the effective management of sensitive burbot populations, which necessitates accurate and precise age estimates. Managing sensitive burbot populations requires an accurate and precise non-lethal alternative. In an effort to identify a non-lethal ageing structure, we compared the precision of age estimates obtained from otoliths, pectoral fin rays, dorsal fin rays and branchiostegal rays from 208 burbot collected from the Green River drainage, Wyoming. Additionally, we compared the accuracy of age estimates from pectoral fin rays, dorsal fin rays and branchiostegal rays to those of otoliths. Dorsal fin rays were immediately deemed a poor ageing structure and removed from further analysis. Age-bias plots of consensus ages derived from branchiostegal rays and pectoral fin rays were appreciably different from those obtained from otoliths. Exact agreement between readers and reader confidence was highest for otoliths and lowest for branchiostegal rays. Age-bias plots indicated that age estimates obtained from branchiostegal rays and pectoral fin rays were substantially different from age estimates obtained from otoliths. Our results indicate that otoliths provide the most precise age estimates for burbot.

Numerical Analysis of Aerodynamic Characteristics of the Finned Surfaces with Cross-inclined Fins

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Lagutin A. E.

2016-12-01

Full Text Available This paper presents results of numerical research and analyses air-side hydraulic performance of tube bundles with cross inclined fins. The numerical simulation of the fin-tube heat exchanger was performed using the Comsol Femlab software. The results of modeling show the influence of fin inclination angle and tube pitch on hydraulic characteristics of finned surfaces. A series of numerical tests were carried out for tube bundles with different inclination angles (γ =900, 850, 650, 60, the fin pitch u=4 mm. The results indicate that tube bundles with cross inclined fins can significantly enhance the average integral value of the air flow rate in channel between fins in comparison with conventional straight fins. Aerodynamic processes on both sides of modificated channel between inclined fins were analyzed. The verification procedures for received results of numerical modeling with experimental data were performed.

The Problem of Retraction in Critical Discussion

NARCIS (Netherlands)

Krabbe, Erik C. W.

2001-01-01

In many contexts a retraction of commitment is frowned upon. For instance, it is not appreciated, generally, if one withdraws a promise or denies an earlier statement. Critical discussion, too, can easily be disrupted by retractions, if these occur too frequently and at critical points. But on the

Frost behavior of a fin surface with temperature variation along heat exchanger fins

International Nuclear Information System (INIS)

Kim, Jung Soo; Kim, Min Soo; Lee, Kwan Soo; Kim, Ook Joong

2007-01-01

This paper presents a mathematical model for predicting the frost behavior formed on heat exchanger fins, considering fin heat conduction under frosting condition. The model is composed of air-side, the frost layer, and fin region, and they are coupled to the frost layer. The frost behavior is more accurately predicted with fin heat conduction considered (Case A) than with a constant fin surface temperature assumed (Case B). The results indicate that the frost thickness and heat transfer rate for Case B are over-predicted in most regions of the fin, as compared to those for Case A. Also, for Case A, the maximum frost thickness varies little with the fin length variations, and the extension of the fin length over 30 mm contributes insignificantly to heat transfer

RETRACTED: Growth of boron-doped diamond nanoclusters using the HFCVD technique

Science.gov (United States)

Azadfar, P.; Ghoranneviss, M.; Elahi, S. M.; Farhadyar, N.; Salar Elahi, A.

2015-04-01

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Principal Editor. After a thorough investigation, the Editor has concluded that the review process for this article was compromised. The acceptance was based on information from one reviewer report that was submitted from an email account provided to the journal as a suggested reviewer during the submission of the article. Although purportedly a real reviewer account, the Editor has concluded that this was not of an appropriate, independent reviewer. This manipulation of the peer-review process represents a clear violation of the fundamentals of peer review, our publishing policies, and publishing ethics standards. Apologies are offered to the reviewer whose identity was assumed and to the readers of the journal that this deception was not detected during the submission process.

Stress analysis of plate-fin structures in recuperator

International Nuclear Information System (INIS)

Matsui, Shingo; Muto, Yasushi; Shiina, Yasuaki

2001-01-01

A high performance compact recuperator with 95% effectiveness is required to achieve a high thermal efficiency power generation of up to 50% in High Temperature Gas Cooled Reactor (HTGR) coupled with closed cycle helium gas turbine. Though a plate-fin type heat exchanger is proposed for this recuperator, much research and development works are needed to establish this high performance goal since there exists no state-of-the-art technology in such a high pressure and high temperature one. One of the important works is to establish the structural analysis and evaluation method in this plate-fin type heat exchanger. This paper describes the results of stress analysis of the plate-fin structure under the internal pressure as the first step of this work. First, the modeling of a unit plate-fin structure for the analysis was examined and a three layers model was confirmed to be most adequate. The stress distribution within the structure was clarified by using this model. Second, the three layers model was simplified to one layer model with sufficient accuracy. By using this model, both the effects of an inclined angle of fin and a thickness of separate on the strength were examined parametrically. Under the relevant design conditions, it was revealed that the optimum inclined angle of fin locates in the neighborhood of 76 degree rather than most difficult fabrication angle 90 degree and there is possibility to adopt thinner thickness than 0.5 mm in the current design. (author)

The success rate of TED upper eyelid retraction reoperations.

Science.gov (United States)

Golan, Shani; Rootman, Dan B; Goldberg, Robert A

2016-12-01

Although reoperation rates for upper lid retraction surgery for thyroid eye disease (TED) typically range between 8% and 23%, there is little literature describing the outcomes of these second operations. In this retrospective observational cohort study, all patients that underwent surgery for upper eyelid retraction over a 14-year period at a single institution were included. Cases were included if a second eyelid retraction surgery was performed during the study period. Success of surgery was defined as a marginal reflex distance (MRD1) of 2.5 to 4.5 mm in each eye and less than 1 mm difference in MRD1 between the eyes. Overcorrection and undercorrection were defined as above and below these bounds, respectively. 72 eyes in 49 patients were included in the study. The mean age was 56.6 (±11.5) years. By definition, all patients had at least 1 lid lengthening surgery for upper eyelid retraction, and at least 1 subsequent surgery. For this second surgery, 61 eyes (85%) underwent retraction surgery and 11 eyes (15%) underwent ptosis surgery. After this second operation, 31% were undercorrected and 33% were overcorrected. A third surgery was performed in 19 eyes (25%), 12 had surgery for residual retraction and 7 for ptosis. After the third operation 10% of eyes were under corrected and 11% were over corrected. Four patients underwent a fourth surgery: one for retraction and three for ptosis. Success was noted in 35% after the second surgery and 44% after the third. Surgical success in eyelid retraction surgery increases from a second to a third consecutive surgery, and residual asymmetry was roughly equally distributed between over- and undercorrection.

Numerical simulation of a plate-fin heat exchanger with offset fins using porous media approach

Science.gov (United States)

Juan, Du; Hai-Tao, Zhao

2018-03-01

In this paper, the study was focused on a double flow plate-fin heat exchanger (PFHE) whose heat transfer element was offset staggered fin. Numerical simulations have been carried out to investigate the thermodynamic characteristics of a full-size PFHE via the porous media approach. Based on the numerical model, the effects of the dynamic viscosity and the locations of the inlet and outlet tubes on flow distribution and pressure drop of the PFHE were studied. The results showed that flow distribution of the PFHE was improved by increasing the dynamic viscosity. Therefore, the relationship between flow distribution and pressure drop was analyzed under various inlet velocity, and a correlation among flow distribution, pressure drop, and Reynolds number was derived. Finally, the middle-based strategy was proposed and numerically verified to improve flow distribution of the PFHE.

A biorobotic model of the sunfish pectoral fin for investigations of fin sensorimotor control

International Nuclear Information System (INIS)

Phelan, Chris; Tangorra, James; Lauder, George; Hale, Melina

2010-01-01

A comprehensive understanding of the control of flexible fins is fundamental to engineering underwater vehicles that perform like fish, since it is the fins that produce forces which control the fish's motion. However, little is known about the fin's sensory system or about how fish use sensory information to modulate the fin and to control propulsive forces. As part of a research program that involves neuromechanical and behavioral studies of the sunfish pectoral fin, a biorobotic model of the pectoral fin and of the fin's sensorimotor system was developed and used to investigate relationships between sensory information, fin ray motions and propulsive forces. This robotic fin is able to generate the motions and forces of the biological fin during steady swimming and turn maneuvers, and is instrumented with a relatively small set of sensors that represent the biological lateral line and receptors hypothesized to exist intrinsic to the pectoral fin. Results support the idea that fin ray curvature, and the pressure in the flow along the wall that represents the fish body, capture time-varying characteristics of the magnitude and direction of the force created throughout a fin beat. However, none of the sensor modalities alone are sufficient to predict the propulsive force. Knowledge of the time-varying force vector with sufficient detail for the closed-loop control of fin ray motion will result from the integration of characteristics of many sensor modalities.

A biorobotic model of the sunfish pectoral fin for investigations of fin sensorimotor control

Energy Technology Data Exchange (ETDEWEB)

Phelan, Chris; Tangorra, James [Department of Mechanical Engineering, Drexel University, Philadelphia, PA 19104 (United States); Lauder, George [Museum of Comparative Zoology, Harvard University, Cambridge, MA 02138 (United States); Hale, Melina, E-mail: tangorra@coe.drexel.ed [Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637 (United States)

2010-09-15

A comprehensive understanding of the control of flexible fins is fundamental to engineering underwater vehicles that perform like fish, since it is the fins that produce forces which control the fish's motion. However, little is known about the fin's sensory system or about how fish use sensory information to modulate the fin and to control propulsive forces. As part of a research program that involves neuromechanical and behavioral studies of the sunfish pectoral fin, a biorobotic model of the pectoral fin and of the fin's sensorimotor system was developed and used to investigate relationships between sensory information, fin ray motions and propulsive forces. This robotic fin is able to generate the motions and forces of the biological fin during steady swimming and turn maneuvers, and is instrumented with a relatively small set of sensors that represent the biological lateral line and receptors hypothesized to exist intrinsic to the pectoral fin. Results support the idea that fin ray curvature, and the pressure in the flow along the wall that represents the fish body, capture time-varying characteristics of the magnitude and direction of the force created throughout a fin beat. However, none of the sensor modalities alone are sufficient to predict the propulsive force. Knowledge of the time-varying force vector with sufficient detail for the closed-loop control of fin ray motion will result from the integration of characteristics of many sensor modalities.

Retraction

Energy Technology Data Exchange (ETDEWEB)

Liu, Zhiheng [Vanderbilt University; Feldman, Leonard C [ORNL; Tolk, Norman H. [Vanderbilt University; Zhang, Zhenyu [ORNL; Cohen, Philip [University of Minnesota

2012-01-01

IN OUR 2006 REPORT, DESORPTION OF H FROM SI(111) BY RESONANT EXCITATION OF THE Si-H vibrational stretch mode (1), we reported resonant photodesorption of hydrogen from a Si(111) surface using tunable infrared radiation that corresponded to the Si-H vibrational stretch mode. Our recent attempts to reproduce these experiments have been unsuccessful, and the free electron laser facility at Vanderbilt, a unique light source for this experiment, has shut down, prohibiting further research. Because our conclusions are now in question, we retract the Report.

Methylmercury in dried shark fins and shark fin soup from American restaurants.

Science.gov (United States)

Nalluri, Deepthi; Baumann, Zofia; Abercrombie, Debra L; Chapman, Demian D; Hammerschmidt, Chad R; Fisher, Nicholas S

2014-10-15

Consumption of meat from large predatory sharks exposes human consumers to high levels of toxic monomethylmercury (MMHg). There also have been claims that shark fins, and hence the Asian delicacy shark fin soup, contain harmful levels of neurotoxic chemicals in combination with MMHg, although concentrations of MMHg in shark fins are unknown. We measured MMHg in dried, unprocessed fins (n=50) of 13 shark species that occur in the international trade of dried shark fins as well as 50 samples of shark fin soup prepared by restaurants from around the United States. Concentrations of MMHg in fins ranged from 9 to 1720 ng/g dry wt. MMHg in shark fin soup ranged from sharks such as hammerheads (Sphyrna spp.). Consumption of a 240 mL bowl of shark fin soup containing the average concentration of MMHg (4.6 ng/mL) would result in a dose of 1.1 μg MMHg, which is 16% of the U.S. EPA's reference dose (0.1 μg MMHg per 1 kg per day in adults) of 7.4 μg per day for a 74 kg person. If consumed, the soup containing the highest measured MMHg concentration would exceed the reference dose by 17%. While shark fin soup represents a potentially important source of MMHg to human consumers, other seafood products, particularly the flesh of apex marine predators, contain much higher MMHg concentrations and can result in substantially greater exposures of this contaminant for people. Copyright © 2014 Elsevier B.V. All rights reserved.

50 CFR 600.1204 - Shark finning; possession at sea and landing of shark fins.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Shark finning; possession at sea and landing of shark fins. 600.1204 Section 600.1204 Wildlife and Fisheries FISHERY CONSERVATION AND... PROVISIONS Shark Finning § 600.1204 Shark finning; possession at sea and landing of shark fins. (a)(1) No...

Retraction: Statement of Retraction: Khaki-khatibi F, Yaghoubi A.R ...

African Journals Online (AJOL)

The article has been retracted upon the request of the corresponding author, Khaki-khatibi F, due to admitted plagiarism. However, this constitutes a violation of publication ethics. It is a breach of warranties made by the author with respect to originality upon which we received, peer-reviewed, accepted and published the ...

A new method for rapid Canine retraction

Directory of Open Access Journals (Sweden)

"Khavari A

2001-06-01

Full Text Available Distraction osteogenesis method (Do in bone lengthening and rapid midpalatal expansion have shown the great ability of osteognic tissues for rapid bone formation under distraction force and special protocol with optimum rate of one millimeter per day. Periodontal membrane of teeth (PDM is the extension of periostium in the alveolar socked. Orthodontic force distracts PDM fibers in the tension side and then bone formation will begin.Objects: Rapid retraction of canine tooth into extraction space of first premolar by DO protocol in order to show the ability of the PDM in rapid bone formation. The other objective was reducing total orthodontic treatment time of extraction cases.Patients and Methods: Tweleve maxillary canines in six patients were retracted rapidly in three weeks by a custom-made tooth-born appliance. Radiographic records were taken to evaluate the effects of heavy applied force on canine and anchorage teeth.Results: Average retraction was 7.05 mm in three weeks (2.35 mm/week. Canines rotated distal- in by mean 3.5 degrees.Anchorage loss was from 0 to 0.8 mm with average of 0.3 mm.Root resorption of canines was negligible, and was not significant clinically. Periodontium was normal after rapid retraction. No hazard for pulp vitality was observed.Discussion: PDM responded well to heavy distraction force by Do protocol. Rapid canine retraction seems to be a safe method and can considerabely reduce orthodontic time.

3D modeling of dual-gate FinFET.

Science.gov (United States)

Mil'shtein, Samson; Devarakonda, Lalitha; Zanchi, Brian; Palma, John

2012-11-13

The tendency to have better control of the flow of electrons in a channel of field-effect transistors (FETs) did lead to the design of two gates in junction field-effect transistors, field plates in a variety of metal semiconductor field-effect transistors and high electron mobility transistors, and finally a gate wrapping around three sides of a narrow fin-shaped channel in a FinFET. With the enhanced control, performance trends of all FETs are still challenged by carrier mobility dependence on the strengths of the electrical field along the channel. However, in cases when the ratio of FinFET volume to its surface dramatically decreases, one should carefully consider the surface boundary conditions of the device. Moreover, the inherent non-planar nature of a FinFET demands 3D modeling for accurate analysis of the device performance. Using the Silvaco modeling tool with quantization effects, we modeled a physical FinFET described in the work of Hisamoto et al. (IEEE Tran. Elec. Devices 47:12, 2000) in 3D. We compared it with a 2D model of the same device. We demonstrated that 3D modeling produces more accurate results. As 3D modeling results came close to experimental measurements, we made the next step of the study by designing a dual-gate FinFET biased at Vg1 >Vg2. It is shown that the dual-gate FinFET carries higher transconductance than the single-gate device.

Retracted: 147 reduced syntaxin-5 in skeletal muscle of patients with type 2 diabetes. A link between lipid storage and insulin resistance.

Science.gov (United States)

Andersson, L; Myhre, S; Bostrom, P; Ståhlman, M; Vind, B; Håversen, L; Borén, J; Hojlund, K; Olofsson, S-O

2011-06-01

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This abstract has been retracted at the request of Jan Borén, co-author, because of conscious fabrication, corruption or suppression of basic material and conscious preparation and presentation of falsified results in the abstract by one of the authors. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

RETRACTED: Novel drug delivery carrier from alginate-carrageenan and glycerol as plasticizer

Directory of Open Access Journals (Sweden)

Handoko Darmokoesoemo

Full Text Available This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy.This article has been retracted at the request of the Editors-in-Chief.After a thorough investigation, the Editors have concluded that the acceptance of this article was based upon the positive advice of at least three illegitimate reviewer reports. The reports were submitted from email accounts which were provided to the journal as suggested reviewers during the submission of the article. Although purportedly real reviewer accounts, the Editors have concluded that these were not of appropriate, independent reviewers.This manipulation of the peer-review process represents a clear violation of the fundamentals of peer review, our publishing policies, and publishing ethics standards. Apologies are offered to the reviewers whose identities were assumed and to the readers of the journal that this deception was not detected during the submission process.

Effects of ultra-thin Si-fin body widths upon SOI PMOS FinFETs

Science.gov (United States)

Liaw, Yue-Gie; Chen, Chii-Wen; Liao, Wen-Shiang; Wang, Mu-Chun; Zou, Xuecheng

2018-05-01

Nano-node tri-gate FinFET devices have been developed after integrating a 14 Å nitrided gate oxide upon the silicon-on-insulator (SOI) wafers established on an advanced CMOS logic platform. These vertical double gate (FinFET) devices with ultra-thin silicon fin (Si-fin) widths ranging from 27 nm to 17 nm and gate length down to 30 nm have been successfully developed with a 193 nm scanner lithography tool. Combining the cobalt fully silicidation and the CESL strain technology beneficial for PMOS FinFETs was incorporated into this work. Detailed analyses of Id-Vg characteristics, threshold voltage (Vt), and drain-induced barrier lowering (DIBL) illustrate that the thinnest 17 nm Si-fin width FinFET exhibits the best gate controllability due to its better suppression of short channel effect (SCE). However, higher source/drain resistance (RSD), channel mobility degradation due to dry etch steps, or “current crowding effect” will slightly limit its transconductance (Gm) and drive current.

Magnetic Retraction of Bowel by Intraluminal Injectable Cyanoacrylate-Based Magnetic Glue

Directory of Open Access Journals (Sweden)

Zhigang Wang

2013-01-01

Full Text Available Magnetic retraction offers advantages over physical retraction by graspers because of reduced tissue trauma. The objectives of this study are to investigate a novel method of magnetisation of bowel segments by intraluminal injection of magnetic glue and to demonstrate the feasibility of magnetic retraction of bowel with sufficient force during minimal access surgery. Following an initial materials characterisation study, selected microparticles of stainless steel (SS410-μPs were mixed with chosen cyanoacrylate glue (Loctite 4014. During intraluminal injection of the magnetic glue using ex vivo porcine colonic segments, a magnetic probe placed at the injected site ensured that the SS410-μPs aggregated during glue polymerisation to form an intraluminal mucosally adherent coagulum. The magnetised colonic segments were retracted by magnetic probes (5 and 10 mm placed external to the bowel wall. A tensiometer was used to record the retraction force. With an injected volume of 2 mL in a particle concentration of 1 g/mL, this technique produced maximal magnetic retraction forces of 2.24 ± 0.23 N and 5.11 ± 0.34 N (, with use of 5 and 10 mm probes, respectively. The results indicate that the formation of an intraluminal coagulum based on SS410-μPs and Loctite 4014 produces sufficient magnetic retraction for bowel retraction.

FinTech in Norway : the effect of FinTech on the traditional Norwegian banking sector

OpenAIRE

Omreng, Stian; Gjendem, Ida

2017-01-01

The purpose of this thesis is to investigate the effect of FinTech on the Norwegian banking industry. We investigate the drivers of FinTech, the current and potential Norwegian FinTech market, and the international competitiveness of the Norwegian FinTech movement. We identify nine segments of FinTech within the traditional banking functions Financing, Asset management, Payments and Authentication, and we find the key drivers behind the rapid growth of the FinTech market as cha...

Performance study of a fin and tube heat exchanger with different fin geometry

DEFF Research Database (Denmark)

Singh, Shobhana; Sørensen, Kim; Condra, Thomas Joseph

2016-01-01

This study analyses the effect of different fin geometries on the heat transfer and pressure loss characteristics of a fin and tube heat exchanger. A numerical investigation is carried out on liquid–gas type double-finned tube heat exchanger under cross-flow condition. Three different cross......-sections namely: a) Rectangular, b) Trapezoidal, c) Triangular are adopted to define the fin geometry. The CFD simulations are performed to incorporate coupled steady state conjugate heat transfer with the turbulent flow phenomenon for the Reynolds number in the range of 5000-13000. Dimensionless heat transfer...... models show that triangular fin geometry can provide higher heat transfer performance in comparison to the fins with rectangular and trapezoidal geometry with lower pressure loss and a bonus of 7.27% reduction in weight under similar operating conditions....

Flow and Mass Transfer Performance in Short Pin-Fin Channels with Different Fin Shapes

OpenAIRE

Goldstein, R. J.; Chen, S. B.

1998-01-01

The mass transfer (analogous to heat transfer) and pressure loss characteristics of staggered short pin-fin arrays are investigated experimentally in the range of Reynolds number 3000 to 18,000 based on fin diameter and mean approach-flow velocity. Three different shapes of fins with aspect ratio of 2 are examined: one uniform-diameter circular fin (UDCF) and two stepped-diameter circular fins (SDCF1 and SDCF2). Flow visualization using oil-lampblack reveals complex flow characteristics assoc...

Eye retraction and rotation during Corvis ST 'air puff' intraocular pressure measurement and its quantitative analysis.

Science.gov (United States)

Boszczyk, Agnieszka; Kasprzak, Henryk; Jóźwik, Agnieszka

2017-05-01

The aim of this study was to analyse the indentation and deformation of the corneal surface, as well as eye retraction, which occur during air puff intraocular pressure (IOP) measurement. A group of 10 subjects was examined using a non-contact Corvis ST tonometer, which records image sequences of corneas deformed by an air puff. Obtained images were processed numerically in order to extract information about corneal deformation, indentation and eyeball retraction. The time dependency of the apex deformation/eye retraction ratio and the curve of dependency between apex indentation and eye retraction take characteristic shapes for individual subjects. It was noticed that the eye globes tend to rotate towards the nose in response to the air blast during measurement. This means that the eye globe not only displaces but also rotates during retraction. Some new parameters describing the shape of this curve are introduced. Our data show that intraocular pressure and amplitude of corneal indentation are inversely related (r 8  = -0.83, P = 0.0029), but the correlation between intraocular pressure and amplitude of eye retraction is low and not significant (r 8  = -0.24, P = 0.51). The curves describing corneal behaviour during air puff tonometry were determined and show that the eye globe rotates towards the nose during measurement. In addition, eye retraction amplitudes may be related to elastic or viscoelastic properties of deeper structures in the eye or behind the eye and this should be further investigated. Many of the proposed new parameters present comparable or even higher repeatability than the standard parameters provided by the Corvis ST. © 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.

Heat transfer enhancement of phase change materials by fins under simultaneous charging and discharging

International Nuclear Information System (INIS)

Joybari, Mahmood Mastani; Haghighat, Fariborz; Seddegh, Saeid; Al-Abidi, Abduljalil A.

2017-01-01

Highlights: • CFD simulation of a finned triplex tube heat exchanger with PCM under simultaneous charging and discharging. • Developed fin configurations for SCD, compatible with natural convection. • More fins enhanced the heat transfer as long as natural convection was not suppressed. • Longer fins enhanced the heat transfer as long as natural convection was not suppressed. • The effect of fin thickness was negligible, similar to non-SCD conditions. - Abstract: Due to the inherent intermittency of renewable energy sources such as solar, latent heat thermal energy storage in phase change materials (PCMs) has received considerable attention. Among several techniques to enhance PCMs’ thermal conductivity, the majority of studies have focused on fin integration due to its simplicity, ease of manufacturing, and low cost. In this study, utilization of extended surfaces (by longitudinal fins) was investigated by development of a numerical model to study the performance of a triplex tube heat exchanger (TTHX) equipped with a PCM under simultaneous charging and discharging (SCD). Governing equations were developed and numerically solved using ANSYS Fluent v16.2. Three conventional fin geometries and six developed fin configurations were compared based on the temperature, liquid fraction, and natural convection behavior under both SCD and non-SCD conditions. The intensity of natural convection was investigated for different fins for the inside heating/outside cooling scenario based on the solid–liquid interface evolution over time. The results indicated that since the buoyancy forces induce upward melted PCM motion, the inner hot tube requires fins on its lower half, while the outer cold one should be extended from its upper half. It was concluded that the case with 3 hot tube fins and 1 cold tube fin is most compatible with natural convection and provides the best performance under SCD conditions.

Nurturing a FinTech Ecosystem

DEFF Research Database (Denmark)

Leong, Carmen; Tan, Barney; Xiao, Xiao

2017-01-01

Financial technology, or FinTech, involves the design and delivery of financial products and services through technology. It impacts financial institutions, regulators, customers, and merchants across a wide range of industries. Pervasive digital technologies are challenging the fundamentals...... of the highly regulated financial sector, leading to the emergence of non-traditional payment systems, peer-to-peer money exchanges and increased turbulence in currency markets. This case study explores the development of a FinTech company in China that offers microloans to college students. Five lessons...... learned are presented for organizations to better manage the challenges and to leverage the opportunities amidst the disruption of financial sector. Our findings also shed light on how digital technology 1) offers the strategic capability for a firm to occupy a market niche in financial sector, 2) enables...

Novel 14-nm Scallop-Shaped FinFETs (S-FinFETs) on Bulk-Si Substrate

OpenAIRE

Xu, Weijia; Yin, Huaxiang; Ma, Xiaolong; Hong, Peizhen; Xu, Miao; Meng, Lingkuan

2015-01-01

In this study, novel p-type scallop-shaped fin field-effect transistors (S-FinFETs) are fabricated using an all-last high-k/metal gate (HKMG) process on bulk-silicon (Si) substrates for the first time. In combination with the structure advantage of conventional Si nanowires, the proposed S-FinFETs provide better electrostatic integrity in the channels than normal bulk-Si FinFETs or tri-gate devices with rectangular or trapezoidal fins. It is due to formation of quasi-surrounding gate electrod...

Bilateral inverse Duane′s retraction syndrome-A case report

Directory of Open Access Journals (Sweden)

Chatterjee Pranab

1991-01-01

Full Text Available Duane′s retraction syndrome is a well known congenital musculo-facial anomaly. Various explanations have been given for the aetiology of this syndrome. Inverse Duane′s retraction syndrome is a condition with reverse clinical features. Abduction of the affected eye is possible to some extent and is accompanied by retraction of the eyeball, narrowing of the palpebral fissure and pseudoptosis. There may be some restriction of movement on adduction. The primary lesion is suspected to be in the medial rectus muscle. Frequently the muscle is found to be entrapped following trauma to the medial wall of the orbit. A case of bilateral inverse Duane′s retraction syndrome and convergent squint along with left-sided perceptive deafness is reported. As is usually the case there was no structural abnormality or entrapment of the muscle from trauma.

Clinical application of micro-implant anchorage in initial orthodontic retraction.

Science.gov (United States)

Wahabuddin, Shaji; Mascarenhas, Rohan; Iqbal, Mahamad; Husain, Akhter

2015-02-01

Micro-implant is a device that is temporarily fixed to bone for the purpose of enhancing orthodontic anchorage either by supporting the teeth of the reactive unit or by obviating the need for the reactive unit altogether, and which is subsequently removed after use. The purpose of this study was to evaluate the clinical efficiency of micro-implants in reinforcing anchorage during the initial retraction of anterior teeth, check the rate of initial retraction for 8 weeks, and assess the stability of micro-implants during this period. Eighteen micro-implants were placed (10 in the maxilla and 8 in the mandible) and immediately loaded with 200-250 g of force using 9-mm closed coil Nitinol springs. The amount of space closure was measured every 2 weeks until the eighth week. Cephalometric measurements were made at the end of the study to evaluate anchor loss, if any. Micro-implant stability was also assessed. The rate of initial retraction in the maxilla at the end of 8 weeks was 1.65 mm/quadrant and 1.51 mm/quadrant in the mandible. The amount of retraction on the left side of the arches was 1.66 mm/quadrant and 1.49 mm/quadrant on the right side. The average initial retraction for both arches per month was 0.78 mm. An anchor loss of 0.1 mm (0.06%) was observed in the maxilla while no mandibular anchor loss was recorded. The rate of initial retraction observed in the maxilla was more than that achieved in the mandible. Initial retraction was also more on the left side of the arches. There was no anchor loss in the mandible. The micro-implant-reinforced anchorage was helpful in minimizing anchor loss and accepted heavy traction forces but did not bring about a faster rate of retraction.

A thermal study of pipes with outer transverse fins

Directory of Open Access Journals (Sweden)

S. Gil

2016-10-01

Full Text Available This paper provides results of thermal investigations on pipes with outer transverse fins produced by placing a strip, being a form of helical spring which functions as a radiator, on the basis pipe. The investigations were carried out at the facility that enables measurements with respect to both natural and forced convection. Performance of the investigated pipes was assessed in relation to a non-finned pipe and a pipe welded with the use of Metal Active Gas (MAG technology. The experiments have shown that the finned pipe welding technology does not markedly affect their thermal efficiency, which has been confirmed by performed model calculations, while the welding technology has a crucial impact on their operating performance.

Article retracted, but the message lives on.

Science.gov (United States)

Greitemeyer, Tobias

2014-04-01

The retraction of an original article aims to ensure that readers are alerted to the fact that the findings are not trustworthy. However, the present research suggests that individuals still believe in the findings of an article even though they were later told that the data were fabricated and that the article was retracted. Participants in a debriefing condition and a no-debriefing condition learned about the scientific finding of an empirical article, whereas participants in a control condition did not. Afterward, participants in the debriefing condition were told that the article had been retracted because of fabricated data. Results showed that participants in the debriefing condition were less likely to believe in the findings than participants in the no-debriefing condition but were more likely to believe in the findings than participants in the control condition, suggesting that individuals do adjust their beliefs in the perceived truth of a scientific finding after debriefing-but insufficiently. Mediational analyses revealed that the availability of generated causal arguments underlies belief perseverance. These results suggest that a retraction note of an empirical article in a scientific journal is not sufficient to ensure that readers of the original article no longer believe in the article's conclusions.

Non-Planar Nano-Scale Fin Field Effect Transistors on Textile, Paper, Wood, Stone, and Vinyl via Soft Material-Enabled Double-Transfer Printing

KAUST Repository

Rojas, Jhonathan Prieto; Sevilla, Galo T.; Alfaraj, Nasir; Ghoneim, Mohamed T.; Kutbee, Arwa T.; Sridharan, Ashvitha; Hussain, Muhammad Mustafa

2015-01-01

The ability to incorporate rigid but high-performance nano-scale non-planar complementary metal-oxide semiconductor (CMOS) electronics with curvilinear, irregular, or asymmetric shapes and surfaces is an arduous but timely challenge in enabling the production of wearable electronics with an in-situ information-processing ability in the digital world. Therefore, we are demonstrating a soft-material enabled double-transfer-based process to integrate flexible, silicon-based, nano-scale, non-planar, fin-shaped field effect transistors (FinFETs) and planar metal-oxide-semiconductor field effect transistors (MOSFETs) on various asymmetric surfaces to study their compatibility and enhanced applicability in various emerging fields. FinFET devices feature sub-20 nm dimensions and state-of-the-art, high-κ/metal gate stack, showing no performance alteration after the transfer process. A further analysis of the transferred MOSFET devices, featuring 1 μm gate length exhibits ION ~70 μA/μm (VDS = 2 V, VGS = 2 V) and a low sub-threshold swing of around 90 mV/dec, proving that a soft interfacial material can act both as a strong adhesion/interposing layer between devices and final substrate as well as a means to reduce strain, which ultimately helps maintain the device’s performance with insignificant deterioration even at a high bending state.

Non-Planar Nano-Scale Fin Field Effect Transistors on Textile, Paper, Wood, Stone, and Vinyl via Soft Material-Enabled Double-Transfer Printing

KAUST Repository

Rojas, Jhonathan Prieto

2015-05-01

The ability to incorporate rigid but high-performance nano-scale non-planar complementary metal-oxide semiconductor (CMOS) electronics with curvilinear, irregular, or asymmetric shapes and surfaces is an arduous but timely challenge in enabling the production of wearable electronics with an in-situ information-processing ability in the digital world. Therefore, we are demonstrating a soft-material enabled double-transfer-based process to integrate flexible, silicon-based, nano-scale, non-planar, fin-shaped field effect transistors (FinFETs) and planar metal-oxide-semiconductor field effect transistors (MOSFETs) on various asymmetric surfaces to study their compatibility and enhanced applicability in various emerging fields. FinFET devices feature sub-20 nm dimensions and state-of-the-art, high-κ/metal gate stack, showing no performance alteration after the transfer process. A further analysis of the transferred MOSFET devices, featuring 1 μm gate length exhibits ION ~70 μA/μm (VDS = 2 V, VGS = 2 V) and a low sub-threshold swing of around 90 mV/dec, proving that a soft interfacial material can act both as a strong adhesion/interposing layer between devices and final substrate as well as a means to reduce strain, which ultimately helps maintain the device’s performance with insignificant deterioration even at a high bending state.

Editor's note: notice of retraction.

Science.gov (United States)

Shafer, Steven L

2014-11-01

In 2009, Joachim Boldt published an article in Anesthesia & Analgesia comparing albumin and hydroxyethyl starch priming cardiopulmonary bypass. The study was retracted in December 2010 for lack of IRB approval. A subsequent investigation by Klinikum Ludwigshafen determined that the study was fabricated. Based on the finding by Landesärztekammer Rheinland-Pfalz, the State Medical Association of Rheinland-Pfalz, that the studies were conducted without IRB approval, Anesthesia & Analgesia retracted 22 papers by Dr. Boldt in 2011 for unethical conduct of research. A subsequent investigation by Klinikum Ludwigshafen found that Boldt’s studies "failed to meet required standards," included "false data" in at least 10 studies, and found "clear evidence of procedural irregularities and research misconduct on the part of Dr. Joachim Boldt." In light of these concerns, Justus-Liebig Universität Giessen undertook an investigation of Dr. Boldt’s work from that institution. This investigation cast doubt on the veracity of Boldt J, Heesen M, Müller M, Pabsdorf M, Hempelmann G. The effects of albumin versus hydroxyethyl starch solution on cardiorespiratory and circulatory variables in critically ill patient. Anesth Analg 1996;83: 254–61. Based on evidence of data manipulation reported by Justus-Liebig Universität Giessen to the journal, this paper is hereby retracted.

Atom-probe for FinFET dopant characterization

Energy Technology Data Exchange (ETDEWEB)

Kambham, A.K., E-mail: kambham@imec.be [K.U.Leuven, Instituut voor Kern-en Stralings fysika, Celestijnenlaan 200D, B-3001, Leuven (Belgium); IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Mody, J.; Gilbert, M.; Koelling, S.; Vandervorst, W. [K.U.Leuven, Instituut voor Kern-en Stralings fysika, Celestijnenlaan 200D, B-3001, Leuven (Belgium); IMEC, Kapeldreef 75, B-3001 Leuven (Belgium)

2011-05-15

With the continuous shrinking of transistors and advent of new transistor architectures to keep in pace with Moore's law and ITRS goals, there is a rising interest in multigate 3D-devices like FinFETs where the channel is surrounded by gates on multiple surfaces. The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions of the device. As a result there is a need for new metrology approach/technique to characterize quantitatively the dopant distribution in these devices with nanometer precision in 3D. In recent years, atom probe tomography (APT) has shown its ability to analyze semiconductor and thin insulator materials effectively with sub-nm resolution in 3D. In this paper we will discuss the methodology used to study FinFET-based structures using APT. Whereas challenges and solutions for sample preparation linked to the limited fin dimensions already have been reported before, we report here an approach to prepare fin structures for APT, which based on their processing history (trenches filled with Si) are in principle invisible in FIB and SEM. Hence alternative solutions in locating and positioning them on the APT-tip are presented. We also report on the use of the atom probe results on FinFETs to understand the role of different dopant implantation angles (10{sup o} and 45{sup o}) when attempting conformal doping of FinFETs and provide a quantitative comparison with alternative approaches such as 1D secondary ion mass spectrometry (SIMS) and theoretical model values. -- Research highlights: {yields} This paper provides the information on how to characterize the FinFET devices using atom probe tomography (APT). {yields} Importance of this work is to assess the performance of these devices at different processing conditions by extracting the compositional profiles. {yields} The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions

Atom-probe for FinFET dopant characterization

International Nuclear Information System (INIS)

Kambham, A.K.; Mody, J.; Gilbert, M.; Koelling, S.; Vandervorst, W.

2011-01-01

With the continuous shrinking of transistors and advent of new transistor architectures to keep in pace with Moore's law and ITRS goals, there is a rising interest in multigate 3D-devices like FinFETs where the channel is surrounded by gates on multiple surfaces. The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions of the device. As a result there is a need for new metrology approach/technique to characterize quantitatively the dopant distribution in these devices with nanometer precision in 3D. In recent years, atom probe tomography (APT) has shown its ability to analyze semiconductor and thin insulator materials effectively with sub-nm resolution in 3D. In this paper we will discuss the methodology used to study FinFET-based structures using APT. Whereas challenges and solutions for sample preparation linked to the limited fin dimensions already have been reported before, we report here an approach to prepare fin structures for APT, which based on their processing history (trenches filled with Si) are in principle invisible in FIB and SEM. Hence alternative solutions in locating and positioning them on the APT-tip are presented. We also report on the use of the atom probe results on FinFETs to understand the role of different dopant implantation angles (10 o and 45 o ) when attempting conformal doping of FinFETs and provide a quantitative comparison with alternative approaches such as 1D secondary ion mass spectrometry (SIMS) and theoretical model values. -- Research highlights: → This paper provides the information on how to characterize the FinFET devices using atom probe tomography (APT). → Importance of this work is to assess the performance of these devices at different processing conditions by extracting the compositional profiles. → The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions. → In this publication we

Pectoral fin contact as a mechanism for social bonding among dolphins

Science.gov (United States)

Dudzinski, Kathleen; Ribic, Christine

2017-01-01

Bottlenose dolphins are large-brained social mammals residing in a fission-fusion society with relationships that are established and maintained over decades. We examined a decade-long data set of inter-individual pectoral fin contact exchanges to better understand how dolphins share information via tactile contact. Sex and age are significant factors in pectoral fin contact within non-kin dolphin dyads. Adult females shared more pectoral fin contacts with other adult females, while younger females showed no pattern of contact. Males shared more pectoral fin contacts with other males as juveniles and as adults, but showed no difference in the number of touches versus rubs as pectoral fin contacts with other males. Whether in the role of initiator as rubber or initiator as rubbee, male dolphins again preferred other males. These results support the notion that dolphins, especially male dolphins, might use pectoral fin contact as one tool in their repertoire for social bonding to establish, maintain and manage their inter-individual relationships. Additionally, it is also likely that the exchange of pectoral fin contact is developed and refined as individuals age, mature socially, and establish their place within a fission-fusion society.

Investigation of material efficient fin patterns for cost-effective operation of fin and tube heat exchanger

DEFF Research Database (Denmark)

Singh, Shobhana; Sørensen, Kim; Condra, Thomas Joseph

2017-01-01

Design management of a thermal energy system is a critical part of identifying basic designs that meet large scale user demand under certain operating characteristics. Fin and tube heat exchangers are among the most commonly used thermal energy systems which are generating considerable interest...... and tube heat exchanger. Computational fluid dynamic models of fin and tube heat exchanger with different fin patterns are developed to investigate the fin pattern behavior on heat transfer and pressure loss performance data. In addition, the numerical results are utilized to analyze the engineering design...... scale-up heat exchanger configurations with each fin pattern focusing on the application of chosen fin and tube heat exchanger in marine exhaust gas boiler. The analysis highlights the impact of material efficient fin patterns investigated and predicts that the polynomial and sinusoidal fin patterns...

Non-invasive measurement of instantaneous forces during aquatic locomotion: a case study of the bluegill sunfish pectoral fin.

Science.gov (United States)

Peng, Jifeng; Dabiri, John O; Madden, Peter G; Lauder, George V

2007-02-01

Swimming and flying animals generate unsteady locomotive forces by delivering net momentum into the fluid wake. Hence, swimming and flying forces can be quantified by measuring the momentum of animal wakes. A recently developed model provides an approach to empirically deduce swimming and flying forces based on the measurement of velocity and vortex added-mass in the animal wake. The model is contingent on the identification of the vortex boundary in the wake. This paper demonstrates the application of that method to a case study quantifying the instantaneous locomotive forces generated by the pectoral fins of the bluegill sunfish (Lepomis macrochirus Rafinesque), measured using digital particle image velocimetry (DPIV). The finite-time Lyapunov exponent (FTLE) field calculated from the DPIV data was used to determine the wake vortex boundary, according to recently developed fluid dynamics theory. Momentum of the vortex wake and its added-mass were determined and the corresponding instantaneous locomotive forces were quantified at discrete time points during the fin stroke. The instantaneous forces estimated in this study agree in magnitude with the time-averaged forces quantified for the pectoral fin of the same species swimming in similar conditions and are consistent with the observed global motion of the animals. A key result of this study is its suggestion that the dynamical effect of the vortex wake on locomotion is to replace the real animal fin with an ;effective appendage', whose geometry is dictated by the FTLE field and whose interaction with the surrounding fluid is wholly dictated by inviscid concepts from potential flow theory. Benefits and limitations of this new framework for non-invasive instantaneous force measurement are discussed, and its application to comparative biomechanics and engineering studies is suggested.

A retractable barb needle for drug darts

Directory of Open Access Journals (Sweden)

G.L. van Rooyen

1973-07-01

Full Text Available The mechanism and action of a new retractable barbneedle for drug darts are described. This dart needle is particularly successful in obviating unnecessary flight reactions andtrauma in darted animals, and facilitates the complete injection of the drug dose before the barb is retracted and the dart is dislogded from the animal. The whole process is completed within a few seconds and the expended dart can usually be retrieved in the immediate vicinity where the animal was darted.

Open Access Works are as Reliable as Other Publishing Models at Retracting Flawed Articles from the Biomedical Literature

Directory of Open Access Journals (Sweden)

Elizabeth Margaret Stovold

2014-09-01

on the time between the date the original article was published and the date of retraction, and the availability of information on the reason for the retraction. Main results – The overall rate of retracted articles in the PMC open access subset compared with the wider PubMed dataset was similar (0.049% and 0.028% respectively. In the group with an accessibility rating of 0, the change in citation rate pre- and post-retraction was -41%. For the group with an accessibility rating of 1, the change was -47% and in those with a rating of 2, the change in citation rate was -59%. Removing articles published in high impact factor journals did not change the results significantly. Retractions were issued more slowly for free access papers compared with open or fee-based articles. The bibliographic records for open access articles disclosed details of the reason for the retraction more frequently than free, non-open papers (91% compared to 53%. Conclusion – Open access literature is similar in its rate of retraction and the reduction in post-retraction citations to the rest of the biomedical literature, and is actually more reliable at reporting the reason for the retraction.

Heat transfer from rotating finned heat exchangers with different orientation angles

Energy Technology Data Exchange (ETDEWEB)

Tawfik, Adel Abdalla [Suez Canal University, Marine Engineering and Naval Architecture Department, Faculty of Engineering, Port Said (Egypt)

2010-03-15

The local and average heat transfer characteristics of spoke like fins that extend outward from a rotating shaft have been determined experimentally. The experiments encompassed a number of geometrical parameters, including the length and chord of the fins, the number of fins deployed around the circumference of the shaft and the orientation angles of the fin. The experiments cover a wider range of rotational speeds, which varies from 25 up to 2,000 rpm. Three wire heat flux sensors have been used in conjunction with a slip ring apparatus to evaluate the local and average heat transfer coefficients. The output results indicated that, the heat transfer transition on rotating fins occurs at Reynolds number lower than encountered on the stationary rectangular fins in crossflow. In general, with non zero incidence angle, the rotating system acts as a fan and creates axial air motion, which enhance the heat transfer rate. However, the effect of orientation angle reduces with increasing the rotational speed. The Nusselt number data are independent of the number of fins in the circumferential array at high rotational speed and are weakly dependent at low Reynolds numbers. To facilitate the use of the results for design, correlations were developed which represent the fin heat transfer coefficient as a continuous function of the investigated independent parameters. (orig.)

Studi Analitik dan Numerik Perpindahan Panas pada Fin Trapesium (Studi Kasus pada Finned Tube Heat Exchanger

Directory of Open Access Journals (Sweden)

Ahmad Zaini

2013-09-01

Full Text Available Penambahan fin pada pipa penukar kalor merupakan suatu upaya memperbesar perpindahan kalor konduksi dan konveksi, dengan cara memperluas bidang geometri. Pada penelitian ini dianalisa secara analitik dan numerik perpindahan kalor pada fin dengan profil longitudinal tidak seragam atau berubah terhadap jarak dari dasar fin, dengan memvariasikan ketebalan ujung fin. Hasil dari kedua studi ini tidak jauh berbeda, pada keduanya menjelaskan bahwa fin dengan ketebalan ujung 0,9 mm (fin trapesium terbalik paling baik dari 5 variasi lainnya; serta perubahan temperatur paling besar terjadi pada sepertiga pertama dari panjang  fin, ini artinya pelepasan kalor terbesar terjadi pada daerah tersebut. Perbedaannya adalah pada persentase penurunan temperatur sepanjang  fin terhadap temperatur dasar fin, untuk ketebalan 0,9 mm pada studi analitik sebesar 91,92% dan pada studi numerik sebesar 91,78%. Hal ini berarti metode penyelesaian persamaan diferensial orde 2 dengan koefisien variabel dengan cara pembedahan koefisien variabel pada ODE, sudah benar dan valid. Namun bila ditinjau dari waktu yang diperlukan untuk komputasinya, studi analitik membutuhkan waktu lebih lama. Waktu yang diperlukan dalam komputasinya tergantung dari fungsi koefisien variabel.

Is Duane retraction syndrome part of the VACTERL association?

Directory of Open Access Journals (Sweden)

Akar S

2013-03-01

Full Text Available Serpil Akar,1 Birsen Gokyigit,1 Isilay Kavadarli,2 Ahmet Demirok11Pediatric Ophthalmology and Strabismus Department, Prof Dr N Resat Belger Beyoglu Education and Research Eye Hospital, Istanbul, 2Department of Ophthalmology, Gaziantep, Kilis State Hospital, Kilis, TurkeyAbstract: We report here a patient with type 1 Duane’s retraction syndrome and multiple congenital abnormalities as a result of the VACTERL association. The presented combination of Duane’s retraction syndrome and the VACTERL association has not been reported in the literature. The present case was instructive for reviewing the continuous spectrum of ocular anomalies that accompany the VACTERL association.Keywords: Duane’s retraction syndrome, VACTERL association, combination

Experimental testing of the thermal performance of finned air coolers

International Nuclear Information System (INIS)

Imhof, A.; Keller, J.; Koelliker, A.

1988-05-01

Finned heat exchangers are often used as regenerators in heat recovery systems or as a heat source for heat pump installations. These exchangers are usually operating as air coolers. Heat is extracted from the air flowing through the heat exchanger. If the fin temperature lies below the dew point at the air inlet, water vapour may be condensed, increasing the thermal performance of the cooler. If the air/water heat exchanger is installed outdoors, the blower is usually mounted directly at the exchaner's case. In general this leads to non-ideal air flow conditions. For the sizing of such components the manufacturers dispose of design rules which are based either on theoretical models or on experiments using a uniform air stream. These rules which are mostly internal codes of the individual companies presumably do not take into account some non-ideal conditions such as an inhomogeneous air flow, a poorly sized blower or an increased pressure drop between the fins due to condensed water vapour. Moreover, these codes are possibly not sophisticated enough to enable a correct sizing of the products for any given condition of operation, especially in heat pumps operating under condensation conditions. Therfore, the Swiss Federal Institute for Reactor Research (EIR) carried out a research program dealing with the thermal performance of commercially available finned air coolers. The results give a strong evidence that the sizing of finned air coolers involving a phase change in one of the heat transfer fluids is not yet a procedure belonging to the common knowledge of most of the manufacturers. Moreover, the correct sizing of the blower is at least as important as the sizing of the finned exchanger itself. However, it is evident that there are companies on the Swiss market which use already reliable design tools. 25 refs., 81 figs., 12 tabs

Comprehensive study of flow and heat transfer at the surface of circular cooling fin

Science.gov (United States)

Mityakov, V. Yu; Grekov, M. A.; Gusakov, A. A.; Sapozhnikov, S. Z.; Seroshtanov, V. V.; Bashkatov, A. V.; Dymkin, A. N.; Pavlov, A. V.; Milto, O. A.; Kalmykov, K. S.

2017-11-01

For the first time is proposed to combine heat flux measurements with thermal imaging and PIV (particle image velocimetry) for a comprehensive study of flow and heat transfer at the surface of the circular cooling fin. The investigated hollow fin is heated from within with saturated water steam; meanwhile the isothermal external surface simulates one of the perfect fin. Flow and heat transfer at the surface of the solid fin of the same size and shape, made of titanium alloy is investigated in the same regimes. Gradient Heat Flux Sensors (GHFS) were installed at different places of the fin surface. Velocity field around a cylinder, temperature field at the surface of the fin and heat flux for each rated time were obtained. Comprehensive method including heat flux measurement, PIV and thermal imaging allow to study flow and heat transfer at the surface of the fin in real time regime. The possibility to study flow and heat transfer for non-isothermal fins is shown; it is allow to improve traditional calculation of the cooling fins.

Folding-retraction of chaotic dynamical manifold and the VAK of vacuum fluctuation

International Nuclear Information System (INIS)

El-Ghoul, M.; El-Ahmady, A.E.; Rafat, H.

2004-01-01

In this paper we introduce the retraction of chaos dynamical manifold. Some properties of chaos dynamical manifold will be deduced. Theorems governing the relation between the folding and retraction of chaos dynamical manifold will be discussed. Some applications of chaos dynamical manifolds and their retractions are achieved in particular high energy particle physics

Quantification of intrusive/retraction force and moment generated during en-masse retraction of maxillary anterior teeth using mini-implants: A conceptual approach

Directory of Open Access Journals (Sweden)

A. Sumathi Felicita

Full Text Available ABSTRACT Objective: The aim of the present study was to clarify the biomechanics of en-masse retraction of the upper anterior teeth and attempt to quantify the different forces and moments generated using mini-implants and to calculate the amount of applied force optimal for en-masse intrusion and retraction using mini-implants. Methods: The optimum force required for en-masse intrusion and retraction can be calculated by using simple mathematical formulae. Depending on the position of the mini-implant and the relationship of the attachment to the center of resistance of the anterior segment, different clinical outcomes are encountered. Using certain mathematical formulae, accurate measurements of the magnitude of force and moment generated on the teeth can be calculated for each clinical outcome. Results: Optimum force for en-masse intrusion and retraction of maxillary anterior teeth is 212 grams per side. Force applied at an angle of 5o to 16o from the occlusal plane produce intrusive and retraction force components that are within the physiologic limit. Conclusion: Different clinical outcomes are encountered depending on the position of the mini-implant and the length of the attachment. It is possible to calculate the forces and moments generated for any given magnitude of applied force. The orthodontist can apply the basic biomechanical principles mentioned in this study to calculate the forces and moments for different hypothetical clinical scenarios.

RETRACTED: A randomized, double-blind comparison of granisetron alone and combined with dexamethasone for post—laparoscopic cholecystectomy emetic symptoms

Directory of Open Access Journals (Sweden)

Yoshitaka Fujii, MD

2003-09-01

Full Text Available This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal.This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy.The following articles are being retracted as a result of overwhelming evidence of fabrication, related to the fact that the distributions of many variables reported by Dr Fujii in these studies could not have occurred by chance, and the inability of Dr Fujii's institutions to attest to the integrity of the study and/or its data conducted under their auspices. Because both the Journal's independent and collaborative attempts have not yielded this required information, the Journal has decided to retract the remaining journal manuscripts authored by Dr. Yoshitaka Fujii. The Publisher apologises that the implementation of this retraction was delayed due to an administrative oversight.Fujii Y, Tanaka H, Kawasaki T. A randomised, double-blind comparison of granisetron alone and combined with dexamethasone for post-laparoscopic choleystectomy emetic symptoms. Current Therapeutic Research 2003;64:514–21. https://www.sciencedirect.com/science/article/pii/S0011393X03001590Fujii Y, Tanaka H, Somekawa Y. Treatment of postoperative emetic symptoms with granisetron in women undergoing abdominal hysterectomy: a randomised, double-blind, placebo-controlled, dose-ranging study. Current Therapeutic Research 2004;65:321–9. https://www.sciencedirect.com/science/article/pii/S0011393X04800018.

Development of non-lethal monitoring of stable isotopes in asp (Leuciscus aspius): a comparison of muscle, fin and scale tissues

Czech Academy of Sciences Publication Activity Database

Vašek, Mojmír; Vejřík, Lukáš; Vejříková, Ivana; Šmejkal, Marek; Baran, Roman; Muška, Milan; Kubečka, Jan; Peterka, Jiří

2017-01-01

Roč. 785, č. 1 (2017), s. 327-335 ISSN 0018-8158 R&D Projects: GA ČR(CZ) GA15-01625S; GA MŠk(CZ) EE2.3.20.0204 Institutional support: RVO:60077344 Keywords : fish fins * fish scales * fractionation * non-lethal sampling * stable isotopes Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 2.056, year: 2016

Retracted: Effect of Paris polyphylla extract on seconddegree burns ...

African Journals Online (AJOL)

2018-01-26

Jan 26, 2018 ... This article previously published in Volume 15 Issue 10 of this journal in October 2016 has been retracted in line with the guidelines from the Committee on Publication Ethics (COPE, http://publicationethics.org/resources/guidelines). Retracted: Ma Z, Yin W, Hu G, Zhu Z, Huang Z. Effect of Paris polyphylla ...

Toward quantum FinFET

CERN Document Server

Wang, Zhiming

2013-01-01

This book reviews a range of quantum phenomena in novel nanoscale transistors called FinFETs, including quantized conductance of 1D transport, single electron effect, tunneling transport, etc. The goal is to create a fundamental bridge between quantum FinFET and nanotechnology to stimulate readers' interest in developing new types of semiconductor technology. Although the rapid development of micro-nano fabrication is driving the MOSFET downscaling trend that is evolving from planar channel to nonplanar FinFET, silicon-based CMOS technology is expected to face fundamental limits in the near future. Therefore, new types of nanoscale devices are being investigated aggressively to take advantage of the quantum effect in carrier transport. The quantum confinement effect of FinFET at room temperatures was reported following the breakthrough to sub-10nm scale technology in silicon nanowires. With chapters written by leading scientists throughout the world, Toward Quantum FinFET provides a comprehensive introductio...

High performance flexible CMOS SOI FinFETs

KAUST Repository

Fahad, Hossain M.

2014-06-01

We demonstrate the first ever CMOS compatible soft etch back based high performance flexible CMOS SOI FinFETs. The move from planar to non-planar FinFETs has enabled continued scaling down to the 14 nm technology node. This has been possible due to the reduction in off-state leakage and reduced short channel effects on account of the superior electrostatic charge control of multiple gates. At the same time, flexible electronics is an exciting expansion opportunity for next generation electronics. However, a fully integrated low-cost system will need to maintain ultra-large-scale-integration density, high performance and reliability - same as today\\'s traditional electronics. Up until recently, this field has been mainly dominated by very weak performance organic electronics enabled by low temperature processes, conducive to low melting point plastics. Now however, we show the world\\'s highest performing flexible version of 3D FinFET CMOS using a state-of-the-art CMOS compatible fabrication technique for high performance ultra-mobile consumer applications with stylish design. © 2014 IEEE.

Retraction in Cariocan Portuguese.

Science.gov (United States)

Reis, Isaias

This study looks at the retraction phenomenon of the alveolar fricatives [s] and [z] in Cariocan Portuguese, the dialect used in Rio de Janeiro, Brazil and its correlation with selected social characteristics of the study's informants. No prior study exists that focuses only on this phonological feature in this dialect. Before describing…

Practice Location Characteristics of Non-Traditional Dental Practices.

Science.gov (United States)

Solomon, Eric S; Jones, Daniel L

2016-04-01

Current and future dental school graduates are increasingly likely to choose a non-traditional dental practice-a group practice managed by a dental service organization or a corporate practice with employed dentists-for their initial practice experience. In addition, the growth of non-traditional practices, which are located primarily in major urban areas, could accelerate the movement of dentists to those areas and contribute to geographic disparities in the distribution of dental services. To help the profession understand the implications of these developments, the aim of this study was to compare the location characteristics of non-traditional practices and traditional dental practices. After identifying non-traditional practices across the United States, the authors located those practices and traditional dental practices geographically by zip code. Non-traditional dental practices were found to represent about 3.1% of all dental practices, but they had a greater impact on the marketplace with almost twice the average number of staff and annual revenue. Virtually all non-traditional dental practices were located in zip codes that also had a traditional dental practice. Zip codes with non-traditional practices had significant differences from zip codes with only a traditional dental practice: the populations in areas with non-traditional practices had higher income levels and higher education and were slightly younger and proportionally more Hispanic; those practices also had a much higher likelihood of being located in a major metropolitan area. Dental educators and leaders need to understand the impact of these trends in the practice environment in order to both prepare graduates for practice and make decisions about planning for the workforce of the future.

PHASE CHANGE AROUND A FINNED TUBE

Directory of Open Access Journals (Sweden)

Aytunç EREK

2003-01-01

Full Text Available This study presents the heat transfer enhancement in the thermal energy storage system by using radially finned tube. The solution of the system consists of the solving the equations of the heat transfer fluid (HTF, the pipe wall and fin, and the phase change material (PCM as one domain. The control volume finite difference approach and the semi implicit solver (SIS are used to solve the equations. Fully developed velocity distribution is taken in the HTF. Flow parameters (Re number and inlet temperature of coolant and fin parameters (the number of fins, fin length, fin thickness are found to influence solidification fronts and the total stored energy.

Exploring the characteristics, global distribution and reasons for retraction of published articles involving human research participants: a literature survey.

Science.gov (United States)

Li, Guowei; Kamel, Mariam; Jin, Yanling; Xu, Michael Kuan; Mbuagbaw, Lawrence; Samaan, Zainab; Levine, Mitchell Ah; Thabane, Lehana

2018-01-01

Article retraction is a measure taken by journals or authors where there is evidence of research misconduct or error, redundancy, plagiarism or unethical research. Recently, the retraction of scientific publications has been on the rise. In this survey, we aimed to describe the characteristics and distribution of retracted articles and the reasons for retractions. We searched retracted articles on the PubMed database and Retraction Watch website from 1980 to February 2016. The primary outcomes were the characteristics and distribution of retracted articles and the reasons for retractions. The secondary outcomes included how article retractions were handled by journals and how to improve the journal practices toward article retractions. We included 1,339 retracted articles. Most retracted articles had six authors or fewer. Article retraction was most common in the USA (26%), Japan (11%) and Germany (10%). The main reasons for article retraction were misconduct (51%, n = 685) and error (14%, n = 193). There were 66% (n = 889) of retracted articles having male senior or corresponding authors. Of the articles retracted after August 2010, 63% (n = 567) retractions were reported on Retraction Watch. Large discrepancies were observed in the ways that different journals handled article retractions. For instance, articles were completely withdrawn from some journals, while in others, articles were still available with no indication of retraction. Likewise, some retraction notices included a detailed account of the events that led to article retraction, while others only consisted of a statement indicating the article retraction. The characteristics, geographic distribution and reasons for retraction of published articles involving human research participants were examined in this survey. More efforts are needed to improve the consistency and transparency of journal practices toward article retractions.

Large fully retractable telescope enclosures still closable in strong wind

Science.gov (United States)

Bettonvil, Felix C. M.; Hammerschlag, Robert H.; Jägers, Aswin P. L.; Sliepen, Guus

2008-07-01

Two prototypes of fully retractable enclosures with diameters of 7 and 9 m have been built for the high-resolution solar telescopes DOT (Dutch Open Telescope) and GREGOR, both located at the Canary Islands. These enclosures protect the instruments for bad weather and are fully open when the telescopes are in operation. The telescopes and enclosures also operate in hard wind. The prototypes are based on tensioned membrane between movable but stiff bows, which fold together to a ring when opened. The height of the ring is small. The prototypes already survived several storms, with often snow and ice, without any damage, including hurricane Delta with wind speeds up to 68 m/s. The enclosures can still be closed and opened with wind speeds of 20 m/s without any problems or restrictions. The DOT successfully demonstrated the open, wind-flushing concept for astronomical telescopes. It is now widely recognized that also large future telescopes benefit from wind-flushing and retractable enclosures. These telescopes require enclosures with diameters of 30 m until roughly 100 m, the largest sizes for the ELTs (Extreme Large Telescopes), which will be built in the near future. We discuss developments and required technology for the realization of these large sizes.

CT radiogenomic characterization of EGFR, K-RAS, and ALK mutations in non-small cell lung cancer

Energy Technology Data Exchange (ETDEWEB)

Rizzo, Stefania; Rampinelli, Cristiano [European Institute of Oncology, Department of Radiology, Milan (Italy); Petrella, Francesco; Spaggiari, Lorenzo [European Institute of Oncology, Department of Thoracic Surgery, Milan (Italy); Buscarino, Valentina; De Maria, Federica [University of Milan, Department of Health Sciences, Milan (Italy); Raimondi, Sara [European Institute of Oncology, Department of Epidemiology and Biostatistics, Milan (Italy); Barberis, Massimo; Fumagalli, Caterina [European Institute of Oncology, Department of Pathology, Milan (Italy); Spitaleri, Gianluca; De Marinis, Filippo [European Institute of Oncology, Department of Thoracic Oncology, Milan (Italy); Bellomi, Massimo [European Institute of Oncology, Department of Radiology, Milan (Italy); University of Milan, Department of Health Sciences, Milan (Italy)

2016-01-15

To assess the association between CT features and EGFR, ALK, KRAS mutations in non-small cell lung cancer. Patients undergoing chest CT and testing for the above gene mutations were included. Qualitative evaluation of CTs included: lobe; lesion diameter; shape; margins; ground-glass opacity; density; cavitation; air bronchogram; pleural thickening; intratumoral necrosis; nodules in tumour lobe; nodules in non-tumour lobes; pleural retraction; location; calcifications; emphysema; fibrosis; pleural contact; pleural effusion. Statistical analysis was performed to assess association of features with each gene mutation. ROC curves for gene mutations were drawn; the corresponding area under the curve was calculated. P-values <0.05 were considered significant. Of 285 patients, 60/280 (21.43 %) were positive for EGFR mutation; 31/270 (11.48 %) for ALK rearrangement; 64/240 (26.67 %) for KRAS mutation. EGFR mutation was associated with air bronchogram, pleural retraction, females, non-smokers, small lesion size, and absence of fibrosis. ALK rearrangements were associated with age and pleural effusion. KRAS mutation was associated with round shape, nodules in non-tumour lobes, and smoking. This study disclosed associations between CT features and alterations of EGFR (air bronchogram, pleural retraction, small lesion size, absence of fibrosis), ALK (pleural effusion) and KRAS (round lesion shape, nodules in non-tumour lobes). (orig.)

Ballistic electron transport calculation of strained germanium-tin fin field-effect transistors

International Nuclear Information System (INIS)

Lan, H.-S.; Liu, C. W.

2014-01-01

The dependence of ballistic electron current on Sn content, sidewall orientations, fin width, and uniaxial stress is theoretically studied for the GeSn fin field-effect transistors. Alloying Sn increases the direct Γ valley occupancy and enhances the injection velocity at virtual source node. (112 ¯ ) sidewall gives the highest current enhancement due to the rapidly increasing Γ valley occupancy. The non-parabolicity of the Γ valley affects the occupancy significantly. However, uniaxial tensile stress and the shrinkage of fin width reduce the Γ valley occupancy, and the currents are enhanced by increasing occupancy of specific indirect L valleys with high injection velocity

Channels with Different Fin Shapes

Directory of Open Access Journals (Sweden)

R. J. Goldstein

1998-01-01

Full Text Available The mass transfer (analogous to heat transfer and pressure loss characteristics of staggered short pin-fin arrays are investigated experimentally in the range of Reynolds number 3000 to 18,000 based on fin diameter and mean approach-flow velocity. Three different shapes of fins with aspect ratio of 2 are examined: one uniform-diameter circular fin (UDCF and two stepped-diameter circular fins (SDCF1 and SDCF2. Flow visualization using oil-lampblack reveals complex flow characteristics associated with the repeated production of horseshoe vortices and fin wakes, and the interactions among these. The SDCF1 and SDCF2 arrays show flow characteristics different from the UDCF array due to downflow from the steps. For all arrays tested, the near-endwall flow varies row by row in the initial rows until it reaches a stable pattern after the third row. The row-averaged Sherwood numbers obtained from the naphthalene sublimation experiment also show a row-by-row variation pattern similar to the flow results. While the SDCF2 array has the highest mass transfer rate, the SDCF1 array has the smallest pressure loss at the same approach-flow velocity. The fin surfaces have higher array-averaged Sherwood number than the endwall and the ratio between these changes with fin shape and Reynolds number. The performance of the pin-fin arrays is analyzed under two different constraints: the mass[heat transfer rate at fixed pumping power, and the mass/heat transfer area and pressure loss to fulfill fixed heat load at a fixed mass flow rate. In both cases, the SDCF2 array shows the best performance.

Comparative photoelastic study of dental and skeletal anchorages in the canine retraction

Directory of Open Access Journals (Sweden)

Cristiane Aparecida de Assis Claro

2014-01-01

Full Text Available OBJECTIVE: To compare dental and skeletal anchorages in mandibular canine retraction by means of a stress distribution analysis. METHODS: A photoelastic model was produced from second molar to canine, without the first premolar, and mandibular canine retraction was simulated by a rubber band tied to two types of anchorage: dental anchorage, in the first molar attached to adjacent teeth, and skeletal anchorage with a hook simulating the mini-implant. The forces were applied 10 times and observed in a circular polariscope. The stresses located in the mandibular canine were recorded in 7 regions. The Mann-Whitney test was employed to compare the stress in each region and between both anchorage systems. The stresses in the mandibular canine periradicular regions were compared by the Kruskal-Wallis test. RESULTS: Stresses were similar in the cervical region and the middle third. In the apical third, the stresses associated with skeletal anchorage were higher than the stresses associated with dental anchorage. The results of the Kruskal-Wallis test showed that the highest stresses were identified in the cervical-distal, apical-distal, and apex regions with the use of dental anchorage, and in the apical-distal, apical-mesial, cervical-distal, and apex regions with the use of skeletal anchorage. CONCLUSIONS: The use of skeletal anchorage in canine retraction caused greater stress in the apical third than the use of dental anchorage, which indicates an intrusive component resulting from the direction of the force due to the position of the mini-implant and the bracket hook of the canine.

CFD Simulations of a Finned Projectile with Microflaps for Flow Control

Directory of Open Access Journals (Sweden)

Jubaraj Sahu

2017-01-01

Full Text Available This research describes a computational study undertaken to determine the effect of a flow control mechanism and its associated aerodynamics for a finned projectile. The flow control system consists of small microflaps located between the rear fins of the projectile. These small microflaps alter the flow field in the aft finned region of the projectile, create asymmetric pressure distributions, and thus produce aerodynamic control forces and moments. A number of different geometric parameters, microflap locations, and the number of microflaps were varied in an attempt to maximize the control authority generated by the flaps. Steady-state Navier-Stokes computations were performed to obtain the control aerodynamic forces and moments associated with the microflaps. These results were used to optimize the control authority at a supersonic speed, M=2.5. Computed results showed not only the microflaps to be effective at this speed, but also configurations with 6 and 8 microflaps were found to generate 25%–50% more control force than a baseline 4-flap configuration. These results led to a new optimized 8-flap configuration that was further investigated for a range of Mach numbers from M=0.8 to 5.0 and was found to be a viable configuration effective in providing control at all of these speeds.

The visibility of scientific misconduct: A review of the literature on retracted journal articles.

Science.gov (United States)

Hesselmann, Felicitas; Graf, Verena; Schmidt, Marion; Reinhart, Martin

2017-10-01

Retractions of scientific articles are becoming the most relevant institution for making sense of scientific misconduct. An increasing number of retracted articles, mainly attributed to misconduct, is currently providing a new empirical basis for research about scientific misconduct. This article reviews the relevant research literature from an interdisciplinary context. Furthermore, the results from these studies are contextualized sociologically by asking how scientific misconduct is made visible through retractions. This study treats retractions as an emerging institution that renders scientific misconduct visible, thus, following up on the sociology of deviance and its focus on visibility. The article shows that retractions, by highlighting individual cases of misconduct and general policies for preventing misconduct while obscuring the actors and processes through which retractions are effected, produce highly fragmented patterns of visibility. These patterns resemble the bifurcation in current justice systems.

Characteristics of fin whale vocalizations recorded on instruments in the northeast Pacific Ocean

Science.gov (United States)

Weirathmueller, Maria Michelle Josephine

This thesis focuses on fin whale vocalizations recorded on ocean bottom seismometers (OBSs) in the Northeast Pacific Ocean, using data collected between 2003 and 2013. OBSs are a valuable, and largely untapped resource for the passive acoustic monitoring of large baleen whales. This dissertation is divided into three parts, each of which uses the recordings of fin whale vocalizations to better understand their calling behaviors and distributions. The first study describes the development of a technique to extract source levels of fin whale vocalizations from OBS recordings. Source levels were estimated using data collected on a network of eight OBSs in the Northeast Pacific Ocean. The acoustic pressure levels measured at the instruments were adjusted for the propagation path between the calling whales and the instruments using the call location and estimating losses along the acoustic travel path. A total of 1241 calls were used to estimate an average source level of 189 +/-5.8 dB re 1uPa 1m. This variability is largely attributed to uncertainties in the horizontal and vertical position of the fin whale at the time of each call, and the effect of these uncertainties on subsequent calculations. The second study describes a semi-automated method for obtaining horizontal ranges to vocalizing fin whales using the timing and relative amplitude of multipath arrivals. A matched filter is used to detect fin whale calls and pick the relative times and amplitudes of multipath arrivals. Ray-based propagation models are used to predict multipath times and amplitudes as function of range. Because the direct and first multiple arrivals are not always observed, three hypotheses for the paths of the observed arrivals are considered; the solution is the hypothesis and range that optimizes the fit to the data. Ray-theoretical amplitudes are not accurate and solutions are improved by determining amplitudes from the observations using a bootstrap method. Data from ocean bottom

An experimental investigation on the airside performance of fin-and-tube heat exchangers having slit fins under wet condition

International Nuclear Information System (INIS)

Kim, Nae Hyun; Kim, Tae Hun

2015-01-01

In this study, the heat transfer and friction characteristics of the 5.3 mm O.D. slit-finned heat exchangers under wet condition have been experimentally investigated. Plain-finned heat exchangers having the same 5.3 mm O.D. tubes are also tested for comparison purpose. The effect of fin pitch on j and f factor is negligible. Slit fin samples yield higher j and f factors than plain fin samples. For one row configuration, the average f factor ratio between slit fin sample and plain fin sample is 2.18. The ratio increases to 2.41 for two row configuration, and to 2.65 for three row configuration. As for the j factor, the ratios are approximately the same (1.61, 1.70 and 1.71 for one, two and three row configuration). Both j and f factor increase as the number of tube row decreases. The same trend is observed for the plain fin samples. At high Reynolds numbers, the j/f ratios of the slit fin are approximately the same as those of the plain fin. At low Reynolds numbers, the j/f ratios of the slit fin are smaller than those of plain fin. Data are compared with existing correlations.

Typology of Retractable Roof Structures in Stadiums and Sports Halls

Directory of Open Access Journals (Sweden)

Andrej Mahovič

2015-10-01

Full Text Available Retractable roof structures are one of the four fundamental systems (in addition to the playing area, stands and facade in a stadium and sports hall. The roof protects users against various weather conditions and creates optimum circumstances for carrying out different activities. Stadiums and sports halls with retractable roof structures can host a greater variety of activities, improve the quality of their implementation and the quality of visitors’ experience, and affect the perception and experience of people using or observing such buildings. A retractable roof structure allows for natural lighting and ventilation of the venue, gives optimal conditions for grass growth on the playing field, and reduces costs of use and maintenance of the building. Different typologies of movement of roof structures (frequency of opening and closing, design of the structure, and methods of movement are categorised in terms of their architectural and structural design. Application of different retractable roof systems worldwide is indicator of their effectiveness and efficiency, and is basis for use of movement also in other fundamental systems of stadiums and sports halls. Research and identification of characteristics of retractable roof structures lead to the design of new moving systems that can with the application of the moving principle change the purpose of movable elements or assume the characteristics of other fundamental systems.

Experimental Investigation on Effect of Fin Shape on the Thermal-Hydraulic Performance of Compact Fin-and-Tube Heat Exchangers

Science.gov (United States)

Moorthy, P.; Oumer, A. N.; Ishak, M.

2018-03-01

The aim of this paper is to investigate the effect of fin shapes on the performance of compact finned flat tube heat exchangers. Three types of fin shapes namely plain, wavy, and rectangular grooved fins attached to three by three arrays of flat tube banks were considered. Moreover, the tubes were deployed in in-line and staggered arrangements. In addition to the fin shapes, the air velocity and the tube inclination angles were varied and the thermal-hydraulic performance was analysed. On the other hand, the temperatures at the tube surfaces were kept constant to produce constant heat flux throughout the study. The results showed that as flowrate increases, the heat transfer increases, however, the friction factor decreases. Staggered arrangement produces higher heat transfer and friction factor than inline fin. Moreover, the rectangular fin is the best in terms of high heat transfer however the drawback of high friction factor leads the fin to have the least efficiency of all. On the other hand, plain fin had the least heat transfer performance however the highest efficiency was achieved. Therefore, plain fin should be used when efficiency is prioritized and rectangular fin when high heat transfer is desired.

RETRACTED: Application of RF magnetron sputtering for growth of AZO on glass substrate

Science.gov (United States)

Ghorannevis, Z.; Akbarnejad, E.; Salar Elahi, A.; Ghoranneviss, M.

2016-08-01

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Principal Editor. After a thorough investigation, the Editor has concluded that the review process for this article was compromised. The acceptance was based on information from at least one reviewer report that was submitted from an email account provided to the journal as a suggested reviewer during the submission of the article. Although purportedly a real reviewer account, the Editor has concluded that this was not of an appropriate, independent reviewer. This manipulation of the peer-review process represents a clear violation of the fundamentals of peer review, our publishing policies, and publishing ethics standards. Apologies are offered to the reviewers whose identities were assumed and to the readers of the journal that this deception was not detected during the submission process. In addition, the author names Z. Ghorannevis and E. Akbarnejad were added to the article at revision - the corresponding author was not able to explain the reason.

Ballistic electron transport calculation of strained germanium-tin fin field-effect transistors

Energy Technology Data Exchange (ETDEWEB)

Lan, H.-S. [Graduate Institute of Electronics Engineering and Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China); Liu, C. W., E-mail: chee@cc.ee.ntu.edu.tw [Graduate Institute of Electronics Engineering and Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China); Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan (China)

2014-05-12

The dependence of ballistic electron current on Sn content, sidewall orientations, fin width, and uniaxial stress is theoretically studied for the GeSn fin field-effect transistors. Alloying Sn increases the direct Γ valley occupancy and enhances the injection velocity at virtual source node. (112{sup ¯}) sidewall gives the highest current enhancement due to the rapidly increasing Γ valley occupancy. The non-parabolicity of the Γ valley affects the occupancy significantly. However, uniaxial tensile stress and the shrinkage of fin width reduce the Γ valley occupancy, and the currents are enhanced by increasing occupancy of specific indirect L valleys with high injection velocity.

Randomized clinical trial comparing control of maxillary anchorage with 2 retraction techniques.

Science.gov (United States)

Xu, Tian-Min; Zhang, Xiaoyun; Oh, Hee Soo; Boyd, Robert L; Korn, Edward L; Baumrind, Sheldon

2010-11-01

The objective of this pilot randomized clinical trial was to investigate the relative effectiveness of anchorage conservation of en-masse and 2-step retraction techniques during maximum anchorage treatment in patients with Angle Class I and Class II malocclusions. Sixty-four growing subjects (25 boys, 39 girls; 10.2-15.9 years old) who required maximum anchorage were randomized to 2 treatment techniques: en-masse retraction (n = 32) and 2-step retraction (n = 32); the groups were stratified by sex and starting age. Each patient was treated by a full-time clinic instructor experienced in the use of both retraction techniques at the orthodontic clinic of Peking University School of Stomatology in China. All patients used headgear, and most had transpalatal appliances. Lateral cephalograms taken before treatment and at the end of treatment were used to evaluate treatment-associated changes. Differences in maxillary molar mesial displacement and maxillary incisor retraction were measured with the before and after treatment tracings superimposed on the anatomic best fit of the palatal structures. Differences in mesial displacement of the maxillary first molar were compared between the 2 treatment techniques, between sexes, and between different starting-age groups. Average mesial displacement of the maxillary first molar was slightly less in the en-masse group than in the 2-step group (mean, -0.36 mm; 95% CI, -1.42 to 0.71 mm). The average mesial displacement of the maxillary first molar for both treatment groups pooled (n = 63, because 1 patient was lost to follow-up) was 4.3 ± 2.1 mm (mean ± standard deviation). Boys had significantly more mesial displacement than girls (mean difference, 1.3 mm; P <0.03). Younger adolescents had significantly more mesial displacement than older adolescents (mean difference, 1.3 mm; P <0.02). Average mesial displacement of the maxillary first molar with 2-step retraction was slightly greater than that for en-masse retraction, but the

Batoid locomotion: effects of speed on pectoral fin deformation in the little skate, Leucoraja erinacea.

Science.gov (United States)

Di Santo, Valentina; Blevins, Erin L; Lauder, George V

2017-02-15

Most batoids have a unique swimming mode in which thrust is generated by either oscillating or undulating expanded pectoral fins that form a disc. Only one previous study of the freshwater stingray has quantified three-dimensional motions of the wing, and no comparable data are available for marine batoid species that may differ considerably in their mode of locomotion. Here, we investigate three-dimensional kinematics of the pectoral wing of the little skate, Leucoraja erinacea , swimming steadily at two speeds [1 and 2 body lengths (BL) s -1 ]. We measured the motion of nine points in three dimensions during wing oscillation and determined that there are significant differences in movement amplitude among wing locations, as well as significant differences as speed increases in body angle, wing beat frequency and speed of the traveling wave on the wing. In addition, we analyzed differences in wing curvature with swimming speed. At 1 BL s -1 , the pectoral wing is convex in shape during the downstroke along the medio-lateral fin midline, but at 2 BL s -1 the pectoral fin at this location cups into the flow, indicating active curvature control and fin stiffening. Wing kinematics of the little skate differed considerably from previous work on the freshwater stingray, which does not show active cupping of the whole fin on the downstroke. © 2017. Published by The Company of Biologists Ltd.

Duane retraction syndrome type 1 with Usher syndrome type 2: an unreported association.

Science.gov (United States)

Khurana, Bhawna Piplani; Khurana, Aruj Kumar; Grover, Sumit

2015-05-07

Duane retraction syndrome is characterized by globe retraction and palpebral fissure narrowing on adduction, with restriction of abduction, adduction, or both. Usher syndrome type 2 consists of congenital bilateral sensorineural hearing loss and retinitis pigmentosa. The authors present a case with a yet unreported association between Duane retraction syndrome type 1 and Usher syndrome type 2. Copyright 2015, SLACK Incorporated.

Effect of fin-endwall fillet on thermal hydraulic performance of airfoil printed circuit heat exchanger

International Nuclear Information System (INIS)

Ma, Ting; Xin, Fei; Li, Lei; Xu, Xiang-yang; Chen, Yi-tung; Wang, Qiu-wang

2015-01-01

Printed circuit heat exchanger (PCHE) is recommended to be used for intermediate heat exchanger in Very High Temperature Reactor (VHTR). One of the key features is that it is manufactured by the photochemical etching in order to maintain the internal structure and metal properties. In this paper, a photochemical etching experiment is conducted to manufacture the airfoil PCHE plate. The result indicates that the airfoil fin is not an ideal airfoil profile, but has a fin-endwall fillet. For the purpose of simplifying the numerical model and saving computational time, a validated model with a single fluid is used to further study the effect of fin-endwall fillet on the thermal hydraulic performance of airfoil PCHE. It is found that the fin-endwall fillet can increase the heat transfer and pressure drop in the cases with the non-dimensional longitudinal pitch being 1.63. The effect of fin-endwall fillet on thermal hydraulic performance decreases with the increase of transverse pitch, but the longitudinal pitch has little effect when the non-dimensional longitudinal pitch is greater than 1.88. In the studied cases, the maximum difference of Nusselt number and friction factor between the two models with and without fin-endwall fillet is up to 6.7% and 6.4%. - Highlights: • Fillets are formed in the endwall of airfoil fins during the photochemical etching. • Two-fluid model can be replaced by single-fluid model to perform simulation. • Fin-endwall fillet can increase heat transfer and pressure drop at ζ_l = 1.63. • Effect of fin-endwall fillet decreases as transverse pitch increases at ζ_l = 1.63. • Longitudinal pitch has little effect at ζ_l ≥ 1.88.

Retractable Pin Tools for the Friction Stir Welding Process

Science.gov (United States)

1998-01-01

Two companies have successfully commercialized a specialized welding tool developed at the Marshall Space Flight Center (MSFC). Friction stir welding uses the high rotational speed of a tool and the resulting frictional heat created from contact to crush, 'stir' together, and forge a bond between two metal alloys. It has had a major drawback, reliance on a single-piece pin tool. The pin is slowly plunged into the joint between two materials to be welded and rotated as high speed. At the end of the weld, the single-piece pin tool is retracted and leaves a 'keyhole,' something which is unacceptable when welding cylindrical objects such as drums, pipes and storage tanks. Another drawback is the requirement for different-length pin tools when welding materials of varying thickness. An engineer at the MSFC helped design an automatic retractable pin tool that uses a computer-controlled motor to automatically retract the pin into the shoulder of the tool at the end of the weld, preventing keyholes. This design allows the pin angle and length to be adjusted for changes in material thickness and results in a smooth hole closure at the end of the weld. Benefits of friction stir welding, using the MSFC retractable pin tool technology, include the following: The ability to weld a wide range of alloys, including previously unweldable and composite materials; provision of twice the fatigue resistance of fusion welds and no keyholes; minimization of material distortion; no creation of hazards such as welding fumes, radiation, high voltage, liquid metals, or arcing; automatic retraction of the pin at the end of the weld; and maintaining full penetration of the pin.

Why does ‘PubPeer’ not acknowledge ‘Retraction Watch’ as a media source?

Directory of Open Access Journals (Sweden)

Jaime A. Teixeira da Silva

2017-05-01

Full Text Available Retraction Watch is a social media organization that relies on a blog to transmit information primarily about retractions in the scientific literature. One of the Retraction Watch co-founders, Ivan Oransky, is in fact a “Distinguished Writer in Residence at New York University’s Carter Journalism Institute” and the vice president of the Association of Health Care Journalists. Sharing a common funder, a philanthropic organization, the Laura and John Arnold Foundation, Retraction Watch regularly coordinates with a whistle-blower website that refers to itself as an “online journal club”, PubPeer. Retraction Watch regularly cites and refers to PubPeer, and vice versa. It is therefore surprising that PubPeer does not list Retraction Watch on its “Press” and media coverage page. This potentially deliberate omission may be equivalent to a hidden conflict of interest, undermining the ethical fortitude and image of these science watchdogs, and fortifying the fake news era.

CFD analysis of fin tube heat exchanger with a pair of delta winglet vortex generators

International Nuclear Information System (INIS)

Hwang, Seong Won; Kim, Dong Hwan; Min, June Kee; Jeong, Ji Hwan

2012-01-01

Among tubular heat exchangers, fin tube types are the most widely used in refrigeration and air-conditioning equipment. Efforts to enhance the performance of these heat exchangers included variations in the fin shape from a plain fin to a slit and louver type. In the context of heat transfer augmentation, the performance of vortex generators has also been investigated. Delta winglet vortex generators have recently attracted research interest, partly due to experimental data showing that their addition to fin-tube heat exchangers considerably reduces pressure loss at heat transfer capacity of nearly the same level. The efficiency of the delta winglet vortex generators widely varies depending on their size and shape, as well as the locations where they are implemented. In this paper, the flow field around delta winglet vortex generators in a common flow up arrangement was analyzed in terms of flow characteristics and heat transfer using computational fluid dynamics methods. Flow mixing due to vortices and delayed separation due to acceleration influence the overall fin performance. The fin with delta winglet vortex generators exhibited a pressure loss lower than that of a plain fin, and the heat transfer performance was enhanced at high air velocity or Reynolds number

CFD analysis of fin tube heat exchanger with a pair of delta winglet vortex generators

Energy Technology Data Exchange (ETDEWEB)

Hwang, Seong Won; Kim, Dong Hwan; Min, June Kee; Jeong, Ji Hwan [Pusan National Univ., Busan (Korea, Republic of)

2012-09-15

Among tubular heat exchangers, fin tube types are the most widely used in refrigeration and air-conditioning equipment. Efforts to enhance the performance of these heat exchangers included variations in the fin shape from a plain fin to a slit and louver type. In the context of heat transfer augmentation, the performance of vortex generators has also been investigated. Delta winglet vortex generators have recently attracted research interest, partly due to experimental data showing that their addition to fin-tube heat exchangers considerably reduces pressure loss at heat transfer capacity of nearly the same level. The efficiency of the delta winglet vortex generators widely varies depending on their size and shape, as well as the locations where they are implemented. In this paper, the flow field around delta winglet vortex generators in a common flow up arrangement was analyzed in terms of flow characteristics and heat transfer using computational fluid dynamics methods. Flow mixing due to vortices and delayed separation due to acceleration influence the overall fin performance. The fin with delta winglet vortex generators exhibited a pressure loss lower than that of a plain fin, and the heat transfer performance was enhanced at high air velocity or Reynolds number.

Fear extinction deficits following acute stress associate with increased spine density and dendritic retraction in basolateral amygdala neurons

Science.gov (United States)

Maroun, Mouna; Ioannides, Pericles J.; Bergman, Krista L.; Kavushansky, Alexandra; Holmes, Andrew; Wellman, Cara L.

2013-01-01

Stress-sensitive psychopathologies such as post-traumatic stress disorder are characterized by deficits in fear extinction and dysfunction of corticolimbic circuits mediating extinction. Chronic stress facilitates fear conditioning, impairs extinction, and produces dendritic proliferation in the basolateral amygdala (BLA), a critical site of plasticity for extinction. Acute stress impairs extinction, alters plasticity in the medial prefrontal cortex-to-BLA circuit, and causes dendritic retraction in the medial prefrontal cortex. Here, we examined extinction learning and basolateral amygdala pyramidal neuron morphology in adult male rats following a single elevated platform stress. Acute stress impaired extinction acquisition and memory, and produced dendritic retraction and increased mushroom spine density in basolateral amygdala neurons in the right hemisphere. Unexpectedly, irrespective of stress, rats that underwent fear and extinction testing showed basolateral amygdala dendritic retraction and altered spine density relative to non-conditioned rats, particularly in the left hemisphere. Thus, extinction deficits produced by acute stress are associated with increased spine density and dendritic retraction in basolateral amygdala pyramidal neurons. Furthermore, the finding that conditioning and extinction as such was sufficient to alter basolateral amygdala morphology and spine density illustrates the sensitivity of basolateral amygdala morphology to behavioral manipulation. These findings may have implications for elucidating the role of the amygdala in the pathophysiology of stress-related disorders. PMID:23714419

Is An Ostomy Rod Useful for Bridging the Retraction During the Creation of a Loop Ileostomy? A Randomized Control Trial.

Science.gov (United States)

Uchino, Motoi; Ikeuchi, Hiroki; Bando, Toshihiro; Chohno, Teruhiro; Sasaki, Hirofumi; Horio, Yuki

2017-08-01

A loop ileostomy is generally created during restorative proctocolectomy (RPC) for treating ulcerative colitis (UC), and an ostomy rod is often used to prevent stoma retraction. However, its usefulness or harmfulness has not been proven. We performed a prospective randomized control study to investigate the non-inferiority of ostomy creation without a rod to prevent stoma retraction. Patients with UC who underwent RPC were enrolled and randomly divided into groups either with or without ostomy rod use. Incidences of stoma retraction and dermatitis were compared. Of the 320 patients in the study groups, 308 qualified for the intention-to-treat (ITT) analysis, and 257 were included in the per-protocol (PP) analysis. Ostomy retraction was recognized in 6 patients, 3 with a rod and 3 without. The difference with rod use (95% confidence interval) was 0.1 (-2.9 to 3.1)% in the PP analysis and 0.0 (-2.2 to 2.2)% in the ITT analysis. There were no significant differences in stoma retraction regardless of whether an ostomy rod was used in either analysis. Dermatitis was more common in patients with rod use (84/154) than in those without (40/154) (p ostomy rod is not routinely needed as it may increase the risk of dermatitis. However, results in obese patients may differ from those shown here, which should be clarified via further studies.

Fin shape thermal optimization using Bejan's constuctal theory

CERN Document Server

Lorenzini, Giulio

2011-01-01

The book contains research results obtained by applying Bejan's Constructal Theory to the study and therefore the optimization of fins, focusing on T-shaped and Y-shaped ones. Heat transfer from finned surfaces is an example of combined heat transfer natural or forced convection on the external parts of the fin, and conducting along the fin. Fin's heat exchange is rather complex, because of variation of both temperature along the fin and convective heat transfer coefficient. Furthermore possible presence of more fins invested by the same fluid flow has to be considered.Classical fin theory tri

Optimization design of LED heat dissipation structure based on strip fins

Science.gov (United States)

Xue, Lingyun; Wan, Wenbin; Chen, Qingguang; Rao, Huanle; Xu, Ping

2018-03-01

To solve the heat dissipation problem of LED, a radiator structure based on strip fins is designed and the method to optimize the structure parameters of strip fins is proposed in this paper. The combination of RBF neural networks and particle swarm optimization (PSO) algorithm is used for modeling and optimization respectively. During the experiment, the 150 datasets of LED junction temperature when structure parameters of number of strip fins, length, width and height of the fins have different values are obtained by ANSYS software. Then RBF neural network is applied to build the non-linear regression model and the parameters optimization of structure based on particle swarm optimization algorithm is performed with this model. The experimental results show that the lowest LED junction temperature reaches 43.88 degrees when the number of hidden layer nodes in RBF neural network is 10, the two learning factors in particle swarm optimization algorithm are 0.5, 0.5 respectively, the inertia factor is 1 and the maximum number of iterations is 100, and now the number of fins is 64, the distribution structure is 8*8, and the length, width and height of fins are 4.3mm, 4.48mm and 55.3mm respectively. To compare the modeling and optimization results, LED junction temperature at the optimized structure parameters was simulated and the result is 43.592°C which approximately equals to the optimal result. Compared with the ordinary plate-fin-type radiator structure whose temperature is 56.38°C, the structure greatly enhances heat dissipation performance of the structure.

Technical pitfalls in a porcine brain retraction model. The impact of brain spatula on the retracted brain tissue in a porcine model: a feasibility study and its technical pitfalls

Energy Technology Data Exchange (ETDEWEB)

Thiex, R.; Hans, F.J.; Gilsbach, J.M. [Aachen University, Department of Neurosurgery, Aachen (Germany); Krings, T. [Aachen University, Department of Neuroradiology, Aachen (Germany); Sellhaus, B. [Aachen University, Department of Neuropathology, Aachen (Germany)

2005-10-01

We describe technical pitfalls of a porcine brain injury model for identifying primary and secondary pathological sequelae following brain retraction by brain spatula. In 16 anaesthetised male pigs, the right frontal brain was retracted in the interhemispheric fissure by a brain spatulum with varying pressures applied by the gravitational force of weights from 10 to 70 g for a duration of 30 min. The retracted brain tissue was monitored for changes in intracranial pressure and perfusion of the cortex using a Laser Doppler Perfusion Imager (MoorLDI). To evaluate the extent of oedema and cortical contusions, MRI was performed 30 min and 72 h after brain retraction. Following the MR scan, the retracted brain areas were histopathologically assessed using H and E and Fluoro-Jade B staining for neuronal damage. Sinus occlusion occurred in four animals, resulting in bilateral cortical contusions and extensive brain oedema. Retracting the brain with weights of 70 g (n=4) caused extensive oedema on FLAIR images that correlated clinically with a hemiparesis in three animals. Morphologically, an increased number of Fluoro-Jade B-positive neurons were found. A sequential decrease in weights prevented functional deficits in animals. A retraction pressure applied by 10-g weights (n=7) caused a mean rise in intracranial pressure to 4.0{+-}3.1 mm Hg, and a decrement in mean cortical perfusion from 740.8{+-}41.5 to 693.8{+-}72.4 PU/cm2, (P<0.24). A meticulous dissection of the interhemispheric fissure and a reduction of weights to 10 g were found to be mandatory to study the cortical impact caused by brain spatula reproducibly. (orig.)

Technical pitfalls in a porcine brain retraction model. The impact of brain spatula on the retracted brain tissue in a porcine model: a feasibility study and its technical pitfalls

International Nuclear Information System (INIS)

Thiex, R.; Hans, F.J.; Gilsbach, J.M.; Krings, T.; Sellhaus, B.

2005-01-01

We describe technical pitfalls of a porcine brain injury model for identifying primary and secondary pathological sequelae following brain retraction by brain spatula. In 16 anaesthetised male pigs, the right frontal brain was retracted in the interhemispheric fissure by a brain spatulum with varying pressures applied by the gravitational force of weights from 10 to 70 g for a duration of 30 min. The retracted brain tissue was monitored for changes in intracranial pressure and perfusion of the cortex using a Laser Doppler Perfusion Imager (MoorLDI). To evaluate the extent of oedema and cortical contusions, MRI was performed 30 min and 72 h after brain retraction. Following the MR scan, the retracted brain areas were histopathologically assessed using H and E and Fluoro-Jade B staining for neuronal damage. Sinus occlusion occurred in four animals, resulting in bilateral cortical contusions and extensive brain oedema. Retracting the brain with weights of 70 g (n=4) caused extensive oedema on FLAIR images that correlated clinically with a hemiparesis in three animals. Morphologically, an increased number of Fluoro-Jade B-positive neurons were found. A sequential decrease in weights prevented functional deficits in animals. A retraction pressure applied by 10-g weights (n=7) caused a mean rise in intracranial pressure to 4.0±3.1 mm Hg, and a decrement in mean cortical perfusion from 740.8±41.5 to 693.8±72.4 PU/cm2, (P<0.24). A meticulous dissection of the interhemispheric fissure and a reduction of weights to 10 g were found to be mandatory to study the cortical impact caused by brain spatula reproducibly. (orig.)

Experimental Validation of Elliptical Fin-Opening Behavior

Directory of Open Access Journals (Sweden)

James M. Garner

2003-01-01

Full Text Available An effort to improve the performance of ordnance has led to the consideration of the use of folding elliptical fins for projectile stabilization. A second order differential equation was used to model elliptical fin deployment history and accounts for: deployment with respect to the geometric properties of the fin, the variation in fin aerodynamics during deployment, the initial yaw effect on fin opening, and the variation in deployment speed based on changes in projectile spin. This model supports tests conducted at the Transonic Experimental Facility, Aberdeen Proving Ground examining the opening behavior of these uniquely shaped fins. The fins use the centrifugal force from the projectile spin to deploy. During the deployment, the fin aerodynamic forces vary with angle-of-attack changes to the free stream. Model results indicate that projectile spin dominates the initial opening rates and aerodynamics dominate near the fully open state. The model results are examined to explain the observed behaviors, and suggest improvements for later designs.

Effect of Using Extra Fins on the Pin Fin Classic Geometry for Enhancement Heat Sink Performance using EGM Method

Directory of Open Access Journals (Sweden)

Kadhum Audaa Jehhef

2018-04-01

Full Text Available In the present study, the effect of new cross-section fin geometries on overall thermal/fluid performance had been investigated. The cross-section included the base original geometry of (triangular, square, circular, and elliptical pin fins by adding exterior extra fins along the sides of the origin fins. The present extra fins include rectangular extra fin of 2 mm (height and 4 mm (width and triangular extra fin of 2 mm (base 4 mm (height. The use of entropy generation minimization method (EGM allows the combined effect of thermal resistance and pressure drop to be assessed through the simultaneous interaction with the heat sink. A general dimensionless expression for the entropy generation rate is obtained by considering a control volume around the pin fin including a base plate and applying the conservations equations of mass and energy with the entropy balance. The dimensionless numbers used includes the aspect ratio (ε, Reynolds number (Re, Nusselt number (Nu, and the drag coefficients (CD. Fourteen different cross-section fin geometries are examined for the heat transfer, fluid friction, and the minimum entropy generation rate. The results showed that the Nusselt number increases with increasing the Reynolds number for all employed models. The ellipse models (ET and ER-models give the highest value in the Nusselt number as compared with the classical pin fins. The fin of the square geometry with four rectangular extra fins (SR-models gives an agreement in Nusselt number as compared with the previous study.

The retraction of the protoplast during PCD is an active, and interruptible, calcium-flux driven process.

Science.gov (United States)

Kacprzyk, Joanna; Brogan, Niall P; Daly, Cara T; Doyle, Siamsa M; Diamond, Mark; Molony, Elizabeth M; McCabe, Paul F

2017-07-01

The protoplast retracts during apoptosis-like programmed cell death (AL-PCD) and, if this retraction is an active component of AL-PCD, it should be used as a defining feature for this type of programmed cell death. We used an array of pharmacological and genetic tools to test if the rates of protoplast retraction in cells undergoing AL-PCD can be modulated. Disturbing calcium flux signalling, ATP synthesis and mitochondrial permeability transition all inhibited protoplast retraction and often also the execution of the death programme. Protoplast retraction can precede loss of plasma membrane integrity and cell death can be interrupted after the protoplast retraction had already occurred. Blocking calcium influx inhibited the protoplast retraction, reduced DNA fragmentation and delayed death induced by AL-PCD associated stresses. At higher levels of stress, where cell death occurs without protoplast retraction, blocking calcium flux had no effect on the death process. The results therefore strongly suggest that retraction of the protoplast is an active biological process dependent on an early Ca 2+ -mediated trigger rather than cellular disintegration due to plasma membrane damage. Therefore this morphologically distinct cell type is a quantifiable feature, and consequently, reporter of AL-PCD. Copyright © 2017 Elsevier B.V. All rights reserved.

Effectiveness of en masse versus two-step retraction: a systematic review and meta-analysis

Directory of Open Access Journals (Sweden)

Mumen Z. Rizk

2018-01-01

Full Text Available Abstract Background This review aims to compare the effectiveness of en masse and two-step retraction methods during orthodontic space closure regarding anchorage preservation and anterior segment retraction and to assess their effect on the duration of treatment and root resorption. Methods An electronic search for potentially eligible randomized controlled trials and prospective controlled trials was performed in five electronic databases up to July 2017. The process of study selection, data extraction, and quality assessment was performed by two reviewers independently. A narrative review is presented in addition to a quantitative synthesis of the pooled results where possible. The Cochrane risk of bias tool and the Newcastle-Ottawa Scale were used for the methodological quality assessment of the included studies. Results Eight studies were included in the qualitative synthesis in this review. Four studies were included in the quantitative synthesis. En masse/miniscrew combination showed a statistically significant standard mean difference regarding anchorage preservation − 2.55 mm (95% CI − 2.99 to − 2.11 and the amount of upper incisor retraction − 0.38 mm (95% CI − 0.70 to − 0.06 when compared to a two-step/conventional anchorage combination. Qualitative synthesis suggested that en masse retraction requires less time than two-step retraction with no difference in the amount of root resorption. Conclusions Both en masse and two-step retraction methods are effective during the space closure phase. The en masse/miniscrew combination is superior to the two-step/conventional anchorage combination with regard to anchorage preservation and amount of retraction. Limited evidence suggests that anchorage reinforcement with a headgear produces similar results with both retraction methods. Limited evidence also suggests that en masse retraction may require less time and that no significant differences exist in the amount of root

从FinTech到RegTech

Institute of Scientific and Technical Information of China (English)

孙国峰[1,2

2017-01-01

本文分析FinTech（金融科技）监管的必要性，并介绍了FinTech监管的国际经验，在此基础上提出了我国可以探索将人工智能应用于金融监管，即以RegTech（监管科技）应对FinTech的建议。

UOP FIN 571 Final Exam Guide New

OpenAIRE

ADMIN

2018-01-01

UOP FIN 571 Final Exam Guide New Check this A+ tutorial guideline at http://www.fin571assignment.com/fin-571-uop/fin-571-final-exam-guide -latest For more classes visit http://www.fin571assignment.com Question 1 The underlying assumption of the dividend growth model is that a stock is worth: A. An amount computed as the next annual dividend divided by the required rate of return. B. An amount computed as the next annual dividend divided by the ma...

Numerical studies on heat transfer and pressure drop characteristics of flat finned tube bundles with various fin materials

Science.gov (United States)

Peng, Y.; Zhang, S. J.; Shen, F.; Wang, X. B.; Yang, X. R.; Yang, L. J.

2017-11-01

The air-cooled heat exchanger plays an important role in the field of industry like for example in thermal power plants. On the other hand, it can be used to remove core decay heat out of containment passively in case of a severe accident circumstance. Thus, research on the performance of fins in air-cooled heat exchangers can benefit the optimal design and operation of cooling systems in nuclear power plants. In this study, a CFD (Computational Fluid Dynamic) method is implemented to investigate the effects of inlet velocity, fin spacing and tube pitch on the flow and the heat transfer characteristics of flat fins constructed of various materials (316L stainless steel, copper-nickel alloy and aluminium). A three dimensional geometric model of flat finned tube bundles with fixed longitudinal tube pitch and transverse tube pitch is established. Results for the variation of the average convective heat transfer coefficient with respect to cooling air inlet velocity, fin spacing, tube pitch and fin material are obtained, as well as for the pressure drop of the cooling air passing through finned tube. It is shown that the increase of cooling air inlet velocity results in enhanced average convective heat transfer coefficient and decreasing pressure drop. Both fin spacing and tube pitch engender positive effects on pressure drop and have negative effects on heat transfer characteristics. Concerning the fin material, the heat transfer performance of copper-nickel alloy is superior to 316L stainless steel and inferior to aluminium.

First Results from the LHCb Vertex Locator

CERN Multimedia

Borghi, S

2010-01-01

LHCb is a dedicated experiment to study new physics in the decays of beauty and charm hadrons at the Large Hadron Collider (LHC) at CERN. The beauty and charm hadrons are identified through their flight distance in the Vertex Locator (VELO), and hence the detector is critical for both the trigger and offline physics analyses. The VELO is the silicon detector surrounding the interaction point, and is the closest LHC vertex detector to the interaction point, located only 7 mm from the LHC beam during normal operation. The detector will operate in an extreme and highly non-uniform radiation environment. The VELO consists of two retractable detector halves with 21 silicon micro-strip tracking modules each. A module is composed of two n+-on-n 300 micron thick half disc sensors with R-measuring and Phi-measuring micro-strip geometry, mounted on a carbon fibre support paddle. The minimum pitch is approximately 40 $\\mu$m. The detector is also equipped with one n-on-p module. The detectors are operated in vacuum and a...

RETRACTED: On a general class of regular rotating black holes based on a smeared mass distribution

Science.gov (United States)

Larranaga, Alexis; Cardenas-Avendano, Alejandro; Torres, Daniel Alexdy

2015-04-01

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. The authors have plagiarized part of a paper that had already appeared in Adv. High Energy Physics, P. Nicolini, A. Orlandi, E. Spallucci, The Final Stage of Gravitationally Collapsed Thick Matter Layers, Vol 2013 (2013), Article ID 812084 http://dx.doi.org/10.1155/2013/812084. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

A wound retraction device for laparoscopic-assisted intestinal surgery in dogs and cats.

Science.gov (United States)

Gower, Sara B; Mayhew, Philipp D

2011-06-01

To report experience with laparoscopic-assisted intestinal resection and anastomosis for treatment of discrete intestinal masses using a novel wound retraction device. Case series. Dogs (n=2) and cats (6). Dogs and cats with discrete intestinal masses identified by ultrasonography without evidence of intestinal perforation or peritonitis, were included. A 2 portal technique was used; 1 portal was enlarged for insertion of the wound retraction device through which the intestine was examined as thoroughly as possible. The diseased portion of the intestine was exteriorized through the wound retractor and resection and anastomosis of the intestinal mass performed. Of the 8 animals, laparoscopic-assisted intestinal resection and anastomosis through the wound retractor was performed in 2 dogs and 3 cats. In 3 cats, based on either location or extent of the lesion, 2 were converted to laparoscopic-assisted intestinal biopsies and 1 to an open colocolostomy. No other intra- or perioperative complications were encountered and all animals survived to discharge. Laparoscopic-assisted intestinal resection and anastomosis can be performed in select canine and feline patients with modestly sized, discrete intestinal masses. © Copyright 2011 by The American College of Veterinary Surgeons.

Inverse heat transfer analysis of a functionally graded fin to estimate time-dependent base heat flux and temperature distributions

International Nuclear Information System (INIS)

Lee, Haw-Long; Chang, Win-Jin; Chen, Wen-Lih; Yang, Yu-Ching

2012-01-01

Highlights: ► Time-dependent base heat flux of a functionally graded fin is inversely estimated. ► An inverse algorithm based on the conjugate gradient method and the discrepancy principle is applied. ► The distributions of temperature in the fin are determined as well. ► The influence of measurement error and measurement location upon the precision of the estimated results is also investigated. - Abstract: In this study, an inverse algorithm based on the conjugate gradient method and the discrepancy principle is applied to estimate the unknown time-dependent base heat flux of a functionally graded fin from the knowledge of temperature measurements taken within the fin. Subsequently, the distributions of temperature in the fin can be determined as well. It is assumed that no prior information is available on the functional form of the unknown base heat flux; hence the procedure is classified as the function estimation in inverse calculation. The temperature data obtained from the direct problem are used to simulate the temperature measurements. The influence of measurement errors and measurement location upon the precision of the estimated results is also investigated. Results show that an excellent estimation on the time-dependent base heat flux and temperature distributions can be obtained for the test case considered in this study.

RETRACTED: Development of carbon paste electrodes modified by molecularly imprinted polymer as potentiometry sensor of uric acid

Directory of Open Access Journals (Sweden)

Miratul Khasanah

Full Text Available This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy.This article has been retracted at the request of the Editors-in-Chief.After a thorough investigation, the Editors have concluded that the acceptance of this article was based upon the positive advice of two illegitimate reviewer reports. The reports were submitted from email accounts which were provided to the journal as suggested reviewers during the submission of the article. Although purportedly real reviewer accounts, the Editors have concluded that these were not of appropriate, independent reviewers.This manipulation of the peer-review process represents a clear violation of the fundamentals of peer review, our publishing policies, and publishing ethics standards. Apologies are offered to the reviewers whose identities were assumed and to the readers of the journal that this deception was not detected during the submission process.

Saddle-fin cell transistors with oxide etch rate control by using tilted ion implantation (TIS-fin) for sub-50-nm DRAMs

International Nuclear Information System (INIS)

Yoo, Min Soo; Choi, Kang Sik; Sun, Woo Kyung

2010-01-01

As DRAM cell pitch size decreases, the need for a high performance transistor is increasing. Though saddle-fin (S-fin) transistors have superior characteristics, S-fin transistors are well known to be more sensitive to process variation. To make uniform S-fin transistors, for the first time, we developed a new fin formation method using tilted ion implantation along the wordline direction after a recess gate etch. Due to the increased etch rate of the oxide film by ion implantation damage, fins are made at the bottom channel of the recess gate after wet etching. The resulting tilt implanted saddle-fin (TIS-fin) transistor has remarkably improved characteristics, such as ∼8% subthreshold swing (SS) and a 40% drain induced barrier lowering (DIBL) decrease. Especially, the TIS-fin with a neutral dopant has a reduced threshold voltage (Vth) variation within a wafer (<100 mV), which is comparable with that of a mass-produced sphere-shaped recessed channel array transistor (SRCAT).

Alkaline phosphatase activity in gingival crevicular fluid during canine retraction.

Science.gov (United States)

Batra, P; Kharbanda, Op; Duggal, R; Singh, N; Parkash, H

2006-02-01

The aim of the study was to investigate alkaline phosphatase activity in the gingival crevicular fluid (GCF) during orthodontic tooth movement in humans. Postgraduate orthodontic clinic. Ten female patients requiring all first premolar extractions were selected and treated with standard edgewise mechanotherapy. Canine retraction was done using 100 g sentalloy springs. Maxillary canine on one side acted as experimental site while the contralateral canine acted as control. Gingival crevicular fluid was collected from mesial and distal of canines before initiation of canine retraction (baseline), immediately after initiation of retraction, and on 1st, 7th, 14th and 21st day and the alkaline phosphatase activity was estimated. The results show significant (p < 0.05) changes in alkaline phosphatase activity on the 7th, 14th and 21st day on both mesial and distal aspects of the compared experimental and control sides. The peak in enzyme activity occurred on the 14th day of initiation of retraction followed by a significant fall in activity especially on the mesial aspect. The study showed that alkaline phosphatase activity could be successfully estimated in the GCF using calorimetric estimation assay kits. The enzyme activity showed variation according to the amount of tooth movement.

Numerical Study of Thermal and Flow Characteristics of Plate-Fin Heat Sink with Longitudinal Vortex Generator Installed on the Ground

Directory of Open Access Journals (Sweden)

Yen-Tso Chang

2014-01-01

Full Text Available This study applied the commercial software ANSYS CFD (FLUENT, for simulating the transient flow field and investigating the influence of each parameter of longitudinal vortex generators (LVGs on the thermal flux of a plate-fin heat sink. Vortex generator was set in front of plate-fin heat sink and under the channel, which was in common-flow-down (CFD and common-flow-up (CFU conditions, which have the result of vortex generator of delta winglet pair (DWP. In this study the parameters were varied, such as the minimum transverse distance between winglet pair, the attack angle of the vortex generator, fins number, the fin height, and the distance between the vortex generator and plate-fin. The coolant fluid flew into the fin-to-fin channel and pushed the vortex from different geometry toward the bottom. This phenomenon took off the heat from the plate to enhance the heat transfer. The numerical results indicated that the LVGs located close to the plate-fin heat sink are zero with the attack angle being 30°, presenting optimal overall conditions.

Numerical analysis on interactions between fluid flow and structure deformation in plate-fin heat exchanger by Galerkin method

Science.gov (United States)

Liu, Jing-cheng; Wei, Xiu-ting; Zhou, Zhi-yong; Wei, Zhen-wen

2018-03-01

The fluid-structure interaction performance of plate-fin heat exchanger (PFHE) with serrated fins in large scale air-separation equipment was investigated in this paper. The stress and deformation of fins were analyzed, besides, the interaction equations were deduced by Galerkin method. The governing equations of fluid flow and heat transfer in PFHE were deduced by finite volume method (FVM). The distribution of strain and stress were calculated in large scale air separation equipment and the coupling situation of serrated fins under laminar situation was analyzed. The results indicated that the interactions between fins and fluid flow in the exchanger have significant impacts on heat transfer enhancement, meanwhile, the strain and stress of fins includes dynamic pressure of the sealing head and flow impact with the increase of flow velocity. The impacts are especially significant at the conjunction of two fins because of the non-alignment fins. It can be concluded that the soldering process and channel width led to structure deformation of fins in the exchanger, and degraded heat transfer efficiency.

Investigation of internally finned LED heat sinks

Science.gov (United States)

Li, Bin; Xiong, Lun; Lai, Chuan; Tang, Yumei

2018-03-01

A novel heat sink is proposed, which is composed of a perforated cylinder and internally arranged fins. Numerical studies are performed on the natural convection heat transfer from internally finned heat sinks; experimental studies are carried out to validate the numerical results. To compare the thermal performances of internally finned heat sinks and externally finned heat sinks, the effects of the overall diameter, overall height, and installation direction on maximum temperature, air flow and heat transfer coefficient are investigated. The results demonstrate that internally finned heat sinks show better thermal performance than externally finned heat sinks; the maximum temperature of internally finned heat sinks decreases by up to 20% compared with the externally finned heat sinks. The existence of a perforated cylinder and the installation direction of the heat sink affect the thermal performance significantly; it is shown that the heat transfer coefficient of the heat sink with the perforated cylinder is improved greater than that with the imperforated cylinder by up to 34%, while reducing the mass of the heat sink by up to 13%. Project supported by the Scientific Research Fund of Sichuan Provincial Education Department (No. 18ZB0516) and the Sichuan University of Arts and Science (No. 2016KZ009Y).

Retraction Notice to ;Fabrication, electromagnetic characteristics of microwave absorbers containing Li0.35Zn0.3Fe2.35O4 micro-belts, nickel-coated carbon fibers; [J. Magn. Magn. Mater. 345 (2013) 249-254

Science.gov (United States)

Zhao, Bin; Wang, Qilei; Zhang, Cunrui

2017-08-01

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy) This article has been retracted at the request of the Editor-in-Chief. The authors have plagiarized part of a paper that had already appeared in Ceram. Int., 39 (2013) 2317-2322, http://dx.doi.org/10.1016/j.ceramint.2012.08.079.

Role of Pectoral Fin Flexibility in Robotic Fish Performance

Science.gov (United States)

Bazaz Behbahani, Sanaz; Tan, Xiaobo

2017-08-01

Pectoral fins play a vital role in the maneuvering and locomotion of fish, and they have become an important actuation mechanism for robotic fish. In this paper, we explore the effect of flexibility of robotic fish pectoral fins on the robot locomotion performance and mechanical efficiency. A dynamic model for the robotic fish is presented, where the flexible fin is modeled as multiple rigid elements connected via torsional springs and dampers. Blade element theory is used to capture the hydrodynamic force on the fin. The model is validated with experimental results obtained on a robotic fish prototype, equipped with 3D-printed fins of different flexibility. The model is then used to analyze the impacts of fin flexibility and power/recovery stroke speed ratio on the robot swimming speed and mechanical efficiency. It is found that, in general, flexible fins demonstrate advantages over rigid fins in speed and efficiency at relatively low fin-beat frequencies, while rigid fins outperform flexible fins at higher frequencies. For a given fin flexibility, the optimal frequency for speed performance differs from the optimal frequency for mechanical efficiency. In addition, for any given fin, there is an optimal power/recovery stroke speed ratio, typically in the range of 2-3, that maximizes the speed performance. Overall, the presented model offers a promising tool for fin flexibility and gait design, to achieve speed and efficiency objectives for robotic fish actuated with pectoral fins.

The shark's fin

International Nuclear Information System (INIS)

Listinsky, J.L.; Griffiths, H.J.

1989-01-01

Initial plain film studies of seven patients with facet fracture-dislocations of the cervical spine were examined retrospectively. Rotation of the cross-table lateral film from a standard vetical viewing orientation to a simulated brow-down position allowed easier appreciation of the dislocated pillar in six of the seven patients. The displaced pillar had an appearance similar to that of the dorsal fin of a shark. We conclude that the finding of a shark's fin appearance of an articular pillar in a traumatized patient warrants further radiographic studies. (author). 8 refs.; 3 figs

The heartstrings mutation in zebrafish causes heart/fin Tbx5 deficiency syndrome.

Science.gov (United States)

Garrity, Deborah M; Childs, Sarah; Fishman, Mark C

2002-10-01

Holt-Oram syndrome is one of the autosomal dominant human "heart-hand" disorders, with a combination of upper limb malformations and cardiac defects. Holt-Oram syndrome is caused by mutations in the TBX5 gene, a member of a large family of T-box transcription factors that play important roles in cell-type specification and morphogenesis. In a screen for mutations affecting zebrafish cardiac function, we isolated the recessive lethal mutant heartstrings, which lacks pectoral fins and exhibits severe cardiac dysfunction, beginning with a slow heart rate and progressing to a stretched, non-functional heart. We mapped and cloned the heartstrings mutation and find it to encode the zebrafish ortholog of the TBX5 gene. The heartstrings mutation causes premature termination at amino acid 316. Homozygous mutant embryos never develop pectoral fin buds and do not express several markers of early fin differentiation. The total absence of any fin bud differentiation distinguishes heartstrings from most other mutations that affect zebrafish fin development, suggesting that Tbx5 functions very early in the pectoral fin induction pathway. Moderate reduction of Tbx5 by morpholino causes fin malformations, revealing an additional early requirement for Tbx5 in coordinating the axes of fin outgrowth. The heart of heartstrings mutant embryos appears to form and function normally through the early heart tube stage, manifesting only a slight bradycardia compared with wild-type siblings. However, the heart fails to loop and then progressively deteriorates, a process affecting the ventricle as well as the atrium. Relative to mammals, fish require lower levels of Tbx5 to produce malformed appendages and display whole-heart rather than atrial-predominant cardiac defects. However, the syndromic deficiencies of tbx5 mutation are remarkably well retained between fish and mammals.

Room to high temperature measurements of flexible SOI FinFETs with sub-20-nm fins

KAUST Repository

Diab, Amer El Hajj

2014-12-01

We report the temperature dependence of the core electrical parameters and transport characteristics of a flexible version of fin field-effect transistor (FinFET) on silicon-on-insulator (SOI) with sub-20-nm wide fins and high-k/metal gate-stacks. For the first time, we characterize them from room to high temperature (150 °C) to show the impact of temperature variation on drain current, gate leakage current, and transconductance. Variation of extracted parameters, such as low-field mobility, subthreshold swing, threshold voltage, and ON-OFF current characteristics, is reported too. Direct comparison is made to a rigid version of the SOI FinFETs. The mobility degradation with temperature is mainly caused by phonon scattering mechanism. The overall excellent devices performance at high temperature after release is outlined proving the suitability of truly high-performance flexible inorganic electronics with such advanced architecture.

Flexible and transparent silicon-on-polymer based sub-20 nm non-planar 3D FinFET for brain-architecture inspired computation

KAUST Repository

Sevilla, Galo T.; Rojas, Jhonathan Prieto; Fahad, Hossain M.; Hussain, Aftab M.; Ghanem, Rawan; Smith, Casey; Hussain, Muhammad Mustafa

2014-01-01

An industry standard 8′′ silicon-on-insulator wafer based ultra-thin (1 μm), ultra-light-weight, fully flexible and remarkably transparent state-of-the-art non-planar three dimensional (3D) FinFET is shown. Introduced by Intel Corporation in 2011 as the most advanced transistor architecture, it reveals sub-20 nm features and the highest performance ever reported for a flexible transistor. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Flexible and transparent silicon-on-polymer based sub-20 nm non-planar 3D FinFET for brain-architecture inspired computation

KAUST Repository

Sevilla, Galo T.

2014-02-22

An industry standard 8′′ silicon-on-insulator wafer based ultra-thin (1 μm), ultra-light-weight, fully flexible and remarkably transparent state-of-the-art non-planar three dimensional (3D) FinFET is shown. Introduced by Intel Corporation in 2011 as the most advanced transistor architecture, it reveals sub-20 nm features and the highest performance ever reported for a flexible transistor. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tracing the spatio-temporal dynamics of endangered fin whales (Balaenoptera physalus) within baleen whale (Mysticeti) lineages: a mitogenomic perspective.

Science.gov (United States)

Yu, Jihyun; Nam, Bo-Hye; Yoon, Joon; Kim, Eun Bae; Park, Jung Youn; Kim, Heebal; Yoon, Sook Hee

2017-12-01

To explore the spatio-temporal dynamics of endangered fin whales (Balaenoptera physalus) within the baleen whale (Mysticeti) lineages, we analyzed 148 published mitochondrial genome sequences of baleen whales. We used a Bayesian coalescent approach as well as Bayesian inferences and maximum likelihood methods. The results showed that the fin whales had a single maternal origin, and that there is a significant correlation between geographic location and evolution of global fin whales. The most recent common female ancestor of this species lived approximately 9.88 million years ago (Mya). Here, North Pacific fin whales first appeared about 7.48 Mya, followed by a subsequent divergence in Southern Hemisphere approximately 6.63 Mya and North Atlantic about 4.42 Mya. Relatively recently, approximately 1.76 and 1.42 Mya, there were two additional occurrences of North Pacific populations; one originated from the Southern Hemisphere and the other from an uncertain location. The evolutionary rate of this species was 1.002 × 10 -3 substitutions/site/My. Our Bayesian skyline plot illustrates that the fin whale population has the rapid expansion event since ~ 2.5 Mya, during the Quaternary glaciation stage. Additionally, this study indicates that the fin whale has a sister group relationship with humpback whale (Meganoptera novaeangliae) within the baleen whale lineages. Of the 16 genomic regions, NADH5 showed the most powerful signal for baleen whale phylogenetics. Interestingly, fin whales have 16 species-specific amino acid residues in eight mitochondrial genes: NADH2, COX2, COX3, ATPase6, ATPase8, NADH4, NADH5, and Cytb.

Synchronous seasonal change in fin whale song in the North Pacific.

Directory of Open Access Journals (Sweden)

Erin M Oleson

Full Text Available Fin whale (Balaenoptera physalus song consists of down-swept pulses arranged into stereotypic sequences that can be characterized according to the interval between successive pulses. As in blue (B. musculus and humpback whales (Megaptera novaeangliae, these song sequences may be geographically distinct and may correlate with population boundaries in some regions. We measured inter-pulse intervals of fin whale songs within year-round acoustic datasets collected between 2000 and 2006 in three regions of the eastern North Pacific: Southern California, the Bering Sea, and Hawaii. A distinctive song type that was recorded in all three regions is characterized by singlet and doublet inter-pulse intervals that increase seasonally, then annually reset to the same shorter intervals at the beginning of each season. This song type was recorded in the Bering Sea and off Southern California from September through May and off Hawaii from December through April, with the song interval generally synchronized across all monitoring locations. The broad geographic and seasonal occurrence of this particular fin whale song type may represent a single population broadly distributed throughout the eastern Pacific with no clear seasonal migratory pattern. Previous studies attempting to infer population structure of fin whales in the North Pacific using synchronous individual song samples have been unsuccessful, likely because they did not account for the seasonal lengthening in song intervals observed here.

Parametric CFD Analysis to Study the Influence of Fin Geometry on the Performance of a Fin and Tube Heat Exchanger

DEFF Research Database (Denmark)

Singh, Shobhana; Sørensen, Kim; Condra, Thomas Joseph

2016-01-01

Heat transfer and pressure loss characteristics of a fin and tube heat exchanger are numerically investigated based on parametric fin geometry. The cross-flow type heat exchanger with circular tubes and rectangular fin profile is selected as a reference design. The fin geometry is varied using...... a design aspect ratio as a variable parameter in a range of 0.1-1.0 to predict the impact on overall performance of the heat exchanger. In this paper, geometric profiles with a constant thickness of fin base are studied. Three-dimensional, steady state CFD model is developed using commercially available...... are determined. The best performed geometric fin profile based on the higher heat transfer and lower pressure loss is predicted. The study provides insights into the impact of fin geometry on the heat transfer performance which help escalate the understanding of heat exchanger designing and manufacturing...

A Miniature Robot for Retraction Tasks under Vision Assistance in Minimally Invasive Surgery

Directory of Open Access Journals (Sweden)

Giuseppe Tortora

2014-03-01

Full Text Available Minimally Invasive Surgery (MIS is one of the main aims of modern medicine. It enables surgery to be performed with a lower number and severity of incisions. Medical robots have been developed worldwide to offer a robotic alternative to traditional medical procedures. New approaches aimed at a substantial decrease of visible scars have been explored, such as Natural Orifice Transluminal Endoscopic Surgery (NOTES. Simple surgical tasks such as the retraction of an organ can be a challenge when performed from narrow access ports. For this reason, there is a continuous need to develop new robotic tools for performing dedicated tasks. This article illustrates the design and testing of a new robotic tool for retraction tasks under vision assistance for NOTES. The retraction robots integrate brushless motors to enable additional degrees of freedom to that provided by magnetic anchoring, thus improving the dexterity of the overall platform. The retraction robot can be easily controlled to reach the target organ and apply a retraction force of up to 1.53 N. Additional degrees of freedom can be used for smooth manipulation and grasping of the organ.

Effect of fin pitch and number of tube rows on the air side performance of herringbone wavy fin and tube heat exchangers

International Nuclear Information System (INIS)

Wongwises, Somchai; Chokeman, Yutasak

2005-01-01

An experimental study is conducted to investigate the effects of a fin pitch and number of tube rows on the air side performance of fin and tube heat exchangers having herringbone wavy fin configuration at various fin thicknesses. A total of 10 samples of fin and tube heat exchanger with a tube outside diameter of 9.53mm, transverse tube pitch of 25.4mm and longitudinal tube pitch of 19.05mm, having various fin pitches, number of tube rows and fin thicknesses, are tested in a well insulated open wind tunnel. The heat exchangers are made from aluminium plate finned, copper tube. Ambient air is used as a working fluid in the air side while hot water is used for the tube side. The results are presented as the variation of the Colburn factor and the friction factor with the Reynolds number based on the fin collar outside diameter (Re D c ). The experimental results reveal that the fin pitch has an insignificant effect on the heat transfer characteristic. The friction factor increases with increasing fin pitch when Re D c >2500, approximately. The Colburn factor and the friction factor decrease with increasing number of tube rows when Re D c <4000, approximately. These results remain the same when the fin thickness is changed

Performance of tubes-and plate fins heat exchangers

International Nuclear Information System (INIS)

Rosman, E.C.

1979-11-01

By means of a two-dimensional analysis performance, and using local heat transfer coefficients, the plate fin temperature distribution, the air bulk temperature along the stream path and the fin efficiency can be obtained, for several Reynolds numbers and fin materials. Herein are also presented the average heat transfer coefficients for isothermal plate fins, referring to heat exchangers with central-tube and rear-tube row and to two-row tubes heat exchangers configurations. It is possible to obtain the real tax or the real area of heat transfer, using the average hea transfer coefficients for isothermal plate fins and the fin efficiency. (Author) [pt

Numeric Simulation on the Performance of an Undulating Fin in the Wake of a Periodic Oscillating Plate

Directory of Open Access Journals (Sweden)

Zhang Yong-Hua

2013-10-01

Full Text Available A two-dimensional unsteady computational fluid dynamics (CFD method using an unstructured, grid-based and unsteady Navier-Stokes solver with automatic adaptive re-meshing to compute the unsteady flow was adopted to study the hydrodynamic interaction between a periodic oscillating plate and a rigid undulating fin in tandem arrangement. The user-defined function (UDF program was compiled to define the undulating and oscillating motion. First, the influence of the distance between the anterior oscillating plate and the posterior undulating fin on the non-dimensional drag coefficient of the fin was investigated. Ten different distances, D=0.2L, 0.4L, 0.6L, 0.8L, 1.0L, 1.2L, 1.4L, 1.6L, 1.8L and 2.0L, were considered. The performance of the fin for different distances (D is different. Second, the plate oscillating angle (5.7°, 10°, 20°, 30°, 40°, 45°, 50° and frequency (0.5 Hz, 1.0 Hz, 1.5 Hz, 2.0 Hz, 2.5 Hz, 3.0 Hz, 3.5 Hz, 4.0 Hz effects on the non-dimensional drag coefficient of the fin were also implemented. The pressure distribution on the fin was computed and integrated to provide fin forces, which were decomposed into lift and thrust. Meanwhile, the flow field was demonstrated and analysed. Based on the flow structures, the reasons for different undulating performances were discussed. It shows that the results largely depend on the distance between the two objects. The plate oscillating angle and frequency also make a certain contribution to the performance of the posterior undulating fin. The results are similar to the interaction between two undulating objects in tandem arrangement and they may provide a physical insight into the understanding of fin interaction in fishes or bio-robotic underwater propulsors that are propelled by multi fins.

Fish locomotion: kinematics and hydrodynamics of flexible foil-like fins

Science.gov (United States)

Lauder, George V.; Madden, Peter G. A.

2007-11-01

The fins of fishes are remarkable propulsive devices that appear at the origin of fishes about 500 million years ago and have been a key feature of fish evolutionary diversification. Most fish species possess both median (midline) dorsal, anal, and caudal fins as well as paired pectoral and pelvic fins. Fish fins are supported by jointed skeletal elements, fin rays, that in turn support a thin collagenous membrane. Muscles at the base of the fin attach to and actuate each fin ray, and fish fins thus generate their own hydrodynamic wake during locomotion, in addition to fluid motion induced by undulation of the body. In bony fishes, the jointed fin rays can be actively deformed and the fin surface can thus actively resist hydrodynamic loading. Fish fins are highly flexible, exhibit considerable deformation during locomotion, and can interact hydrodynamically during both propulsion and maneuvering. For example, the dorsal and anal fins shed a vortex wake that greatly modifies the flow environment experienced by the tail fin. New experimental kinematic and hydrodynamic data are presented for pectoral fin function in bluegill sunfish. The highly flexible sunfish pectoral fin moves in a complex manner with two leading edges, a spanwise wave of bending, and substantial changes in area through the fin beat cycle. Data from scanning particle image velocimetry (PIV) and time-resolved stereo PIV show that the pectoral fin generates thrust throughout the fin beat cycle, and that there is no time of net drag. Continuous thrust production is due to fin flexibility which enables some part of the fin to generate thrust at all times and to smooth out oscillations that might arise at the transition from outstroke to instroke during the movement cycle. Computational fluid dynamic analyses of sunfish pectoral fin function corroborate this conclusion. Future research on fish fin function will benefit considerably from close integration with studies of robotic model fins.

Fear extinction deficits following acute stress associate with increased spine density and dendritic retraction in basolateral amygdala neurons.

Science.gov (United States)

Maroun, Mouna; Ioannides, Pericles J; Bergman, Krista L; Kavushansky, Alexandra; Holmes, Andrew; Wellman, Cara L

2013-08-01

Stress-sensitive psychopathologies such as post-traumatic stress disorder are characterized by deficits in fear extinction and dysfunction of corticolimbic circuits mediating extinction. Chronic stress facilitates fear conditioning, impairs extinction, and produces dendritic proliferation in the basolateral amygdala (BLA), a critical site of plasticity for extinction. Acute stress impairs extinction, alters plasticity in the medial prefrontal cortex-to-BLA circuit, and causes dendritic retraction in the medial prefrontal cortex. Here, we examined extinction learning and basolateral amygdala pyramidal neuron morphology in adult male rats following a single elevated platform stress. Acute stress impaired extinction acquisition and memory, and produced dendritic retraction and increased mushroom spine density in basolateral amygdala neurons in the right hemisphere. Unexpectedly, irrespective of stress, rats that underwent fear and extinction testing showed basolateral amygdala dendritic retraction and altered spine density relative to non-conditioned rats, particularly in the left hemisphere. Thus, extinction deficits produced by acute stress are associated with increased spine density and dendritic retraction in basolateral amygdala pyramidal neurons. Furthermore, the finding that conditioning and extinction as such was sufficient to alter basolateral amygdala morphology and spine density illustrates the sensitivity of basolateral amygdala morphology to behavioral manipulation. These findings may have implications for elucidating the role of the amygdala in the pathophysiology of stress-related disorders. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

FinFET modeling for IC simulation and design

CERN Document Server

Hu, Chenming; Lu, Darsen D

2015-01-01

This book is the first to explain FinFET modeling for IC simulation and the industry standard - BSIM-CMG - describing the rush in demand for advancing the technology from planar to 3D architecture, as now enabled by the approved industry standard. The book gives a strong foundation on the physics and operation of FinFET, details aspects of the BSIM-CMG model such as surface potential, charge and current calculations, and includes a dedicated chapter on parameter extraction procedures, providing a step-by-step approach for the efficient extraction of model parameters. With this book you will learn: * Why you should use FinFET* The physics and operation of FinFET* Details of the FinFET standard model (BSIM-CMG)* Parameter extraction in BSIM-CMG* FinFET circuit design and simulation * Authored by the lead inventor and developer of FinFET, and developers of the BSIM-CM standard model, providing an experts' insight into the specifications of the standard* The first book on the industry-standard FinFET model - BSIM...

Experimental Study of Heat Transfer Enhancements from Array of Alternate Rectangular Dwarf Fins at Different Inclinations

Science.gov (United States)

Awasarmol, Umesh Vandeorao; Pise, Ashok T.

2018-02-01

The main objective of this experimental work is to investigate and compare heat transfer enhancement of alternate dwarf fin array at different angles of inclination. In this study, the steady state heat transfer from the full length fin arrays and alternate dwarf fin arrays are measured in natural convection and radiation environment. Largest increase in the Nusselt number was achieved with alternate dwarf fin at angle of orientation 90°, which shows about 28% enhanced heat transfer coefficient as opposed to the full-length fin array with 25% saving in material. In case of non-black FAB, contribution of radiation heat transfer is found to be very small nearly within 1% of the heater input. After coating lamp black contribution of radiation heat transfer is found to increase to about 3-4% of the heater input in the range of temperatures considered in this study.

A biorobotic pectoral fin for autonomous undersea vehicles.

Science.gov (United States)

Tangorra, James L; Davidson, S Naomi; Madden, Peter G; Lauder, George V; Hunter, Ian W

2006-01-01

A biorobotic fin for autonomous undersea vehicles (AUVs) was developed based on studies of the anatomy, kinematics, and hydrodynamics of the bluegill sunfish pectoral fin. The biorobotic fin was able to produce many of the complex fin motions used by the sunfish during steady swimming and was used to investigate mechanisms of thrust production and control. This biorobotic fin is an excellent experimental tool and is an important first step towards developing propulsive devices that give AUVs maneuvering characteristics that match and exceed those of highly maneuverable fish.

When Scholarly Publishing Goes Awry: Educating Ourselves and Our Patrons about Retracted Articles

Science.gov (United States)

Thielen, Joanna

2018-01-01

Retracted articles, articles that violate professional ethics, are an unsettling, yet integral, part of the scholarly publishing process seldom discussed in the academy. Unfortunately, article retractions continue to rise across all disciplines. Although academic librarians consistently provide instruction on scholarly publishing, little has been…

Academic medical libraries' policies and procedures for notifying library users of retracted scientific publications.

Science.gov (United States)

Hughes, C

1998-01-01

Academic medical libraries have a responsibility to inform library users regarding retracted publications. Many have created policies and procedures that identify flawed journal articles. A questionnaire was sent to the 129 academic medical libraries in the United States and Canada to find out how many had policies and procedures for identifying retracted publications. Of the returned questionnaires, 59% had no policy and no practice for calling the attention of the library user to retracted publications. Forty-one percent of the libraries called attention to retractions with or without a formal policy for doing so. Several responding libraries included their policy statement with the survey. The increasing number of academic medical libraries that realize the importance of having policies and practices in place highlights the necessity for this procedure.

A Comprehensive Analysis of Articles Retracted Between 2004 and 2013 from Biomedical Literature – A Call for Reforms

Directory of Open Access Journals (Sweden)

Harkanwal Preet Singh

2014-07-01

Full Text Available Science is a dynamic subject and it was never free of misconduct or bad research. Indeed, the scientific method itself is intended to overcome mistakes and misdeeds. So, we aimed to assess various factors associated with retraction of scientific articles from 2004 to 2013. Data were retrieved from PubMed and Medline using the keywords retraction of articles, retraction notice, and withdrawal of article in April 2014 to detect articles retracted from 2004 to 2013. Statistical analysis was carried out using t-test and Karl Pearson's correlation coefficient. Results showed that a total of 2343 articles were retracted between 2004 and 2013, and original articles followed by case reports constituted major part of it. Time interval between submission and retraction of article has reduced in recent times. Impact factor and retraction do not have any significant correlation. We conclude that although retraction of articles is a rare event, its constant rise in scientific literature is quite worrisome. It is still unclear whether misconduct/mistakes in articles are increasing hastily or the articles are retracted at a rapid rate in recent times. So, it should be considered as an urgent issue and it is the responsibility of journal editors to track misconduct by following Committee on Publication Ethics (COPE guidelines and making an effective strategy.

FinTech in Denmark

OpenAIRE

Hategan, Ramona Anamaria; Mockus, Gytis; Trinkunaite, Sarune

2017-01-01

ABSTRACTThe purpose of this paper has been to seek understanding and knowledge of FinTech phenomenon, with a particular focus on the effect of its emergence on the Danish financial sector. We have attempted to answer our initial research question with the help of a theoretical and methodological framework conceived of concepts belonging to Actor-Network Theory, Diffusion of Innovation Theory and alluding to Foucault’s concepts of power, knowledge and discourses. We have followed FinTech as an...

Small Tails Tell Tall Tales--Intra-Individual Variation in the Stable Isotope Values of Fish Fin.

Directory of Open Access Journals (Sweden)

Brian Hayden

Full Text Available Fish fin is a widely used, non-lethal sample material in studies using stable isotopes to assess the ecology of fishes. However, fish fin is composed of two distinct tissues (ray and membrane which may have different stable isotope values and are not homogeneously distributed within a fin. As such, estimates of the stable isotope values of a fish may vary according to the section of fin sampled.To assess the magnitude of this variation, we analysed carbon (δ13C, nitrogen (δ15N, hydrogen (δ2H and oxygen (δ18O stable isotopes of caudal fin from juvenile, riverine stages of Atlantic salmon (Salmo salar and brown trout (Salmo trutta. Individual fins were sub-sectioned into tip, mid and base, of which a further subset were divided into ray and membrane.Isotope variation between fin sections, evident in all four elements, was primarily related to differences between ray and membrane. Base sections were13C depleted relative to tip (~1‰ with equivalent variation evident between ray and membrane. A similar trend was evident in δ2H, though the degree of variation was far greater (~10‰. Base and ray sections were 18O enriched (~2‰ relative to tip and membrane, respectively. Ray and membrane sections displayed longitudinal variation in 15N mirroring that of composite fin (~1‰, indicating that variation in15N values was likely related to ontogenetic variation.To account for the effects of intra-fin variability in stable isotope analyses we suggest that researchers sampling fish fin, in increasing priority, 1 also analyse muscle (or liver tissue from a subsample of fish to calibrate their data, or 2 standardize sampling by selecting tissue only from the extreme tip of a fin, or 3 homogenize fins prior to analysis.

Flexible nanoscale high-performance FinFETs

KAUST Repository

Sevilla, Galo T.

2014-10-28

With the emergence of the Internet of Things (IoT), flexible high-performance nanoscale electronics are more desired. At the moment, FinFET is the most advanced transistor architecture used in the state-of-the-art microprocessors. Therefore, we show a soft-etch based substrate thinning process to transform silicon-on-insulator (SOI) based nanoscale FinFET into flexible FinFET and then conduct comprehensive electrical characterization under various bending conditions to understand its electrical performance. Our study shows that back-etch based substrate thinning process is gentler than traditional abrasive back-grinding process; it can attain ultraflexibility and the electrical characteristics of the flexible nanoscale FinFET show no performance degradation compared to its rigid bulk counterpart indicating its readiness to be used for flexible high-performance electronics.

Indirect adaptive output feedback control of a biorobotic AUV using pectoral-like mechanical fins

International Nuclear Information System (INIS)

Naik, Mugdha S; Singh, Sahjendra N; Mittal, Rajat

2009-01-01

This paper treats the question of servoregulation of autonomous underwater vehicles (AUVs) in the yaw plane using pectoral-like mechanical fins. The fins attached to the vehicle have oscillatory swaying and yawing motion. The bias angle of the angular motion of the fin is used for the purpose of control. Of course, the design approach considered here is applicable to AUVs for other choices of oscillation patterns of the fins, which produce periodic forces and moments. It is assumed that the vehicle parameters, hydrodynamic coefficients, as well the fin forces and moments are unknown. For the trajectory control of the yaw angle, a sampled-data indirect adaptive control system using output (yaw angle) feedback is derived. The control system has a modular structure, which includes a parameter identifier and a stabilizer. For the control law derivation, an internal model of the exosignals (reference signal (constant or ramp) and constant disturbance) is included. Unlike the direct adaptive control scheme, the derived control law is applicable to minimum as well as nonminimum phase biorobotic AUVs (BAUVs). This is important, because for most of the fin locations on the vehicle, the model is a nonminimum phase. In the closed-loop system, the yaw angle trajectory tracking error converges to zero and the remaining state variables remain bounded. Simulation results are presented which show that the derived modular control system accomplishes precise set point yaw angle control and turning maneuvers in spite of the uncertainties in the system parameters using only yaw angle feedback

Implications of fin profiles on overall performance and weight reduction of a fin and tube heat exchanger

DEFF Research Database (Denmark)

Singh, Shobhana; Sørensen, Kim; Simonsen, Anders Schou

2017-01-01

Fin and tube heat exchangers are being used in several industrial applications by means of novel design and optimized performance. Improvements in geometric design may deliver energy efficient and cost-effective heat exchanger performance with reduced weight. In this paper, a systematic study...... on a cross-flow type fin and tube heat exchanger design for a waste heat recovery application is conducted. The geometric profile of the fin is characterized by a dimensionless design variable named aspect ratio which is parametrically varied to obtain different profiles. Two cases, case-I, and case......,000 using computational fluid dynamics. The numerical results obtained for the reference fin profile are verified with the experimental correlations. Dimensionless parameters such as Nusselt number, Euler number, and efficiency index are calculated to predict the overall performance of the heat exchanger...

RETRACTED: Development of electrode carbon paste modified by molecularly imprinted polymer as sensor for analysis of creatinine by potentiometric

Directory of Open Access Journals (Sweden)

Miratul Khasanah

Full Text Available This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy.This article has been retracted at the request of the Editors-in-Chief.After a thorough investigation, the Editors have concluded that the acceptance of this article was based upon the positive advice of two illegitimate reviewer reports. The reports were submitted from email accounts which were provided to the journal as suggested reviewers during the submission of the article. Although purportedly real reviewer accounts, the Editors have concluded that these were not of appropriate, independent reviewers.This manipulation of the peer-review process represents a clear violation of the fundamentals of peer review, our publishing policies, and publishing ethics standards. Apologies are offered to the reviewers whose identities were assumed and to the readers of the journal that this deception was not detected during the submission process.

FinTech in Taiwan: a case study of a Bank's strategic planning for an investment in a FinTech company

OpenAIRE

Hung, Jui-long; Luo, Binjie

2016-01-01

Introduction: Since 2015 is the year of FinTech in Taiwan, it is worth investigating the challenges that emerged when banks were encouraged to invest in FinTech companies for collaboration. This study aims to identify the strategic considerations in the process of searching for FinTech investment targets. Case description: This study used a case study investigation of a top-5 bank in Taiwan. The major data sources include the meeting notes of the FinTech investment task force and interviews w...

Undulating fins produce off-axis thrust and flow structures.

Science.gov (United States)

Neveln, Izaak D; Bale, Rahul; Bhalla, Amneet Pal Singh; Curet, Oscar M; Patankar, Neelesh A; MacIver, Malcolm A

2014-01-15

While wake structures of many forms of swimming and flying are well characterized, the wake generated by a freely swimming undulating fin has not yet been analyzed. These elongated fins allow fish to achieve enhanced agility exemplified by the forward, backward and vertical swimming capabilities of knifefish, and also have potential applications in the design of more maneuverable underwater vehicles. We present the flow structure of an undulating robotic fin model using particle image velocimetry to measure fluid velocity fields in the wake. We supplement the experimental robotic work with high-fidelity computational fluid dynamics, simulating the hydrodynamics of both a virtual fish, whose fin kinematics and fin plus body morphology are measured from a freely swimming knifefish, and a virtual rendering of our robot. Our results indicate that a series of linked vortex tubes is shed off the long edge of the fin as the undulatory wave travels lengthwise along the fin. A jet at an oblique angle to the fin is associated with the successive vortex tubes, propelling the fish forward. The vortex structure bears similarity to the linked vortex ring structure trailing the oscillating caudal fin of a carangiform swimmer, though the vortex rings are distorted because of the undulatory kinematics of the elongated fin.

Steam condensation on finned tubes, in the presence of non-condensable gases and aerosols: Influence of impaction, diffusiophoresis and settling on aerosol deposition

International Nuclear Information System (INIS)

Munoz-Cobo, J.L.; Pena, J.; Herranz, L.E.; Perez-Navarro, A.

2005-01-01

This paper presents a mechanistic model to predict the steam condensation on containment finned tube heat exchangers in the presence of non-condensable gases (NC) and aerosols. The total thermal resistance from the bulk gas to the coolant is formulated as a parallel combination of the convective and condensation gas resistances coupled in series to those of condensate layer, the aerosol fouling layer, the wall, and the coolant. The condensate layer thermal resistance is calculated by means of an Adamek-based condensation model. The aerosol fouling layer is computed based on diffusiophoresis, settling and impaction mechanisms. The gas mixture (steam plus NC) thermal resistance is formulated based on a diffusion layer modeling. Finally, this paper presents a Montecarlo method implemented in the FORTRAN code TAEROSOL that is able to compute the amount of aerosol mass that is deposited by impaction on the top of the finned tubes. The model results are compared with the available experimental data of the CONGA European project

A Theoretical Study of Steady State and Transient Condensation on Axisymmetric Fins Under Combined Capillary and Gravitational Forces

Science.gov (United States)

Kostoglou, M.; Karapantsios, T. D.; Buffone, C.; Glushchuk, A.; Iorio, C.

2016-10-01

The present work attempts to model the case of combined gravitational and capillary motion of condensate for an axisymmetric fin under steady and transient fin operation conditions. The focus here is to examine the structure of the mathematical problem and to develop suitable numerical techniques rather than yield information on the macroscopic condensate flow rate and fin efficiency. The problem is formulated starting from general conditions and is simplified step by step by introducing corresponding assumptions. The particular fin shape of a paraboloid from revolution is chosen and the equations are properly non-dimensionalized. A vast reduction of the number of problem parameters is achieved in this way. The cases of isothermal fin, steady state operation and dynamic operation are treated separately using specialized numerical solution techniques developed for each case in order to improve computational efficiency and accuracy. Typical results of fin temperature and condensate film thickness are presented and discussed.

Strain relaxation of germanium-tin (GeSn) fins

Science.gov (United States)

Kang, Yuye; Huang, Yi-Chiau; Lee, Kwang Hong; Bao, Shuyu; Wang, Wei; Lei, Dian; Masudy-Panah, Saeid; Dong, Yuan; Wu, Ying; Xu, Shengqiang; Tan, Chuan Seng; Gong, Xiao; Yeo, Yee-Chia

2018-02-01

Strain relaxation of biaxially strained Ge1-xSnx layer when it is patterned into Ge1-xSnx fin structures is studied. Ge1-xSnx-on-insulator (GeSnOI) substrate was realized using a direct wafer bonding (DWB) technique and Ge1-xSnx fin structures were formed by electron beam lithography (EBL) patterning and dry etching. The strain in the Ge1-xSnx fins having fin widths (WFin) ranging from 1 μm down to 80 nm was characterized using micro-Raman spectroscopy. Raman measurements show that the strain relaxation increases with decreasing WFin. Finite element (FE) simulation shows that the strain component in the transverse direction relaxes with decreasing WFin, while the strain component along the fin direction remains unchanged. For various Ge1-xSnx fin widths, transverse strain relaxation was further extracted using micro-Raman spectroscopy, which is consistent with the simulation results.

Radiation therapy apparatus having retractable beam stopper

International Nuclear Information System (INIS)

Coad, G.L.

1983-01-01

This invention relates to a radiation therapy apparatus which utilized a linear translation mechanism for positioning a beam stopper. An apparatus is described wherein the beam stopper is pivotally attached to the therapy machine with an associated drive motor in such a way that the beam stopper retracts linearly

Retractions of the gingival margins evaluated by holographic methods

Science.gov (United States)

Sinescu, Cosmin; Negrutiu, Meda Lavinia; Manole, Marius; de Sabata, Aldo; Rusu, Laura-Cristina; Stratul, Stefan; Dudea, Diana; Dughir, Ciprian; Duma, Virgil-Florin

2015-05-01

The periodontal disease is one of the most common pathological states of the teeth and gums system. The issue is that its evaluation is a subjective one, i.e. it is based on the skills of the dental medical doctor. As for any clinical condition, a quantitative evaluation and monitoring in time of the retraction of the gingival margins is desired. This phenomenon was evaluated in this study with a holographic method by using a He-Ne laser with a power of 13 mW. The holographic system we have utilized - adapted for dentistry applications - is described. Several patients were considered in a comparative study of their state of health - regarding their oral cavity. The impressions of the maxillary dental arch were taken from a patient during his/her first visit and after a period of six months. The hologram of the first model was superposed on the model cast after the second visit. The retractions of the gingival margins could be thus evaluated three-dimensionally in every point of interest. An evaluation of the retraction has thus been made. Conclusions can thus be drawn for the clinical evaluation of the health of the teeth and gums system of each patient.

Experimental Investigation of Temperature Distribution along the Length of Uniform Area Fin for Forced and Free Convection

Science.gov (United States)

Kannojiya, Vikas; Sharma, Riya; Gaur, Rahul; Jangra, Anil; Yadav, Pushpender; Prajapati, Pooja

2018-03-01

The overheating of an industrial component sometimes may leads to system failure. The convection heat transfer from a heated surface can be effectively enhanced by employing fins on that surface. This Paper emphasizes on the experimental investigation of temperature distribution along the length of pin shaped fin. The analysis is performed on a 100 mm long fin made up of brass with 19.6 mm diameter having thermal conductivity as 111 W/m.K. Temperature at different section of the fin along its length is evaluated experimentally and theoretically. The influence of convection mode viz natural & forced convection and variable heat input on the temperature distribution is evaluated. The result outcomes are then compared with the widely accepted analytical relations. A comparison of convective heat transfer coefficient for uniform and non-uniform area fin is also presented. The results by experimental and analytical method are found to be in good agreement for free convection phenomenon.

Duane retraction syndrome: causes, effects and management strategies

Directory of Open Access Journals (Sweden)

Kekunnaya R

2017-10-01

Full Text Available Ramesh Kekunnaya, Mithila Negalur Pediatric Ophthalmology and Strabismus Services, Child Sight Institute, Jasti V Ramannama Children’s Eye Care Center, KAR Campus, Hyderabad, India Abstract: Duane retraction syndrome (DRS is a congenital eye movement anomaly characterized by variable horizontal duction deficits, with narrowing of the palpebral fissure and globe retraction on attempted adduction, occasionally accompanied by upshoot or downshoot. The etiopathogenesis of this condition can be explained by a spectrum of mechanical, innervational, neurologic and genetic abnormalities occurring independently or which influence each other giving rise to patterns of clinical presentations along with a complex set of ocular and systemic anomalies. Huber type I DRS is the most common form of DRS with an earlier presentation, while Huber type II is the least common presentation. Usually, patients with unilateral type I Duane syndrome have esotropia more frequently than exotropia, those with type II have exotropia and those with type III have esotropia and exotropia occurring equally common. Cases of bilateral DRS may have variable presentation depending upon the type of presentation in each eye. As regards its management, DRS classification based on primary position deviation as esotropic, exotropic or orthotropic is more relevant than Huber’s classification before planning surgery. Surgical approach to these patients is challenging and must be individualized based on the amount of ocular deviation, abnormal head position, associated globe retraction and overshoots. Keywords: Duane syndrome, strabismus surgery, esotropia, overshoots

RETRACTED: Development of electrode carbon paste/molecularly imprinted polymer (MIP with methacrylic acid as monomer to analyze glucose by potentiometry

Directory of Open Access Journals (Sweden)

Miratul Khasanah

Full Text Available This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy.This article has been retracted at the request of the Editors-in-Chief.After a thorough investigation, the Editors have concluded that the acceptance of this article was based upon the positive advice of two illegitimate reviewer reports. The reports were submitted from email accounts which were provided to the journal as suggested reviewers during the submission of the article. Although purportedly real reviewer accounts, the Editors have concluded that these were not of appropriate, independent reviewers.This manipulation of the peer-review process represents a clear violation of the fundamentals of peer review, our publishing policies, and publishing ethics standards. Apologies are offered to the reviewers whose identities were assumed and to the readers of the journal that this deception was not detected during the submission process.

Steady-state and transient heat transfer through fins of complex geometry

Directory of Open Access Journals (Sweden)

Taler Dawid

2014-06-01

Full Text Available Various methods for steady-state and transient analysis of temperature distribution and efficiency of continuous-plate fins are presented. For a constant heat transfer coefficient over the fin surface, the plate fin can be divided into imaginary rectangular or hexangular fins. At first approximate methods for determining the steady-state fin efficiency like the method of equivalent circular fin and the sector method are discussed. When the fin geometry is complex, thus transient temperature distribution and fin efficiency can be determined using numerical methods. A numerical method for transient analysis of fins with complex geometry is developed. Transient temperature distributions in continuous fins attached to oval tubes is computed using the finite volume - finite element methods. The developed method can be used in the transient analysis of compact heat exchangers to calculate correctly the heat flow rate transferred from the finned tubes to the fluid.

Effect of annealing ambient on anisotropic retraction of film edges during solid-state dewetting of thin single crystal films

Energy Technology Data Exchange (ETDEWEB)

Kim, Gye Hyun; Thompson, Carl V., E-mail: cthomp@mit.edu [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 01239 (United States); Ma, Wen [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 01239 (United States); Yildiz, Bilge [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 01239 (United States); Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 01239 (United States)

2016-08-21

During solid-state dewetting of thin single crystal films, film edges retract at a rate that is strongly dependent on their crystallographic orientations. Edges with kinetically stable in-plane orientations remain straight as they retract, while those with other in-plane orientations develop in-plane facets as they retract. Kinetically stable edges have retraction rates that are lower than edges with other orientations and thus determine the shape of the natural holes that form during solid-state dewetting. In this paper, measurements of the retraction rates of kinetically stable edges for single crystal (110) and (100) Ni films on MgO are presented. Relative retraction rates of kinetically stable edges with different crystallographic orientations are observed to change under different annealing conditions, and this accordingly changes the initial shapes of growing holes. The surfaces of (110) and (100) films were also characterized using low energy electron diffraction, and different surface reconstructions were observed under different ambient conditions. The observed surface structures were found to correlate with the observed changes in the relative retraction rates of the kinetically stable edges.

Evaluating the Amount of Tooth Movement and Root Resorption during Canine Retraction with Friction versus Frictionless Mechanics Using Cone Beam Computed Tomography.

Science.gov (United States)

Makhlouf, Mohamed; Aboul-Ezz, Amr; Fayed, Mona Salah; Hafez, Hend

2018-02-15

The current study was carried out to compare the amount of tooth movement during canine retraction comparing two different retraction mechanics; friction mechanics represented by a NiTi closed coil spring versus frictionless mechanics represented by T - loop, and their effect on root resorption using Cone Beam Computed Tomography (CBCT). Ten patients were selected in a split-mouth study design that had a malocclusion that necessitates the extraction of maxillary first premolars and retraction of maxillary canines. The right maxillary canines were retracted using T - loops fabricated from 0.017 X 0.025 TMA wires. The left maxillary canines received NiTi coil spring with 150 gm of retraction force. Pre retraction and post retraction Cone Beam Computed Tomography were taken to evaluate the amount of tooth movement and root resorption using three-dimensional planes. T - loop side showed statistically significant higher mean anteroposterior measurement than NiTi coil spring side, indicating a lower amount of canine movement pre and post a canine retraction. Concerning the root resorption, there was no statistically significant change in the mean measurements of canine root length post retraction. The NiTi coil spring side showed more distal movement more than the T-loop side. Both retraction mechanics with controlled retraction force, do not cause root resorption.

MODEL CORRELATION STUDY OF A RETRACTABLE BOOM FOR A SOLAR SAIL SPACECRAFT

Science.gov (United States)

Adetona, O.; Keel, L. H.; Oakley, J. D.; Kappus, K.; Whorton, M. S.; Kim, Y. K.; Rakpczy, J. M.

2005-01-01

To realize design concepts, predict dynamic behavior and develop appropriate control strategies for high performance operation of a solar-sail spacecraft, we developed a simple analytical model that represents dynamic behavior of spacecraft with various sizes. Since motion of the vehicle is dominated by retractable booms that support the structure, our study concentrates on developing and validating a dynamic model of a long retractable boom. Extensive tests with various configurations were conducted for the 30 Meter, light-weight, retractable, lattice boom at NASA MSFC that is structurally and dynamically similar to those of a solar-sail spacecraft currently under construction. Experimental data were then compared with the corresponding response of the analytical model. Though mixed results were obtained, the analytical model emulates several key characteristics of the boom. The paper concludes with a detailed discussion of issues observed during the study.

RETRACTED: Study on the magnetic viscosity of Nd45Pr15Fe30−xCoxAl10 (x=0, 10) bulk amorphous Alloys

International Nuclear Information System (INIS)

Qi, Guoquan; Fan, Haiping; Wu, Gang; Song, Shengyin; Wei, Dong; Bai, Qiang

2013-01-01

This article has been retracted: please see Elsevier Policy on Article Withdrawal ( (http://www.elsevier.com/locate/withdrawalpolicy)). This article has been retracted at the request of the Author. The authors have used experimental data of which the ownership is with the Shanghai university. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. In the article the authors have used, without permission, experimental data owned by Shanghai university. The authors apologise for this error on their part. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process

Effect of a cordless retraction paste on titanium surface: a topographic, chemical and biocompatibility evaluation

Directory of Open Access Journals (Sweden)

Katherine Cooper

2013-06-01

Full Text Available Good exposure of the preparation margins and haemostasis in the sulcular gingiva are necessary for accurate impressions to produce precise restorations. The use of cordless retraction paste material in implant dentistry is a relatively novel application. However, few studies have been conducted on the use of retraction pastes and their possible interaction with implant surfaces. Recent literature has described remnants on titanium implant surfaces and expressed the need for an assessment of the biocompatibility of the exposed surface (Chang et al.. This in vitro study evaluated the effect of a cordless gingival retraction paste on sterile titanium disks. Surface chemistry was determined using energy-dispersive X-ray spectroscopy (EDS, and further investigated using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS. After exposure to retraction paste, surface chemistry alterations were identified. A fibroblast cell line (L929 was exposed to the disks and the live/dead viability/cytotoxicity assay was used to determine any effects on the proliferation and health of cells. The disks exposed to the retraction paste showed fewer dead cells compared to the unexposed disks. This was statistically significant.

Relationships of mercury concentrations across tissue types, muscle regions and fins for two shark species

KAUST Repository

O'Bryhim, Jason R.

2017-01-31

Mercury (Hg) exposure poses a threat to both fish and human health. Sharks are known to bioaccumulate Hg, however, little is known regarding how Hg is distributed between different tissue groups (e.g. muscle regions, organs). Here we evaluated total mercury (THg) concentrations from eight muscle regions, four fins (first dorsal, left and right pectorals, caudal-from both the inner core and trailing margin of each fin), and five internal organs (liver, kidney, spleen, heart, epigonal organ) from two different shark species, bonnethead (Sphyrna tiburo) and silky shark (Carcharhinus falciformis) to determine the relationships of THg concentrations between and within tissue groups. Total Hg concentrations were highest in the eight muscle regions with no significant differences in THg concentrations between the different muscle regions and muscle types (red and white). Results from tissue collected from any muscle region would be representative of all muscle sample locations. Total Hg concentrations were lowest in samples taken from the fin inner core of the first dorsal, pectoral, and caudal (lower lobe) fins. Mercury concentrations for samples taken from the trailing margin of the dorsal, pectoral, and caudal fins (upper and lower lobe) were also not significantly different from each other for both species. Significant relationships were found between THg concentrations in dorsal axial muscle tissue and the fin inner core, liver, kidney, spleen and heart for both species as well as the THg concentrations between the dorsal fin trailing margin and the heart for the silky shark and all other sampled tissue types for the bonnethead shark. Our results suggest that biopsy sampling of dorsal muscle can provide data that can effectively estimate THg concentrations in specific organs without using more invasive, or lethal methods.

RETRACTED: Adaptive neuro-fuzzy prediction of modulation transfer function of optical lens system

Science.gov (United States)

Petković, Dalibor; Shamshirband, Shahaboddin; Anuar, Nor Badrul; Md Nasir, Mohd Hairul Nizam; Pavlović, Nenad T.; Akib, Shatirah

2014-07-01

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor. Sections ;1. Introduction; and ;2. Modulation transfer function;, as well as Figures 1-3, plagiarize the article published by N. Gül and M. Efe in Turk J Elec Eng & Comp Sci 18 (2010) 71 (http://journals.tubitak.gov.tr/elektrik/issues/elk-10-18-1/elk-18-1-6-0811-9.pdf). Sections ;4. Adaptive neuro-fuzzy inference system; and ;6. Conclusion; duplicate parts of the articles previously published by the corresponding author et al in ;Expert Systems with Applications; 39 (2012) 13295-13304, http://dx.doi.org/10.1016/j.eswa.2012.05.072 and ;Expert Systems with Applications; 40 (2013) 281-286, http://dx.doi.org/10.1016/j.eswa.2012.07.076. One of the conditions of submission of a paper for publication is that authors declare explicitly that the paper is not under consideration for publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents an abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

Analysis of non-linear aeroelastic response of a supersonic thick fin with plunging, pinching and flapping free-plays

Science.gov (United States)

Firouz-Abadi, R. D.; Alavi, S. M.; Salarieh, H.

2013-07-01

The flutter of a 3-D rigid fin with double-wedge section and free-play in flapping, plunging and pitching degrees-of-freedom operating in supersonic and hypersonic flight speed regimes have been considered. Aerodynamic model is obtained by local usage of the piston theory behind the shock and expansion analysis, and structural model is obtained based on Lagrange equation of motion. Such model presents fast, accurate algorithm for studying the aeroelastic behavior of the thick supersonic fin in time domain. Dynamic behavior of the fin is considered over large number of parameters that characterize the aeroelastic system. Results show that the free-play in the pitching, plunging and flapping degrees-of-freedom has significant effects on the oscillation exhibited by the aeroelastic system in the supersonic/hypersonic flight speed regimes. The simulations also show that the aeroelastic system behavior is greatly affected by some parameters, such as the Mach number, thickness, angle of attack, hinge position and sweep angle.

Retraction notice to “Methylation of apoptosis related genes in the pathogenesis and prognosis of prostate cancer” [Cancer Lett. 242 (2) (2006) 222–230]. Makoto Suzuki, Hisayuki Shigematsu, Narayan Shivapurkar, Jyotsna Reddy, Kuniharu Miyajima, Takao Takahashi, Adi F. Gazdar, Eugene P. Frenke.

Science.gov (United States)

2015-04-28

Available online . This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the first author, who accepts responsibility. Following an internal review at the UT Southwestern Medical Center in Dallas, evidence has been found of improper manipulation and duplication of Figure 1 in this article.

Open Channel Natural Convection Heat Transfer on a Vertical Finned Plate

International Nuclear Information System (INIS)

Park, Joo Hyun; Heo, Jeong Hwan; Chung, Bum Jin

2013-01-01

The natural convection heat transfer of vertical plate fin was investigated experimentally. Heat transfer systems were replaced by mass-transfer systems, based on the analogy concept. The experimental results lie within the predictions of the existing heat transfer correlations of plate-fin for the natural convections. An overlapped thermal boundary layers caused increasing heat transfer, and an overlapped momentum boundary layers caused decreasing heat transfer. As the fin height increases, heat transfer was enhanced due to increased inflow from the open side of the fin spacing. When fin spacing and fin height are large, heat transfer was unaffected by the fin spacing and fin height. Passive cooling by natural convection becomes more and more important for the nuclear systems as the station black out really happened at the Fukushima NPPs. In the RCCS (Reactor Cavity Cooling System) of a VHTR (Very High Temperature Reactor), natural convection cooling through duct system is adopted. In response to the stack failure event, extra cooling capacity adopting the fin array has to be investigated. The finned plate increases the surface area and the heat transfer increases. However, the plate of fin arrays may increase the pressure drop and the heat transfer decreases. Therefore, in order to enhance the passive cooling with fin arrays, the parameters for the fin arrays should be optimized. According to Welling and Wooldridge, a natural convection on vertical plate fin is function of Gr, Pr, L, t, S, and H. The present work investigated the natural convection heat transfer of a vertical finned plate with varying the fin height and the fin spacing. In order achieve high Rayleigh numbers, an electroplating system was employed and the mass transfer rates were measured using a copper sulfate electroplating system based on the analogy concept

RETRACTED: Nucleation and growth behavior of well-aligned ZnO nanorods on organic substrates in aqueous solutions

Science.gov (United States)

Lin, Chin-Ching; Chen, San-Yuan; Cheng, Syh-Yuh

2005-09-01

Available online : 21 July 2005 This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Two papers published in the Journal of Crystal Growth are being retracted due to a case of misrepresentation and reuse of data. A reader of the Journal has brought to our attention the reuse of data within two published papers: Growth behavior and microstructure evolution of ZnO nanorods grown on Si in aqueous solution, Sz-Chian Liou, Chi-Sheng Hsiao, San-Yuan Chen, Journal of Crystal Growth 274 (2005) 438-446. DOI: 10.1016/j.jcrysgro.2004.10.025 Nucleation and growth behavior of well-aligned ZnO nanorods on organic substrates in aqueous solutions, Chin-Ching Lin, San-Yuan Chen, and Syh-Yuh Cheng, Journal of Crystal Growth 283 (2005) 141-146. DOI: 10.1016/j.jcrysgro.2005.05.065 In these papers the same transmission electron micrograph was used to describe two different experimental situations and results bringing into question the content of these papers. The reuse of data without proper attribution is not acceptable within the scientific publishing community. In the present case, this is compounded by the attribution of the micrograph to a different experimental situation and drawing , as a result, new conclusions from data obtained from different samples. Such behavior undermines the integrity of the scientific publishing endeavor and is not acceptable. The authors are responsible for the content of their papers.

Plate-fin array cooling using a finger-like piezoelectric fan

International Nuclear Information System (INIS)

Shyu, Jin-Cherng; Syu, Jhih-Zong

2014-01-01

In this study, the heat transfer of a plate-fin array cooled by a vibrating finger-like piezoelectric fan comprising four flexible rectangular blades was investigated. The results indicated that the heat transfer enhancement of the fin array cooled by a vibrating piezoelectric fan at x/L = 0.5 and H = 5 mm ranged between 1.5 and 3.3, regardless of the fin array orientation. However, the heat transfer enhancement caused by a fan being placed at either edge of the fin array yielded a dissimilar result between both of the fin array orientations because of the superimposed effects of the boundary layer development and the air flow induced by the fan. This dissimilarity was especially noticeable when the piezoelectric fan was composed of aluminum blades to accommodate the moderate Reynolds number. In addition to the Reynolds number, the ratio of the fan blade vibration envelope to the source area determined the Nu number of the piezoelectric fan-cooled fin array. This design enhanced the fin array heat transfer and reduced cooler volume by embedding multiple vibrating beams into the fin array. -- Highlights: • Heat transfer of a piezoelectric fan-cooled plate-fin array was investigated. • Effects of fan position, fan height and fan material on heat transfer were examined. • Similar heat transfer enhancement range was shown for both fin array orientations. • Fin heat transfer with a running Al fan at x = 0 was higher than that at x = 0.25L. • Besides fan Reynolds number, the area ratio also determined Nu of the fin array

Finite element analysis of rapid canine retraction through reducing resistance and distraction

Directory of Open Access Journals (Sweden)

Junjie XUE

2014-01-01

Full Text Available Objective: The aims of this study were to compare different surgical approaches to rapid canine retraction by designing and selecting the most effective method of reducing resistance by a three-dimensional finite element analysis. Material and Methods: Three-dimensional finite element models of different approaches to rapid canine retraction by reducing resistance and distraction were established, including maxillary teeth, periodontal ligament, and alveolar. The models were designed to dissect the periodontal ligament, root, and alveolar separately. A 1.5 N force vector was loaded bilaterally to the center of the crown between first molar and canine, to retract the canine distally. The value of total deformation was used to assess the initial displacement of the canine and molar at the beginning of force loading. Stress intensity and force distribution were analyzed and evaluated by Ansys 13.0 through comparison of equivalent (von Mises stress and maximum shear stress. Results: The maximum value of total deformation with the three kinds of models occurred in the distal part of the canine crown and gradually reduced from the crown to the apex of the canine; compared with the canines in model 3 and model 1, the canine in model 2 had the maximum value of displacement, up to 1.9812 mm. The lowest equivalent (von Mises stress and the lowest maximum shear stress were concentrated mainly on the distal side of the canine root in model 2. The distribution of equivalent (von Mises stress and maximum shear stress on the PDL of the canine in the three models was highly concentrated on the distal edge of the canine cervix. . Conclusions: Removal of the bone in the pathway of canine retraction results in low stress intensity for canine movement. Periodontal distraction aided by surgical undermining of the interseptal bone would reduce resistance and effectively accelerate the speed of canine retraction.

[Imaging manifestations and pathologic basis for hepatic capsular retraction syndrome caused by benign and malignant liver tumors].

Science.gov (United States)

Ou, Youkuan; Xiao, Enhua; Shang, Quanliang; Chen, Juan

2015-10-01

To investigate the imaging manifestations of CT, MRI and pathological basis for hepatic capsular retraction syndrome caused by benign and malignant liver tumors.
 CT or MRI images and pathological features for hepatic capsular retraction syndrome were retrospectively analyzed in 50 patients with benign and malignant liver tumors. Picture archive and communication system (PACS) was used to observe and compare the morphology, size, width, depth, edge of the capsular retraction and the status of liquid under the liver capsule. The structure, differentiation and proliferation of the tumor were analyzed under the microscope.
 There were malignant liver tumors in 44 patients and benign tumor in 6 patients. The smooth or rough for the edge of capsular retraction was significant difference between the benign tumors and the malignant tumors with three differentiated grades (all PBenign and malignant hepatic tumors may appear capsule retraction syndrome, but there are morphological differences between them. The differences are closely related with the lesion size, differentiated degree of tumor and fibrous tissue proliferation.

A note on the heat transfer in convective fins

International Nuclear Information System (INIS)

Razelos, P.

1979-01-01

In this paper a generalized approach to the problem of heat transfer through convective fins is given. The proper dimensionless variables, which specify the general problem are identified, and upper bounds of the values of the dimensionless number Nsub(r) defined as 'the ratio of the heat transferred by the fin to that of the corresponding bare surface' are derived. It was shown that these limiting values of the Nsub(r) are 1/√B 1 and √2/B 1 for longitudinal fins and spines respectively, where B 1 is the Biot number hb/k, while for annular fins of constant thickness and hyperbolic profile, Nsub(r) 1 , where K(β) is a number determined by the profile of the fin and the ratio β = x 2 /x 1 of the outside to the inside radii. It was also shown that for longitudinal fins and spinces the possible adverse insulating effect by the use of the fin is avoided, if one selects the value of √hA/kC [de

Eye retraction in the giant guitarfish, Rhynchobatus djiddensis (Elasmobranchii: Batoidea): a novel mechanism for eye protection in batoid fishes.

Science.gov (United States)

Tomita, Taketeru; Murakumo, Kiyomi; Miyamoto, Kei; Sato, Keiichi; Oka, Shin-ichiro; Kamisako, Haruka; Toda, Minoru

2016-02-01

Eye retraction behavior has evolved independently in some vertebrate linages such as mudskippers (fish), frogs and salamanders (amphibians), and cetaceans (mammals). In this paper, we report the eye retraction behavior of the giant guitarfish (Rhynchobatus djiddensis) for the first time, and discuss its mechanism and function. The eye retraction distance was nearly the same as the diameter of the eyeball itself, indicating that eye retraction in the giant guitarfish is probably one of the largest among vertebrates. Eye retraction is achieved by unique arrangement of the eye muscle: one of the anterior eye muscles (the obliquus inferior) is directed ventrally from the eyeball and attaches to the ventral surface of the neurocranium. Due to such muscle arrangement, the obliquus inferior can pull the eyeball ventrally. This mechanism was also confirmed by electrical stimulation of the obliquus inferior. The eye retraction ability of the giant guitarfish likely represents a novel eye protection behavior of elasmobranch fishes. Copyright © 2015 Elsevier GmbH. All rights reserved.

Criteria for analysis and optimization of longitudinal fins with convective tip

International Nuclear Information System (INIS)

Gomes, E.S.

1983-01-01

The problem of heat transfer in longitudinal fins with the main geometries used in equipaments of heat transfer by convection is analyzed. The equation of energy is solved analytically of several geometries fins, with unidimensional formulation, through the use of the convective heat transfer coefficient. The problem of fin optimization is approached analytically yielding the parameters which allow the maximum heat transfer for each particular material waste in the fin. The use of the insulated tip model suggests the use of fins and its optimization for any Biot number of the fin. The use of the convective tip model allows us to determine when is vantageous or disadvantageous to use fins and when fin optimization is possible according to the value of the Biot number and to a convection parameter on the fin tip. (Author) [pt

Compensation of flow maldistribution in fin-and-tube evaporators for residential air-conditioning

DEFF Research Database (Denmark)

Kærn, Martin Ryhl; Brix, Wiebke; Elmegaard, Brian

2011-01-01

Compensation of flow maldistribution in multi-channel fin-and-tube evaporators for residential air-conditioning is investigated by numerical modeling. The considered sources of maldistribution are distribution of the liquid and vapor phases in the distributor and non-uniform airflow distribution....

Ergodic Retractions for Families of Asymptotically Nonexpansive Mappings

Directory of Open Access Journals (Sweden)

Saeidi Shahram

2010-01-01

Full Text Available We prove some theorems for the existence of ergodic retractions onto the set of common fixed points of a family of asymptotically nonexpansive mappings. Our results extend corresponding results of Benavides and Ramírez (2001, and Li and Sims (2002.

Retraction: Evaluation of Carcinogenic Effects of Electromagnetic Fields (Emf

Directory of Open Access Journals (Sweden)

Bakir Mehic

2010-08-01

Full Text Available This retracts the article "EVALUATION OF CARCINOGENIC EFFECTS OF ELECTROMAGNETIC FIELDS (EMF" on page 245. The Editor-in-chief of the Bosnian Journal ofBasic Medical Sciences has decided to retract the article from Bayazit V et al. [1] entitled as: “Evaluation of carcinogenic effects of electromagnetic fields (EMF” published in Bosn J Basic Med Sci. 2010 Aug;10(3:245-50.After the editorial office was alerted of possible plagiarism in the article, it conducted thorough investigation and concluded that the article apparently represents plagiarized material from two World Health Organization reports, one European Commission report and other sources. Since this is considered scientific plagiarism and scientific misconduct, Editor-in-chief has decided to withdraw the article. The authors have agreed with the editorial office decision.

Cancer cells cause vascular endothelial cell (vEC) retraction via 12(S)HETE secretion; the possible role of cancer cell derived microparticle.

Science.gov (United States)

Uchide, Keiji; Sakon, Masato; Ariyoshi, Hideo; Nakamori, Syouji; Tokunaga, Masaru; Monden, Morito

2007-02-01

Cancer cell mediated vascular endothelial cell (vEC) retraction plays a pivotal role in cancer metastasis. The aim of this study is to clarify the biochemical character of vEC retraction factor derived from human breast cancer cell line, MCF-7. In order to estimate vEC retracting activity, transwell chamber assay system was employed. We first tested the effects of trypsin digestion as well as lipid extraction of culture medium (CM). Trypsin digestion of CM resulted in approximately 40% loss of vEC retracting activity and lipid extraction of CM by Brigh and Dyer methods recovered approximately 60% of vEC retracting activity, suggesting that approximately 60% of vEC retracting activity in MCF-7 derived CM is due to lipid. Although Nordihydroguaiaretic acid (NDGA), the specific lipoxygenase inhibitor, suppressed vEC retracting activity in CM, Acetyl salicylic acid (ASA), a specific cyclooxygenase inhibitor, did not affect the activity, suggesting that lipid exerting vEC retracting activity in CM belongs to lipoxygenase mediated arachidonate metabolites. Thin layer chromatography clearly demonstrated that Rf value of lipid vEC retracting factor in CM is identical to 12HETE. Authentic 12(S)HETE, but not 12(R)HETE, showed vEC retracting activity. After the ultracentrifugation of CM, most lipid vEC retracting activity was recovered from the pellet fraction, and flow cytometric analysis using specific antibody against 12(S)HETE clearly showed the association of 12(S)HETE with small particle in CM. These findings suggested the principal involvement of 12(S)HETE in cancer cell derived microparticles in cancer cell mediated vEC retraction.

Actuation of a robotic fish caudal fin for low reaction torque

Science.gov (United States)

Yun, Dongwon; Kim, Kyung-Soo; Kim, Soohyun; Kyung, Jinho; Lee, Sunghee

2011-07-01

In this paper, a novel caudal fin for actuating a robotic fish is presented. The proposed caudal fin waves in a vertical direction with a specific spatial shape, which is determined by a so-called shape factor. For a specific shape factor, a traveling wave with a vertical phase difference is formed on a caudal fin during fin motion. It will be shown by the analysis that the maximum reaction torque at the joint of a caudal fin varies depending on the shape factors. Compared with a conventional plate type caudal fin, the proposed fin with a shape factor of 2π can eliminate the reaction torque perfectly, while keeping the propulsion force unchanged. The benefits of the proposed fin will be demonstrated by experiments.

Fast breeder cladding tubes provided with helical fins

International Nuclear Information System (INIS)

Baumgaertner, E.; Hoffmann, H.; Miller, H.; Jacobi, O.; Bojarski, E.; Freund, D.; Reiser, H.

1977-04-01

Development of fast breeder tubes with helical fins started around 1966. The development was initiated mainly by the search for a more favorable alternative to the conventional spacers such as grids and spiral wires. First of all the possibility was investigated of fabricating them on an industrial scale. The first thermohydraulic and fluiddynamic tests were made in parallel by AEG, GfK and Interatom. Besides the possibility of industrial fabrication the problems of non-destructive testing for geometry and material defects had to be treated with priority. In this report the different stages of development are shown and, finally, two rather large projects are described. These projects are the study ready for the licensing procedure concerning the irradiation of finned tube oxide fuel elements in KNK II and the already completed 19-rod fuel element bundle irradiation experiment Mol 7D of GfK performed in the 500 kW sodium loop of the Belgian BR2 reactor. In this BR2 experiment the maximum target burnup of 85,000 MWd/t of oxide was attained without trouble. (orig.) [de

Deformation retracts of Stein spaces

International Nuclear Information System (INIS)

Hamm, H.; Mihalache, N.

1995-01-01

If X is an n-dimensional Stein space, it was proved that X has the homotopy type of a CW-complex of dimension≤n and in the algebraic case this was proved with the additional conclusion that the CW-complex is finite. In this paper the authors give an answer to the question if there exists a subset Q of X with the same topological properties as X, for instance Q is a strong deformation retract of X, and Q is a CW-complex of dimension≤n. 15 refs

Constructal design of finned tubes used in air-cooled heat exchangers

Energy Technology Data Exchange (ETDEWEB)

Shokouhmand, Hossein; Mahjoub, Shoeib [University of Tehran, Tehran (Iran, Islamic Republic of); Salimpour, Mohammad Reza [Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

2014-06-15

The present study documents the constructal design and optimization of finned tubes used in air-cooled heat exchangers. The considered tubes are equipped with annular fins. The aim is to minimize the overall thermal resistance by morphing the geometry. The geometrical and thermo-physical parameters considered are the number of fins, ratio of fin height to tube diameter, Stanton number, ratio of fin conductivity to air conductivity, ratio of in-tube fluid conductivity to air conductivity and dimensionless pressure drop. Two constraints are applied in the optimization process: fixed overall volume of heat exchanger and fixed volume fraction of fin material. It is found that there exist optimal values for the number and the height of fins. Moreover, the optimal heat transfer has an extremum in a special volume fraction of fin material.

Constructal design of finned tubes used in air-cooled heat exchangers

International Nuclear Information System (INIS)

Shokouhmand, Hossein; Mahjoub, Shoeib; Salimpour, Mohammad Reza

2014-01-01

The present study documents the constructal design and optimization of finned tubes used in air-cooled heat exchangers. The considered tubes are equipped with annular fins. The aim is to minimize the overall thermal resistance by morphing the geometry. The geometrical and thermo-physical parameters considered are the number of fins, ratio of fin height to tube diameter, Stanton number, ratio of fin conductivity to air conductivity, ratio of in-tube fluid conductivity to air conductivity and dimensionless pressure drop. Two constraints are applied in the optimization process: fixed overall volume of heat exchanger and fixed volume fraction of fin material. It is found that there exist optimal values for the number and the height of fins. Moreover, the optimal heat transfer has an extremum in a special volume fraction of fin material.

Computational thermal analysis of cylindrical fin design parameters and a new methodology for defining fin structure in LED automobile headlamp cooling applications

International Nuclear Information System (INIS)

Sökmen, Kemal Furkan; Yürüklü, Emrah; Yamankaradeniz, Nurettin

2016-01-01

Highlights: • In the study, cooling of LED headlamps in automotive is investigated. • The study is based on free convection cooling of LED module. • Besides free convection, Monte Carlo model is used as radiation model as well. • A new algorithm is presented for designing optimum fin structure. • Suggested algorithm for optimum design is verified by various simulations. - Abstract: In this study, the effects of fin design, fin material, and free and forced convection on junction temperature in automotive headlamp cooling applications of LED lights are researched by using ANSYS CFX 14 software. Furthermore a new methodology is presented for defining the optimum cylindrical fin structure within the given limits. For measuring the performance of methodology, analyses are carried out for various ambient temperatures (25 °C, 50 °C and 80 °C) and different LED power dissipations (0.5 W, 0.75 W, 1 W and 1.25 W). Then, analyses are repeated at different heat transfer coefficients and different fin materials in order to calculate LED junction temperature in order to see if the fin structure proposed by the methodology is appropriate for staying below the given safety temperature limit. As a result, the suggested method has always proposed proper fin structures with optimum characteristics for given LED designs. As another result, for safe junction temperature ranges, it is seen that for all LED power dissipations, adding aluminum or copper plate behind the printed circuit board at low ambient temperatures is sufficient. Also, as the ambient temperature increases, especially in high powered LED lights, addition of aluminum is not sufficient and fin usage becomes essential. High heat transfer coefficient and using copper fin affect the junction temperature positively.

Heat transfer enhancement for fin-tube heat exchanger using vortex generators

International Nuclear Information System (INIS)

Yoo, Seong Yeon; Park, Dong Seong; Chung, Min Ho; Lee, Sang Yun

2002-01-01

Vortex generators are fabricated on the fin surface of a fin-tube heat exchanger to augment the convective heat transfer. In addition to horseshoe vortices formed naturally around the tube of the fin-tube heat exchanger, longitudinal vortices are artificially created on the fin surface by vortex generators. The purpose of this study is to investigate the local heat transfer phenomena in the fin-tube heat exchangers with and without vortex generators, and to evaluate the effect of vortices on the heat transfer enhancement. Naphthalene sublimation technique is employed to measure local mass transfer coefficients, then analogy equation between heat and mass transfer is used to calculate heat transfer coefficients. Experiments are performed for the model of fin-circular tube heat exchangers with and without vortex generators, and of fin-flat tube heat exchangers with and without vortex generators. Average heat transfer coefficients of fin-flat tube heat exchanger without vortex generator are much lower than those of fin-circular tube heat exchanger. On the other hand, fin-flat tube heat exchanger with vortex generators has much higher heat transfer value than conventional fin-circular tube heat exchanger. At the same time, pressure losses for four types of heat exchanger is measured and compared

Numerical study of an innovative design of a finned double-pipe heat exchanger with variable fin-tip thickness

International Nuclear Information System (INIS)

Syed, K.S.; Ishaq, Muhammad; Iqbal, Zafar; Hassan, Ahmad

2015-01-01

Highlights: • Variable fin tip angle significantly effect the velocity and temperature distribution. • Significant gain in the thermal performance with decrease in the friction factor. • Variable fin tip angle must be considered an important parameter in designing finned annulus. - Abstract: The analysis of fully developed laminar convective heat transfer in an innovate design of a finned double-pipe heat exchanger (DPHE) with longitudinal fins of variable thickness of the tip subjected to the constant heat transfer rate boundary conditions is investigated here. The tip thickness is controlled by the ratio of tip to base angles as a parameter whose values varying from 0 to 1 correspond to the fin shapes varying from the triangular to the rectangular cross-section. Upto the knowledge of the authors, this parameter is being introduced for the first time in the literature. Discontinuous Galerkin finite element method (DG-FEM) has been employed in the present work. The overall performance of the proposed DPHE has been investigated by considering the friction factor, the Nusselt number and the j-factor. Upto 178% gain in the Nusselt number and 89% gain in the j-factor have been achieved relative to the rectangular cross-section. Such gains relative to the triangular cross-section are respectively 9.5% and 19%. The results indicate that the newly introduced parameter the ratio of tip to base angles has proved to play significant role in the design of a double-pipe heat exchanger in reducing the cost, weight and frictional loss, in improving the heat transfer rate and making the exchanger energy-efficient. Therefore, it must be considered as an important design parameter for heat exchanger design

Retraction: Redundant Publication of the article Dental caries and ...

African Journals Online (AJOL)

Retraction: Redundant Publication of the article Dental caries and oral health practices among 12 year old children in Nairobi West and Mathira West Districts, Kenya. Gladwell Gathecha et al. The Pan African Medical Journal. 2012;12:42.

Effect of botulinum toxin for eyelid retraction in dysthyroid ophthalmopathy as related to hypertrophy of intraorbital muscles

International Nuclear Information System (INIS)

Komoto, Noriko; Kozaki, Ai; Yu, Fumihiko; Inoue, Rishu; Maeda, Toshine; Inoue, Toyoko; Inoue, Yoichi

2007-01-01

The purpose of this study was to report the effect of botulinum toxin for eyelid retraction in dysthyroid ophthalmopathy with or without hypertrophy of intraorbital muscles. We reviewed 28 eyes of 23 cases who received injection of botulinum toxin for eyelid retraction. Eyelid retraction improved in 23 eyes (82%). The height of palpebral fissure ranged from 8 to 12 mm, average 10.8 mm, before treatment. It ranged from 5 to 12 mm, average 9.4 mm, 2 weeks after treatment. The difference was significant. By magnetic resonance imaging (MRI), hypertrophy of levator and/or superior rectus muscle was present in 19 eyes and absent in 9 eyes. Eyelid retraction improved in 2 eyes (11%) in the former group and in one eye (11%) in the latter. Dalrymple sign was present in 28 eyes before and disappeared in 14 eyes after treatment. Graefe sign was present in 28 eyes before and disappeared in one eye after treatment. Botulinum toxin is effective for eyelid retraction and not for Graefe sign in dysthyroid ophthalmopathy. (author)

Ice nucleating particles measured during the laboratory and field intercomparisons FIN-2 and FIN-3 by the diffusion chamber FRIDGE

Science.gov (United States)

Weber, Daniel; Schrod, Jann; Curtius, Joachim; Haunold, Werner; Thomson, Erik; Bingemer, Heinz

2016-04-01

The measurement of atmospheric ice nucleating particles (INP) is still challenging. In the absence of easily applicable INP standards the intercomparison of different methods during collaborative laboratory and field workshops is a valuable tool that can shine light on the performance of individual methods for the measurement of INP [1]. FIN-2 was conducted in March 2015 at the AIDA facility in Karlsruhe as an intercomparison of mobile instruments for measuring INP [2]. FIN-3 was a field campaign at the Desert Research Institutes Storm Peak Laboratory in Colorado in September 2015 [3]. The FRankfurt Ice nucleation Deposition freezinG Experiment (FRIDGE) participated in both experiments. FRIDGE measures ice nucleating particles by electrostatic precipitation of aerosol particles onto Si-wafers in a collection unit, followed by activation, growth, and optical detection of ice crystals on the substrate in an isostatic diffusion chamber [4,5]. We will present and discuss results of our measurements of deposition/condensation INP and of immersion INP with FRIDGE during FIN-2 and FIN-3. Acknowledgements: The valuable contributions of the FIN organizers and their institutions, and of the FIN Workshop Science team are gratefully acknowledged. Our work was supported by Deutsche Forschungsgemeinschaft (DFG) under the Research Unit FOR 1525 (INUIT) and the EU FP7-ENV- 2013 BACCHUS project under Grant Agreement 603445.

Numerical simulation of heat exchangers elliptical tubes and corrugated fins

International Nuclear Information System (INIS)

Borrajo Pérez, Rubén; González Bayón, Juan José; Menéndez Pérez, Alberto

2015-01-01

The intensified heat exchangers fins are widely used in the automotive and domestic industry. The low heat transfer coefficients on the air side are the main reason why these fins of heat exchangers need to be intensified. In this paper, the numerical simulation of a wavy fin type is made with elliptical tubes. The dimensions of the fin is in the range of those used in air conditioning equipment. The friction factor and the mass transfer coefficient as a function of the Reynolds number for this type of fin, always within the laminar regime is determined. The numerical model against experimental results published in the literature is validated. In addition the mechanisms that produce intensified heat transfer fin in such occur. (full text)

Composition, Enzymes Analysis and Retraction Time of Columellar ...

African Journals Online (AJOL)

With the aid of columellar muscle, snails retract the soft part into the shell when disturbed. The response time of three Giant African Land Snail (GALS) species: Archachatina marginata, Achatina achatina and Achatina fulica to touch and sodium chloride (NaCl) solution was examined. Chemical composition (protein, glucose ...

RETRACTED: The revised stratigraphy of the hominin-bearing site of Kromdraai (Gauteng, South Africa) and associated perspectives.

Science.gov (United States)

Bruxelles, Laurent; Maire, Richard; Beaudet, Amélie; Couzens, Raymond; Duranthon, Francis; Fourvel, Jean-Baptiste; Stratford, Dominic; Thackeray, Francis; Braga, José

2018-01-01

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the co-Editors-in-Chief and the authors. The Results and Discussion of this article duplicate significant parts of book chapter "A revised stratigraphy of Kromdraai", published by L.B., R.M., R.C., F.T. and J.B. in Braga, J. and Thackeray, J.F. (Eds.), "Kromdraai. A Birthplace of Paranthropus in the Cradle of Humankind" (2016, SUN MeDIA MeTRO, pp. 31-47), https://doi.org/10.18820/9781928355076. One of the conditions of submission of a paper to Journal of Human Evolution is that authors declare explicitly that that their work is original and has not been published previously. Reuse of any data should be appropriately cited. As such this article represents an abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process. Copyright © 2017 Elsevier Ltd. All rights reserved.

FinFET memory cell improvements for higher immunity against single event upsets

Science.gov (United States)

Sajit, Ahmed Sattar

The 21st century is witnessing a tremendous demand for transistors. Life amenities have incorporated the transistor in every aspect of daily life, ranging from toys to rocket science. Day by day, scaling down the transistor is becoming an imperious necessity. However, it is not a straightforward process; instead, it faces overwhelming challenges. Due to these scaling changes, new technologies, such as FinFETs for example, have emerged as alternatives to the conventional bulk-CMOS technology. FinFET has more control over the channel, therefore, leakage current is reduced. FinFET could bridge the gap between silicon devices and non-silicon devices. The semiconductor industry is now incorporating FinFETs in systems and subsystems. For example, Intel has been using them in their newest processors, delivering potential saving powers and increased speeds to memory circuits. Memory sub-systems are considered a vital component in the digital era. In memory, few rows are read or written at a time, while the most rows are static; hence, reducing leakage current increases the performance. However, as a transistor shrinks, it becomes more vulnerable to the effects from radioactive particle strikes. If a particle hits a node in a memory cell, the content might flip; consequently, leading to corrupting stored data. Critical fields, such as medical and aerospace, where there are no second chances and cannot even afford to operate at 99.99% accuracy, has induced me to find a rigid circuit in a radiated working environment. This research focuses on a wide spectrum of memories such as 6T SRAM, 8T SRAM, and DICE memory cells using FinFET technology and finding the best platform in terms of Read and Write delay, susceptibility level of SNM, RSNM, leakage current, energy consumption, and Single Event Upsets (SEUs). This research has shown that the SEU tolerance that 6T and 8T FinFET SRAMs provide may not be acceptable in medical and aerospace applications where there is a very high

DETERMINATION OF THE TEMPERATURE DISTRIBUTION THE PERFORATED FINS UNDER

Directory of Open Access Journals (Sweden)

Aziz7 M. Mhamuad

2015-02-01

Full Text Available This work treats the problem of heat transfer for perforated fins under natural convection. The temperature distribution is examined for an array of rectangular fins (15 fins with uniform cross-sectional area (100x270 mm embedded with various vertical body perforations that extend through the fin thickness. The patterns of perforations include 18 circular perforations (holes. Experiments were carried out in an experimental facility that was specifically design and constructed for this purpose. The heat transfer rate and the coefficient of heat transfer increases with perforation diameter increased. 

TCDQ-TCT retraction and losses during asynchronous beam dump

CERN Document Server

Bracco, Chiara; Quaranta, Elena; CERN. Geneva. ATS Department

2016-01-01

The protection provided by the TCDQs in case of asynchronous beam dump depends strongly on their correct setup. They have to respect the strict hierarchy of the full collimation system and shield the tertiary collimators in the experimental regions. This MD aimed at performing asynchronous beam dump tests with different configurations, in order to assess the minimum allowed retraction between TCTs and TCDQs and, as a consequence, on the The protection provided by the TCDQs in case of asynchronous beam dump depends strongly on their correct setup. They have to respect the strict hierarchy of the full collimation system and shield the tertiary collimators in the experimental regions. This MD aimed at performing asynchronous beam dump tests with different configurations, in order to assess the minimum allowed retraction between TCTs and TCDQs and, as a consequence, on the β* reach.

RETRACTED: Granular and intergranular conduction in La1.32Sr1.68Mn2O7 layered manganite system

International Nuclear Information System (INIS)

Narjis, A.; El kaaouachi, A.; Dlimi, S.; Biskupski, G.; Daoudi, E.; Errai, M.; Sybous, A.; Limouny, L.

2013-01-01

This article has been retracted: please see Elsevier Policy on Article Withdrawal ( (http://www.elsevier.com/locate/withdrawalpolicy)). This article has been retracted at the request of the Editors. The authors have plagiarized part of a paper that had already appeared in J. Appl. Phys. 106, 093709 (2009); (10.1063/1.3256182) (6 pages): Title: Effects of pressure on charge transport and magnetic properties of La1.32Sr1.68Mn2O7 layered manganite by M. Kumaresavanji, M. S. Reis, Y. T. Xing, and M. B. Fontes. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process

Backset and cervical retraction capacity among occupants in a modern car.

Science.gov (United States)

Jonsson, Bertil; Stenlund, Hans; Svensson, Mats Y; Björnstig, Ulf

2007-03-01

The horizontal distance between the back of the head and the frontal of the head restraint (backset) and rearward head movement relative to the torso (cervical retraction) were studied in different occupant postures and positions in a modern car. A stratified randomized population of 154 test subjects was studied in a Volvo V70 year model 2003 car, in driver, front passenger, and rear passenger position. In each position, the subjects adopted (i) a self-selected posture, (ii) a sagging posture, and (iii) an erect posture. Cervical retraction, backset, and vertical distance from the top of the head restraint to the occipital protuberance in the back of the head of the test subject were measured. These data were analyzed using repeated measures ANOVA and linear regression analysis with a significance level set to p self-selected posture, the average backset was 61 mm for drivers, 29 mm for front passengers, and 103 mm for rear passengers (p self-selected driving position. Backset was larger and cervical retraction capacity lower in the sagging posture than in the self-selected posture for occupants in all three occupant positions. Rear passengers had the largest backset values. Backset values decreased with increased age. The average cervical retraction capacity in self-selected posture was 35 mm for drivers, 30 mm for front passengers, and 33 mm for rear passengers (p < 0.001). Future design of rear-end impact protection may take these study results into account when trying to reduce backset before impact. Our results might be used for future development and use of BioRID manikins and rear-end tests in consumer rating test programs such as Euro-NCAP.

Survey of Regulations Applicable to the Finned Containment in Korean Nuclear Power Plant for Light Water Reactor

International Nuclear Information System (INIS)

Noh, Hyung Gyun; Kang, Hie Chan

2016-01-01

In severe accident, the molten corium would discharge into the reactor cavity and interact with water and concrete of cavity. Molten corium includes non-oxidation metals such as Zr, Fe and Cr. These metal species reacted with water emit hydrogen gas. In addition to this, a mount of steam can be emitted to the containment such as steam line break accident. As a result, steam and hydrogen gas can pressurize containment over the design pressure and threaten its integrity. For this reasons, a concept equipped with finned on the containment building was proposed for coping with prolonged accident. Finned containment can enhance heat transfer to the ambient, and the building itself is working as a heat sink. Multiple metal fins and metal rod are penetrated into containment wall, and the rods are working as an additional path of heat removal. To be accepted in the nuclear power plants, this configuration should satisfy the requirement of heat removal and follow all regulations related with containment also. For applying to Korean nuclear power plants, the finned containment should follow all regulations specialized in Korea such as Nuclear regulatory criteria for light water reactor and Guidelines of nuclear safety examination for light water reactor. A concept of containment as a passive cooling system has been proposed. Furthermore, the new containment concept can be applied on the real containment which satisfies the various regulations. Finned containment would be expected positive effects on heat removal from the containment. If the fins are properly welded to the liner, finned containment could satisfy the leak tightness and prevention of external influences. Finned containment could be favorable to protect external impact like aircraft crash because of the additional structural integrity by the fins

Survey of Regulations Applicable to the Finned Containment in Korean Nuclear Power Plant for Light Water Reactor

Energy Technology Data Exchange (ETDEWEB)

Noh, Hyung Gyun [Pohang University, Pohang (Korea, Republic of); Kang, Hie Chan [Kunsan University, Gunsan (Korea, Republic of)

2016-05-15

In severe accident, the molten corium would discharge into the reactor cavity and interact with water and concrete of cavity. Molten corium includes non-oxidation metals such as Zr, Fe and Cr. These metal species reacted with water emit hydrogen gas. In addition to this, a mount of steam can be emitted to the containment such as steam line break accident. As a result, steam and hydrogen gas can pressurize containment over the design pressure and threaten its integrity. For this reasons, a concept equipped with finned on the containment building was proposed for coping with prolonged accident. Finned containment can enhance heat transfer to the ambient, and the building itself is working as a heat sink. Multiple metal fins and metal rod are penetrated into containment wall, and the rods are working as an additional path of heat removal. To be accepted in the nuclear power plants, this configuration should satisfy the requirement of heat removal and follow all regulations related with containment also. For applying to Korean nuclear power plants, the finned containment should follow all regulations specialized in Korea such as Nuclear regulatory criteria for light water reactor and Guidelines of nuclear safety examination for light water reactor. A concept of containment as a passive cooling system has been proposed. Furthermore, the new containment concept can be applied on the real containment which satisfies the various regulations. Finned containment would be expected positive effects on heat removal from the containment. If the fins are properly welded to the liner, finned containment could satisfy the leak tightness and prevention of external influences. Finned containment could be favorable to protect external impact like aircraft crash because of the additional structural integrity by the fins.

Chromium Is Elevated in Fin Whale (Balaenoptera physalus) Skin Tissue and Is Genotoxic to Fin Whale Skin Cells

Science.gov (United States)

Wise, Catherine F.; Wise, Sandra S.; Thompson, W. Douglas; Perkins, Christopher; Wise, John Pierce

2015-01-01

Hexavalent chromium (Cr(VI)) is present in the marine environment and is a known carcinogen and reproductive toxicant. Cr(VI) is the form of chromium that is well absorbed through the cell membrane. It is also the most prevalent form in seawater. We measured the total Cr levels in skin biopsies obtained from healthy free-ranging fin whales from the Gulf of Maine and found elevated levels relative to marine mammals in other parts of the world. The levels in fin whale biopsies ranged from 1.71 ug/g to 19.6 ug/g with an average level of 10.07 ug/g. We also measured the cytotoxicity and genotoxicity of Cr(VI) in fin whale skin cells. We found that particulate and soluble Cr(VI) are both cytotoxic and genotoxic to fin whale skin cells in a concentration-dependent manner. The concentration range used in our cell culture studies used environmentally relevant concentrations based on the biopsy measurements. These data suggest that Cr(VI) may be a concern for whales in the Gulf of Maine. PMID:25805270

Study of Swept Angle Effects on Grid Fins Aerodynamics Performance

Science.gov (United States)

Faza, G. A.; Fadillah, H.; Silitonga, F. Y.; Agoes Moelyadi, Mochamad

2018-04-01

Grid fin is an aerodynamic control surface that usually used on missiles and rockets. In the recent several years many researches have conducted to develop a more efficient grid fins. There are many possibilities of geometric combination could be done to improve aerodynamics characteristic of a grid fin. This paper will only discuss about the aerodynamics characteristics of grid fins compared by another grid fins with different swept angle. The methodology that used to compare the aerodynamics is Computational Fluid Dynamics (CFD). The result of this paper might be used for future studies to answer our former question or as a reference for related studies.

Optimization of Peripheral Finned-Tube Evaporators Using Entropy Generation Minimization

OpenAIRE

Pussoli, Bruno; Barbosa Jr., Jader; da Silva, Luciana; Kaviany, Massoud

2012-01-01

The peripheral finned-tube (PFT) is a new geometry for enhanced air-side heat transfer under moisture condensate blockage (evaporators). It consists of individual hexagonal (peripheral) fin arrangements with radial fins whose bases are attached to the tubes and tips are interconnected with the peripheral fins. In this paper, experimentally validated semi-empirical models for the air-side heat transfer and pressure drop are combined with the entropy generation minimization theory to determine ...

Correlated evolution of body and fin morphology in the cichlid fishes.

Science.gov (United States)

Feilich, Kara L

2016-10-01

Body and fin shapes are chief determinants of swimming performance in fishes. Different configurations of body and fin shapes can suit different locomotor specializations. The success of any configuration is dependent upon the hydrodynamic interactions between body and fins. Despite the importance of body-fin interactions for swimming, there are few data indicating whether body and fin configurations evolve in concert, or whether these structures vary independently. The cichlid fishes are a diverse family whose well-studied phylogenetic relationships make them ideal for the study of macroevolution of ecomorphology. This study measured body, and caudal and median fin morphology from radiographs of 131 cichlid genera, using morphometrics and phylogenetic comparative methods to determine whether these traits exhibit correlated evolution. Partial least squares canonical analysis revealed that body, caudal fin, dorsal fin, and anal fin shapes all exhibited strong correlated evolution consistent with locomotor ecomorphology. Major patterns included the evolution of deep body profiles with long fins, suggestive of maneuvering specialization; and the evolution of narrow, elongate caudal peduncles with concave tails, a combination that characterizes economical cruisers. These results demonstrate that body shape evolution does not occur independently of other traits, but among a suite of other morphological changes that augment locomotor specialization. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Why does Retraction Watch continue to offer support to Jeffrey Beall, and legitimize his post-mortem “predatory” lists?

Directory of Open Access Journals (Sweden)

Jaime A. Teixeira da Silva

2017-07-01

Full Text Available Retraction Watch is a science watchdog that may give the impression of being both an anti-bad science and an anti-science blog. This blog has tried to legitimize its ethical stance by naming its parent organization The Center for Science Integrity Inc. (CSI, and by appointing a former Chair of the Committee on Publication Ethics (COPE, Elizabeth Wager, to the CSI board of directors. Jeffrey Beall, another science watchdog, often appears in public alongside Adam Marcus and Ivan Oransky, the CSI secretary and president, respectively, and participates in events with Wager. Beall became academically redundant on January 15, 2017. This is because his blog, which hosted a faulty, controversial and misleading list (and thus potentially libelous of “predatory” open access journals and publishers, suddenly went blank. Beall offered no apology or explanation to the public, but was offered intellectual asylum and protection by the University of Colorado, Denver, where he works as a librarian. After a grace period of almost two months, members of the global academic community have now largely lost respect for Beall because of his silence, which may be equated with irresponsibility and/or cowardice. Despite this near extinct academic status, Retraction Watch continues to laud Beall, refer to his now-defunct site and lists as valid, as many as 25 times, and even rely on the Beall blog and lists to support several of their journalistic claims. In the world of science publishing, the legitimization of a “fact” using a defunct or false (i.e., non-factual source, is equivalent to publishing misconduct, and feeds into the “false facts” and “alternative truths” epidemic in journalism that Retraction Watch is now impregnating into science publishing. Why then is Retraction Watch allowed to operate under an ethically superior platform, while expecting scientists and academics to respect basic rules of citing valid references, but while practicing

Fin de Copenhague

DEFF Research Database (Denmark)

Baumeister, Ruth

2016-01-01

FIN DE COPENHAGUE this book by the Danish Cobra artist Asger Jorn and the French philosopher Guy Debord, is the first in a series of two and was published in 1957, shortly before the authors founded the Situationist International. According to Jorn, upon arrival to Copenhagen, they stole some...

The optimization of longitudinal convective fins with internal heat generation

International Nuclear Information System (INIS)

Razelos, P.

1979-01-01

The solution of the optimization problem for longitudinal convective fins of constant thickness, triangular or parabolic profile, and uniform internal heat generation, is presented. The cases considered are those of a given heat generation density, total heat generation and heat generation per unit width of the fin, when either the heat dissipation or the width of the fin is prescribed. The results are set forth in a nondimensional form, which are presented graphically. The effect of the fin's thermal conductivity upon the optimum dimensions is discussed, and limiting values for the heat generation and the heat dissipation, which may be imposed on the fin for a feasible optimization, are also obtained. (Auth.)

[Simultaneous intrusion and retraction of the anterior teeth using a three-piece base arch].

Science.gov (United States)

Liu, D; Bai, D; Wang, C; Sun, W; Guo, J; Xi, R

2000-06-01

To evaluate the effects of the three-piece base arch on overbite correction of Class II malocclusion. 20 patients with high angle, flared incisors were treated using a three-piece base arch appliance. The intrusion force of four upper incisors was adjusted to approximately 50 g. The line of force action was 2 mm distally to the resistant center(RC) and the retraction force was 20 g, the right and left posterior segments were joined by a palatal bar. Cephalograms were taken before treatment (T1) and six months after treatment (T2). The upper molars moved mesially 0.60 +/- 0.35 mm and the distance of the vertical extrusion was 0.80 +/- 0.52 mm. The distances of the upper central incisor retraction and intrusion were -4.20 +/- 2.12 mm and 3.10 +/- 0.54 mm respectively. The RC of the central incisor retracted -4.12 +/- 1.96 mm and intruded 3.20 +/- 0.66 mm. The axial inclination of the upper incisor-palatal plane changed from 123.21 degrees +/- 4.26 degrees to 116.00 degrees +/- 3.96 degrees. The three-piece segmented approach can effectively intrude and retract the upper anterior teeth for flared incisors and deep overbite.

Research on dynamic characteristics of new chaotic-advection fins

International Nuclear Information System (INIS)

Kong Songtao; Dong Qiwu; Liu Minshan; Zhu Qing

2007-01-01

Analysis and the numerical simulation has confirmed that the flow is of the chaotic advection in the flow channel of the new fin. The chaotic advection results in stronger mixing under low Re, and thus enhances the heat transfer and anti-scaling ability. The new fin provides the beneficial exploration to the concept of chaotic advection which applies to the plate-fin heat exchanger. (authors)

Strain characterization of FinFETs using Raman spectroscopy

International Nuclear Information System (INIS)

Kaleli, B.; Hemert, T. van; Hueting, R.J.E.; Wolters, R.A.M.

2013-01-01

Metal induced strain in the channel region of silicon (Si) fin-field effect transistor (FinFET) devices has been characterized using Raman spectroscopy. The strain originates from the difference in thermal expansion coefficient of Si and titanium-nitride. The Raman map of the device region is used to determine strain in the channel after preparing the device with the focused ion beam milling. Using the Raman peak shift relative to that of relaxed Si, compressive strain values up to – 0.88% have been obtained for a 5 nm wide silicon fin. The strain is found to increase with reducing fin width though it scales less than previously reported results from holographic interferometry. In addition, finite-element method (FEM) simulations have been utilized to analyze the amount of strain generated after thermal processing. It is shown that obtained FEM simulated strain values are in good agreement with the calculated strain values obtained from Raman spectroscopy. - Highlights: ► Strain is characterized in nanoscale devices with Raman spectroscopy. ► There is a fin width dependence of the originated strain. ► Strain levels obtained from this technique is in correlation with device simulations

RETRACTED: A new perspective on structural, materials, and simulation of flow and cavitation around the propeller with energy saving system

Science.gov (United States)

Fathololumi, S.; Hassanabad, M. Ghodsi

2016-12-01

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Principal Editor. After a thorough investigation, the Editor has concluded that the review process for this article was compromised. The acceptance was based on information from two reviewer reports that were submitted from email accounts provided to the journal as suggested reviewers during the submission of the article. Although purportedly real reviewer accounts, the Editor has concluded that these were not of appropriate, independent reviewers. This manipulation of the peer-review process represents a clear violation of the fundamentals of peer review, our publishing policies, and publishing ethics standards. Apologies are offered to the reviewers whose identities were assumed and to the readers of the journal that this deception was not detected during the submission process. Further, no reason has been provided for the removal of three authors and addition of the authors S. Fathololumi and M. Ghodsi Hassanabad upon revision of the article.

The Influence of Culture on the International Management of Shark Finning

Science.gov (United States)

Dell'Apa, Andrea; Chad Smith, M.; Kaneshiro-Pineiro, Mahealani Y.

2014-08-01

Shark finning is prohibited in many countries, but high prices for fins from the Asian market help maintain the international black-market and poaching. Traditional shark fin bans fail to recognize that the main driver of fin exploitation is linked to cultural beliefs about sharks in traditional Chinese culture. Therefore, shark finning should be addressed considering the social science approach as part of the fishery management scheme. This paper investigates the cultural significance of sharks in traditional Chinese and Hawaiian cultures, as valuable examples of how specific differences in cultural beliefs can drive individuals' attitudes toward the property of shark finning. We suggest the use of a social science approach that can be useful in the design of successful education campaigns to help change individuals' attitudes toward shark fin consumption. Finally, alternative management strategies for commercial fishers are provided to maintain self-sustainability of local coastal communities.

Notice of retraction: Role of Cerebrospinal Fluid in Spaceflight-induced Ocular Changes and Visual Impairment in Astronauts.

Science.gov (United States)

Alperin, Noam; Bagci, Ahmet M; Oliu, Carlos J; Lee, Sang H; Lam, Byron L

2017-10-16

Notice of retraction: the article "Role of Cerebral Spinal Fluid in Space Flight Induced Ocular Changes and Visual Impairment in Astronauts" by Alperin et al This article has been retracted due to security concerns raised by NASA, the sponsoring agency. © RSNA, 2017.

Stress distribution and displacement of maxillary anterior teeth during en-masse intrusion and retraction: A FEM study

Directory of Open Access Journals (Sweden)

Parag Bohara

2017-01-01

Full Text Available Background: Space closure by en masse intrusion and retraction in orthodontics is of particular interest. Aim: The aim of this study was to evaluate the stress distribution and displacement of maxillary anterior teeth. Materials and Methods: Four different finite element models of maxillary arch were constructed to understand the nature of stresses and displacement patterns of anterior teeth during en masse intrusion and retraction on force application with different combinations of mini-implants and retraction hooks. Results: In this study, tensile stresses were seen in the cervical region and various movements of teeth such as lingual crown tipping, bodily movement, lingual root tipping, intrusion, and extrusion were observed. Conclusion: Nature of stresses changes from tensile to compressive from cervical area to apical area. Various tooth displacements suggest that different combinations of mini-implants and retraction hooks affect the direction of the tooth movement.

RETRACTED: An analytical approach to soliton of the saturable non-linear Schrödinger equation determination and consideration of stability of solitary solutions of cubic-quintic non-linear Schrödinger equation (CQNLSE)

Science.gov (United States)

Adib, Behrooz; Heidari, Alireza; Tayyari, Sayyed Faramarz

2009-05-01

This article has been retracted: please see Elsevier Policy on Article Withdrawal. This article has been retracted at the request of the Editor-in-Chief and Author. The authors have plagiarized part of a paper that had already appeared in Iran. J. Phys. Res., 2 (2000) 103-111 and Iran. J. Phys. Res., 4 (2003) 41-47. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

情报研究在FinTech实践中的应用展望%The Application Prospect of Information Science in FinTech Practice

Institute of Scientific and Technical Information of China (English)

徐扬; 刘姝雯; 腾菲; 罗晶

2017-01-01

[目的/意义]针对金融科技(FinTech)发展的特征、现状及问题,探究情报学知识和技术在FinTech实践中的应用和发展方向.[方法/过程]梳理Fintech概念在国内外的发展历程和现状,并从情报学视角,讨论FinTech在特征、应用、监管等方面的研究展望,提出相应的建议.[结果/结论]研究结果表明,情报学与FinTech相辅相成,共同发展.未来,可以进一步强化FinTech业务的信息化与数字化,加强情报分析、商务智能以及情报学视角的大数据分析,为FinTech的发展注入更多的活力.

Forced convection heat transfer correlation for finned plates in a duct

International Nuclear Information System (INIS)

Chae, Myeong-Seon; Moon, Je-Young; Chung, Bum-Jin

2014-01-01

Forced convection heat transfer experiments were conducted for plate-fin in a duct using various fin spacing, fin height, duct width, Reynolds number for Prandtl numbers 2,014. Based upon analogy concept, mass transfer rate were measured instead of heat transfer rates. The heat transfer rates were enhanced with the increase of fin height and decrease of fin spacing as they increase the heat transfer area. Meanwhile, heat transfer rates were impaired with the increase of the duct width as the bypass flows increased to tip clearance region. Forced convection heat transfer correlations were developed for laminar and turbulent flow conditions and for narrow and wide ducts. The work draws attention to the tip clearance on the heat transfer of the finned plate in a duct. (author)

Retractable Robotic Anchor for Hard Rock and Granular Soils, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — ProtoInnovations, LLC, is developing an innovative retractable robotic anchor that works in hard rock and granular soils permitting anchoring and subsequent...

Externally finned circular tube immerse in a phase-change material

International Nuclear Information System (INIS)

Alves, C.L.F.; Ismail, K.A.R.

1985-01-01

In an attempt to increase the heat transfer rate and reduce the convective currents during the freezing of phase change materials (PCM) in storage tanks, externally finned circular tubes are studied experimentally. The parameters analysed in this work include number of fins, fin length, initial degree of superheat and freezing time

Investigation of thermal effects on FinFETs in the quasi-ballistic regime

Science.gov (United States)

Yin, Longxiang; Shen, Lei; Di, Shaoyan; Du, Gang; Liu, Xiaoyan

2018-04-01

In this work, the thermal effects of FinFETs in the quasi-ballistic regime are investigated using the Monte Carlo method. Bulk Si nFinFETs with the same fin structure and two different gate lengths L g = 20 and 80 nm are investigated and compared to evaluate the thermal effects on the performance of FinFETs in the quasi-ballistic regime. The on current of the 20 nm FinFET with V gs = 0.7 V does not decrease with increasing lattice temperature (T L) at a high V ds. The electrostatic properties in the 20 nm FinFET are more affected by T L than those in the 80 nm FinFET. However, the electron transport in the 20 nm FinFET is less affected by T L than that in the 80 nm FinFET. The electrostatic properties being more sensitive and the electron transport being less sensitive to thermal effects in the quasi-ballistic regime than in the diffusive regime should be considered for effective device modeling and design.

Experimental and numerical analysis of the optimized finned-tube heat exchanger for OM314 diesel exhaust exergy recovery

International Nuclear Information System (INIS)

Hatami, M.; Ganji, D.D.; Gorji-Bandpy, M.

2015-01-01

Highlights: • An optimized finned-tube heat exchanger is modeled. • Artificial Neural Networks and Genetic Algorithm are applied. • Exergy recovery from exhaust of a diesel engine is studied. - Abstract: In this research, a multi objective optimization based on Artificial Neural Network (ANN) and Genetic Algorithm (GA) are applied on the obtained results from numerical outcomes for a finned-tube heat exchanger (HEX) in diesel exhaust heat recovery. Thirty heat exchangers with different fin length, thickness and fin numbers are modeled and those results in three engine loads are optimized with weight functions for pressure drop, recovered heat and HEX weight. Finally, two cases of HEXs (an optimized and a non-optimized) are produced experimentally and mounted on the exhaust of an OM314 diesel engine to compare their results in heat and exergy recovery. All experiments are done for five engine loads (0%, 20%, 40%, 60% and 80% of full load) and four water mass flow rates (50, 40, 30 and 20 g/s). Results show that maximum exergy recovers occurs in high engine loads and optimized HEX with 10 fins have averagely 8% second law efficiency in exergy recovery

Self-propelled heaving and pitching flexible fin in a quiescent flow

International Nuclear Information System (INIS)

Kim, Boyoung; Park, Sung Goon; Huang, Weixi; Sung, Hyung Jin

2016-01-01

Highlights: • A self-propelled flexible fin with heaving and pitching motions in a quiescent flow has been simulated by using the penalty immersed boundary method. • The cruising speed and the swimming efficiency of the self-propelled fin were determined as functions of the bending coefficient (γ), the heaving amplitude (A_h). • We optimized the cruising speed and the swimming efficiency with respect to γ, f, A_h, A_p, and Δϕ. - Abstract: A self-propelled flexible fin with heaving and pitching motions in a quiescent flow has been simulated by using the penalty immersed boundary method. The flexible fin can move freely in the horizontal direction and the body of the flexible fin moves passively along with the active head motion. The position of the head of the fin was described as a harmonic heaving oscillation in the vertical direction, while the inclination angle of the head was prescribed as a harmonic oscillation with a moving clamped condition for the heaving and pitching fin. The cruising speed and the swimming efficiency of the self-propelled fin were determined as functions of the bending stiffness (γ), the heaving amplitude (A_h), the pitching amplitude (A_p), the flapping frequency (f) and the phase difference (Δϕ) between A_h and A_p. We optimized the cruising speed and the swimming efficiency with respect to γ, f, A_h, A_p and Δϕ. For a certain range of A_p, the swimming efficiency of the heaving and pitching fin is larger than that of a heaving-only fin.

Vortex Shedding from Finned Circular Cylinders

Science.gov (United States)

1980-11-01

FINNED CIRCULAR CYLINDERSo ,rm"" 1..UTNOI .)R*., r. *.040, 111SPOR- / T NuMBII f.John G. elute asOHans J.’/, ugt -. . . , ,<-. -. ,:. =., .. Siil P3RPIO...fins and other sharp protuberances. These purely two-dimensional flows then may be used in a strip theory to include at least some aspects of three...boundary- layer theory . Such a prediction method, together with a technique to provide for a vortex sheet at the separation point, will be included in

Retractable Robotic Anchor for Hard Rock and Granular Soils, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — ProtoInnovations proposes to research, develop, and validate an innovative retractable robotic anchoring mechanism that works both in hard rock and granular soils...

Assessment of Eustachian tube function in patients with tympanic membrane retraction and in normal subjects.

Science.gov (United States)

Canali, Inesângela; Petersen Schmidt Rosito, Letícia; Siliprandi, Bruno; Giugno, Cláudia; Selaimen da Costa, Sady

The diagnosis of Eustachian tube dysfunctions is essential for better understanding of the pathogenesis of chronic otitis media. A series of tests to assess tube function are described in the literature; however, they are methodologically heterogeneous, with differences ranging from application protocols to standardization of tests and their results. To evaluate the variation in middle ear pressure in patients with tympanic membrane retraction and in normal patients during tube function tests, as well as to evaluate intra-individual variation between these tests. An observational, contemporary, cross-sectional study was conducted, in which the factor under study was the variation in middle ear pressure during tube function tests (Valsalva maneuver, sniff test, Toynbee maneuver) in healthy patients and in patients with mild and moderate/severe tympanic retraction. A total of 38 patients (76 ears) were included in the study. Patients underwent tube function tests at two different time points to determine pressure measurements after each maneuver. Statistical analysis was performed using SPSS software, version 18.0, considering p-values <0.05 as statistically significant. Mean (standard deviation) age was 11 (2.72) years; 55.3% of patients were male and 44.7% female. The prevalence of type A tympanogram was higher among participants with healthy ears and those with mild retraction, whereas type C tympanograms were more frequent in the moderate/severe retraction group. An increase in middle ear pressure was observed during the Valsalva maneuver at the first time point evaluated in all three groups of ears (p=0.012). The variation in pressure was not significant either for the sniff test or for the Toynbee maneuver at the two time points evaluated (p≥0.05). Agreement between measurements obtained at the two different time points was weak to moderate for all tests in all three groups of ears, and the variations in discrepancy between measurements were higher in ears

Highly flexible SRAM cells based on novel tri-independent-gate FinFET

Science.gov (United States)

Liu, Chengsheng; Zheng, Fanglin; Sun, Yabin; Li, Xiaojin; Shi, Yanling

2017-10-01

In this paper, a novel tri-independent-gate (TIG) FinFET is proposed for highly flexible SRAM cells design. To mitigate the read-write conflict, two kinds of SRAM cells based on TIG FinFETs are designed, and high tradeoff are obtained between read stability and speed. Both cells can offer multi read operations for frequency requirement with single voltage supply. In the first TIG FinFET SRAM cell, the strength of single-fin access transistor (TIG FinFET) can be flexibly adjusted by selecting five different modes to meet the needs of dynamic frequency design. Compared to the previous double-independent-gate (DIG) FinFET SRAM cell, 12.16% shorter read delay can be achieved with only 1.62% read stability decrement. As for the second TIG FinFET SRAM cell, pass-gate feedback technology is applied and double-fin TIG FinFETs are used as access transistors to solve the severe write-ability degradation. Three modes exist to flexibly adjust read speed and stability, and 68.2% larger write margin and 51.7% shorter write delay are achieved at only the expense of 26.2% increase in leakage power, with the same layout area as conventional FinFET SRAM cell.

On retracting properties and covering homotopy theorem for S-maps into Sχ-cofibrations and Sχ-fibrations

Directory of Open Access Journals (Sweden)

Amin Saif

2016-10-01

Full Text Available In this paper we generalize the retracting property in homotopy theory for topological semigroups by introducing the notions of deformation S-retraction with its weaker forms and ES-homotopy extension property. Furthermore, the covering homotopy theorems for S-maps into Sχ-fibrations and Sχ-cofibrations are introduced and pullbacks for Sχ-fibrations behave properly.

Efficiency of piezosurgery technique in miniscrew supported en-masse retraction: a single-centre, randomized controlled trial.

Science.gov (United States)

Tunçer, Nilüfer Irem; Arman-Özçirpici, Ayça; Oduncuoglu, Bahar Füsun; Göçmen, Jülide Sedef; Kantarci, Alpdogan

2017-11-30

Piezoelectric surgery is a newly introduced technique for rapid tooth movement. However, the efficiency of this technique has not been investigated on en-masse retraction cases yet. To investigate the efficiency of piezosurgery technique in accelerating miniscrew supported en-masse retraction and study the biological tissue response. In addition, to show if this technique induces a difference in dental, skeletal and soft tissue changes on lateral cephalograms, and in canine and molar rotations, besides intercanine and intermolar widths on dental casts. We conducted a randomized, single-centred, parallel-group, controlled trial, requiring upper right and left first premolar extractions on 30 patients above the minimum age of 14 years at the beginning of retraction. Piezosurgery-assisted versus conventional en-masse retraction anchored from miniscrews placed between second premolars and first molars, bilaterally. The main outcome was the en-masse retraction rate. Secondary outcomes were gingival crevicular fluid (GCF) volume and GCF content of receptor activator of nuclear factor κβ ligand (RANKL), changes regarding cephalometric and dental cast variables, and miniscrew success rates. Accomplished with opaque, sealed envelopes. Applicable for data assessment only. Commenced in February 2013 and ended in October 2014. Thirty-one patients were included in the study and divided into 2 groups of piezosurgery (n = 16) and control (n = 15). After 9.3 months of follow-up, no statistically significant difference was observed between groups for neither retraction rates (P = 0.958) nor GCF parameters (P > 0.05). Changes in lateral cephalometric and dental cast variables, and miniscrew success rates did not show significant differences either. Based on the results of this study, piezosurgery technique was found to be ineffective in accelerating en-masse retraction, and promoting a difference in the studied GCF parameters, skeletal and dental variables. The trial was not

Ecomorphological inferences in early vertebrates: reconstructing Dunkleosteus terrelli (Arthrodira, Placodermi) caudal fin from palaeoecological data.

Science.gov (United States)

Ferrón, Humberto G; Martínez-Pérez, Carlos; Botella, Héctor

2017-01-01

Our knowledge about the body morphology of many extinct early vertebrates is very limited, especially in regard to their post-thoracic region. The prompt disarticulation of the dermo-skeletal elements due to taphonomic processes and the lack of a well-ossified endoskeleton in a large number of groups hinder the preservation of complete specimens. Previous reconstructions of most early vertebrates known from partial remains have been wholly based on phylogenetically closely related taxa. However, body design of fishes is determined, to a large extent, by their swimming mode and feeding niche, making it possible to recognise different morphological traits that have evolved several times in non-closely related groups with similar lifestyles. Based on this well-known ecomorphological correlation, here we propose a useful comparative framework established on extant taxa for predicting some anatomical aspects in extinct aquatic vertebrates from palaeoecological data and vice versa. For this, we have assessed the relationship between the locomotory patterns and the morphological variability of the caudal region in extant sharks by means of geometric morphometrics and allometric regression analysis. Multivariate analyses reveal a strong morphological convergence in non-closely related shark species that share similar modes of life, enabling the characterization of the caudal fin morphology of different ecological subgroups. In addition, interspecific positive allometry, affecting mainly the caudal fin span, has been detected. This phenomenon seems to be stronger in sharks with more pelagic habits, supporting its role as a compensation mechanism for the loss of hydrodynamic lift associated with the increase in body size, as previously suggested for many other living and extinct aquatic vertebrates. The quantification of shape change per unit size in each ecological subgroup has allowed us to establish a basis for inferring not only qualitative aspects of the caudal fin

Ecomorphological inferences in early vertebrates: reconstructing Dunkleosteus terrelli (Arthrodira, Placodermi caudal fin from palaeoecological data

Directory of Open Access Journals (Sweden)

Humberto G. Ferrón

2017-12-01

Full Text Available Our knowledge about the body morphology of many extinct early vertebrates is very limited, especially in regard to their post-thoracic region. The prompt disarticulation of the dermo-skeletal elements due to taphonomic processes and the lack of a well-ossified endoskeleton in a large number of groups hinder the preservation of complete specimens. Previous reconstructions of most early vertebrates known from partial remains have been wholly based on phylogenetically closely related taxa. However, body design of fishes is determined, to a large extent, by their swimming mode and feeding niche, making it possible to recognise different morphological traits that have evolved several times in non-closely related groups with similar lifestyles. Based on this well-known ecomorphological correlation, here we propose a useful comparative framework established on extant taxa for predicting some anatomical aspects in extinct aquatic vertebrates from palaeoecological data and vice versa. For this, we have assessed the relationship between the locomotory patterns and the morphological variability of the caudal region in extant sharks by means of geometric morphometrics and allometric regression analysis. Multivariate analyses reveal a strong morphological convergence in non-closely related shark species that share similar modes of life, enabling the characterization of the caudal fin morphology of different ecological subgroups. In addition, interspecific positive allometry, affecting mainly the caudal fin span, has been detected. This phenomenon seems to be stronger in sharks with more pelagic habits, supporting its role as a compensation mechanism for the loss of hydrodynamic lift associated with the increase in body size, as previously suggested for many other living and extinct aquatic vertebrates. The quantification of shape change per unit size in each ecological subgroup has allowed us to establish a basis for inferring not only qualitative aspects of

Review of various liver retraction techniques in single incision laparoscopic surgery for the exposure of hiatus.

Science.gov (United States)

Palanivelu, Praveenraj; Patil, Kedar Pratap; Parthasarathi, Ramakrishnan; Viswambharan, Jaiganesh K; Senthilnathan, Palanisami; Palanivelu, Chinnusamy

2015-01-01

The main aspect of concern for upper GI procedures has been the retraction of the liver especially large left lobes as commonly encountered in Bariatric surgery. Not doing so would compromise the view of the hiatus, hence theoretically reducing the quality of the surgery and increasing the possibility of complications. The aim of this study was to review the various liver retraction techniques in single incision surgery being done at our institute and analyze them. A retrospective study of the various techniques and a subsequent analysis was made based on advantages and disadvantages of each method. Objectively a quantitative measure of hiatal exposure was done using a scoring system based on the grade of exposure after reviewing the surgical videos. From January 2011 to January 2013 total 104 patients underwent single incision surgery with the various liver retraction techniques with following grades of exposure -liver suspension tube technique with naso gastric tubing (2.11) and with corrugated drain (2.09) needlescopic method (1.2), Umbilical tape sling (1.95), crural stitch method (2.5). Needeloscopic method has the best grade of exposure and is the easiest to start with. The average time to create the liver retraction was 2.8 to 8.6 min.There was no procedure related morbidity or mortality. The mentioned liver retraction techniques are cost effective and easy to learn. We recommend using these techniques to have a good exposure of hiatus, without compromising the safety of surgery in single incision surgery.

The Cx43-like connexin protein Cx40.8 is differentially localized during fin ontogeny and fin regeneration.

Directory of Open Access Journals (Sweden)

Sarah V Gerhart

Full Text Available Connexins (Cx are the subunits of gap junctions, membraneous protein channels that permit the exchange of small molecules between adjacent cells. Cx43 is required for cell proliferation in the zebrafish caudal fin. Previously, we found that a Cx43-like connexin, cx40.8, is co-expressed with cx43 in the population of proliferating cells during fin regeneration. Here we demonstrate that Cx40.8 exhibits novel differential subcellular localization in vivo, depending on the growth status of the fin. During fin ontogeny, Cx40.8 is found at the plasma membrane, but Cx40.8 is retained in the Golgi apparatus during regeneration. We next identified a 30 amino acid domain of Cx40.8 responsible for its dynamic localization. One possible explanation for the differential localization is that Cx40.8 contributes to the regulation of Cx43 in vivo, perhaps modifying channel activity during ontogenetic growth. However, we find that the voltage-gating properties of Cx40.8 are similar to Cx43. Together our findings reveal that Cx40.8 exhibits differential subcellular localization in vivo, dependent on a discrete domain in its carboxy terminus. We suggest that the dynamic localization of Cx40.8 differentially influences Cx43-dependent cell proliferation during ontogeny and regeneration.

Hydrodynamical analysis of the effect of fish fins morphology

Science.gov (United States)

Azwadi Che Sidik, Nor; Yen, Tey Wah

2013-12-01

The previous works on the biomechanics of fishes focuses on the locomotion effect of the fish bodies. However, there is quite a insufficiency in unveiling the respective function of fins when the fishes pose statics and exposed to fluid flow. Accordingly, this paper's focus is to investigate the hydrodynamic effect of the fins configuration to the fluid flow of shark-shaped-inspired structure. The drag and lift coefficient is computed for different cases of fish fins addition and configuration. The k-epsilon turbulence model is deployed using finite volume method with the aid of commercial software ANSYS CFX. The finding will demystify some of the functions of the fish's fins in term of their contribution to the hydrodynamic flow around the fishes.

On the Hydrodynamics of Anomalocaris Tail Fins.

Science.gov (United States)

Sheppard, K A; Rival, D E; Caron, J-B

2018-04-25

Anomalocaris canadensis, a soft-bodied stem-group arthropod from the Burgess Shale, is considered the largest predator of the Cambrian period. Thanks to a series of lateral flexible lobes along its dorso-ventrally compressed body, it is generally regarded as an efficient swimmer, well-adapted to its predatory lifestyle. Previous theoretical hydrodynamic simulations have suggested a possible optimum in swimming performance when the lateral lobes performed as a single undulatory lateral fin, comparable to the pectoral fins in skates and rays. However, the role of the unusual fan-like tail of Anomalocaris has not been previously explored. Swimming efficiency and maneuverability deduced from direct hydrodynamic analysis are here studied in a towing tank facility using a three-vane physical model designed as an abstraction of the tail fin. Through direct force measurements, it was found that the model exhibited a region of steady-state lift and drag enhancement at angles of attack greater than 25° when compared to a triangular-shaped reference model. This would suggest that the resultant normal force on the tail fin of Anomalocaris made it well-suited for turning maneuvers, giving it the ability to turn quickly and through small radii of curvature. These results are consistent with an active predatory lifestyle, although detailed kinematic studies integrating the full organism, including the lateral lobes, would be required to test the effect of the tail fin on overall swimming performance. This study also highlights a possible example of evolutionary convergence between the tails of Anomalocaris and birds, which, in both cases, are well-adapted to efficient turning maneuvers.

Performance and optimum design of convective-radiative rectangular fin with convective base heating, wall conduction resistance, and contact resistance between the wall and the fin base

International Nuclear Information System (INIS)

Aziz, Abdul; Beers-Green, Arlen B.

2009-01-01

This paper investigates the performance and optimum design of a longitudinal rectangular fin attached to a convectively heated wall of finite thickness. The exposed surfaces of the fin lose heat to the environmental sink by simultaneous convection and radiation. The tip of the fin is assumed to lose heat by convection and radiation to the same sink. The analysis and optimization of the fin is conducted numerically using the symbolic algebra package Maple. The temperature distribution, the heat transfer rates, and the fin efficiency data is presented illustrating how the thermal performance of the fin is affected by the convection-conduction number, the radiation-conduction number, the base convection Biot number, the convection and radiation Biot numbers at the tip, and the dimensionless sink temperature. Charts are presented showing the relationship between the optimum convection-conduction number and the optimum radiation-conduction number for different values of the base convection Biot number and dimensionless sink temperature and fixed values of the convection and radiation Biot numbers at the tip. Unlike the few other papers which have applied the Adomian's decomposition and the differential quadrature element method to this problem but give illustrative results for specific fin geometry and thermal variables, the present graphical data are generally applicable and can be used by fin designers without delving into the mathematical details of the computational techniques.

A numerical method for PCM-based pin fin heat sinks optimization

International Nuclear Information System (INIS)

Pakrouh, R.; Hosseini, M.J.; Ranjbar, A.A.; Bahrampoury, R.

2015-01-01

Highlights: • Optimization of PCM-based heat sink by using the Taguchi method. • Derivation of optimal PCM percentage to reach the maximum critical time. • Optimization is performed for four different critical temperatures. • Effective design factors are fins’ height and fins’ number. • The optimum configuration depends on geometric properties and the critical temperature. - Abstract: This paper presents a numerical investigation on geometric optimization of PCM-based pin fin heat sinks. Paraffin RT44HC is used as PCM while the fins and heat sink base is made of aluminum. The fins act as thermal conductivity enhancers (TCEs). The main goal of the study is to obtain the configurations that maximize the heat sink operational time. An approach witch couples Taguchi method with numerical simulations is utilized for this purpose. Number of fins, fins height, fins thickness and the base thickness are parameters which are studied for optimization. In this study natural convection and PCM volume variation during melting process are considered in the simulations. Optimization is performed for different critical temperatures of 50 °C, 60 °C, 70 °C and 80 °C. Results show that a complex relation exists between PCM and TCE volume percentages. The optimal case strongly depends on the fins’ number, fins’ height and thickness and also the critical temperature. The optimum PCM percentages are found to be 60.61% (corresponds to 100 pin fin heat sink with 4 mm thick fins) for critical temperature of 50 °C and 82.65% (corresponds to 100 pin fin heat sink with 2 mm thick fins) for other critical temperatures

Design, Implementation and Control of a Fish Robot with Undulating Fins

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Mohsen Siahmansouri

2011-11-01

Full Text Available Biomimetic robots can potentially perform better than conventional robots in underwater vehicle designing. This paper describes the design of the propulsion system and depth control of a robotic fish. In this study, inspired by knife fish, we have designed and implemented an undulating fin to produce propulsive force. This undulating fin is a segmental anal fin that produces sinusoidal wave to propel the robot. The relationship between the individual fin segment and phase angles with the overall fin trajectory has also been discussed. This propulsive force can be adjusted and directed for fish robot manoeuvre by a mechanical system with two servomotors. These servomotors regulate the direction and depth of swimming. A wireless remote control system is designed to adjust the servomotors which enables us to control revolution, speed and phase differences of neighbor servomotors of fins. Finally, Field trials are conducted in an outdoor pool to demonstrate the relationship between robotic fish speed and fin parameters like phase difference, the number of phase and undulatory amplitude.

FinTech transformation: how it-enabled innovations shape the financial sector

OpenAIRE

Zavolokina, Liudmila; Dolata, Mateusz; Schwabe, Gerhard

2016-01-01

FinTech, the phenomenon which spans over the areas of information technologies and financial innovation, is currently on the rise and is gaining more and more attention from practitioners, investors and researchers. FinTech is broadly discussed by the media, which constitutes its understanding and represents social opinion, however, this perception of FinTech should be supported by empirical evidences. Therefore, we examine five Swiss FinTech companies through the lens of the conceptual frame...

Status and prospects of the LHCb Vertex Locator

CERN Document Server

van Beuzekom, Martin

2007-01-01

The Vertex Locator of the LHCb experiment is a dedicated subdetector for the reconstruction of primary and secondary vertices in b-hadron decays. The vertex detector features two halves with 21 modules each, mounted on retractable bases. Each module consists of two half-disk silicon micro-strip sensors measuring hits in R and $\\Phi$ coordinates. The strip pitch ranges from 40 to about 100 $\\mu$m. A vacuum boy with a 300 $\\mu$m thick aluminium foil shields the sensors from the wakefields of the proton beams which are passing at a distance of 8 mm from the active area of the sensors. Because of the harsh non-uniform radiation environment we opted for n-on-n strips in diffusion oxygenated float zone silicon. The current status of the vertex detector, which has recently entered the commissioning phase, will be discussed. Given the limited lifetime of the detector due to the radiation environment, developments for a detector replacement with n-on-p type modules have already started. Possible upgrade scenarios fo...

Fish Pectoral Fin Hydrodynamics; Part III: Low Dimensional Models via POD Analysis

Science.gov (United States)

Bozkurttas, M.; Madden, P.

2005-11-01

The highly complex kinematics of the pectoral fin and the resulting hydrodynamics does not lend itself easily to analysis based on simple notions of pitching/heaving/paddling kinematics or lift/drag based propulsive mechanisms. A more inventive approach is needed to dissect the fin gait and gain insight into the hydrodynamic performance of the pectoral fin. The focus of the current work is on the hydrodynamics of the pectoral fin of a bluegill sunfish in steady forward motion. The 3D, time-dependent fin kinematics is obtained via a stereo-videographic technique. We employ proper orthogonal decomposition to extract the essential features of the fin gait and then use CFD to examine the hydrodynamics of simplified gaits synthesized from the POD modes. The POD spectrum shows that the first two, three and five POD modes capture 55%, 67%, and 80% of the motion respectively. The first three modes are in particular highly distinct: Mode-1 is a ``cupping'' motion where the fin cups forward as it is abducted; Mode-2 is an ``expansion'' motion where the fin expands to present a larger area during adduction and finally Mode-3 involves a ``spanwise flick'' of the dorsal edge of the fin. Numerical simulation of flow past fin gaits synthesized from these modes lead to insights into the mechanisms of thrust production; these are discussed in detail.

Thermohydraulic analysis of smooth and finned annular ducts

International Nuclear Information System (INIS)

Braga, C.V.M.

1987-01-01

The present work is concerned with the turbulent heat transfer and pressure drop in smooth and finned annular ducts overage heat transfer coefficients have been obtained by means of the heat exchanger theory. In addition, friction factors have also been determined. The experiments were performed by utilizing four double-pipe heat exchangers. The flowing fluids, in the heat exchangers, were air and water. The average heat transfer coefficients, for air flowing in the annular section, were determined by measuring the overall heat transfer coefficients of the heat exchangers. In order to attain fully developed conditions, the heat exchangers had a starting length of 30 hydraulic diameters. The thermal boundary conditions consisted of uniform temperature on the inner surface, the outer surface being insulated. The heat transfer coefficients and friction factors are presented in dimensionaless forms, as functions of the Reynolds number of the flow. The results for the smooth and finned annular ducts were compared. The purpose of such comparison was to study the influence of the fins on the pressure drop and heat transfer rate. In the case of the finned nular ducts, it is shown that the fin efficiency has some fluence on the heat transfer rates. The, a two-dimensional at transfer analysis was performed in order to obtain the n efficiency and the annular region efficiency. It is also shown that the overall thermal performance of finned surfaces epends mainly on the Nusselt number and on the region eficiency. These parameters are presented as functions of the Reynolds number of the flow and the geometry of the problem. (author) [pt

Heat transfer and pressure drop characteristics of mini-fin structures

International Nuclear Information System (INIS)

Jiang Peixue; Xu Ruina

2007-01-01

Forced convection heat transfer of air and water in bronze and pure copper mini-fin structures and mini-channel structures was investigated experimentally. The mini-fin dimensions were 0.7 mm x 0.2 mm and 0.8 mm x 0.4 mm. The tests included both staggered diamond-shaped and in-line square mini-fin arrangements. The tests investigated the effects of structures, mini-fin dimensions and arrangement, test section materials, and fluid properties on the convection heat transfer and heat transfer enhancement. For the tested conditions, the convection heat transfer coefficient was increased 9-21 fold for water and 12-38 fold for air in the mini-fin structures compared with an empty plate channel. The friction factor and flow resistance in the mini-channel structures and the in-line square mini-fin arrangement were much less than in the staggered diamond-shaped mini-fin arrangement. For the small channel width, W c = 0.2 mm, the convection heat transfer with the in-line square array structure was more intense than with the staggered diamond-shaped structure, the mini-channel structure or the porous media. For the larger channel width, W c = 0.4 mm, the convection heat transfer in the staggered diamond-shaped array structure was more intense than in the others systems while the in-line square structure had the best overall thermal-hydraulic performance

Correcting false information in memory: manipulating the strength of misinformation encoding and its retraction.

Science.gov (United States)

Ecker, Ullrich K H; Lewandowsky, Stephan; Swire, Briony; Chang, Darren

2011-06-01

Information that is presumed to be true at encoding but later on turns out to be false (i.e., misinformation) often continues to influence memory and reasoning. In the present study, we investigated how the strength of encoding and the strength of a later retraction of the misinformation affect this continued influence effect. Participants read an event report containing misinformation and a subsequent correction. Encoding strength of the misinformation and correction were orthogonally manipulated either via repetition (Experiment 1) or by imposing a cognitive load during reading (Experiment 2). Results suggest that stronger retractions are effective in reducing the continued influence effects associated with strong misinformation encoding, but that even strong retractions fail to eliminate continued influence effects associated with relatively weak encoding. We present a simple computational model based on random sampling that captures this effect pattern, and conclude that the continued influence effect seems to defy most attempts to eliminate it.

Emergency retraction mechanism for the manipulator arm of a nuclear reactor vessel inspection apparatus

International Nuclear Information System (INIS)

1980-01-01

Nuclear reactor vessels are made using numerous welds. These have to be inspected, often using ultrasonic transducers mounted on a manipulator arm. This invention seeks to solve the problem of retracting the manipulator arm should an emergency occur while it is fully extended, particularly within one of the reactor vessel nozzles. Of specific concern is the situation where power fails with the manipulator arm so extended. Details are given of an emergency retraction mechanism for use in reactor vessel inspection apparatus. A manual retraction means is used; the manipulator arm is slidably mounted within a frame. This comprises a member mounted on the arm for looping engagement by a cable, the cable being fixed at one end of the arm frame and engaging the member, and a clamp for detachably securing the cable at its other end to the arm frame at a point which is accessible from above the vessel. (U.K.)

A Numerical Study of Natural Convection Heat Transfer in Fin Ribbed Radiator

Directory of Open Access Journals (Sweden)

Hua-Shu Dou

2015-01-01

Full Text Available This paper numerically investigates the thermal flow and heat transfer by natural convection in a cavity fixed with a fin array. The computational domain consists of both solid (copper and fluid (air areas. The finite volume method and the SIMPLE scheme are used to simulate the steady flow in the domain. Based on the numerical results, the energy gradient function K of the energy gradient theory is calculated. It is observed from contours of the temperature and energy gradient function that the position where thermal instability takes place correlates well with the region of large K values, which demonstrates that the energy gradient method reveals the physical mechanism of the flow instability. Furthermore, the effects of the fin height, the fin number, and the fin shape on the heat transfer rate are also investigated. It is found that the thermal performance of the fin array is determined by the combined effect of the fin space and fin height. It is also observed that the effect of fin shape on heat transfer is insignificant.

Application of homotopy analysis method and inverse solution of a rectangular wet fin

International Nuclear Information System (INIS)

Panda, Srikumar; Bhowmik, Arka; Das, Ranjan; Repaka, Ramjee; Martha, Subash C.

2014-01-01

Highlights: • Solution of a wet fin with is obtained by homotopy analysis method (HAM). • Present HAM results have been well-validated with literature results. • Inverse analysis is done using genetic algorithm. • Measurement error of ±10–12% (approx.) is found to yield satisfactory reconstructions. - Abstract: This paper presents the analytical solution of a rectangular fin under the simultaneous heat and mass transfer across the fin surface and the fin tip, and estimates the unknown thermal and geometrical configurations of the fin using inverse heat transfer analysis. The local temperature field is obtained by using homotopy analysis method for insulated and convective fin tip boundary conditions. Using genetic algorithm, the thermal and geometrical parameters, viz., thermal conductivity of the material, surface heat transfer coefficient and dimensions of the fin have been simultaneously estimated for the prescribed temperature field. Earlier inverse studies on wet fin have been restricted to the analysis of nonlinear governing equation with either insulated tip condition or finite tip temperature only. The present study developed a closed-form solution with the consideration of nonlinearity effects in both governing equation and boundary condition. The study on inverse optimization leads to many feasible combination of fin materials, thermal conditions and fin dimensions. Thus allows the flexibility for designing a fin under wet conditions, based on multiple combinations of fin materials, fin dimensions and thermal configurations to achieve the required heat transfer duty. It is further determined that the allowable measurement error should be limited to ±10–12% in order to achieve satisfactory reconstruction

Retraction: Two novel duck antibacterial peptides, avian β-defensins 9 and 10, with antimicrobial activity.

Science.gov (United States)

2013-01-01

The article by Ma et al. that published in the Journal of Microbiology and Biotechnology (2009, 19: 1447-1455) was used the same data in two journal articles (Acta Veterinaria et Zootechnica Sinica, 2009, 40(9): 1320-1326, Scientia Agricultura Sinica, 2009, 42(4): 1406-1412). Therefore, the article is retracted from JMB as a misconduct of the authors. JMB as the publisher regrets for any inconvenience may have caused by the retraction to readers.

Dry/wet performance of a plate-fin air-cooled heat exchanger with continuous corrugated fins

International Nuclear Information System (INIS)

Hauser, S.G.; Kreid, D.K.; Johnson, B.M.

1981-01-01

The performance and operating characteristics of a plate-fin heat exchanger in dry/wet or deluge operations was experimentally determined. Development of the deluge heat/mass transfer model continued. The experiments were conducted in a specially-designed wind tunnel at the PNL. Air that was first heated and humidified to specified conditions was circulated at a controlled rate through a 2 ft x 6 ft heat exchanger module. The heat exchanger used in the tests was a wavy surface, plate fin on tube configuration. Hot water was circulated through the tubes at high flow rates to maintain an essentially isothermal condition on the tube side. Deionized water sprayed on the top of the vertically oriented plate fins was collected at the bottom of the core and recirculated. Instrumentation was provided for measurement of flow rates and thermodynamic conditions in the air, in the core circulation water, and in the deluge water. Measurements of the air side pressure drop and heat rejection rate were made as a function of air flow rate, air inlet temperature and humidity, deluge water flow rate, and the core inclination from the vertical. An overall heat transfer coefficient and an effective deluge film convective coefficient was determined. The deluge model, for predicting heat transfer from a wet finned heat exchanger was further developed and refined, and a major extension of the model was formulated that permits simultaneous calculation of both the heat transfer and evaporation rates from the wetted surface. The experiments showed an increase in the heat rejection rate due to wetting, accompanied by a proportional increase in the air side pressure drop. For operation at the same air side pressure drop, the enhancement ratio Q/sub w//Q/sub d/ varied between 2 and 5 for the conditions tested. Thus, the potential enhancement of heat transfer due to wetting can be substantial

Reduced arterial stiffness may contribute to angiotensin-converting enzyme inhibitor induced improvements in walking time in peripheral arterial disease patients: Retraction.

Science.gov (United States)

2015-12-01

J Hypertension 2008, 26:1037–1042. The following authors, Drs A.M. Dart, A. Lawler, P.A. Blombery, Prof. B.A. Kingwell, have requested retraction of a paper by A.A. Ahimastos et al. An investigation by the Research Conduct Office of the Baker Heart and Diabetes Institute found irregularities in a study, including falsification of patients' records and misrepresentation of results, from which this article was derived. On the basis of this investigation the Baker Heart and Diabetes Institute strongly supports retraction and points out the co-authors asking for retraction were found not be involved in the research misconduct. The article is retracted.

Retraction and expansion of flock mobility in central asia: costs and ...

African Journals Online (AJOL)

Retraction and expansion of flock mobility in central asia: costs and consequences. Carol Kerven, Ilya Ilych Alimaev, Roy Behnke, Grant Davidson, Leen Franchois, Nurlan Malmakov, Erik Mathijs, Aidos Smailov, Sayat Temirbekov, Iain Wright ...

Control characteristics for wrap-around fins on cruise missiles configurations

Science.gov (United States)

Sawyer, W. C.; Monta, W. J.; Carter, W. V.; Alexander, W. K.

1981-01-01

This paper presents selected results of a panel loads study conducted as part of the final phase of an extensive investigation of an air-breathing missile concept employing wrap-around aerodynamic surfaces. Typical results for M = 2.36 are presented for the fin load results, plus a brief review of basic results of the previously reported tests. Vapor screen results are also discussed. The present results indicate that the fin load characteristics are nearly identical for planar and curved fins having the same projected planform and would permit the use of planar-surface predictions for supersonic speeds in the preliminary design stages of missiles employing wrap-around curved fins.

Thermal analysis of annular fins with temperature-dependent thermal properties

Institute of Scientific and Technical Information of China (English)

I. G. AKSOY

2013-01-01

The thermal analysis of the annular rectangular profile fins with variable thermal properties is investigated by using the homotopy analysis method (HAM). The thermal conductivity and heat transfer coefficient are assumed to vary with a linear and power-law function of temperature, respectively. The effects of the thermal-geometric fin parameter and the thermal conductivity parameter variations on the temperature distribution and fin efficiency are investigated for different heat transfer modes. Results from the HAM are compared with numerical results of the finite difference method (FDM). It can be seen that the variation of dimensionless parameters has a significant effect on the temperature distribution and fin efficiency.

Characteristics of a micro-fin evaporator: Theoretical analysis and experimental verification

Directory of Open Access Journals (Sweden)

Zheng Hui-Fan

2013-01-01

Full Text Available A theoretical analysis and experimental verification on the characteristics of a micro-fin evaporator using R290 and R717 as refrigerants were carried out. The heat capacity and heat transfer coefficient of the micro-fin evaporator were investigated under different water mass flow rate, different refrigerant mass flow rate, and different inner tube diameter of micro-fin evaporator. The simulation results of the heat transfer coefficient are fairly in good agreement with the experimental data. The results show that heat capacity and the heat transfer coefficient of the micro-fin evaporator increase with increasing logarithmic mean temperature difference, the water mass flow rate and the refrigerant mass flow rate. Heat capacity of the micro-fin evaporator for diameter 9.52 mm is higher than that of diameter 7.00 mm with using R290 as refrigerant. Heat capacity of the micro-fin evaporator with using R717 as refrigerant is higher than that of R290 as refrigerant. The results of this study can provide useful guidelines for optimal design and operation of micro-fin evaporator in its present or future applications.

Enhancement of heat transfer. The performance of micro-fin tubes

International Nuclear Information System (INIS)

Muzzio, A.

2001-01-01

Micro-fin tubes are characterised by numerous, very small integral fins that spiral down the inner surface. A very interesting feature of their performance in flow boiling and condensation is a large heat transfer enhancement accompanied by a low pressure drop penalty. This paper presents a general overview of micro-fin tubes and of their performance in evaporation, condensation and single-phase flow [it

Review of various liver retraction techniques in single incision laparoscopic surgery for the exposure of hiatus

Directory of Open Access Journals (Sweden)

Praveenraj Palanivelu

2015-01-01

Full Text Available Background: The main aspect of concern for upper GI procedures has been the retraction of the liver especially large left lobes as commonly encountered in Bariatric surgery. Not doing so would compromise the view of the hiatus, hence theoretically reducing the quality of the surgery and increasing the possibility of complications. The aim of this study was to review the various liver retraction techniques in single incision surgery being done at our institute and analyze them. Material and Methods: A retrospective study of the various techniques and a subsequent analysis was made based on advantages and disadvantages of each method. Objectively a quantitative measure of hiatal exposure was done using a scoring system based on the grade of exposure after reviewing the surgical videos. From January 2011 to January 2013 total 104 patients underwent single incision surgery with the various liver retraction techniques with following grades of exposure -liver suspension tube technique with naso gastric tubing (2.11 and with corrugated drain (2.09 needlescopic method (1.2, Umbilical tape sling (1.95, crural stitch method (2.5. Needeloscopic method has the best grade of exposure and is the easiest to start with. The average time to create the liver retraction was 2.8 to 8.6 min.There was no procedure related morbidity or mortality. Conclusions: The mentioned liver retraction techniques are cost effective and easy to learn. We recommend using these techniques to have a good exposure of hiatus, without compromising the safety of surgery in single incision surgery.

Aluminum fin-stock alloys

International Nuclear Information System (INIS)

Gul, R.M.; Mutasher, F.

2007-01-01

Aluminum alloys have long been used in the production of heat exchanger fins. The comparative properties of the different alloys used for this purpose has not been an issue in the past, because of the significant thickness of the finstock material. However, in order to make fins lighter in weight, there is a growing demand for thinner finstock materials, which has emphasized the need for improved mechanical properties, thermal conductivity and corrosion resistance. The objective of this project is to determine the effect of iron, silicon and manganese percentage increment on the required mechanical properties for this application by analyzing four different aluminum alloys. The four selected aluminum alloys are 1100, 8011, 8079 and 8150, which are wrought non-heat treatable alloys with different amount of the above elements. Aluminum alloy 1100 serve as a control specimen, as it is commercially pure aluminum. The study also reports the effect of different annealing cycles on the mechanical properties of the selected alloys. Metallographic examination was also preformed to study the effect of annealing on the precipitate phases and the distribution of these phases for each alloy. The microstructure analysis of the aluminum alloys studied indicates that the precipitated phase in the case of aluminum alloys 1100 and 8079 is beta-FeAI3, while in 8011 it is a-alfa AIFeSi, and the aluminum alloy 8150 contains AI6(Mn,Fe) phase. The comparison of aluminum alloys 8011 and 8079 with aluminum alloy 1100 show that the addition of iron and silicon improves the percent elongation and reduces strength. The manganese addition increases the stability of mechanical properties along the annealing range as shown by the comparison of aluminum alloy 8150 with aluminum alloy 1100. Alloy 8150 show superior properties over the other alloys due to the reaction of iron and manganese, resulting in a preferable response to thermal treatment and improved mechanical properties. (author)

Spatial-orientation priming impedes rather than facilitates the spontaneous control of hand-retraction speeds in patients with Parkinson's disease.

Directory of Open Access Journals (Sweden)

Polina Yanovich

Full Text Available BACKGROUND: Often in Parkinson's disease (PD motor-related problems overshadow latent non-motor deficits as it is difficult to dissociate one from the other with commonly used observational inventories. Here we ask if the variability patterns of hand speed and acceleration would be revealing of deficits in spatial-orientation related decisions as patients performed a familiar reach-to-grasp task. To this end we use spatial-orientation priming which normally facilitates motor-program selection and asked whether in PD spatial-orientation priming helps or hinders performance. METHODS: To dissociate spatial-orientation- and motor-related deficits participants performed two versions of the task. The biomechanical version (DEFAULT required the same postural- and hand-paths as the orientation-priming version (primed-UP. Any differences in the patients here could not be due to motor issues as the tasks were biomechanically identical. The other priming version (primed-DOWN however required additional spatial and postural processing. We assessed in all three cases both the forward segment deliberately aimed towards the spatial-target and the retracting segment, spontaneously bringing the hand to rest without an instructed goal. RESULTS AND CONCLUSIONS: We found that forward and retracting segments belonged in two different statistical classes according to the fluctuations of speed and acceleration maxima. Further inspection revealed conservation of the forward (voluntary control of speed but in PD a discontinuity of this control emerged during the uninstructed retractions which was absent in NC. Two PD groups self-emerged: one group in which priming always affected the retractions and the other in which only the more challenging primed-DOWN condition was affected. These PD-groups self-formed according to the speed variability patterns, which systematically changed along a gradient that depended on the priming, thus dissociating motor from spatial

Mechanism of tonal noise generation from circular cylinder with spiral fin

Science.gov (United States)

Yamashita, Ryo; Hayashi, Hidechito; Okumura, Tetsuya; Hamakawa, Hiromitsu

2014-12-01

The pitch of the spiral finned tube influences seriously to the acoustic resonance in the heat exchanger. In this research, the flow characteristics in relating to the aeolian tone from the finned cylinder are studied by the numerical simulation. It is observed that the tonal noise generated from the finned tube at two pitch spaces. The ratio of the fin pitch to the cylinder diameter is changed at 0.11 and 0.27. The tone level increases and the frequency decreases with the pitch shorter. The separation flow from the cylinder generates the span-wise vortices, Karman vortices, and the separation flow from the fin generates the stream-wise vortices. When the fin pitch ratio is small, the stream-wise vortices line up to span-wise and become weak rapidly. Only the Karman vortices are remained and integrate in span. So the Karman vortex became large. This causes the low frequency and the large aeolian tone.

Fgf16 is essential for pectoral fin bud formation in zebrafish

International Nuclear Information System (INIS)

Nomura, Ryohei; Kamei, Eriko; Hotta, Yuuhei; Konishi, Morichika; Miyake, Ayumi; Itoh, Nobuyuki

2006-01-01

Zebrafish pectoral fin bud formation is an excellent model for studying morphogenesis. Fibroblast growth factors (Fgfs) and sonic hedgehog (shh) are essential for pectoral fin bud formation. We found that Fgf16 was expressed in the apical ectodermal ridge (AER) of fin buds. A knockdown of Fgf16 function resulted in no fin bud outgrowth. Fgf16 is required for cell proliferation and differentiation in the mesenchyme and the AER of the fin buds, respectively. Fgf16 functions downstream of Fgf10, a mesenchymal factor, signaling to induce the expression of Fgf4 and Fgf8 in the AER. Fgf16 in the AER and shh in the zone of polarizing activity (ZPA) interact to induce and/or maintain each other's expression. These findings have revealed that Fgf16, a newly identified AER factor, plays a crucial role in pectoral fin bud outgrowth by mediating the interactions of AER-mesenchyme and AER-ZPA

Ontogenetic scaling of caudal fin shape in Squalus acanthias (Chondrichthyes, Elasmobranchii): a geometric morphometric analysis with implications for caudal fin functional morphology.

Science.gov (United States)

Reiss, Katie L; Bonnan, Matthew F

2010-07-01

The shark heterocercal caudal fin and its contribution to locomotion are of interest to biologists and paleontologists. Current hydrodynamic data show that the stiff dorsal lobe leads the ventral lobe, both lobes of the tail are synchronized during propulsion, and tail shape reflects its overall locomotor function. Given the difficulties surrounding the analysis of shark caudal fins in vivo, little is known about changes in tail shape related to ontogeny and sex in sharks. A quantifiable analysis of caudal fin shape may provide an acceptable proxy for inferring gross functional morphology where direct testing is difficult or impossible. We examined ontogenetic and sex-related shape changes in the caudal fins of 115 Squalus acanthias museum specimens, to test the hypothesis that significant shape changes in the caudal fin shape occur with increasing size and between the sexes. Using linear and geometric morphometrics, we examined caudal shape changes within the context of current hydrodynamic models. We found no statistically significant linear or shape difference between sexes, and near-isometric scaling trends for caudal dimensions. These results suggest that lift and thrust increase linearly with size and caudal span. Thin-plate splines results showed a significant allometric shape change associated with size and caudal span: the dorsal lobe elongates and narrows, whereas the ventral lobe broadens and expands ventrally. Our data suggest a combination of caudal fin morphology with other body morphology aspects, would refine, and better elucidate the hydrodynamic factors (if any) that underlie the significant shape changes we report here for S. acanthias.

Notice: PSPB articles by authors with retracted articles at PSPB or other journals: Stapel, Smeesters, and Sanna.

Science.gov (United States)

Funder, David

2014-01-01

Numerous articles by the social psychologists Diederick Stapel, Dirk Smeesters, and Lawrence Sanna have been retracted in several different journals. The present notice reports the results of an investigation into papers authored or coauthored by these individuals, and published in Personality and Social Psychology Bulletin, that have not been retracted. The status of these papers range from data confirmed as legitimate by coauthors to, in many cases, being unknown as to their legitimacy. Given the lack of information in the latter cases, there is insufficient basis to recommend retraction at this time. Researchers using the results of these papers in their own work are advised to take the information reported in this notice into account.

Comparison of canine retraction using single and Siamese edgewise brackets: An in vivo study

Directory of Open Access Journals (Sweden)

Zeeshan Iqbal Bhat

2013-01-01

Full Text Available Objectives: The purpose of this study was to check the rate of canine retraction with bodily mechanics using two different pre-adjusted edgewise bracket Systems. Materials and Methods: A split mouth study with twenty patients who were randomly selected and allotted to a single operator. Duration of canine retraction, angulation of canine during its retraction, degree of Rotation, anchorage Loss, distance between canine and premolar at different time intervals were then evaluated, pre- (To, 3 months- (T1 and canine tip touches the second premolar- (T2. Descriptive statistics including mean values and standard deviations were calculated. Paired and unpaired t-test was performed to evaluate the differences between the groups. Results: Rotation and angulation of the canines did not show significant difference in both the systems. There was statistically significant difference (P<0.01 in anchorage loss between single wing and Siamese bracket being 2.65 ±1.41 mm and 1.31 ± 0.93 respectively. There was statistically significant intergroup difference (P<0.01 in canine movement i.e distance between canine and premolar was recorded as 4.72mm (15.06 ± 1.69 to 10.34 ± 1.68mm in single wing bracket and 6.25mm in Siamese (15.52 ± 1.41 to 9.27 ± 1.94. Conclusion: In cases where high anchorage is required and the rate of canine retraction is a concern, Siamese brackets pose a definite advantage over Single wing brackets.

Accurately bearing measurement in non-cooperative passive location system

International Nuclear Information System (INIS)

Liu Zhiqiang; Ma Hongguang; Yang Lifeng

2007-01-01

The system of non-cooperative passive location based on array is proposed. In the system, target is detected by beamforming and Doppler matched filtering; and bearing is measured by a long-base-ling interferometer which is composed of long distance sub-arrays. For the interferometer with long-base-line, the bearing is measured accurately but ambiguously. To realize unambiguous accurately bearing measurement, beam width and multiple constraint adoptive beamforming technique is used to resolve azimuth ambiguous. Theory and simulation result shows this method is effective to realize accurately bearing measurement in no-cooperate passive location system. (authors)

High temperature mechanical properties on multi stage blazed fin body with ultra fine off-set fin for compact heat exchanger

International Nuclear Information System (INIS)

Ishiyama, Shintaro; Muto, Yasushi

2003-01-01

Three stage blazed plate fin body with ultra fine off-set fin (thickness x height x pitch x off-set pitch = 0.22 mm x 1.2 mm x 1.6 mm x 5 mm) for 600 MWt High Temperature Gas Cooled Reactor Gas Turbin (HTGR-GT) system was fabricated and tested on its high temperature mechanical properties and the following results were derived. (1) tested body shows almost the same strength an fatigue behavior of SUS 304 as main structural material at elevated temperatures up to 873 K, (2) static and fatigue fracture mainly occurred at ultra fine off-set and (3) high temperature strength and fatigue life are improved by blazing technique to double side walls of the fin by Ni blaze material. (author)

Flow-structure Interaction Modeling of a Fish Caudal Fin during Steady Swimming

Science.gov (United States)

Liu, Geng; Geng, Biao; Zheng, Xudong; Xue, Qian; Dong, Haibo

2017-11-01

It's widely thought that the flexibilities of fish fins play critical roles in propulsive performance enhancement (such as thrust augment and efficiency improvement) in nature. In order to explore the formation mechanisms of the fish fin's flexible morphing and its hydrodynamic benefits as well, a high-fidelity flow-structure/membrane interaction modeling of the fish caudal fin is conducted in this work. Following the realistic configuration of the fish caudal fin, a thin membrane supported by a series of beams is constructed. The material properties of the membrane and the beams are reversely determined by the realistic fin morphing obtained from the high-speed videos and the high fidelity flow-structure interaction simulations. With the accurate material property, we investigate the interplay between structure, kinematics and fluid flow in caudal fin propulsion. Detailed analyses on the relationship between the flexural stiffness, fin morphing patterns, hydrodynamic forces and vortex dynamics are then conducted.

Effects of fin shape on condensation in herringbone microfin tubes

Energy Technology Data Exchange (ETDEWEB)

Miyara, Akio [Saga University (Japan). Dept. of Mechanical Engineering; Otsubo, Yusuke; Ohtsuka, Satoshi; Mizuta, Yoshihiko [Saga University (Japan). Graduate School of Science and Engineering

2003-06-01

Effects of fin height and helix angle on condensation inside a herringbone microfin tube have been experimentally investigated with five types of herringbone microfin tubes. Heat transfer coefficients are about 2-4 times higher than that of the helical microfin tube under high mass velocity conditions. In the low mass velocity, they are equal to that of the helical microfin tube. The heat transfer enhancement increases with fin height up to 0.18 mm; higher fin heights show enhancement values similar to the 0.18 mm results. Pressure drop increases with the fin height. Larger helix angle yields higher heat transfer and higher pressure drop. For the lowest fin and/or smallest helix angle, the pressure drop is comparable with that of the helical microfin tube, while the heat transfer enhancement is higher. The enhancement mechanism is discussed from flow pattern observations. Effect of mass transfer resistance for R410A is estimated and negligible effects have been proved. (author)

Development of a Simulation Model for Swimming with Diving Fins

Directory of Open Access Journals (Sweden)

Motomu Nakashima

2018-02-01

Full Text Available The simulation model to assess the performance of diving fin was developed by extending the swimming human simulation model SWUM. A diving fin was modeled as a series of five rigid plates and connected to the human model by springs and dampers. These plates were connected to each other by virtual springs and dampers, and fin’s bending property was represented by springs and dampers as well. An actual diver’s swimming motion with fins was acquired by a motion capture experiment. In order to determine the bending property of the fin, two bending tests on land were conducted. In addition, an experiment was conducted in order to determine the fluid force coefficients in the fluid force model for the fin. Finally, using all measured and identified information, a simulation, in which the experimental situation was reproduced, was carried out. It was confirmed that the diver in the simulation propelled forward in the water successfully.

RETRACTED: Synthesis, characterization and catalytic activity of silver nanoparticles using Tribulus terrestris leaf extract

Science.gov (United States)

Ashokkumar, S.; Ravi, S.; Kathiravan, V.; Velmurugan, S.

2014-03-01

This article has been retracted: please see Elsevier Policy on Article Withdrawal. This article has been retracted at the request of the Editor. The article contains duplicate images (Fig. 5A and B as well as Fig. 5C and D) which differ only in magnification and orientation despite being described as different samples. Figure 3 displays duplicated data despite being described as different samples. The scientific community takes a very strong view on this scientific misbehavior and apologies are offered to readers of the journal that this was not detected during the submission process.

Water flow and fin shape polymorphism in coral reef fishes.

Science.gov (United States)

Binning, Sandra A; Roche, Dominique G

2015-03-01

Water flow gradients have been linked to phenotypic differences and swimming performance across a variety of fish assemblages. However, the extent to which water motion shapes patterns of phenotypic divergence within species remains unknown. We tested the generality of the functional relationship between swimming morphology and water flow by exploring the extent of fin and body shape polymorphism in 12 widespread species from three families (Acanthuridae, Labridae, Pomacentridae) of pectoral-fin swimming (labriform) fishes living across localized wave exposure gradients. The pectoral fin shape of Labridae and Acanthuridae species was strongly related to wave exposure: individuals with more tapered, higher aspect ratio (AR) fins were found on windward reef crests, whereas individuals with rounder, lower AR fins were found on leeward, sheltered reefs. Three of seven Pomacentridae species showed similar trends, and pectoral fin shape was also strongly related to wave exposure in pomacentrids when fin aspect ratios of three species were compared across flow habitats at very small spatial scales (fish body fineless ratio across habitats or depths. Contrary to our predictions, there was no pattern relating species' abundances to polymorphism across habitats (i.e., abundance was not higher at sites where morphology is better adapted to the environment). This suggests that there are behavioral and/or physiological mechanisms enabling some species to persist across flow habitats in the absence of morphological differences. We suggest that functional relationships between swimming morphology and water flow not only structure species assemblages, but are yet another important variable contributing to phenotypic differences within species. The close links between fin shape polymorphism and local water flow conditions appear to be important for understanding species' distributions as well as patterns of diversification across environmental gradients.

Hydrodynamic function of dorsal fins in spiny dogfish and bamboo sharks during steady swimming.

Science.gov (United States)

Maia, Anabela; Lauder, George V; Wilga, Cheryl D

2017-11-01

A key feature of fish functional design is the presence of multiple fins that allow thrust vectoring and redirection of fluid momentum to contribute to both steady swimming and maneuvering. A number of previous studies have analyzed the function of dorsal fins in teleost fishes in this context, but the hydrodynamic function of dorsal fins in freely swimming sharks has not been analyzed, despite the potential for differential functional roles between the anterior and posterior dorsal fins. Previous anatomical research has suggested a primarily stabilizing role for shark dorsal fins. We evaluated the generality of this hypothesis by using time-resolved particle image velocimetry to record water flow patterns in the wake of both the anterior and posterior dorsal fins in two species of freely swimming sharks: bamboo sharks ( Chiloscyllium plagiosum ) and spiny dogfish ( Squalus acanthias ). Cross-correlation analysis of consecutive images was used to calculate stroke-averaged mean longitudinal and lateral velocity components, and vorticity. In spiny dogfish, we observed a velocity deficit in the wake of the first dorsal fin and flow acceleration behind the second dorsal fin, indicating that the first dorsal fin experiences net drag while the second dorsal fin can aid in propulsion. In contrast, the wake of both dorsal fins in bamboo sharks displayed increased net flow velocity in the majority of trials, reflecting a thrust contribution to steady swimming. In bamboo sharks, fluid flow in the wake of the second dorsal fin had higher absolute average velocity than that for first dorsal fin, and this may result from a positive vortex interaction between the first and second dorsal fins. These data suggest that the first dorsal fin in spiny dogfish has primarily a stabilizing function, while the second dorsal fin has a propulsive function. In bamboo sharks, both dorsal fins can contribute thrust and should be considered as propulsive adjuncts to the body during steady

En Defensa del Fin de Lucro en Salud.

Directory of Open Access Journals (Sweden)

Ramón Abel Castaño Yepes

2007-06-01

La quinta premisa se deriva de la cuarta y de la segunda, es decir, que si el diseño del sistema de salud introducido por la Ley 100 tiene como elemento distintivo el fin de lucro, entonces el resultado de dicho diseño tiene que ser indeseable, puesto que el fin de lucro es indeseable...

Effects of the partially movable control fin with end plate of underwater vehicle

Directory of Open Access Journals (Sweden)

Chul-Min Jung

2017-01-01

Full Text Available Underwater torpedo has control fin with very low aspect ratio due to launching from limited size of cylindrical torpedo tube. If the aspect ratio of control fin of underwater vehicle is very low three-dimensional flow around control fin largely reduces control forces. In this study, the end plate was applied to reduce the three-dimensional flow effects of partially movable control fin of underwater vehicle. Through numerical simulations the flow field around control fin was examined with and without end plate for different flap angles. The pressure, vorticity, lift and torque on the control fin were analyzed and compared to experiments. The comparison have shown a reasonable agreement between numerical and experimental results and the effect of end plate on a low aspect ratio control fin. When the end plate was attached to the movable control fin, the lift increased and the actuator shaft torque did not significantly change. As this means less consumption of the actuator shaft torque compared to the control fin that has the same control force, the inner actuator capacity can be reduced and energy consumption can be saved. Considering this, it is expected to be effectively applied to the control fin design of underwater vehicles such as torpedoes.

An experimental investigation into the deployment of 3-D, finned wing and shape memory alloy vortex generators in a forced air convection heat pipe fin stack

International Nuclear Information System (INIS)

Aris, M.S.; McGlen, R.; Owen, I.; Sutcliffe, C.J.

2011-01-01

Forced air convection heat pipe cooling systems play an essential role in the thermal management of electronic and power electronic devices such as microprocessors and IGBT's (Integrated Gate Bipolar Transistors). With increasing heat dissipation from these devices, novel methods of improving the thermal performance of fin stacks attached to the heat pipe condenser section are required. The current work investigates the use of a wing type surface protrusions in the form of 3-D delta wing tabs adhered to the fin surface, thin wings punched-out of the fin material and TiNi shape memory alloy delta wings which changed their angles of attack based on the fin surface temperature. The longitudinal vortices generated from the wing designs induce secondary mixing of the cooler free stream air entering the fin stack with the warmer fluid close to the fin surfaces. The change in angle of the attack of the active delta wings provide heat transfer enhancement while managing flow pressure losses across the fin stack. A heat transfer enhancement of 37% compared to a plain fin stack was obtained from the 3-D tabs in a staggered arrangement. The punched-out delta wings in the staggered and inline arrangements provided enhancements of 30% and 26% respectively. Enhancements from the active delta wings were lower at 16%. However, as these devices reduce the pressure drop through the fin stack by approximately 19% in the de-activate position, over the activated position, a reduction in fan operating cost may be achieved for systems operating with inlet air temperatures below the maximum inlet temperature specification for the device. CFD analysis was also carried out to provide additional detail of the local heat transfer enhancement effects. The CFD results corresponded well with previously published reports and were consistent with the experimental findings. - Highlights: → Heat transfer enhancements of heat pipe fin stacks was successfully achieved using fixed and active delta

Simulation study of a 3-D device integrating FinFET and UTBFET

KAUST Repository

Fahad, Hossain M.; Hu, Chenming; Hussain, Muhammad Mustafa

2015-01-01

By integrating 3-D nonplanar fins and 2-D ultrathin bodies, wavy FinFETs merge two formerly competing technologies on a silicon-on-insulator platform to deliver enhanced transistor performance compared with conventional trigate Fin

An experimental method for detecting blood splatter from retractable phlebotomy and intravascular devices.

Science.gov (United States)

Haiduven, Donna; Applegarth, Shawn; Shroff, Miloni

2009-03-01

This study was designed to evaluate the safety of retractable intravascular devices in terms of their potential to produce blood splatter. A method for measuring this blood splatter designed by the research team was used to evaluate 3 specific intravascular devices. Scientific filters were positioned around the retraction mechanisms of the devices and weighed with an analytical scale, both before and after activation, in a simulated vein containing mock venous blood. The difference in filter mass was used as the primary unit of analysis to detect blood splatter. In addition, the filters were visually inspected for the presence or absence of blood. A paired t-test revealed significant differences in the prefilter and postfilter groups for 2 of the 3 devices tested (P blood was detected on 23% to 40% of the scientific filters for 2 of the devices. Our findings indicate a potential for bloodborne pathogen exposure with the use of intravascular devices with a retractable mechanism. This experiment may serve as a model in the design and implementation of future sharps device evaluation protocols to validate the threat of bloodborne pathogen exposure.

Soldered Power Arm: An Easy and Effective Method for Intrusion and Retraction of Anterior Teeth

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Ketan K Vakil

2014-01-01

Full Text Available The orthodontic correction of deep overbite can be achieved with several mechanisms that will result in true intrusion of anterior teeth, extrusion of posterior teeth, or a combination of both. For the orthodontic correction of bimaxillary dentoalveolar protrusion with deep bite, there are several treatment modalities like segmented arch approach, retraction and intrusion utility arches, temporary anchorage devices. Though not a novel therapeutic concept, the use of miniscrew implants to obtain absolute anchorage has recently become very popular in clinical orthodontic approaches. To allow the use of sliding mechanics for bodily retraction with intrusion of anterior teeth, we devised a soldered power arm (SPA on standard molar tube. It is simple, stable, precise and effective in cases where anterior teeth need to be simultaneously retracted and intruded. A power arm can be readily fabricated from 20 gauge stainless steel wire and soldered on the molar buccal tube so as to avoid any distortion or loosening of power arm from molar tube during the course of the treatment. The SPA works efficiently with the molar being stabilized in all three planes of space. The resultant force vector is directed more apically toward the center of resistance of the anchor unit, which resulted in the treatment outcome of retraction and intrusion of the anterior teeth and correction of the deep bite.

Numerical studies of static aeroelastic effects on grid fin aerodynamic performances

Directory of Open Access Journals (Sweden)

Chengde HUANG

2017-08-01

Full Text Available The grid fin is an unconventional control surface used on missiles and rockets. Although aerodynamics of grid fin has been studied by many researchers, few considers the aeroelastic effects. In this paper, the static aeroelastic simulations are performed by the coupled viscous computational fluid dynamics with structural flexibility method in transonic and supersonic regimes. The developed coupling strategy including fluid–structure interpolation and volume mesh motion schemes is based on radial basis functions. Results are presented for a vertical and a horizontal grid fin mounted on a body. Horizontal fin results show that the deformed fin is swept backward and the axial force is increased. The deformations also induce the movement of center of pressure, causing the reduction and reversal in hinge moment for the transonic flow and the supersonic flow, respectively. For the vertical fin, the local effective incidences are increased due to the deformations so that the deformed normal force is greater than the original one. At high angles of attack, both the deformed and original normal forces experience a sudden reduction due to the interference of leeward separated vortices on the fin. Additionally, the increment in axial force is shown to correlate strongly with the increment in the square of normal force.

Integrated Rudder/Fin Concise Control Based on Frequency Domain Analysis

OpenAIRE

W. Guan; Z. J. Su; G. Q. Zhang

2013-01-01

This paper describes a concise robust controller design of integrated rudder and fin control system in use of the closed loop gain shaping algorithm (CGSA) strategy. Compared with the arbitrary selection of weighting function in integrated rudder and fin H∞ mixed sensitivity control design procedures, the CGSA methods provided a relatively more straightforward and concise design method. Simulations were described that the overall performance of each CGSA rudder and fin control loop and the in...

Differential induction of four msx homeobox genes during fin development and regeneration in zebrafish.

Science.gov (United States)

Akimenko, M A; Johnson, S L; Westerfield, M; Ekker, M

1995-02-01

To study the genetic regulation of growth control and pattern formation during fin development and regeneration, we have analysed the expression of four homeobox genes, msxA, msxB, msxC and msxD in zebrafish fins. The median fin fold, which gives rise to the unpaired fins, expresses these four msx genes during development. Transcripts of the genes are also present in cells of the presumptive pectoral fin buds. The most distal cells, the apical ectodermal ridge of the paired fins and the cleft and flanking cells of the median fin fold express all these msx genes with the exception of msxC. Mesenchymal cells underlying the most distal cells express all four genes. Expression of the msx genes in the fin fold and fin buds is transient and, by 3 days after fertilization, msx expression in the median fin fold falls below levels detectable by in situ hybridization. Although the fins of adult zebrafish normally have levels of msx transcripts undetectable by in situ hybridization, expression of all four genes is strongly reinduced during regeneration of both paired and unpaired fins. Induction of msx gene expression in regenerating caudal fins occurs as early as 30 hours postamputation. As the blastema forms, the levels of expression increase and reach a maximum between the third and fifth days. Then, msx expression progressively declines and disappears by day 12 when the caudal fin has grown back to its normal size. In the regenerating fin, the blastema cells that develop at the tip of each fin ray express msxB and msxC. Cells of the overlying epithelium express msxA and msxD, but do not express msxB or msxC. Amputations at various levels along the proximodistal axis of the fin suggest that msxB expression depends upon the position of the blastema, with cells of the rapidly proliferating proximal blastema expressing higher levels than the cells of the less rapidly proliferating distal blastema. Expression of msxC and msxD is independent of the position of the blastema cell

Gene expression profiles of fin regeneration in loach (Paramisgurnus dabryanu).

Science.gov (United States)

Li, Li; He, Jingya; Wang, Linlin; Chen, Weihua; Chang, Zhongjie

2017-11-01

Teleost fins can regenerate accurate position-matched structure and function after amputation. However, we still lack systematic transcriptional profiling and methodologies to understand the molecular basis of fin regeneration. After histological analysis, we established a suppression subtraction hybridization library containing 418 distinct sequences expressed differentially during the process of blastema formation and differentiation in caudal fin regeneration. Genome ontology and comparative analysis of differential distribution of our data and the reference zebrafish genome showed notable subcategories, including multi-organism processes, response to stimuli, extracellular matrix, antioxidant activity, and cell junction function. KEGG pathway analysis allowed the effective identification of relevant genes in those pathways involved in tissue morphogenesis and regeneration, including tight junction, cell adhesion molecules, mTOR and Jak-STAT signaling pathway. From relevant function subcategories and signaling pathways, 78 clones were examined for further Southern-blot hybridization. Then, 17 genes were chosen and characterized using semi-quantitative PCR. Then 4 candidate genes were identified, including F11r, Mmp9, Agr2 and one without a match to any database. After real-time quantitative PCR, the results showed obvious expression changes in different periods of caudal fin regeneration. We can assume that the 4 candidates, likely valuable genes associated with fin regeneration, deserve additional attention. Thus, our study demonstrated how to investigate the transcript profiles with an emphasis on bioinformatics intervention and how to identify potential genes related to fin regeneration processes. The results also provide a foundation or knowledge for further research into genes and molecular mechanisms of fin regeneration. Copyright © 2017 Elsevier B.V. All rights reserved.

Comprehensive performance comparison of airfoil fin PCHEs with NACA 00XX series airfoil

Energy Technology Data Exchange (ETDEWEB)

Chen, Fei, E-mail: chenfei@iet.cn [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China); Heating Technology Research and Development Center, Beijing District Heating Group, Beijing 100028 (China); Zhang, Lishen, E-mail: lishenzhang@sina.com [Heating Technology Research and Development Center, Beijing District Heating Group, Beijing 100028 (China); Huai, Xiulan, E-mail: hxl@iet.cn [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China); Li, Jufeng, E-mail: lijufeng.net@163.com [Nuclear and Radiation Safety Center, Ministry of Environmental Protection, Beijing 100082 (China); Zhang, Hang, E-mail: zhanghang@iet.cn [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Zhigang, E-mail: zgliu9322@163.com [Energy Research Institute of Shandong Academy of Sciences, Jinan, Shandong 250014 (China)

2017-04-15

Highlights: • Pressure drop of NACA 0020 airfoil fin PCHE reduces strikingly in comparison with the zigzag PCHE. • Pressure drop of NACA 00XX airfoil fin PCHE decreases as airfoil thickness increases. • Heat transfer performance of NACA 00XX airfoil fin PCHE increases as airfoil thickness rises. • Comprehensive performance of NACA 00XX airfoil fin PCHE degrades as airfoil thickness increases. - Abstract: Printed circuit heat exchanger (PCHE) can be used in supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle. The present study compares NACA 0020 airfoil fin PCHE with conventional zigzag PCHE by numerical analysis. Pressure drop of the former has a striking reduction while maintaining excellent heat transfer performance. Comparison on four NACA 00XX series airfoil fin PCHEs is performed to investigate the influence of airfoil profile on flow and heat transfer performance. With a fixed vertical pitch, heat transfer performance of NACA series airfoil fin PCHE increases as airfoil thickness increases. However, comprehensive performance, in which both flow and heat transfer are taken into account, degrades with increasing airfoil thickness. Among four NACA airfoil fin PCHEs presented in this paper, NACA 0010 airfoil fin PCHE demonstrates the best comprehensive performance.

Comprehensive performance comparison of airfoil fin PCHEs with NACA 00XX series airfoil

International Nuclear Information System (INIS)

Chen, Fei; Zhang, Lishen; Huai, Xiulan; Li, Jufeng; Zhang, Hang; Liu, Zhigang

2017-01-01

Highlights: • Pressure drop of NACA 0020 airfoil fin PCHE reduces strikingly in comparison with the zigzag PCHE. • Pressure drop of NACA 00XX airfoil fin PCHE decreases as airfoil thickness increases. • Heat transfer performance of NACA 00XX airfoil fin PCHE increases as airfoil thickness rises. • Comprehensive performance of NACA 00XX airfoil fin PCHE degrades as airfoil thickness increases. - Abstract: Printed circuit heat exchanger (PCHE) can be used in supercritical carbon dioxide (S-CO_2) Brayton cycle. The present study compares NACA 0020 airfoil fin PCHE with conventional zigzag PCHE by numerical analysis. Pressure drop of the former has a striking reduction while maintaining excellent heat transfer performance. Comparison on four NACA 00XX series airfoil fin PCHEs is performed to investigate the influence of airfoil profile on flow and heat transfer performance. With a fixed vertical pitch, heat transfer performance of NACA series airfoil fin PCHE increases as airfoil thickness increases. However, comprehensive performance, in which both flow and heat transfer are taken into account, degrades with increasing airfoil thickness. Among four NACA airfoil fin PCHEs presented in this paper, NACA 0010 airfoil fin PCHE demonstrates the best comprehensive performance.

Necropsy report of a fin whale (Balaenoptera physalus) stranded in Denmark in 2010

DEFF Research Database (Denmark)

Alstrup, Aage K. O.; Hedayat, Abdi; Jensen, Trine Hammer

2013-01-01

There is little detailed information on stranded fin whales (Balaenoptera physalus) in the scientific literature (Notarbartolo di Sciara et al., 2003). In Denmark, at least eight fin whales stranded between the years 1603 and 1958 (Kinze, 1995). On 16 June 2010, a live subadult or adult male fin...... whale stranded in the Bay of Vejle (55º 69' N, 9º 58' E), Denmark. Despite several attempts, it was not possible to rescue the fin whale, which was only partially exposed by the water. The fin whale succumbed after 5 d stranded in shallow water. The dead fin whale was transported to a nearby pier...

FIN5 positively regulates far-red light responses in Arabidopsis thaliana

International Nuclear Information System (INIS)

Cho, D.S.; Hong, S.H.; Nam, H.G.; Soh, M.S.

2003-01-01

We report the characterization of a semi-dominant mutation fin5-1 (far-red insensitive 5-1) of Arabidopsis, which was isolated from genetic screening of phytochrome A (phyA) signaling components. Plants with the fin5-1 mutation exhibited a long hypocotyl phenotype when grown under far-red (FR) light, but not under red light. Physiological analyses implied that FIN5 might be differentially involved in diverse responses that are regulated by phyA under continuous FR light. Anthocyanin accumulation, gravitropic response of hypocotyl growth, and FR light-preconditioned blocking of greening were also impaired in the fin5-1 mutant, whereas photoperiodic floral induction was not, if at all, significantly affected. Moreover, light-regulated expression of the CHS, PORA and PsbS genes was attenuated in fin5-1 mutant plants, while the light-induced expression of CAB was normal. The mutation exhibited semi-dominance regarding control of hypocotyl growth in FR light. We suggest that FIN5 defines a novel branch in the network of phyA signaling in Arabidopsis. (author)

新加坡FinTech生态系统建设及其启示%Singapore’s FinTech Ecological System Construction and Its Enlightenment

Institute of Scientific and Technical Information of China (English)

钟鸣长

2016-01-01

Since the financial crisis, the integration of finance and technology has become a new trend in global economic development, and become a hot issue in the political, business, and academic attention. Singapore government maps out a strategy and introduces a series of policies to build FinTech ecosystem, such as financial support, establishing FinTech SUB, and implementing regulatory sandbox. Thus, Singapore will transform the existing financial system, construct the FinTech hub, and become an intelligent country of S&T and intelligent financial center. However, Internet finance in China is still at the stage of FinTech1.0 currently, which appears to be fast, slant, and disordered. So it is urgent to be transformed and upgraded. Meanwhile, we should not only be fully aware of the necessity and urgency of FinTech ecosystem development, clarify the relation between Internet financial and FinTech, but also we should learn from Singapore’s advanced experience to develop the FinTech ecosystem in all aspects, for example, setting up specialized management institutions, determining specific development goals, providing financial support, promoting “Regulatory Sandbox”, mobilizing domestic and international market resources, and exerting the role of the government, market, and enterprises.%金融危机以来，金融与科技的融合成为全球经济发展的一股新潮流和趋势，成为政、商、学界关注的热点话题。新加坡从资金支持、搭建创业加速平台、推行监管沙盒等方面推出了打造FinTech生态系统的组合拳，旨在改造现有金融体系、建设FinTech枢纽中心，立志成为世界智慧科技大国和智慧金融中心。中国互联网金融目前总体上还处于FinTech1.0阶段，呈现一种“快、偏、乱”的现象，亟需转型与升级。因此，我们不仅要充分意识到FinTech产业发展的必要性和紧迫性，厘清互联网金融与Fin

The performance of a new gas to gas heat exchanger with strip fin

NARCIS (Netherlands)

Wang, J.; Hirs, Gerard; Rollmann, P.

1999-01-01

A compact gas to gas heat exchanger needs large heat transfer areas on both fluid sides. This can be realised by adding secondary surfaces. The secondary surfaces are plate fin, strip fin, and louvered fin, etc. The fins extend the heat transfer surfaces and promote turbulence. This paper presents a

Performance Analysis of a Self-Propelling Flat Plate Fin with Joint Compliance

Science.gov (United States)

Reddy, N. Srinivasa; Sen, Soumen; Pal, Sumit; Shome, Sankar Nath

2017-12-01

Fish fin muscles are compliant and they regulate the stiffness to suit different swimming conditions. This article attempts to understand the significance of presence of compliance in fin muscle with help of a flexible joint flat plate fin model. Blade element method is employed to model hydrodynamics and to compute the forces of interaction during motion of the plate within fluid. The dynamic model of self-propelling fin is developed through multi-body dynamics approach considering the hydrodynamic forces as external forces acting on the fin. The derived hydrodynamic model is validated with experiments on rigid flat plate fin. The effect of the joint stiffness and flapping frequency on the propulsion speed and efficiency is investigated through simulations using the derived and validated model. The propulsion efficiency is found to be highly influenced by the joint stiffness at a given flapping frequency. The fin attained maximum propulsion efficiency when the joint stiffness is tuned to a value at which flapping frequency matches near natural frequency of the fin. At this tuned joint stiffness and flapping frequency, the resulted Strouhal numbers are observed to fall within the optimum range (0.2 to 0.4) for maximized propulsion efficiency of flying birds and swimming aquatic animals reported in literature.

Robotic Pectoral Fin Thrust Vectoring Using Weighted Gait Combinations

Directory of Open Access Journals (Sweden)

John S. Palmisano

2012-01-01

Full Text Available A method was devised to vector propulsion of a robotic pectoral fin by means of actively controlling fin surface curvature. Separate flapping fin gaits were designed to maximize thrust for each of three different thrust vectors: forward, reverse, and lift. By using weighted combinations of these three pre-determined main gaits, new intermediate hybrid gaits for any desired propulsion vector can be created with smooth transitioning between these gaits. This weighted gait combination (WGC method is applicable to other difficult-to-model actuators. Both 3D unsteady computational fluid dynamics (CFD and experimental results are presented.

Time-Dependent Response of Polypropylene/Clay Nanocomposites Under Tension and Retraction

DEFF Research Database (Denmark)

Drozdov, Aleksey; Christiansen, Jesper de Claville

2013-01-01

Observations are reported in relaxation tests under tension and retraction on polypropylene/clay nanocomposites with various contents of filler. A two-phase constitutive model is developed in cyclic viscoelasticity and viscoplasticity of nanocomposites. Adjustable parameters in the stress–strain ...

Retraction Note: Radiation Sialadenitis Induced by High-dose Radioactive Iodine Therapy

International Nuclear Information System (INIS)

Jeong, Shin Young; Lee, Jaetae

2014-01-01

The senior author (J. Lee) and the first author (S. Y. Jeong) have retracted this review article due to misconduct. They have discovered multiple instances of misreferencing and misquotation in the text which raise the concern of potential plagiarism

Retraction Note: Radiation Sialadenitis Induced by High-dose Radioactive Iodine Therapy

Energy Technology Data Exchange (ETDEWEB)

Jeong, Shin Young; Lee, Jaetae [Kyungpook National Univ. Hospital, Daegu (Korea, Republic of)

2014-06-15

The senior author (J. Lee) and the first author (S. Y. Jeong) have retracted this review article due to misconduct. They have discovered multiple instances of misreferencing and misquotation in the text which raise the concern of potential plagiarism.

Heat transfer in laminar flow for a finned double - tube

International Nuclear Information System (INIS)

Colle, S.

1977-01-01

An analitical study of the steady-state heat transfer in laminar flow in finned double-tube heat exchangers is presented. The fins are plane, straight and continous, equally spaced and are fixed over the external surface of the inner tube. A constant peripheral temperature distribution is assumed to apply over the inner tube surface and each fin, and a constant peripheral heat flux is assumed to apply over the outer tube surface, while the overall heat flux is suposed to be uniform in the longitudinal direction of the duct. The prediction of the thermal performance of the finned double-tube is made by means of the relationship between the Nusselt number, the boundary conditions and the geometric characteristcs of the duct. (author) [pt

3D site specific sample preparation and analysis of 3D devices (FinFETs) by atom probe tomography.

Science.gov (United States)

Kambham, Ajay Kumar; Kumar, Arul; Gilbert, Matthieu; Vandervorst, Wilfried

2013-09-01

With the transition from planar to three-dimensional device architectures such as Fin field-effect-transistors (FinFETs), new metrology approaches are required to meet the needs of semiconductor technology. It is important to characterize the 3D-dopant distributions precisely as their extent, positioning relative to gate edges and absolute concentration determine the device performance in great detail. At present the atom probe has shown its ability to analyze dopant distributions in semiconductor and thin insulating materials with sub-nm 3D-resolution and good dopant sensitivity. However, so far most reports have dealt with planar devices or restricted the measurements to 2D test structures which represent only limited challenges in terms of localization and site specific sample preparation. In this paper we will discuss the methodology to extract the dopant distribution from real 3D-devices such as a 3D-FinFET device, requiring the sample preparation to be carried out at a site specific location with a positioning accuracy ∼50 nm. Copyright © 2013 Elsevier B.V. All rights reserved.

Propulsion of a fin whale (Balaenoptera physalus): why the fin whale is a fast swimmer.

Science.gov (United States)

Bose, N; Lien, J

1989-07-22

Measurements of an immature fin whale (Balaenoptera physalus), which died as a result of entrapment in fishing gear near Frenchmans Cove, Newfoundland (47 degrees 9' N, 55 degrees 25' W), were made to obtain estimates of volume and surface area of the animal. Detailed measurements of the flukes, both planform and sections, were also obtained. A strip theory was developed to calculate the hydrodynamic performance of the whale's flukes as an oscillating propeller. This method is based on linear, two-dimensional, small-amplitude, unsteady hydrofoil theory with correction factors used to account for the effects of finite span and finite amplitude motion. These correction factors were developed from theoretical results of large-amplitude heaving motion and unsteady lifting-surface theory. A model that makes an estimate of the effects of viscous flow on propeller performance was superimposed on the potential-flow results. This model estimates the drag of the hydrofoil sections by assuming that the drag is similar to that of a hydrofoil section in steady flow. The performance characteristics of the flukes of the fin whale were estimated by using this method. The effects of the different correction factors, and of the frictional drag of the fluke sections, are emphasized. Frictional effects in particular were found to reduce the hydrodynamic efficiency of the flukes significantly. The results are discussed and compared with the known characteristics of fin-whale swimming.

Real-time CARS imaging reveals a calpain-dependent pathway for paranodal myelin retraction during high-frequency stimulation.

Directory of Open Access Journals (Sweden)

Terry B Huff

2011-03-01

Full Text Available High-frequency electrical stimulation is becoming a promising therapy for neurological disorders, however the response of the central nervous system to stimulation remains poorly understood. The current work investigates the response of myelin to electrical stimulation by laser-scanning coherent anti-Stokes Raman scattering (CARS imaging of myelin in live spinal tissues in real time. Paranodal myelin retraction at the nodes of Ranvier was observed during 200 Hz electrical stimulation. Retraction was seen to begin minutes after the onset of stimulation and continue for up to 10 min after stimulation was ceased, but was found to reverse after a 2 h recovery period. The myelin retraction resulted in exposure of Kv 1.2 potassium channels visualized by immunofluorescence. Accordingly, treating the stimulated tissue with a potassium channel blocker, 4-aminopyridine, led to the appearance of a shoulder peak in the compound action potential curve. Label-free CARS imaging of myelin coupled with multiphoton fluorescence imaging of immuno-labeled proteins at the nodes of Ranvier revealed that high-frequency stimulation induced paranodal myelin retraction via pathologic calcium influx into axons, calpain activation, and cytoskeleton degradation through spectrin break-down.

Optimization of geometric parameters of heat exchange pipes pin finning

Science.gov (United States)

Akulov, K. A.; Golik, V. V.; Voronin, K. S.; Zakirzakov, A. G.

2018-05-01

The work is devoted to optimization of geometric parameters of the pin finning of heat-exchanging pipes. Pin fins were considered from the point of view of mechanics of a deformed solid body as overhang beams with a uniformly distributed load. It was found out under what geometric parameters of the nib (diameter and length); the stresses in it from the influence of the washer fluid will not exceed the yield strength of the material (aluminum). Optimal values of the geometric parameters of nibs were obtained for different velocities of the medium washed by them. As a flow medium, water and air were chosen, and the cross section of the nibs was round and square. Pin finning turned out to be more than 3 times more compact than circumferential finning, so its use makes it possible to increase the number of fins per meter of the heat-exchanging pipe. And it is well-known that this is the main method for increasing the heat transfer of a convective surface, giving them an indisputable advantage.

Numerical simulation of natural convection in annuli with internal fins

International Nuclear Information System (INIS)

Ha, Man Yeong; Kim, Joo Goo

2004-01-01

The solution for the natural convection in internally finned horizontal annuli is obtained by using a numerical simulation of time-dependent and two-dimensional governing equations. The fins existing in annuli influence the flow pattern, temperature distribution and heat transfer rate. The variations of the fin configuration suppress or accelerate the free convective effects compared to those of the smooth tubes. The effects of fin configuration, number of fins and ratio of annulus gap width to the inner cylinder radius on the fluid flow and heat transfer in annuli are demonstrated by the distribution of the velocity vector, isotherms and streamlines. The governing equations are solved efficiently by using a parallel implementation. The technique is adopted for reduction of the computation cost. The parallelization is performed with the domain decomposition technique and message passing between sub-domains on the basis of the MPI library. The results from parallel computation reveal in consistency with those of the sequential program. Moreover, the speed-up ratio shows linearity with the number of processor

Collector Efficiency in Downward-Type Internal-Recycle Solar Air Heaters with Attached Fins

Directory of Open Access Journals (Sweden)

Chii-Dong Ho

2013-10-01

Full Text Available The internal-recycle operation effect on collector efficiency in downward-type rectangular solar air heaters with attached fins is theoretically investigated. It is found that considerable collector efficiency is obtainable if the collector has attached fins and the operation is carried out with internal recycling. The recycling operation increases the fluid velocity to decrease the heat transfer resistance, compensating for the undesirable effect of decreasing the heat transfer driving force (temperature difference due to remixing. The attached fins provide an enlarged heat transfer area. The order of performance in a device of same size is: double pass with recycle and fins > double pass with recycle but without fins > single pass without recycle and fins.

Embedded SMA wire actuated biomimetic fin: a module for biomimetic underwater propulsion

International Nuclear Information System (INIS)

Wang Zhenlong; Hang Guanrong; Wang Yangwei; Li Jian; Du Wei

2008-01-01

An embedded shape memory alloy (SMA) wire actuated biomimetic fin is presented, and based on this module for biomimetic underwater propulsion, a micro robot fish (146 mm in length, 30 g in weight) and a robot squid (242 mm in length, 360 g in weight) were developed. Fish swim by undulating their body and/or fins. Squid and cuttlefish can also swim by undulating their fins. To simplify engineering modeling, the undulating swimming movement is assumed to be the integration of the movements of many flexible bending segments connected in parallel or in series. According to this idea, a biomimetic fin which can bend flexibly was developed. The musculature of a cuttlefish fin was investigated to aid the design of the biomimetic fin. SMA wires act as 'muscle fibers' to drive the biomimetic fin just like the transverse muscles of the cuttlefish fin. During the bending phase, elastic energy is stored in the elastic substrate and skin, and during the return phase, elastic energy is released to power the return movement. Theorem analysis of the bending angle was performed to estimate the bending performance of the biomimetic fin. Experiments were carried out on single-face fins with latex rubber skin and silicone skin (SF-L and SF-S) to compare the bending angle, return time, elastic energy storage and reliability. Silicone was found to be the better skin. A dual-face fin with silicone skin (DF-S) was tested in water to evaluate the actuating performance and to validate the reliability. Thermal analysis of the SMA temperature was performed to aid the control strategy. The micro robot fish and robot squid employ one and ten DF-S, respectively. Swimming experiments with different actuation frequencies were carried out. The speed and steering radius of the micro robot fish reached 112 mm s −1 and 136 mm, respectively, and the speed and rotary speed of the robot squid reached 40 mm s −1 and 22° s −1 , respectively

Fin field effect transistor directionality impacts printing of implantation shapes

Science.gov (United States)

Wang, Xiren; Granik, Yuri

2018-01-01

In modern integrated circuit (IC) fabrication processes, the photoresist receives considerable illumination energy that is reflected by underlying topography during optical lithography of implantation layers. Bottom antireflective coating (BARC) is helpful to mitigate the reflection. Often, however, BARC is not used, because its removal is technically challenging, in addition to its relatively high economic cost. Furthermore, the advanced technology nodes, such as 14/10-nm nodes, have introduced fin field effect transistor (FinFET), which makes reflection from nonuniform silicon substrates exceptionally complicated. Therefore, modeling reflection from topography becomes obligatory to accurately predict printing of implantation shapes. Typically, FinFET is always fixed in one direction in realistic designs. However, the same implantation rectangle may be oriented in either horizontal or vertical direction. Then, there are two types of relations between the critical dimension (CD) and FinFET, namely a parallel-to and a perpendicular-to relation. We examine the fin directionality impact on CD. We found that this impact may be considerable in some cases. We use our in-house rigorous optical topography simulator to reveal underlining physical reasons. One of the major causes of the CD differences is that in the parallel orientation, the solid sidewalls of the fins conduct considerable light reflections unlike for the perpendicular orientation. This finding can aid the compact modeling in optical proximity correction of implantation masks.

Protective Role of Comfrey Leave Extracts on UV-induced Zebrafish Fin Damage

OpenAIRE

Cheng, Chien-Chung; Chou, Chi-Yuan; Chang, Yao-Chin; Wang, Hsuan-Wen; Wen, Chi-Chung; Chen, Yau-Hung

2014-01-01

In zebrafish, UV exposure leads to fin malformation phenotypes including fin reduction or absence. The present study evaluated UV-protective activities of comfrey leaves extracts in a zebrafish model by recording fin morphological changes. Chemopreventive effects of comfrey leave extracts were evaluated using Kaplan-Meier analysis and Cox proportional hazards regression. The results showed that (1) the mean times of return to normal fin in the UV+comfrey (50 and 100 ppm) groups were 3.43 and ...

RETRACTED: Granular and intergranular conduction in La{sub 1.32}Sr{sub 1.68}Mn{sub 2}O{sub 7} layered manganite system

Energy Technology Data Exchange (ETDEWEB)

Narjis, A., E-mail: NARJIS78@gmail.com [Research Group ESNPS, Physics department, University Ibn Zohr, Faculty of Sciences, B.P 8106, Hay Dakhla, 80000 Agadir (Morocco); El kaaouachi, A.; Dlimi, S. [Research Group ESNPS, Physics department, University Ibn Zohr, Faculty of Sciences, B.P 8106, Hay Dakhla, 80000 Agadir (Morocco); Biskupski, G. [Laboratoire de Spectroscopie Hertzienne LSH, Bâtiment P5, Université des Sciences et Technologies, de Lille I 59 655 Villeneuve d’Ascq Cedex (France); Daoudi, E.; Errai, M.; Sybous, A.; Limouny, L. [Research Group ESNPS, Physics department, University Ibn Zohr, Faculty of Sciences, B.P 8106, Hay Dakhla, 80000 Agadir (Morocco)

2013-06-15

This article has been retracted: please see Elsevier Policy on Article Withdrawal ( (http://www.elsevier.com/locate/withdrawalpolicy)). This article has been retracted at the request of the Editors. The authors have plagiarized part of a paper that had already appeared in J. Appl. Phys. 106, 093709 (2009); (10.1063/1.3256182) (6 pages): Title: Effects of pressure on charge transport and magnetic properties of La1.32Sr1.68Mn2O7 layered manganite by M. Kumaresavanji, M. S. Reis, Y. T. Xing, and M. B. Fontes. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

Computational investigation of heat transfer and pressure drop in a typical louver fin-and-tube heat exchanger for various louver angles and fin pitches

Directory of Open Access Journals (Sweden)

Okbaz Abdulkerim

2017-01-01

Full Text Available In this study 3-D numerical simulations on heat transfer and pressure drop characteristics for a typical louver fin-and- double-row tube heat exchanger were carried out. The heat transfer improvement and the corresponding pressure drop amounts were investigated depending on louver angles, fin pitch and Reynolds number, and reported in terms of Colburn j-factor and Fanning friction factor f. The heat transfer improvement and the corresponding pressure drop amounts were investigated depending on louver angles between 20° ≤Ө≤ 30°, louver pitch of Lp=3.8 mm and frontal velocities of U between 1.22 m/s - 3 m/s. In addition, flow visualization of detailed flow features results, such as velocity vectors, streamlines and temperature counters have been shown to understand heat transfer enhancement mechanism. The present results indicated that louver angle and fin pitch noticeably affected the thermal and hydraulic performance of heat exchanger. It has been seen that increasing louver angle, increases thermal performance while decreasing hydraulic performance associated to pressure drop for fin pitches of 3.2 mm and 2.5 mm. Fin pitch determines the flow behaviour that for fin pitch of 2 mm, increasing louver angle decreased heat transfer and pressure drop. Velocity vectors and streamlines give considerable information about the flow whether it is duct directed or louver directed. For all conditions the flow is louver directed.

Characteristics and formation mechanism for stainless steel fiber with periodic micro-fins

Science.gov (United States)

Tang, Tao; Wan, Zhenping; Lu, Longsheng; Tang, Yong

2016-05-01

Metal fibers have been widely used in many industrial applications due to their unique advantages. In certain applications, such as catalyst supports or orthopedic implants, a rough surface or tiny outshoots on the surface of metal fibers to increase surface area are needed. However, it has not been concerned about the surface morphologies of metal fiber in the current research of metal fiber manufacturing. In this paper, a special multi-tooth tool composed of a row of triangular tiny teeth is designed. The entire cutting layer of multi-tooth tool bifurcates into several thin cutting layers due to tiny teeth involved in cutting. As a result, several stainless steel fibers with periodic micro-fins are produced simultaneously. Morphology of periodic micro-fins is found to be diverse and can be classified into three categories: unilateral plane, unilateral tapering and bilateral. There are two forming mechanisms for the micro-fins. One is that periodic burrs remained on the free side of cutting layer of a tiny tooth create micro-fins of stainless steel fiber produced by the next neighboring tiny tooth; the other is that the connections between two fibers stuck together come to be micro-fins if the two fibers are finally detached. Influence of cutting conditions on formation of micro-fins is investigated. Experimental results show that cutting depth has no significant effect on micro-fin formation, high cutting speed is conducive to micro-fin formation, and feed should be between 0.12 mm/r and 0.2 mm/r to reliably obtain stainless steel fiber with micro-fins. This research presents a new pattern of stainless steel fiber characterized by periodic micro-fins formed on the edge of fiber and its manufacturing method.

印度尼西亚FinTech生态圈的发展及机遇%Development and Opportunities of FinTech Ecosystem in Indonesia

Institute of Scientific and Technical Information of China (English)

熊琦

2018-01-01

印尼FinTech是新兴行业,自2014年以来呈现井喷式增长,其生态圈竞争优势主要体现在需求方面:潜在市场巨大,资本投入增长迅猛,但人才优势尚显不足,政策上积极学习国际经验,已推出"监管沙盒"和针对P2P的严格管控法规,从长远看能促进FinTech包容性发展;印尼银行渗透率低,银行分支机构少,物理基础设施建设不足,且印尼人的FinTech意识较弱,中国FinTech企业在印尼的个人消贷和中小企业融资领域将大有作为;可加大对印尼的资金支持以帮助当地建设,更好地进行合作发展FinTech行业,实现共赢.

A Novel Implementation of a Flexible Robotic Fin Actuated by Shape Memory Alloy

Institute of Scientific and Technical Information of China (English)

Qin Yan; Lei Wang; Bo Liu; Jie Yang; Shiwu Zhang

2012-01-01

In this paper,study of a novel flexible robotic-fin actuated by Shape Memory Alloy (SMA) is presented.The developed robotic fin is capable of implementing various 3-Dimensional (3D) motions,which plays an important role in robot propulsion and maneuverability.Firstly,the morphological and mechanics parameters of a real pectoral fin from a carp are investigated.Secondly,a detailed design of the flexible pectoral fin driven by SMA is presented according to the previous morphological and mechanics analyses.Thirdly,a simplified theoretical model on the SMA fin plate is derived.The thermodynamics of the SMA plate and the relationship between curvature and phase transformation are analyzed.Finally,several simulations and model experiments are conducted according to the previous analyses.The results of the experiments are useful for the control of the robotic fin.The experimental results reveal that the SMA actuated fin ray has a good actuating performance.

Evolution of neck vertebral shape and neck retraction at the transition to modern turtles: an integrated geometric morphometric approach.

Science.gov (United States)

Werneburg, Ingmar; Wilson, Laura A B; Parr, William C H; Joyce, Walter G

2015-03-01

The unique ability of modern turtles to retract their head and neck into the shell through a side-necked (pleurodiran) or hidden-necked (cryptodiran) motion is thought to have evolved independently in crown turtles. The anatomical changes that led to the vertebral shapes of modern turtles, however, are still poorly understood. Here we present comprehensive geometric morphometric analyses that trace turtle vertebral evolution and reconstruct disparity across phylogeny. Disparity of vertebral shape was high at the dawn of turtle evolution and decreased after the modern groups evolved, reflecting a stabilization of morphotypes that correspond to the two retraction modes. Stem turtles, which had a very simple mode of retraction, the lateral head tuck, show increasing flexibility of the neck through evolution towards a pleurodiran-like morphotype. The latter was the precondition for evolving pleurodiran and cryptodiran vertebrae. There is no correlation between the construction of formed articulations in the cervical centra and neck mobility. An increasing mobility between vertebrae, associated with changes in vertebral shape, resulted in a more advanced ability to retract the neck. In this regard, we hypothesize that the lateral tucking retraction of stem turtles was not only the precondition for pleurodiran but also of cryptodiran retraction. For the former, a kink in the middle third of the neck needed to be acquired, whereas for the latter modification was necessary between the eighth cervical vertebra and first thoracic vertebra. Our paper highlights the utility of 3D shape data, analyzed in a phylogenetic framework, to examine the magnitude and mode of evolutionary modifications to vertebral morphology. By reconstructing and visualizing ancestral anatomical shapes, we provide insight into the anatomical features underlying neck retraction mode, which is a salient component of extant turtle classification. © The Author(s) 2014. Published by Oxford University Press

[Treatment of eyelid retraction in Grave's disease by recession of the levator complex].

Science.gov (United States)

Fichter, N; Schittkowski, M; Guthoff, R F

2004-11-01

The chronic stage in Grave's orbitopathy is characterised by fibrotic changes within the orbital soft tissues, especially the extraocular muscles. Retraction of the eyelids is a common clinical feature of this phenomenon. To solve this problem several techniques for lengthening the upper eyelid have been described with variable rates of success. In this report we describe our modified Harvey's technique for the correction of upper eyelid retraction which includes a complete recession of the Muller's muscle/levator complex from the tarsal plate without the interposition of a spacer. Finally only the skin and the superficial orbicularis muscle are sutured. We also report about our results with this procedure. 8 patients (1 male, 7 female) with lid retraction in Grave's ophthalmopathy were recorded who had undergone the modified lengthening technique by an external approach between 2001 and 2004. Four patients underwent a bilateral procedure and 1 patient showed a significant under-correction, necessitating reoperation. So a total of 13 procedures were included in this follow-up study. Beside the common ophthalmological examination, special interest was put in the difference of the two eyelid apertures in primary position pre- and postoperatively. Within a follow-up period of at least 3 months we recorded an averaged lengthening of the upper eyelid of 3.1 mm. The difference of the two eyelid apertures in primary position improved from 2.2 mm preoperatively to 1.0 mm postoperatively. Only 1 patient needed reoperation because of a significant under-correction. There were no late over-corrections observed. The modified Harvey's technique to lengthen the upper eyelid is a safe and effective method to reduce upper eyelid retraction in Grave's disease. An eventually required orbital decompression or extraocular muscle surgery has to be done before the lid surgery.

The FLUFF code for calculating finned surface heat transfer -description and user's guide

International Nuclear Information System (INIS)

Fry, C.J.

1985-08-01

FLUFF is a computer code for calculating heat transfer from finned surfaces by convection and radiation. It can also represent heat transfer by radiation to a partially emitting and absorbing medium within the fin cavity. The FLUFF code is useful not only for studying the behaviour of finned surfaces but also for deriving heat fluxes which can be applied as boundary conditions to other heat transfer codes. In this way models of bodies with finned surfaces may be greatly simplified since the fins need not be explicitly represented. (author)

Evaluation of integrally finned cladding for LMFBR fuel pins

International Nuclear Information System (INIS)

Cantley, D.A.; Sutherland, W.H.

1975-01-01

An integral fin design effectively reduces the coolant temperature gradients within an LMFBR subassembly by redistributing coolant flow so as to reduce the maximum cladding temperature and increase the duct wall temperature. The reduced cladding temperatures are offset by strain concentrations resulting from the fin geometry, so there is little net effect on predicted fuel pin performance. The increased duct wall temperatures, however, significantly reduce the duct design lifetime so that the final conclusion is that the integral fin design is inferior to the standard wire wrap design. This result, however, is dependent upon the material correlations used. Advanced alloys with improved irradiation properties could alter this conclusion

Experimental study of flow friction characteristics of integral pin-fin tubes

International Nuclear Information System (INIS)

Ding Ming; Yan Changqi; Sun Licheng

2007-01-01

Friction characteristics of integral pin-fin tubes, through which lubricating-oil flowed vertically, were studied experimentally. Effects of the pitch, the height of fins and the machining direction on friction coefficient were analyzed. The experimental results showed that the friction coefficient of the integral pin-fro tube was obviously lager than that of smooth tube. Compared with other influential factors, the effect of the height of fins was dominant. Because the three-dimensional pin fin could disturb and destroy the boundary layer, when the Reynolds Number reached 200-300, the friction coefficient curve began to bend, that was, a turning point was appeared in the friction coefficient curve. (authors)

Osseous outgrowth on the buccal maxilla associated with piezosurgery-assisted en-masse retraction: A case series.

Science.gov (United States)

Tunçer, Nilüfer İrem; Arman-Özçırpıcı, Ayça; Oduncuoğlu, Bahar Füsun; Kantarcı, Alpdoğan

2018-01-01

Piezoelectric surgery is a novel surgical approach used in orthodontic treatment for rapid tooth movement. This paper presents a case series wherein osseous outgrowths were observed in response to piezosurgery-assisted en-masse retraction. Sixteen patients requiring upper premolar extractions were treated with miniscrew-supported en-masse retraction and received minimally invasive decortication via piezosurgery. Computed tomography (CT) of the maxillary anterior region was performed to investigate the nature of the outgrowths. In 8 of the 16 patients, hemispheric or disc-shaped osseous outgrowths were observed on the sites where piezosurgery was performed during retraction. CT images revealed that these outgrowths were alveolar bone. This case series presents a previously unreported osseous response to piezosurgery-assisted tooth movement during orthodontic treatment. The response is mostly transient and is observed in 50% of the treated patients, suggesting a bone turnover that can be assessed clinically and radiographically.

Surge in Journal Retractions May Mask Decline in Actual Problems

Science.gov (United States)

Basken, Paul

2012-01-01

Scientific journals have been retracting unreliable articles at rapidly escalating rates in the past few years, raising concern about whether research faces a burgeoning ethical crisis. Various causes have been suspected, with the common theme being that journals are seeing more cases of plagiarism and fudging of data as researchers and editors…

RETRACTED: Diagnosis of cervical cancer cell taken from scanning electron and atomic force microscope images of the same patients using discrete wavelet entropy energy and Jensen Shannon, Hellinger, Triangle Measure classifier

Science.gov (United States)

Aytac Korkmaz, Sevcan

2016-05-01

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy) This article has been retracted at the request of the Editors. After a thorough investigation, the Publisher has concluded that the Editor was misled into accepting this article based upon the positive advice of at least one suggested reviewer report. The report was submitted from an email account provided by the author, that was later determined not to be the email of the supposed expert reviewer. This manipulation of the peer-review process represents a clear violation of the fundamentals of peer review, our publishing policies, and publishing ethics standards. Apologies are offered to the reviewers whose identities were assumed and to the readers of the journal that this deception was not detected during the submission process.

An IPMC-enabled bio-inspired bending/twisting fin for underwater applications

Science.gov (United States)

Palmre, Viljar; Hubbard, Joel J.; Fleming, Maxwell; Pugal, David; Kim, Sungjun; Kim, Kwang J.; Leang, Kam K.

2013-01-01

This paper discusses the design, fabrication, and characterization of an ionic polymer-metal composite (IPMC) actuator-based bio-inspired active fin capable of bending and twisting motion. It is pointed out that IPMC strip actuators are used in the simple cantilever configuration to create simple bending (flapping-like) motion for propulsion in underwater autonomous systems. However, the resulting motion is a simple 1D bending and performance is rather limited. To enable more complex deformation, such as the flapping (pitch and heaving) motion of real pectoral and caudal fish fins, a new approach which involves molding or integrating IPMC actuators into a soft boot material to create an active control surface (called a ‘fin’) is presented. The fin can be used to realize complex deformation depending on the orientation and placement of the actuators. In contrast to previously created IPMCs with patterned electrodes for the same purpose, the proposed design avoids (1) the more expensive process of electroless plating platinum all throughout the surface of the actuator and (2) the need for specially patterning the electrodes. Therefore, standard shaped IPMC actuators such as those with rectangular dimensions with varying thicknesses can be used. One unique advantage of the proposed structural design is that custom shaped fins and control surfaces can be easily created without special materials processing. The molding process is cost effective and does not require functionalizing or ‘activating’ the boot material similar to creating IPMCs. For a prototype fin (90 mm wide × 60 mm long × 1.5 mm thick), the measured maximum tip displacement was approximately 44 mm and the twist angle of the fin exceeded 10°. Lift and drag measurements in water where the prototype fin with an airfoil profile was dragged through water at a velocity of 21 cm s-1 showed that the lift and drag forces can be affected by controlling the IPMCs embedded into the fin structure. These

A three-dimensional numerical study and comparison between the air side model and the air/water side model of a plain fin-and-tube heat exchanger

International Nuclear Information System (INIS)

Borrajo-Pelaez, R.; Ortega-Casanova, J.; Cejudo-Lopez, J.M.

2010-01-01

CFD is becoming an important heat exchanger research technique. It constitutes an inexpensive prediction method, avoiding the need of testing numerous prototypes. Current work in this field is mostly based on air flow models assuming constant temperature of fin-and-tube surface. The purpose of this paper is to present an enhanced model, whose innovation lies in considering additionally the water flow in the tubes and the conduction heat transfer through the fin and tubes, to demonstrate that the neglect of these two phenomena causes a simulation result accuracy reduction. 3-D Numerical simulations were accomplished to compare both an air side and an air/water side model. The influence of Reynolds number, fin pitch, tube diameter, fin length and fin thickness was studied. The exchanger performance was evaluated through two non-dimensional parameters: the air side Nusselt number and a friction factor. It was found that the influence of the five parameters over the mechanical and thermal efficiencies can be well reported using these non-dimensional coefficients. The results from the improved model showed more real temperature contours, with regard to those of the simplified model. Therefore, a higher accuracy of the heat transfer was achieved, yielding better predictions on the exchanger performance.

Fish's Muscles Distortion and Pectoral Fins Propulsion of Lift-Based Mode

Science.gov (United States)

Yang, S. B.; Han, X. Y.; Qiu, J.

As a sort of MPF(median and/or paired fin propulsion), pectoral fins propulsion makes fish easier to maneuver than other propulsion, according to the well-established classification scheme proposed by Webb in 1984. Pectoral fins propulsion is classified into oscillatory propulsion, undulatory propulsion and compound propulsion. Pectoral fins oscillatory propulsion, is further ascribable to two modes: drag-based mode and lift-based mode. And fish exhibits strong cruise ability by using lift-based mode. Therefore to robot fish design using pectoral fins lift-based mode will bring a new revolution to resources exploration in blue sea. On the basis of the wave plate theory, a kinematic model of fish’s pectoral fins lift-based mode is established associated with the behaviors of cownose ray (Rhinoptera bonasus) in the present work. In view of the power of fish’s locomotion from muscle distortion, it would be helpful benefit to reveal the mechanism of fish’s locomotion variation dependent on muscles distortion. So this study puts forward the pattern of muscles distortion of pectoral fins according to the character of skeletons and muscles of cownose ray in morphology and simulates the kinematics of lift-based mode using nonlinear analysis software. In the symmetrical fluid field, the model is simulated left-right symmetrically or asymmetrically. The results qualitatively show how muscles distortion determines the performance of fish locomotion. Finally the efficient muscles distortion associated with the preliminary dynamics is induced.

Performance investigation of an innovative offset strip fin arrays in compact heat exchangers

International Nuclear Information System (INIS)

Peng, Hao; Ling, Xiang; Li, Juan

2014-01-01

Highlights: • The effect of fin pitch, length and bending distance on thermal performance were presented. • The corresponding Re C values at the j and f slope changes are in the range of 2000–2100. • The numerical results showed a good agreement with the experimental data. • Local high Nu values near the channel inlet, decreasing through the flow directions. - Abstract: Experimental and numerical studies on the flow and heat transfer characteristics for an innovative offset strip fins compact heat exchangers were performed. First, five fin schemes were investigated with various air flow velocities and a constant inlet steam pressure by experiments. The Reynolds number ranged from 500 to 5000 at the air side. The experimental results indicated that the fin pitch (P f ), fin length (L f ) and fin bending distance (C f ) have a significant influence on thermal performance of fins. The Colburn factor j, friction factor f and ‘point of transition’ were calculated from the experimental data. Then, the thermal–hydraulic performances of the novel offset strip fins were analyzed numerically. The simulation results obtained are in agreement with experimental data. Based on these simulations, the maximum values for local Nu number are at the channel inlet which is due to the thermal entrance effect. The longitudinal vortexes near the fin region will increase velocity gradient and reduce the thickness of boundary layer to improve heat transfer. The main conclusion draws from this work will be helpful for future development and design of a high-efficiency heat exchangers involving offset strip fin structures

Thermoelectric generator with hinged assembly for fins

International Nuclear Information System (INIS)

Purdy, D.L.; Shapiro, Z.M.; Hursen, T.F.; Maurer, G.W.

1976-01-01

A cylindrical casing has a central shielded capsule of radioisotope fuel. A plurality of thermonuclear modules are axially arranged with their hot junctions resiliently pressed toward the shield and with their cold junctions adjacent a transition member having fins radiating heat to the environment. For each module, the assembly of transition member and fins is hinged to the casing for swinging to permit access to and removal of such module. A ceramic plate having gold layers on opposite faces prevents diffusion bonding of the hot junction to the shield

Resolution of ray-finned fish phylogeny and timing of diversification.

Science.gov (United States)

Near, Thomas J; Eytan, Ron I; Dornburg, Alex; Kuhn, Kristen L; Moore, Jon A; Davis, Matthew P; Wainwright, Peter C; Friedman, Matt; Smith, W Leo

2012-08-21

Ray-finned fishes make up half of all living vertebrate species. Nearly all ray-finned fishes are teleosts, which include most commercially important fish species, several model organisms for genomics and developmental biology, and the dominant component of marine and freshwater vertebrate faunas. Despite the economic and scientific importance of ray-finned fishes, the lack of a single comprehensive phylogeny with corresponding divergence-time estimates has limited our understanding of the evolution and diversification of this radiation. Our analyses, which use multiple nuclear gene sequences in conjunction with 36 fossil age constraints, result in a well-supported phylogeny of all major ray-finned fish lineages and molecular age estimates that are generally consistent with the fossil record. This phylogeny informs three long-standing problems: specifically identifying elopomorphs (eels and tarpons) as the sister lineage of all other teleosts, providing a unique hypothesis on the radiation of early euteleosts, and offering a promising strategy for resolution of the "bush at the top of the tree" that includes percomorphs and other spiny-finned teleosts. Contrasting our divergence time estimates with studies using a single nuclear gene or whole mitochondrial genomes, we find that the former underestimates ages of the oldest ray-finned fish divergences, but the latter dramatically overestimates ages for derived teleost lineages. Our time-calibrated phylogeny reveals that much of the diversification leading to extant groups of teleosts occurred between the late Mesozoic and early Cenozoic, identifying this period as the "Second Age of Fishes."

Drosophila motor neuron retraction during metamorphosis is mediated by inputs from TGF-β/BMP signaling and orphan nuclear receptors.

Directory of Open Access Journals (Sweden)

Ana Boulanger

Full Text Available Larval motor neurons remodel during Drosophila neuro-muscular junction dismantling at metamorphosis. In this study, we describe the motor neuron retraction as opposed to degeneration based on the early disappearance of β-Spectrin and the continuing presence of Tubulin. By blocking cell dynamics with a dominant-negative form of Dynamin, we show that phagocytes have a key role in this process. Importantly, we show the presence of peripheral glial cells close to the neuro-muscular junction that retracts before the motor neuron. We show also that in muscle, expression of EcR-B1 encoding the steroid hormone receptor required for postsynaptic dismantling, is under the control of the ftz-f1/Hr39 orphan nuclear receptor pathway but not the TGF-β signaling pathway. In the motor neuron, activation of EcR-B1 expression by the two parallel pathways (TGF-β signaling and nuclear receptor triggers axon retraction. We propose that a signal from a TGF-β family ligand is produced by the dismantling muscle (postsynapse compartment and received by the motor neuron (presynaptic compartment resulting in motor neuron retraction. The requirement of the two pathways in the motor neuron provides a molecular explanation for the instructive role of the postsynapse degradation on motor neuron retraction. This mechanism insures the temporality of the two processes and prevents motor neuron pruning before postsynaptic degradation.

Drosophila motor neuron retraction during metamorphosis is mediated by inputs from TGF-β/BMP signaling and orphan nuclear receptors.

Science.gov (United States)

Boulanger, Ana; Farge, Morgane; Ramanoudjame, Christophe; Wharton, Kristi; Dura, Jean-Maurice

2012-01-01

Larval motor neurons remodel during Drosophila neuro-muscular junction dismantling at metamorphosis. In this study, we describe the motor neuron retraction as opposed to degeneration based on the early disappearance of β-Spectrin and the continuing presence of Tubulin. By blocking cell dynamics with a dominant-negative form of Dynamin, we show that phagocytes have a key role in this process. Importantly, we show the presence of peripheral glial cells close to the neuro-muscular junction that retracts before the motor neuron. We show also that in muscle, expression of EcR-B1 encoding the steroid hormone receptor required for postsynaptic dismantling, is under the control of the ftz-f1/Hr39 orphan nuclear receptor pathway but not the TGF-β signaling pathway. In the motor neuron, activation of EcR-B1 expression by the two parallel pathways (TGF-β signaling and nuclear receptor) triggers axon retraction. We propose that a signal from a TGF-β family ligand is produced by the dismantling muscle (postsynapse compartment) and received by the motor neuron (presynaptic compartment) resulting in motor neuron retraction. The requirement of the two pathways in the motor neuron provides a molecular explanation for the instructive role of the postsynapse degradation on motor neuron retraction. This mechanism insures the temporality of the two processes and prevents motor neuron pruning before postsynaptic degradation.

Combined natural convection heat and mass transfer from vertical fin arrays

International Nuclear Information System (INIS)

Giri, A.; Narasimham, G.S.V.L.; Krishna Murthy, M.V.

2003-01-01

Natural convection transport processes play an important role in many applications like ice-storage air-conditioning. A mathematical formulation of natural convection heat and mass transfer over a shrouded vertical fin array is developed. The base plate is maintained at a temperature below the dew point of the surrounding moist air. Hence there occurs condensation of moisture on the base plate, while the fins may be partially or fully wet. A numerical study is performed by varying the parameters of the problem. The local and average Nusselt numbers decrease in streamwise direction and tend to approach fully developed values for sufficiently large values of the fin length. The results show that beyond a certain streamwise distance, further fin length does not improve the sensible and latent heat transfer performance, and that if dry fin analysis is used under moisture condensation conditions, the overall heat transfer will be underestimated by about 50% even at low buoyancy ratios

Optimization of convective-radiative fins by using differential quadrature element method

International Nuclear Information System (INIS)

Malekzadeh, P.; Rahideh, H.; Karami, G.

2006-01-01

A first endeavor to exploit the differential quadrature element method (DQEM) as a simple, accurate and computationally efficient numerical tool for the shape optimization of convective-radiating extended surfaces or fins is made. The formulations are general so that the spatial and spatial-temperature dependent geometrical and thermal parameters can easily be implemented. The thermal conductivity of the fin is assumed to vary as a linear function of the temperature. The effects of a convective-radiative condition at the fin tip and effective convective condition at the fin base are considered. The optimization of fins with uniform and step cross-sections is investigated. The accuracy of the method is demonstrated by comparing its results with those generated by Adomian's decomposition technique, Taylor transformation technique and finite difference method. It is shown that, using few grid points, highly accurate results are obtained. Less computational effort of the method with respect to the finite difference method is shown

Retracted: "Hydrogeochemical behavior of arsenic-enriched groundwater in the deltaic environment: Comparison between two study sites in West Bengal, India" [Journal of Contaminant Hydrology 99 (2008) 22-30

Science.gov (United States)

Mukherjee-Goswami, Aishwaya; Nath, Bibhash; Jana, Joydev; Sahu, Sudip Jyoti; Sarkar, Madhav Jyoti; Jacks, Gunnar; Bhattacharya, Prosun; Mukherjee, Abhijit; Polya, David A.; Jean, Jiin-Shuh; Chatterjee, Debashis

2013-03-01

The above paper has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editors-in-Chief. Despite the inclusion of interesting original data in this paper, serious concerns have been raised about the manner of their interpretation in the Discussion section. Parts of papers Appl Geochem, 19 (2004), 1255-1293http://dx.doi.org/10.1016/j.apgeochem.2004.02.001 and Water Res. Research, 37(2001), 109-117http://dx.doi.org/10.1029/2000WR900270 have been plagiarized. An initial attempt to address this issue with the authors resulted in a Corrigendum but the explanations offered in this were not subjected to sufficient scrutiny, due to a combination of errors by the Publisher and the Editors-in-Chief, and were later judged to be incomplete.

Numerical Modeling of Transient Heat Transfer in Longitudinal Fin

Directory of Open Access Journals (Sweden)

Farshad Panahizadeh

2017-11-01

Full Text Available The main objective of the present numerical study is to investigate the transient heat transfer in one kind of all-purpose longitudinal fin with the triangular profile. The lateral surface of the concerned fin and the tip of it are subjected to general situations included heat flux at the base and insulation on the tip. For this study developed a one dimensional in house code written by Fortran 90 programming language by using finite difference method with an implicit scheme in unsteady state condition. Generally, the result of this study in time variation state after 700 seconds is steady. The results also show the fin efficiency by increasing the time of study decreases due to a reduction in the total heat transfer which is happened in the fin. The grid independence study shows that for the number of nodes greater than 20 the result will not be changed and same as before. Finally, the result of Fortran code verified by commercial CFD code which relies on finite difference method and it was shown have a consistent agreement

Effect of storage media and time on fin explants culture in the ...

African Journals Online (AJOL)

The effect of storage media and time was investigated on fin explants culture in the goldfish (Carassius auratus). Fin explants under sterile conditions were able to produce cells at different storage media and time. On the outgrowth of cells, fin explants stored for seven days before culturing showed significantly higher growth ...

Control of anterior segment using an antero-posterior lingual sliding retraction system: a preliminary cone-beam CT study

Directory of Open Access Journals (Sweden)

Min Hwang

2018-01-01

Full Text Available Abstract Background This study was performed to evaluate the treatment effects of the antero-posterior lingual retractor (APLR, focusing on the 3-dimensional (3D tooth movement of the maxillary anterior teeth and their alveolar bone levels. Methods En masse retraction was performed using either the C-lingual retractor (CLR, C-group, n = 9 or the antero-posterior lingual retractor (APLR, AP-group, n = 8. We evaluated 3D movement of the maxillary anterior teeth and alveolar bone levels, root length of the central incisors, long axes of the maxillary canines, and occlusal plane changes from CBCT images. Results After retraction, the central incisors were more significantly intruded and their root apex was more retracted in the AP-group. The long axis of the canine was well maintained in the AP-group. There were no differences in the steepness of occlusal plane and the incidence of alveolar bone loss or of root resorption during en masse retraction with the two retractors. Conclusions The clockwise bowing effect of the anterior segment was less with the APLR, which prevented unwanted canine movement.

Characteristics of a micro-fin evaporator: Theoretical analysis and experimental verification

OpenAIRE

Zheng Hui-Fan; Fan Xiao-Wei; Wang Fang; Liang Yao-Hua

2013-01-01

A theoretical analysis and experimental verification on the characteristics of a micro-fin evaporator using R290 and R717 as refrigerants were carried out. The heat capacity and heat transfer coefficient of the micro-fin evaporator were investigated under different water mass flow rate, different refrigerant mass flow rate, and different inner tube diameter of micro-fin evaporator. The simulation results of the heat transfer coefficient are fairly in good a...

A novel louvered fin design to enhance thermal and drainage performances during periodic frosting/defrosting conditions

International Nuclear Information System (INIS)

Kim, Min-Hwan; Kim, Hisuk; Kim, Dong Rip; Lee, Kwan-Soo

2016-01-01

Highlights: • Thermal and drainage performances of a novel design louvered fin were investigated. • The thermal performance of the asymmetric fin was improved in the re-frosting cycle. • The asymmetric louvered fin exhibited better drainage on the leading edge of fins. • Lower surface tension between fin surface and water droplet improved the drainage. - Abstract: The retention water on fin surface can significantly degrade the thermal performance of heat exchangers under periodic frosting/defrosting conditions, which also leads to a decrease in the energy efficiency of air-source heat pumps. A novel louvered fin design was suggested to improve the drainage and the thermal performance of heat exchanger. The novel louvered fin had an asymmetric louver arrangement by flattening two louvers on the leading edge. The retention water formed on fin surface markedly decreased the heat transfer rate of the conventional symmetric louvered fins in re-frosting cycles. On the other hand, the asymmetric louvered fins improved the drainage performance of the retention water, which enhanced the heat transfer rate. To identify the reason of the difference in drainage performance between two fin geometries, additional experiments were carried out with enlargement models. The improvement in drainage performance of the asymmetric fin design originated from the lowered surface tension between the fin surface and water droplet.

Hydrodynamic response of fuel rod with longitudinal fins to upstream generated vortices

International Nuclear Information System (INIS)

Naot, D.; Oron, A.; Technion-Israel Inst. of Tech., Haifa. Dept. of Mechanical Engineering)

1984-01-01

The hydrodynamic response of turbulent channel flow to upstream generated vortices was numerically simulated for fuel element with longitudinal cooling fins. Turbulence is modelled by an algebraic stress model and an energy-dissipation model. The developing flow is solved using a parabolic pressure correction algorithm. The decay of the initial vortices in non-circular sub-channel in the presence of geometry driven secondary currents is described and the uncertainty in the local turbulent shear stresses is discussed. (orig.)

Enhancement of heat transfer from a continuously moving porous fin exposed in convective–radiative environment

International Nuclear Information System (INIS)

Bhanja, Dipankar; Kundu, Balaram; Aziz, Abdul

2014-01-01

Highlights: • Analytical model for thermal analysis of moving porous fins. • Heat transfer from the fin surface due to convection and radiation. • For practical design aspects, optimization analysis was carried out. • Comparative study was made between the solid and porous moving fins. • Porous moving fin has more heat transfer ability than the stationary fin. - Abstract: In the present article, an exercise has been devoted to establish an analytical model for the determination of temperature distribution, fin efficiency and optimum design parameters of a porous moving fin which is losing heat by simultaneous convection and radiation to its surroundings. For the adaptation of this consideration, the governing equation becomes highly nonlinear. An analytical technique called Adomian decomposition method (ADM) is proposed for the solution methodology. The accuracy of the analytic solution is validated by using a numeric scheme called finite difference method. The results indicate that the numerical data and analytical approach are in agreement with each other. As the present study is an analytic, it is extended to the analysis for determination of optimum dimensions of said fin by satisfying either the maximization of rate of heat transfer for a given fin volume or by the minimization of fin volume for a desired heat transfer rate. The study is further extended to the porous fin in stationary condition and it is found that porous fin in moving condition transfers more heat than stationary condition. Investigation has also been made on solid moving fin to compare the outcomes of these parameters

The Effect of Using Self-ligating Brackets on Maxillary Canine Retraction: A Split-mouth Design Randomized Controlled Trial.

Science.gov (United States)

Hassan, Siba E; Hajeer, Mohammad Y; Alali, Osama H; Kaddah, Ayham S

2016-06-01

The results of previous studies about the efficacy of using self-ligating brackets (SLBs) in controlling canine movement during retraction are not in harmony. Therefore, the current study aimed to compare the effects of using new passive SLBs on maxillary canine retraction with sliding mechanics vs conventional ligating brackets (CLBs) tied with metal ligatures. The sample comprised 15 adult patients (4 males, 11 females; 18-24 years) requiring bilateral extraction of maxillary first premolars. Units of randomization are the left or right maxillary canines within the same patient. The two maxillary canines in each patient were randomly assigned to one of the two groups in a simple split-mouth design. The canines in the SLBs group (n = 15) were bracketed with SLBs (Damon Q™), while the canines in the CLBs group (n = 15) were bracketed with conventional brackets (Mini Master Series). Transpalatal bars were used for anchorage. After leveling and alignment, 0.019 × 0.025" stainless steel working archwires were placed. Canines were retracted using a nickel-titanium close-coil springs with a 150 gm force. The amount and rate of maxillary canine retraction, canine rotation, and loss of anchorage were measured on study models collected at the beginning of canine retraction (T0) and 12 weeks later (T1). Differences were analyzed using paired-samples t-tests. The effect differences were statistically significant (p brackets gave better results compared to the CLBs in terms of rate of movement, amount of canine rotation following extraction, and anchorage loss.

RETRACTED: The Application of Symmetric Key Cryptographic Algorithms in Wireless Sensor Networks

Science.gov (United States)

Si, Lingling; Ji, Zhigang; Wang, Zhihui

This article has been retracted: please see Elsevier Policy on Article Withdrawal. This article has been retracted at the request of the Publisher. The authors have plagiarized a paper that had already appeared in "Queen's 25th Biennial Symposium on Communications", page 168-172, print ISBN 978-1-4244-5709-0, http://dx.doi.org/10.1109/BSC.2010.5472979. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

Notices and Policies for Retractions, Expressions of Concern, Errata and Corrigenda: Their Importance, Content, and Context.

Science.gov (United States)

Teixeira da Silva, Jaime A; Dobránszki, Judit

2017-04-01

A retraction notice is an essential scientific historical document because it should outline the reason(s) why a scientific manuscript was retracted, culpability (if any) and any other factors that have given reason for the authors, editors, or publisher, to remove a piece of the literature from science's history books. Unlike an expression of concern (EoC), erratum or corrigendum, a retraction will usually result in a rudimentary vestige of the work. Thus, any retraction notice that does not fully indicate a set of elements related to the reason and background for the retraction serves as a poor historical document. Moreover, poorly or incompletely worded retraction notices in fact do not serve their intended purpose, i.e., to hold all parties accountable, and to inform the scientific and wider public of the problem and reason for the paper's demise. This paper takes a look at the definitions and the policies of clauses for retractions, EoCs, errata and corrigenda in place by 15 leading science, technology and medicine (STM) publishers and four publishing-related bodies that we believe have the greatest influence on the current fields of science, technology and medicine. The primary purpose was to assess whether there is a consistency among these entities and publishers. Using an arbitrary 5-scale classification system, and evaluating the different categories of policies separately, we discovered that in almost all cases (88.9 %), the wording used to define these four categories of polices differs from that of the Committee on Publication Ethics (COPE), which is generally considered to be the guiding set of definitions in science publishing. In addition, as much as 61 % deviation in policies (wording and meaning), relative to COPE guidelines, was discovered. When considering the average pooled deviation across all categories of policies, we discovered that there was either no deviation or a small deviation, only in the wording, in the definition of policies when

An IPMC-enabled bio-inspired bending/twisting fin for underwater applications

International Nuclear Information System (INIS)

Palmre, Viljar; Pugal, David; Kim, Sungjun; Kim, Kwang J; Hubbard, Joel J; Fleming, Maxwell; Leang, Kam K

2013-01-01

This paper discusses the design, fabrication, and characterization of an ionic polymer–metal composite (IPMC) actuator-based bio-inspired active fin capable of bending and twisting motion. It is pointed out that IPMC strip actuators are used in the simple cantilever configuration to create simple bending (flapping-like) motion for propulsion in underwater autonomous systems. However, the resulting motion is a simple 1D bending and performance is rather limited. To enable more complex deformation, such as the flapping (pitch and heaving) motion of real pectoral and caudal fish fins, a new approach which involves molding or integrating IPMC actuators into a soft boot material to create an active control surface (called a ‘fin’) is presented. The fin can be used to realize complex deformation depending on the orientation and placement of the actuators. In contrast to previously created IPMCs with patterned electrodes for the same purpose, the proposed design avoids (1) the more expensive process of electroless plating platinum all throughout the surface of the actuator and (2) the need for specially patterning the electrodes. Therefore, standard shaped IPMC actuators such as those with rectangular dimensions with varying thicknesses can be used. One unique advantage of the proposed structural design is that custom shaped fins and control surfaces can be easily created without special materials processing. The molding process is cost effective and does not require functionalizing or ‘activating’ the boot material similar to creating IPMCs. For a prototype fin (90 mm wide × 60 mm long × 1.5 mm thick), the measured maximum tip displacement was approximately 44 mm and the twist angle of the fin exceeded 10°. Lift and drag measurements in water where the prototype fin with an airfoil profile was dragged through water at a velocity of 21 cm s −1 showed that the lift and drag forces can be affected by controlling the IPMCs embedded into the fin structure

Laser Welding Of Finned Tubes Made Of Austenitic Steels

Directory of Open Access Journals (Sweden)

Stolecki M.

2015-09-01

Full Text Available This paper describes the technology of welding of finned tubes made of the X5CrNi1810 (1.4301 austenitic steel, developed at Energoinstal SA, allowing one to get high quality joints that meet the requirements of the classification societies (PN-EN 15614, and at the same time to significantly reduce the manufacturing costs. The authors described an automatic technological line equipped with a Trumph disc laser and a tube production technological process. To assess the quality of the joints, one performed metallographic examinations, hardness measurements and a technological attempt to rupture the fin. Analysis of the results proved that the laser-welded finned tubes were performed correctly and that the welded joints had shown no imperfections.

Simulation study of a 3-D device integrating FinFET and UTBFET

KAUST Repository

Fahad, Hossain M.

2015-01-01

By integrating 3-D nonplanar fins and 2-D ultrathin bodies, wavy FinFETs merge two formerly competing technologies on a silicon-on-insulator platform to deliver enhanced transistor performance compared with conventional trigate FinFETs with unprecedented levels of chip-area efficiency. This makes it suitable for ultralarge-scale integration high-performance logic at and beyond the 10-nm technology node.

Erratum: Retraction Note to: Effect of Carbon Content on the Electrical Conductivity of Carbon Black-Filled PMC with Various Matrices

Science.gov (United States)

Shin, Soon-Gi

2018-03-01

The Editor-in-Chief and Editorial Board of Electronic Materials Letters have retracted this article [1] because its contents have been previously published by Miyasaka et al. [2]. The contents of this article are therefore redundant. Author Soon-Gi Shin has not responded to correspondence from the Editor about this retraction.

Bifenthrin causes neurite retraction in the absence of cell death: a model for pesticide associated neurodegeneration.

Science.gov (United States)

Nandi, Avishek; Chandil, Daljit; Lechesal, Rethabile; Pryor, Stephen C; McLaughlin, Ashlea; Bonventre, Josephine A; Flynnx, Katherine; Weeks, Benjamin S

2006-05-01

Bifenthrin is a synthetic pyrethroid insecticide derivative of naturally occurring pyrethrins from chrysanthemum flowers. Bifenthrin is considered relatively safe and therefore incorporated as the active ingredient in preparations sold over the counter for household use. Recent studies have raised concern that chronic exposure to pesticides in the home setting may increase the risk for neurodegenerative diseases. To address this concer, in the present study, bifenthrin is added to pre-differentiated PC12 and effect of bifenthrin on the retraction of existing neurites is observed a model for neurodegeneration. PC12 cells were differentiated with nerve growth factor for twenty-four hours and then treated with what was determined to be a sublethal dose of bifenthrin for up to an additional 48 hours. The percent of cells with neurites was assessed at various times before and after nerve growth factor treatment. Bifenthrin toxicity was determined using trypan blue exclusion. Bifenthrin was not toxic to PC12 cells at concentrations ranging from 1 x 10(-10) M to 1 x 10(-4) M. Twenty-four hours after nerve growth factor treatment, a maximum percent of cells had formed neurites and with a treatment of 1 x 10(-5) M bifenthrin, approximately 80% of these neurites retracted in within 12 additional hours and almost all neurites had retracted within 48 hours. Trypan exclusion showed that these cells were viable. These data show that bifenthrin can stimulate the retraction of neurites in the absence of frank toxicity.

The Phosphatase Inhibitor Calyculin-A Impairs Clot Retraction, Platelet Activation, and Thrombin Generation

Directory of Open Access Journals (Sweden)

Renáta Hudák

2017-01-01

Full Text Available The aim of this study was to investigate the effect of the serine/threonine protein phosphatase inhibitor, calyculin-A (CLA, on clot formation and on the procoagulant activity of human platelets. Platelet-rich plasma (PRP samples were preincubated with buffer or CLA and subsequently platelets were activated by the protease-activated receptor 1 (PAR-1 activator, thrombin receptor activating peptide (TRAP. Clot retraction was detected by observing clot morphology up to 1 hour, phosphatidylserine- (PS- expression was studied by flow cytometry, and thrombin generation was measured by a fluorimetric assay. For the intracellular Ca2+ assay, platelets were loaded with calcium-indicator dyes and the measurements were carried out using a ratiometric method with real-time confocal microscopy. CLA preincubation inhibited clot retraction, PS-expression, and thrombin formation. TRAP activation elicited Ca2+ response and PS-expression in a subset of platelets. The activated PRP displayed significantly faster and enhanced thrombin generation compared to nonactivated samples. CLA pretreatment abrogated PS-exposure and clot retraction also in TRAP-activated samples. As a consequence of the inhibitory effect on calcium elevation and PS-expression, CLA significantly downregulated thrombin generation in PRP. Our results show that CLA pretreatment may be a useful tool to investigate platelet activation mechanisms that contribute to clot formation and thrombin generation.

Investigation on flow and heat transfer characteristics in rectangular channel with drop-shaped pin fins

Directory of Open Access Journals (Sweden)

Fengming Wang

2012-12-01

Full Text Available The flow and heat transfer characteristics inside a rectangular channel embedded with pin fins were numerically and experimentally investigated. Several differently shaped pin fins (i.e., circular, elliptical, and drop-shaped with the same cross-sectional areas were compared in a staggered arrangement. The Reynolds number based on the obstructed section hydraulic diameter (defined as the ratio of the total wetted surface area to the open duct volume available for flow was varied from 4800 to 8200. The more streamlined drop-shaped pin fins were better at delaying or suppressing separation of the flow passing through them, which decreased the aerodynamic penalty compared to circular pin fins. The heat transfer enhancement of the drop-shaped pin fins was less than that of the circular pin fins. In terms of specific performance parameters, drop-shaped pin fins are a promising alternative configuration to circular pin fins.

Multi-Mode Electric Actuator Dynamic Modelling for Missile Fin Control

Directory of Open Access Journals (Sweden)

Bhimashankar Gurav

2017-06-01

Full Text Available Linear first/second order fin direct current (DC actuator model approximations for missile applications are currently limited to angular position and angular velocity state variables. Furthermore, existing literature with detailed DC motor models is decoupled from the application of interest: tail controller missile lateral acceleration (LATAX performance. This paper aims to integrate a generic DC fin actuator model with dual-mode feedforward and feedback control for tail-controlled missiles in conjunction with the autopilot system design. Moreover, the characteristics of the actuator torque information in relation to the aerodynamic fin loading for given missile trim velocities are also provided. The novelty of this paper is the integration of the missile LATAX autopilot states and actuator states including the motor torque, position and angular velocity. The advantage of such an approach is the parametric analysis and suitability of the fin actuator in relation to the missile lateral acceleration dynamic behaviour.

FINCRUSH : a computer program for impact analysis of radioactive material transport cask with fins

International Nuclear Information System (INIS)

Ikushima, Takeshi

1997-05-01

In drop impact analyses for radioactive material transport cask with cooling fins, relationship between fin plastic deformation and fin energy absorption is used. This relationship was obtained by ORNL experiments and MONSER Co. in Canada. Based on ORNL experiments, a computer program FINCRUSH has been developed for rapid safety analysis of cask drop impact to obtain the maximum impact acceleration and the maximum fin deformation. Main features of FINCRUSH are as follows: (1) annulus fins on a cylindrical shell and plate fins on a disk can be treated, (2) it is capable of graphical representations for calculation results and fin absorption energy data and (3) not only main frame computer but also work stations (OS UNIX) and personal computer (OS Windows) are available for use of the FINCRUSH. In the paper, brief illustration of calculation method of FINCRUSH is presented. The second section presents comparisons between FINCRUSH and experimental results. The third section provides a use's guide for FINCRUSH. (author)

FINCRUSH : a computer program for impact analysis of radioactive material transport cask with fins

Energy Technology Data Exchange (ETDEWEB)

Ikushima, Takeshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1997-05-01

In drop impact analyses for radioactive material transport cask with cooling fins, relationship between fin plastic deformation and fin energy absorption is used. This relationship was obtained by ORNL experiments and MONSER Co. in Canada. Based on ORNL experiments, a computer program FINCRUSH has been developed for rapid safety analysis of cask drop impact to obtain the maximum impact acceleration and the maximum fin deformation. Main features of FINCRUSH are as follows: (1) annulus fins on a cylindrical shell and plate fins on a disk can be treated, (2) it is capable of graphical representations for calculation results and fin absorption energy data and (3) not only main frame computer but also work stations (OS UNIX) and personal computer (OS Windows) are available for use of the FINCRUSH. In the paper, brief illustration of calculation method of FINCRUSH is presented. The second section presents comparisons between FINCRUSH and experimental results. The third section provides a use`s guide for FINCRUSH. (author)

Line-edge roughness induced single event transient variation in SOI FinFETs

International Nuclear Information System (INIS)

Wu Weikang; An Xia; Jiang Xiaobo; Chen Yehua; Liu Jingjing; Zhang Xing; Huang Ru

2015-01-01

The impact of process induced variation on the response of SOI FinFET to heavy ion irradiation is studied through 3-D TCAD simulation for the first time. When FinFET biased at OFF state configuration (V gs = 0, V ds = V dd ) is struck by a heavy ion, the drain collects ionizing charges under the electric field and a current pulse (single event transient, SET) is consequently formed. The results reveal that with the presence of line-edge roughness (LER), which is one of the major variation sources in nano-scale FinFETs, the device-to-device variation in terms of SET is observed. In this study, three types of LER are considered: type A has symmetric fin edges, type B has irrelevant fin edges and type C has parallel fin edges. The results show that type A devices have the largest SET variation while type C devices have the smallest variation. Further, the impact of the two main LER parameters, correlation length and root mean square amplitude, on SET variation is discussed as well. The results indicate that variation may be a concern in radiation effects with the down scaling of feature size. (paper)

Determination of optimum fin profile for a zero-G capillary drained condenser

Science.gov (United States)

Mccormick, John A.; Valenzuela, Javier A.; Choudhury, Dipanker

1990-01-01

This paper presents the analytical formulation and numerical results for heat transfer in a high heat flux condenser that relies on capillary flow along shaped fins (Gregorig surfaces) and a drainage network embedded in the condenser walls. Results are shown for a variety of fin profile shapes in order to show the geometric trade-offs involved in seeking a maximum effective heat transfer coefficient for the fin. Predictions of the model show excellent agreement with previously reported measurements for steam. Based on this work, a profile has been selected for a 2 kW ammonia condenser currently under development for use in space. In that design the fin half width is 0.5 mm and the model predicts a heat transfer coefficient referred to the base of the fin of 9 W/sq cm deg C for a heat flux of 10/W sq cm at the base.

Thermal performance of circular convective–radiative porous fins with different section shapes and materials

International Nuclear Information System (INIS)

Hatami, M.; Ganji, D.D.

2013-01-01

Graphical abstract: - Highlights: • LSM is an accurate technique for simulating heat transfer in circular porous fins. • Rectangular, convex, triangular and exponential variable sections are considered. • Radiation and convection from porous fin are considered. • Effects of material and geometry on heat transfer from fins are studied. - Abstract: In this study, heat transfer and temperature distribution equations for circular convective–radiative porous fins are presented. It’s assumed that the thickness of circular fins varies with radius so four different shapes, rectangular, convex, triangular and exponential, are considered. The heat transfer through porous media is simulated using passage velocity from the Darcy’s model. After deriving equation for each geometry, Least Square Method (LSM) and fourth order Runge–Kutta method (NUM) are applied for predicting the temperature distribution in the porous fins. The selected porous fin’s materials are Al, SiC, Cu and Si 3 N 4 . Results reveal that LSM has very effective and accurate in comparison with the numerical results. As a main outcome, Si 3 N 4 -exponential section fin has the maximum amount of transferred heat among other fins

Comparison of rate of En masse retraction and anchorage loss in conventional labial appliance with labial and lingual force: A clinical study

Directory of Open Access Journals (Sweden)

Dilshad Quraishi

2018-01-01

Full Text Available Aims: The rate of en masse retraction and anchorage loss were compared between labial appliance with lingual force and conventional labial appliance. Subjects and Methods: The sample consists of 14 patients and they were divided into two groups. In Group 1 – labial appliance with lingual force, elastomeric chain was placed from the palatal surface of the canines to the palatal surface of the molars. In Group 2 – labial appliance with labial force, elastomeric chain was placed from the crimpable hook distal to lateral incisor to the molar tube hooks. The rate of en masse retraction and anchorage loss was calculated for both the groups during retraction in dental casts (R0, initial; R1, 4 weeks; R2, 8 weeks; and R3, 12 weeks. Statistical Analysis Used: Student's paired t-test. Results: The rate of retraction was faster and anchorage loss was lower with labial appliance with lingual force, i.e., Group 1. The difference of anchorage loss in Group 1 and Group 2 shows t = 4.824 and P value= 0.000, which is statistically highly significant. The difference of rate of retraction in Group 1 and Group 2 shows t = 3.573 and P value = 0.004, which is statistically signifcant. Conclusions: The rate of retraction was faster and anchorage loss was lower with labial appliance with lingual force, thus indicating that this new technique of space closure utilizes biomechanical advantage of lingual force in conventional labial appliance.

Optimum length of finned pipe for waste heat recovery

International Nuclear Information System (INIS)

Soeylemez, M.S.

2008-01-01

A thermoeconomic feasibility analysis is presented yielding a simple algebraic optimization formula for estimating the optimum length of a finned pipe that is used for waste heat recovery. A simple economic optimization method is used in the present study by combining it with an integrated overall heat balance method based on fin effectiveness for calculating the maximum savings from a waste heat recovery system

Relying on fin erosion to identify hatchery-reared brown trout in a Tennessee river

Science.gov (United States)

Meerbeek, Jonathan R.; Bettoli, Phillip William

2012-01-01

Hatchery-induced fin erosion can be used to identify recently stocked catchable-size brown trout Salmo trutta during annual surveys to qualitatively estimate contributions to a fishery. However, little is known about the longevity of this mark and its effectiveness as a short-term (≤ 1 year) mass-marking technique. We evaluated hatchery-induced pectoral fin erosion as a mass-marking technique for short-term stocking evaluations by stocking microtagged brown trout in a tailwater and repeatedly sampling those fish to observe and measure their pectoral fins. At Dale Hollow National Fish Hatchery, 99.1% (228 of 230) of microtagged brown trout in outdoor concrete raceways had eroded pectoral fins 1 d prior to stocking. Between 34 and 68 microtagged and 26-35 wild brown trout were collected during eight subsequent electrofishing samples. In a blind test based on visual examination of pectoral fins at up to 322 d poststocking, one observer correctly identified 91.7% to 100.0% (mean of 96.9%) of microtagged brown trout prior to checking for microtags. In the laboratory, pectoral fin length and width measurements were recorded to statistically compare the fin measurements of wild and microtagged hatchery brown trout. With only one exception, all pectoral fin measurements on each date averaged significantly larger for wild trout than for microtagged brown trout. Based on the number of pectoral fin measurements falling below 95% prediction intervals, 93.7% (148 of 158) of microtagged trout were correctly identified as hatchery fish based on regression models up to 160 d poststocking. Only 72.2% (70 of 97) of microtagged trout were identified correctly after 160 d based on pectoral fin measurements and the regression models. We concluded that visual examination of pectoral fin erosion was a very effective way to identify stocked brown trout for up to 322 d poststocking.

Establishing a Dynamic Database of Blue and Fin Whale Locations from Recordings at the IMS CTBTO hydro-acoustic network. The Baleakanta Project

Science.gov (United States)

Le Bras, R. J.; Kuzma, H.

2013-12-01

Falling as they do into the frequency range of continuously recording hydrophones (15-100Hz), blue and fin whale songs are a significant source of noise on the hydro-acoustic monitoring array of the International Monitoring System (IMS) of the Comprehensive Nuclear Test Ban Treaty Organization (CTBTO). One researcher's noise, however, can be a very interesting signal in another field of study. The aim of the Baleakanta Project (www.baleakanta.org) is to flag and catalogue these songs, using the azimuth and slowness of the signal measured at multiple hydrophones to solve for the approximate location of singing whales. Applying techniques borrowed from human speaker identification, it may even be possible to recognize the songs of particular individuals. The result will be a dynamic database of whale locations and songs with known individuals noted. This database will be of great value to marine biologists studying cetaceans, as there is no existing dataset which spans the globe over many years (more than 15 years of data have been collected by the IMS). Current whale song datasets from other sources are limited to detections made on small, temporary listening devices. The IMS song catalogue will make it possible to study at least some aspects of the global migration patterns of whales, changes in their songs over time, and the habits of individuals. It is believed that about 10 blue whale 'cultures' exist with distinct vocal patterns; the IMS song catalogue will test that number. Results and a subset of the database (delayed in time to mitigate worries over whaling and harassment of the animals) will be released over the web. A traveling museum exhibit is planned which will not only educate the public about whale songs, but will also make the CTBTO and its achievements more widely known. As a testament to the public's enduring fascination with whales, initial funding for this project has been crowd-sourced through an internet campaign.

Open-Coil Retraction Spring

Directory of Open Access Journals (Sweden)

Pavankumar Janardan Vibhute

2011-01-01

Full Text Available Sliding mechanic has become a popular method for space closure with developments in preadjusted edgewise appliance. Furthermore, various space closing auxiliaries have been developed and evaluated extensively for their clinical efficiency. Their effectiveness enhanced with optimum force magnitude and low-load deflection rate (LDR/force decay. With the advent of NiTi springs in orthodontics, LDRs have been markedly reduced. For use of NiTi, clinician has to depend upon prefabricated closed coil springs. “Open Coil Retraction Spring (OCRS” is developed utilizing NiTi open-coil spring for orthodontic space closure. This paper describes fabrication and clinical application of OCRS which have number of advantages. It sustains low LDR with optimum force magnitude. Its design is adjustable for desired length and force level. It is fail-safe for both activation and deactivation (i.e., it cannot be over activated, and decompression limit of open coil is also controlled by the operator, resp.. A possibility to offset the OCRS away from mucosa helps to reduce its soft-tissue impingement.

Optimization of a Finned Shell and Tube Heat Exchanger Using a Multi-Objective Optimization Genetic Algorithm

Directory of Open Access Journals (Sweden)

Heidar Sadeghzadeh

2015-08-01

Full Text Available Heat transfer rate and cost significantly affect designs of shell and tube heat exchangers. From the viewpoint of engineering, an optimum design is obtained via maximum heat transfer rate and minimum cost. Here, an analysis of a radial, finned, shell and tube heat exchanger is carried out, considering nine design parameters: tube arrangement, tube diameter, tube pitch, tube length, number of tubes, fin height, fin thickness, baffle spacing ratio and number of fins per unit length of tube. The “Delaware modified” technique is used to determine heat transfer coefficients and the shell-side pressure drop. In this technique, the baffle cut is 20 percent and the baffle ratio limits range from 0.2 to 0.4. The optimization of the objective functions (maximum heat transfer rate and minimum total cost is performed using a non-dominated sorting genetic algorithm (NSGA-II, and compared against a one-objective algorithm, to find the best solutions. The results are depicted as a set of solutions on a Pareto front, and show that the heat transfer rate ranges from 3517 to 7075 kW. Also, the minimum and maximum objective functions are specified, allowing the designer to select the best points among these solutions based on requirements. Additionally, variations of shell-side pressure drop with total cost are depicted, and indicate that the pressure drop ranges from 3.8 to 46.7 kPa.

Surgical effects in patients with Duane retraction syndrome

Directory of Open Access Journals (Sweden)

Shui-Lian Zhou

2017-03-01

Full Text Available AIM: To investigate the clinical characteristics and surgical effects in patients with Duane retraction syndrome(DRS.METHODS: Totally 13 patients with DRS during June 2011 to December 2015 were analyzed retrospectively. The data including clinical types and manifestations, surgical methods and outcomes were reviewed and analyzed. RESULTS: There were 11 male cases and 2 female cases who all had no ocular and systemic anomalies. The left eye was involved in 9 cases, the right eye was involved in 3 cases and 1 case involved in both eyes. Six cases were type Ⅰ,1 case was typeⅡand 6 cases were type Ⅲ. Eleven cases had abnormal head posture(AHP, 9 cases had the up- or down-shoot phenomenon. The surgical treatment was designed according to subtypes and clinical features which included medial rectus recession, lateral rectus recession, recession of both horizontal rectus muscles and lateral rectus recession combined with Y splitting. After surgery, horizontal deviation was less than ±10△ in all patients, and AHP disappeared in 4 cases and improved in 7 cases. The up- or down-shoot and global retraction disappeared in 5 cases and improved in 4 cases. Simultaneously, the restriction of ocular motility was improved in all patients. CONCLUSION: The clinical features of DRS are variant in different types. Detailed examination before surgery and reasonable surgical design are important in treatment of patients with DRS.

Plan de Mercadeo para una “FinTech”.

OpenAIRE

Escalante Lee, Maria Alejandra

2016-01-01

Las empresas deben contar con una misión clara, estableciendo los objetivos de apoyo, diseñando una cartera de negocio sólida y coordinar sus estrategias a futuro, con el fin de cumplir las metas propuestas para entregar e intercambiar ofertas que tienen valor para los consumidores, clientes, socios y la sociedad en general. El presente trabajo de grado tiene como objetivo proponer un plan de mercadeo para la empresa Comyno una FinTech ubicada en Frankfurt am Main, en Alemania. Este tiene ...

Integral finned heater and cooler for stirling engines

Science.gov (United States)

Corey, John A.

1984-01-01

A piston and cylinder for a Stirling engine and the like having top and bottom meshing or nesting finned conical surfaces to provide large surface areas in close proximity to the working gas for good thermal (addition and subtraction of heat) exchange to the working gas and elimination of the usual heater and cooler dead volume. The piston fins at the hot end of the cylinder are perforated to permit the gas to pass into the piston interior and through a regenerator contained therein.

Bio-inspired flexible joints with passive feathering for robotic fish pectoral fins.

Science.gov (United States)

Behbahani, Sanaz Bazaz; Tan, Xiaobo

2016-05-04

In this paper a novel flexible joint is proposed for robotic fish pectoral fins, which enables a swimming behavior emulating the fin motions of many aquatic animals. In particular, the pectoral fin operates primarily in the rowing mode, while undergoing passive feathering during the recovery stroke to reduce hydrodynamic drag on the fin. The latter enables effective locomotion even with symmetric base actuation during power and recovery strokes. A dynamic model is developed to facilitate the understanding and design of the joint, where blade element theory is used to calculate the hydrodynamic forces on the pectoral fins, and the joint is modeled as a paired torsion spring and damper. Experimental results on a robotic fish prototype are presented to illustrate the effectiveness of the joint mechanism, validate the proposed model, and indicate the utility of the proposed model for the optimal design of joint depth and stiffness in achieving the trade-off between swimming speed and mechanical efficiency.

Propagation of errors in citation networks: a study involving the entire citation network of a widely cited paper published in, and later retracted from, the journal Nature

NARCIS (Netherlands)

Vet, Van Der Paul E.; Nijveen, Harm

2016-01-01

Background
In about one in 10,000 cases, a published article is retracted. This very often means that the results it reports are flawed. Several authors have voiced concerns about the presence of retracted research in the memory of science. In particular, a retracted result is propagated by

Propagation of errors in citation networks: a study involving the entire citation network of a widely cited paper published in, and later retracted from, the journal Nature

NARCIS (Netherlands)

van der Vet, P.E.; Nijveen, Harmen

2016-01-01

Background In about one in 10,000 cases, a published article is retracted. This very often means that the results it reports are flawed. Several authors have voiced concerns about the presence of retracted research in the memory of science. In particular, a retracted result is propagated by citing

Erratum: Retraction Note to: "The Second Version of the OCARS Catalog of Optical Characteristics of Astrometric Radio Sources" [Astronomy Reports 60, 996 (2016)

Science.gov (United States)

Malkin, Z. M.

2018-04-01

The Editor-in-Chief is retracting this article [1] because data from the RFC catalog, http://astrogeo.org/rfc, were used without permission from the copyright holder. The author admitted the decision to retract.

The pelvic fin and girdle of Panderichthys and the origin of tetrapod locomotion.

Science.gov (United States)

Boisvert, Catherine A

2005-12-22

One of the most marked transformations in the vertebrate transition to land was that of fins to limbs. This transformation involved not only the generation of morphological novelties (digits, sacrum) but also a shift in locomotory dominance from the pectoral to the pelvic appendage. Despite its importance, the transformation from pelvic fin to hindlimb is the least studied and least well-documented part of this transformation, which is bracketed by the osteolepiform Eusthenopteron and the early tetrapods Ichthyostega and Acanthostega, but is not directly illuminated by any intermediate form. Panderichthys is the closest tetrapod relative currently represented by complete fossils, but its pelvic fin skeleton has not been described. Here, I present the only known articulated pelvic fin endoskeleton and associated partial pelvis of Panderichthys. The pelvic girdle is even less tetrapod-like than that of the osteolepiform Eusthenopteron, but the pelvic fin endoskeleton shares derived characteristics with basal tetrapods despite being more primitive than the pectoral fin of Panderichthys. The evolution of tetrapod locomotion appears to have passed through a stage of body-flexion propulsion, in which the pelvic fins played a relatively minor anchoring part, before the emergence of hindlimb-powered propulsion in the interval between Panderichthys and Acanthostega.

Mediterranean Fin Whales (Balaenoptera physalus) Threatened by Dolphin MorbilliVirus.

Science.gov (United States)

Mazzariol, Sandro; Centelleghe, Cinzia; Beffagna, Giorgia; Povinelli, Michele; Terracciano, Giuliana; Cocumelli, Cristiano; Pintore, Antonio; Denurra, Daniele; Casalone, Cristina; Pautasso, Alessandra; Di Francesco, Cristina Esmeralda; Di Guardo, Giovanni

2016-02-01

During 2011-2013, dolphin morbillivirus was molecularly identified in 4 stranded fin whales from the Mediterranean Sea. Nucleoprotein, phosphoprotein, and hemagglutinin gene sequences of the identified strain were highly homologous with those of a morbillivirus that caused a 2006-2007 epidemic in the Mediterranean. Dolphin morbillivirus represents a serious threat for fin whales.

Thermal-Hydraulic Performance of a Corrugated Cooling Fin with Louvered Surfaces

DEFF Research Database (Denmark)

Sønderby, Simon Kaltoft; Hosseini, Seyed Mojtaba Mir; Rezaniakolaei, Alireza

2017-01-01

The main objective of the article is to investigate thermal-hydraulic performance of a corrugated cooling fin with louvered surfaces. The investigation is carried out using the fin geometry of one most commonly used liquid-to-air heat exchangers. The investigation was carried out by numerically...... simulating the airflow with louvered fin geometry. The simulation model was verified by comparing simulated j- and f-factors with the corresponding values of several experimental correlations. The j-factors deviated less than 10.7 % from two of the experimental correlations, whereas deviations ranging...

Retracted: Effect of Paris polyphylla extract on second- degree burns ...

African Journals Online (AJOL)

2018-01-26

Jan 26, 2018 ... Retracted: Ma Z, Yin W, Hu G, Zhu Z, Huang Z. Effect of Paris polyphylla extract on second-degree burns in rats. Trop J Pharm Res 2016; 15(10):2131-2135 doi: http://dx.doi.org/10.4314/tjpr.v15i10.11. From the Editor. Our attention was drawn to the falsification of the data published in this article which was ...

Stereotactic Body Radiotherapy for Centrally Located Non-small Cell Lung Cancer

Directory of Open Access Journals (Sweden)

Yuming WAN

2018-05-01

Full Text Available A few study has proven that about 90% of local control rates might be benefit from stereotactic body radiotherapy (SBRT for patients with medically inoperable stage I non-small cell lung cancer (NSCLC, it is reported SBRT associated overall survival and tumor specific survival is comparable with those treated with surgery. SBRT has been accepted as the first line treatment for inoperable patients with peripheral located stage I NSCLC. However, the role of SBRT in centrally located lesions is controversial for potential toxic effects from the adjacent anatomical structure. This paper will review the definition, indication, dose regimens, dose-volume constraints for organs at risk, radiation technology, treatment side effect of centrally located NSCLC treated with SBRT and stereotactic body proton therapy.

Fin Type Variation of Lionhead Strain Goldfish (Carassius auratus Offspring

Directory of Open Access Journals (Sweden)

M. Syaifudin

2007-12-01

Full Text Available  Lionhead strain goldfish (Carassius auratus inheritance produce many variations in phenotype qualitative traits of their offspring that is not common with the parents. Lionhead is an ornamental freshwater fish, they do not have a dorsal fin, but it is a beauty finfish, is popular to the people and have a high economic value. Of the 846 offspring of lionhead is produced in this experiment, and 57,7% of them have dorsal fin (42,3% normal, 13,1% of them have anal fin which did not similar with their parents, 58,6% caudal fin of them did not have similar to their parents. It might be caused by incompletely segregation in meiosis and many gen responsible to certain phenotype trait. Another abnormalities such as no anal fin, blindness, stumped and no pigmen in their gill lamella also occurred. Key words: Inheritance, fin, phenotype, abnormality   ABSTRAK Ikan maskoki strain lionhead menghasilkan keturunan dengan fenotip yang sangat bervariasi dan berbeda dengan induknya. Ikan ini merupakan ikan hias air tawar yang tidak memiliki sirip punggung namun tetap memiliki keindahan, sehingga menjadi begitu populer di masyarakat dan memiliki nilai ekonomi yang tinggi. Sebanyak 846 keturunan (anakan telah dihasilkan dalam percobaan ini, dan sebanyak 57,7% dari populasi tersebut memiliki sirip punggung (berarti 42,3% merupakan keturunan normal, 13,1% memiliki sirip dubur yang tidak mirip dengan induknya. Variasi keturunan ikan maskoki strain lionhead ini disebabkan oleh segregasi yang tidak sempurna dalam proses meiosis dan banyaknya gen yang terlibat dalam pembentukan penotip tertentu. Abnormalitas lainnya juga terjadi pada keturunan ikan maskoki strain lionhead ini, seperti tidak adanya sirip dubur, mata buta, tubuh pendek dan tidak adanya pigmen pada lemela insang Kata kunci: Keturunan, sirip, fenotip, abnormalitas  

A Comparative Study of Conventional and Tip-Fin Propeller Performance

DEFF Research Database (Denmark)

Andersen, Poul

1997-01-01

During more than a decade several attempts have been made to obtain higher propeller efficiencies by radically modifying the geometry in the tip region of the blade. In the tip-fin propeller a tip fin or winglet is attached to the blade tip and integrated into the blade in such a way that the bla...

Eddy current test of fin tubes for a heat exchanger

International Nuclear Information System (INIS)

KIm, Young Joo; Lee, Se Kyung; Chung, Min Hwa

1992-01-01

Eddy current probes were designed for the test of fin tubes. Fin tubes, often used for heat exchangers, have uneven outer and inner surfaces to enhance the heat emission. The surface roughness make it difficult to detect flaws employing eddy current test(ECT). In order to overcome the difficulties we performed two types of works, one is the delopment of ECT probes, and the other is the signal processing including fast Fourier transform and digital filtering. In the development of ECT probes, we adopted empirical design method. Our ECT probes for fin tubes are inside diameter type. And we are specially concerned about geometric features such as the widths of the coils composing an ECT probe. We fabricated four probes with various coil widths. Eddy current test was performed using those ECT probes on specimens with artificial flaws. After analyzing the output signals, we found that, in order for the effective testing, the width of a coil should be determined considering the pitch of the fins of a tube. And we also learned that the frequency filtering could improve the s/n ratio.

Impact of line edge roughness on the performance of 14-nm FinFET: Device-circuit Co-design

Science.gov (United States)

Rathore, Rituraj Singh; Rana, Ashwani K.

2018-01-01

With the evolution of sub-20 nm FinFET technology, line edge roughness (LER) has been identified as a critical problem and may result in critical device parameter variation and performance limitation in the future VLSI circuit application. In the present work, an analytical model of fin-LER has been presented, which shows the impact of correlated and uncorrelated LER on FinFET structure. Further, the influence of correlated and uncorrelated fin- LER on all electrical performance parameters is thoroughly investigated using the three-dimensional (3-D) Technology Computer Aided Design (TCAD) simulations for 14-nm technology node. Moreover, the impact of all possible fin shapes on threshold voltage (VTH), drain induced barrier lowering (DIBL), on-current (ION), and off-current (IOFF) has been compared with the well calibrated rectangular FinFET structure. In addition, the influence of all possible fin geometries on the read stability of six-transistor (6-T) Static-Random-Access-Memory (SRAM) has been investigated. The study reveals that fin-LER plays a vital role as it directly governs the electrostatics of the FinFET structure. This has been found that there is a high degree of fluctuations in all performance parameters for uncorrelated fin-LER type FinFETs as compared to correlated fin-LER with respect to rectangular FinFET structure. This paper gives physical insight of FinFET design, especially in sub-20 nm technology nodes by concluding that the impact of LER on electrical parameters are minimum for correlated LER.

Anisotropic stress in narrow sGe fin field-effect transistor channels measured using nano-focused Raman spectroscopy

Science.gov (United States)

Nuytten, T.; Bogdanowicz, J.; Witters, L.; Eneman, G.; Hantschel, T.; Schulze, A.; Favia, P.; Bender, H.; De Wolf, I.; Vandervorst, W.

2018-05-01

The continued importance of strain engineering in semiconductor technology demands fast and reliable stress metrology that is non-destructive and process line-compatible. Raman spectroscopy meets these requirements but the diffraction limit prevents its application in current and future technology nodes. We show that nano-focused Raman scattering overcomes these limitations and can be combined with oil-immersion to obtain quantitative anisotropic stress measurements. We demonstrate accurate stress characterization in strained Ge fin field-effect transistor channels without sample preparation or advanced microscopy. The detailed analysis of the enhanced Raman response from a periodic array of 20 nm-wide Ge fins provides direct access to the stress levels inside the nanoscale channel, and the results are validated using nano-beam diffraction measurements.

Clot retraction is mediated by factor XIII-dependent fibrin-αIIbβ3-myosin axis in platelet sphingomyelin-rich membrane rafts.

Science.gov (United States)

Kasahara, Kohji; Kaneda, Mizuho; Miki, Toshiaki; Iida, Kazuko; Sekino-Suzuki, Naoko; Kawashima, Ikuo; Suzuki, Hidenori; Shimonaka, Motoyuki; Arai, Morio; Ohno-Iwashita, Yoshiko; Kojima, Soichi; Abe, Mitsuhiro; Kobayashi, Toshihide; Okazaki, Toshiro; Souri, Masayoshi; Ichinose, Akitada; Yamamoto, Naomasa

2013-11-07

Membrane rafts are spatially and functionally heterogenous in the cell membrane. We observed that lysenin-positive sphingomyelin (SM)-rich rafts are identified histochemically in the central region of adhered platelets where fibrin and myosin are colocalized on activation by thrombin. The clot retraction of SM-depleted platelets from SM synthase knockout mouse was delayed significantly, suggesting that platelet SM-rich rafts are involved in clot retraction. We found that fibrin converted by thrombin translocated immediately in platelet detergent-resistant membrane (DRM) rafts but that from Glanzmann's thrombasthenic platelets failed. The fibrinogen γ-chain C-terminal (residues 144-411) fusion protein translocated to platelet DRM rafts on thrombin activation, but its mutant that was replaced by A398A399 at factor XIII crosslinking sites (Q398Q399) was inhibited. Furthermore, fibrin translocation to DRM rafts was impaired in factor XIII A subunit-deficient mouse platelets, which show impaired clot retraction. In the cytoplasm, myosin translocated concomitantly with fibrin translocation into the DRM raft of thrombin-stimulated platelets. Furthermore, the disruption of SM-rich rafts by methyl-β-cyclodextrin impaired myosin activation and clot retraction. Thus, we propose that clot retraction takes place in SM-rich rafts where a fibrin-αIIbβ3-myosin complex is formed as a primary axis to promote platelet contraction.

A successful application of homotopy perturbation method for efficiency and effectiveness assessment of longitudinal porous fins

International Nuclear Information System (INIS)

Cuce, Erdem; Cuce, Pinar Mert

2015-01-01

Highlights: • Homotopy perturbation method has been applied to porous fins. • Dimensionless efficiency and effectiveness expressions have been firstly developed. • Effects of porous and convection parameters on thermal analysis have been clarified. • Ratio of porous fin to solid fin heat transfer rate has been given for various cases. • Reliability and practicality of homotopy perturbation method has been illustrated. - Abstract: In our previous works, thermal performance of straight fins with both constant and temperature-dependent thermal conductivity has been investigated in detail and dimensionless analytical expressions of fin efficiency and fin effectiveness have been developed for the first time in literature via homotopy perturbation method. In this study, previous works have been extended to porous fins. Governing equations have been formulated by performing Darcy’s model. Dimensionless temperature distribution along the length of porous fin has been determined as a function of porosity and convection parameters. The ratio of porous fin to solid fin heat transfer rate has also been evaluated as a function of thermo-geometric fin parameter. The results have been compared with those of finite difference method for a specific case and an excellent agreement has been observed. The expressions developed are beneficial for thermal engineers for preliminary assessment of thermophysical systems instead of consuming time in heat conduction problems governed by strongly nonlinear differential equations

Comparative study on thermal performance of natural draft cooling towers with finned shells

International Nuclear Information System (INIS)

Goodarzi, Mohsen

2016-01-01

The cooling efficiency of natural draft cooling towers under crosswind condition should be improved. In the present research work three different externally finned shells were considered for a typical natural draft cooling tower to investigate the cooling improvement. They were numerically simulated under normal and crosswind conditions. Numerical results show that twisting four fin plates over the tower shell along the 45 peripheral angle, could improve the cooling efficiency up to 6.5 %. Because of the periodic shape of the fin plates, the cooling efficiency of the cooling tower with finned shell is less sensitive to the change of wind.

Comparative study on thermal performance of natural draft cooling towers with finned shells

Energy Technology Data Exchange (ETDEWEB)

Goodarzi, Mohsen [Bu-Ali Sina Univ., Hamedan (Iran, Islamic Republic of). Dept. of Mechanical Engineering

2016-10-15

The cooling efficiency of natural draft cooling towers under crosswind condition should be improved. In the present research work three different externally finned shells were considered for a typical natural draft cooling tower to investigate the cooling improvement. They were numerically simulated under normal and crosswind conditions. Numerical results show that twisting four fin plates over the tower shell along the 45 peripheral angle, could improve the cooling efficiency up to 6.5 %. Because of the periodic shape of the fin plates, the cooling efficiency of the cooling tower with finned shell is less sensitive to the change of wind.

Performance measurement of plate fin heat exchanger by exploration: ANN, ANFIS, GA, and SA

OpenAIRE

A.K. Gupta; P. Kumar; R.K. Sahoo; A.K. Sahu; S.K. Sarangi

2017-01-01

An experimental work is conducted on counter flow plate fin compact heat exchanger using offset strip fin under different mass flow rates. The training, testing, and validation set of data has been collected by conducting experiments. Next, artificial neural network merged with Genetic Algorithm (GA) utilized to measure the performance of plate-fin compact heat exchanger. The main aim of present research is to measure the performance of plate-fin compact heat exchanger and to provide full exp...

Three-dimensional numerical study of heat transfer characteristics of plain plate fin-and-tube heat exchangers from view point of field synergy principle

International Nuclear Information System (INIS)

He, Y.L.; Tao, W.Q.; Song, F.Q.; Zhang, W.

2005-01-01

In this paper, 3-D numerical simulations were performed for laminar heat transfer and fluid flow characteristics of plate fin-and-tube heat exchanger. The effects of five factors were examined: Re number, fin pitch, tube row number, spanwise and longitudinal tube pitch. The Reynolds number based on the tube diameter varied from 288 to 5000, the non-dimensional fin pitch based on the tube diameter varied from 0.04 to 0.5, the tube row number from 1 to 4, the spanwise tube pitch S 1 /d varies from 1.2 to 3, and the longitudinal tube pitch S 2 /d from 1.0 to 2.4. The numerical results were analyzed from the view point of field synergy principle, which says that the reduction of the intersection angle between velocity and fluid temperature gradient is the basic mechanism to enhance convective heat transfer. It is found that the effects of the five parameters on the heat transfer performance of the finned tube banks can be well described by the field synergy principle, i.e., the enhancement or deterioration of the convective heat transfer across the finned tube banks is inherently related to the variation of the intersection angle between the velocity and the fluid temperature gradient. It is also recommended that to further enhance the convective heat transfer, the enhancement techniques, such as slotting the fin, should be adopted mainly in the rear part of the fin where the synergy between local velocity and temperature gradient become worse

Numerical analysis of steady state and transient analysis of high temperature ceramic plate-fin heat exchanger

International Nuclear Information System (INIS)

Nagarajan, Vijaisri; Chen, Yitung; Wang, Qiuwang; Ma, Ting

2014-01-01

Highlights: • Rip saw fin design is considered to be the best because it has thin fins and has higher heat transfer coefficient. • Minimum principal stress and maximum safety factor are obtained for the inverted bolt fin design. • Maximum principal stress and minimum safety factor are obtained for triangular fin design. • Thermal stress has significant impact than mechanical stress. • High principal stress is found at the startup and shutdown stage. - Abstract: In this study three-dimensional model of ceramic plate-fin high temperature heat exchanger with different fin designs and arrangements is analyzed numerically using ANSYS FLUENT and ANSYS structural module. The ability of ceramics to withstand high temperature and corrosion makes silicon carbide (SiC) suitable candidate material to be used in high temperature heat exchanger. The operating temperature of heat exchanger is 950 °C and the operating pressure is 1.5 MPa. The working fluids are helium, sulfur trioxide, sulfur dioxide, oxygen and the water vapor. Fluid flow and heat transfer analysis are carried out for steady and transient state in FLUENT. The obtained thermal and pressure load for the steady and transient state from ANSYS FLUENT are imported to ANSYS structural module to obtain the principal stress and the factor of safety. Different arrangements of rectangular fins, triangular fins, inverted bolt fins and ripsaw fins are studied. From the results it is found that the minimum stress and the maximum safety factor are obtained for inverted bolt fins. The triangular fins have the maximum principal stress and minimum factor of safety. However, the fluid flow and heat transfer analysis show inverted bolt fins and triangular fins produce higher pressure drop and friction factor. The steady state maximum principal stress is 10.08 MPa, 9.90 MPa and 11.43 MPa for straight, staggered and top and bottom ripsaw fin arrangement. The corresponding safety factors are 21.80, 21.95 and 19

Feasibility Study to Reduce Thermal Resistance of Finned Containment Wall in Simplified OPR1000

Energy Technology Data Exchange (ETDEWEB)

Lee, Jong Hwi; Kang, Hie Chan [Kunsan National University, Gunsan (Korea, Republic of); Noh, Hyung Gyun [Pohang University, Pohang (Korea, Republic of)

2016-05-15

This concept is securing of cooling capability by using finned containment itself, it could be another alternative for achieving decompression of containment as heat sink. The objective of this study is a feasibility test to estimate the heat transfer performance from the finned containment wall in case of OPR1000. The commercial code, ANSYS CFX 16 was used in this work. The number of grids is about 1.8 million. Therefore, 250mm rebar affects more considerable than that of 50mm to the temperature distribution. For this reasons, temperature distribution of z-axis direction was showed significant changes in (c). The heat transfer in three types of containment was 267.6W, 265.2W and 307.8W, respectively. The Type B case increased up to 15% of heat transfer than the baseline containment building. Three different types of containment wall were tested by numerical simulation to understand the cooling performance of finned containment wall. We can conclude as follows: For the finned containment wall type A that fins are installed inside and outside with the same rebar configuration of conventional containment building, the heat transfer is almost the same as conventional containment wall. The finned containment wall type B that volume fraction of rebar is increased transfer the heat 15% more compared with conventional one. The cross-sectional area or volume fraction of the rebar to attach fin is important to enhance the heat transfer. The fin efficiency of the fin is very low as 3.1% in the present cases.

Role of fin material and nanofluid in performance enhancement of automobile radiator

Science.gov (United States)

Jadar, Raju; Shashishekar, K. S.; Channa Keshava Naik, N.

2018-04-01

An effective cooling system can avoid engine and its components from overheating and helps in achieving optimum engine performance. This work deals with the fabrication and performance evaluation of an automobile radiator with i) Aluminum fins and ii) Al-MWCNT fins using 0.1 w/v% f-MWCNT nanofluid. F-MWCNT nanoparticles in the base fluid improves the rate of heat transfer in an automobile radiator integrated with Al-MWCNT fins. The enhancement of heat transfer mainly depends on the quantity of F-MWCNT nanoparticles added to the host fluid. During the study it was found that at a low weight by volume concentration of nanofluid the heat transfer enhancement of 8% was achieved using Al-MWCNT fins compared to base fluid.

Inverse analysis of a rectangular fin using the lattice Boltzmann method

International Nuclear Information System (INIS)

Bamdad, Keivan; Ashorynejad, Hamid Reza

2015-01-01

Highlights: • Lattice Boltzmann method is used to study a transient conductive-convective fin. • LBM and Conjugate Gradient Method (CGM) are used to solve an inverse problem in fins. • LBM–ACGM estimates the unknown boundary conditions of fins accurately. • The accuracy and CPU time of LBM–ACGM are compared to IFDM–ACGM. • LBM–ACGM could be a good alternative for the conventional inverse methods. - Abstract: Inverse methods have many applications in determining unknown variables in heat transfer problems when direct measurements are impossible. As most common inverse methods are iterative and time consuming especially for complex geometries, developing more efficient methods seems necessary. In this paper, a direct transient conduction–convection heat transfer problem (fin) under several boundary conditions was solved by using lattice Boltzmann method (LBM), and then the results were successfully validated against both the finite difference method and analytical solution. Then, in the inverse problem both unknown base temperatures and heat fluxes in the rectangular fin were estimated by combining the adjoint conjugate gradient method (ACGM) and LBM. A close agreement between the exact values and estimated results confirmed the validity and accuracy of the ACGM–LBM. To compare the calculation time of ACGM–LBM, the inverse problem was solved by implicit finite difference methods as well. This comparison proved that the ACGM–LBM was an accurate and fast method to determine unknown thermal boundary conditions in transient conduction–convection heat transfer problems. The findings can efficiently determine the unknown variables in fins when a desired temperature distribution is available

Arm retraction dynamics of entangled star polymers: A forward flux sampling method study

Science.gov (United States)

Zhu, Jian; Likhtman, Alexei E.; Wang, Zuowei

2017-07-01

The study of dynamics and rheology of well-entangled branched polymers remains a challenge for computer simulations due to the exponentially growing terminal relaxation times of these polymers with increasing molecular weights. We present an efficient simulation algorithm for studying the arm retraction dynamics of entangled star polymers by combining the coarse-grained slip-spring (SS) model with the forward flux sampling (FFS) method. This algorithm is first applied to simulate symmetric star polymers in the absence of constraint release (CR). The reaction coordinate for the FFS method is determined by finding good agreement of the simulation results on the terminal relaxation times of mildly entangled stars with those obtained from direct shooting SS model simulations with the relative difference between them less than 5%. The FFS simulations are then carried out for strongly entangled stars with arm lengths up to 16 entanglements that are far beyond the accessibility of brute force simulations in the non-CR condition. Apart from the terminal relaxation times, the same method can also be applied to generate the relaxation spectra of all entanglements along the arms which are desired for the development of quantitative theories of entangled branched polymers. Furthermore, we propose a numerical route to construct the experimentally measurable relaxation correlation functions by effectively linking the data stored at each interface during the FFS runs. The obtained star arm end-to-end vector relaxation functions Φ (t ) and the stress relaxation function G(t) are found to be in reasonably good agreement with standard SS simulation results in the terminal regime. Finally, we demonstrate that this simulation method can be conveniently extended to study the arm-retraction problem in entangled star polymer melts with CR by modifying the definition of the reaction coordinate, while the computational efficiency will depend on the particular slip-spring or slip

Velocity Deficits in the Wake of Model Lemon Shark Dorsal Fins Measured with Particle Image Velocimetry

Science.gov (United States)

Terry, K. N.; Turner, V.; Hackett, E.

2017-12-01

Aquatic animals' morphology provides inspiration for human technological developments, as their bodies have evolved and become adapted for efficient swimming. Lemon sharks exhibit a uniquely large second dorsal fin that is nearly the same size as the first fin, the hydrodynamic role of which is unknown. This experimental study looks at the drag forces on a scale model of the Lemon shark's unique two-fin configuration in comparison to drag forces on a more typical one-fin configuration. The experiments were performed in a recirculating water flume, where the wakes behind the scale models are measured using particle image velocimetry. The experiments are performed at three different flow speeds for both fin configurations. The measured instantaneous 2D distributions of the streamwise and wall-normal velocity components are ensemble averaged to generate streamwise velocity vertical profiles. In addition, velocity deficit profiles are computed from the difference between these mean streamwise velocity profiles and the free stream velocity, which is computed based on measured flow rates during the experiments. Results show that the mean velocities behind the fin and near the fin tip are smallest and increase as the streamwise distance from the fin tip increases. The magnitude of velocity deficits increases with increasing flow speed for both fin configurations, but at all flow speeds, the two-fin configurations generate larger velocity deficits than the one-fin configurations. Because the velocity deficit is directly proportional to the drag force, these results suggest that the two-fin configuration produces more drag.

Two-dimensional nonlinear transient heat transfer analysis of variable section pin fins

Energy Technology Data Exchange (ETDEWEB)

Malekzadeh, P. [Department of Mechanical Engineering, School of Engineering, Persian Gulf University, Boushehr 75168 (Iran); Rahideh, H. [Department of Chemical Engineering, School of Engineering, Persian Gulf University, Boushehr 75168 (Iran)

2009-04-15

The two-dimensional nonlinear transient heat transfer analysis of variable cross section pin-fins is studied using the incremental differential quadrature method (IDQM) as a simple, accurate, and computationally efficient numerical tool. The formulations are general so that it can easily be used for arbitrary continuously varying cross section pin fins with the spatial-temperature dependent thermal parameters. On all external surfaces of the pin fin, the convective-radiative condition is considered. The effects of two different types of boundary conditions at the base of pin fin are investigated: time and spatial dependent temperature, and the convection heat transfer. The thermal conductivity of the pin fin is assumed to vary as a linear function of the temperature. The accuracy of the method is demonstrated by comparing its results with those generated by finite difference method. It is shown that using few grid points, results in excellent agreements with those of FDM are obtained. Less computational efforts of the method with respect to finite difference method is shown. (author)

A comparison of pectoral fin contact between two different wild dolphin populations

Science.gov (United States)

Dudzinski, K.M.; Gregg, J.D.; Ribic, C.A.; Kuczaj, S.A.

2009-01-01

Contact behaviour involving the pectoral fin has been documented in a number of dolphin species, and various explanations about its function have been offered. Pectoral fin contact can take a variety of forms, and involves a number of body parts and movements, likely differing depending upon social or ecological context. For this study, we compare the pectoral fin contact behaviour of two species of wild dolphins: Indo-Pacific bottlenose dolphins (Tursiops aduncus) from around Mikura Island, Japan, and Atlantic spotted dolphins (Stenella frontalis) from The Bahamas. The two study populations exhibit surprising similarity in the ways in which pectoral fin contacts are used, despite differences in species and environmental conditions at the two sites. Differences in contact rates for calves between the two sites suggest that calf-focused aggression from adult dolphins is more prevalent at Mikura than in The Bahamas. Our results suggest that pectoral fin contact behaviour seems to be driven primarily by social pressures, and may be similar in function to allogrooming described in primates. ?? 2008 Elsevier B.V.

Protective Role of Comfrey Leave Extracts on UV-induced Zebrafish Fin Damage.

Science.gov (United States)

Cheng, Chien-Chung; Chou, Chi-Yuan; Chang, Yao-Chin; Wang, Hsuan-Wen; Wen, Chi-Chung; Chen, Yau-Hung

2014-07-01

In zebrafish, UV exposure leads to fin malformation phenotypes including fin reduction or absence. The present study evaluated UV-protective activities of comfrey leaves extracts in a zebrafish model by recording fin morphological changes. Chemopreventive effects of comfrey leave extracts were evaluated using Kaplan-Meier analysis and Cox proportional hazards regression. The results showed that (1) the mean times of return to normal fin in the UV+comfrey (50 and 100 ppm) groups were 3.43 and 2.86 days and were quicker compared with that in the UV only group (4.21 days); (2) zebrafish fins in the UV+comfrey (50 and 100 ppm) groups were 2.05 and 3.25 times more likely to return to normal than those in the UV only group; and (3) comfrey leave extracts had UV-absorbance abilities and significantly reduced ROS production in UV-exposed zebrafish embryos, which may attenuate UV-mediated apoptosis. In conclusion, comfrey leaves extracts may have the potential to be developed as UV-protective agents to protect zebrafish embryos from UV-induced damage.

NON-GRAMMATICAL APOPHONY IN ENGLISH.

Science.gov (United States)

WESCOTT, ROGER W.

AN APOPHONE MAY BE DEFINED GENERALLY AS A POLYSYLLABIC VOWEL SEQUENCE SUCH THAT EACH CONTAINED VOWEL IS LOWER OR MORE RETRACTED THAN THE VOWEL WHICH PRECEDES IT --"SING, SANG, SUNG," AND "CLINK, CLANK, CLUNK" ARE EXAMPLES IN ENGLISH. FOR NEARLY EVERY CASE OF GRAMMATICAL APOPHONY IN ENGLISH THERE IS A NON-GRAMMATICAL (YET…

3-D NUMERICAL STUDY AND COMPARISON OF ECCENTRIC AND CONCENTRIC ANNULAR-FINNED TUBE HEAT EXCHANGERS

Directory of Open Access Journals (Sweden)

FAROUK TAHROUR

2015-11-01

Full Text Available The use of 3-D computational fluid dynamics (CFD is proposed to simulate the conjugate conduction-convection of heat transfer problems in eccentric annularfinned tube heat exchangers. The numerical simulation results allow us to evaluate the heat transfer coefficient over fin surfaces, the fin efficiency and the pressure drop. The aim of the present paper is to determine the optimum tube position in the circular fin that maximizes heat dissipation and minimizes pressure drop. In addition, this study analyzes the effects of fin spacing and fin tube diameter on heat transfer and flow characteristics for a range of Reynolds numbers, 4500≤Re≤22500. A satisfactory qualitative and quantitative agreement was obtained between the numerical predictions and the results published in the literature. For small fin spacings, the eccentric annular finned tube is more efficient than the concentric one. Among the cases examined, the average heat transfer coefficient of the eccentric annular-finned tube, for a tube shift St =12 mm and a Reynolds number Re = 9923, was 7.61% greater than that of the concentric one. This gain is associated with a 43.09% reduction in pressure drop.

Flexible nanoscale high-performance FinFETs

KAUST Repository

Sevilla, Galo T.; Ghoneim, Mohamed T.; Fahad, Hossain M.; Rojas, Jhonathan Prieto; Hussain, Aftab M.; Hussain, Muhammad Mustafa

2014-01-01

With the emergence of the Internet of Things (IoT), flexible high-performance nanoscale electronics are more desired. At the moment, FinFET is the most advanced transistor architecture used in the state-of-the-art microprocessors. Therefore, we show

Numerical Study of Compact Plate-Fin Heat Exchanger for Rotary-Vane Gas Refrigeration Machine

Directory of Open Access Journals (Sweden)

V. V. Trandafilov

2017-10-01

Full Text Available Plate-fin heat exchangers are widely used in refrigeration technique. They are popular because of their compactness and excellent heat transfer performance. Here we present a numerical model for the development, research and optimization of a plate-fin heat exchanger for a rotary-vane gas refrigeration machine. The method of analysis by graphic method of plate - fin heat exchanger is proposed. The model describes the effects of secondary parameters such as axial thermal conductivity through a metal matrix of the heat exchanger. The influence of geometric parameters and heat transfer coefficient is studied. Graphs of dependences of length, efficiency of a fin and pressure drop in a heat exchanger on the thickness of the fin and the number of fins per meter are obtained. To analyze the results of numerical simulation, the heat exchanger was designed in the Aspen HYSYS program. The simulation results show that the total deviation from the proposed numerical model is not more than 15%. 

Optimization analysis of convective–radiative longitudinal fins with temperature-dependent properties and different section shapes and materials

International Nuclear Information System (INIS)

Mosayebidorcheh, S.; Hatami, M.; Mosayebidorcheh, T.; Ganji, D.D.

2015-01-01

Graphical abstract: Temperature distribution along the fins obtained for different material and section shapes. - Highlights: • The steady state thermal analysis of longitudinal fins is presented. • The properties of fins are assumed as a function of temperature. • The rectangular, convex, triangular and concave profiles are considered for fin shape. • Least Square Method (LSM) is used for solving the governing equation. • Thermal optimization of fin geometry is presented based on maximum value of heat transfer. - Abstract: The main aim of this study is to obtain an optimum design point for fin geometry, so that heat transfer rate reaches to a maximum value in a constant fin volume. Effect of fin thicknesses ratio (τ), convection coefficient power index (m), profile power parameter (n), base thickness (δ) and fin material are evaluated in the fin optimization point for heat transfer rate, effectiveness and efficiency. It’s assumed that the thickness of longitudinal fins varies with length in a special profile, so four different shapes (rectangular, convex, triangular and concave) are considered. In present study, temperature-dependent heat generation, convection and radiation are considered and an analytical technique based on the least square method is proposed for the solution methodology. Results show that by increasing the fin thicknesses ratio, maximum heat transfer rate decreases and Copper among the other materials has the most heat transfer rate in a constant volume.

Swimming performance of a bio-inspired robotic vessel with undulating fin propulsion.

Science.gov (United States)

Liu, Hanlin; Curet, Oscar M

2018-06-18

Undulatory fin propulsion exhibits high degree of maneuver control -- an ideal for underwater vessels exploring complex environments. In this work, we developed and tested a self-contained, free-swimming robot with a single undulating fin running along the length of the robot, which controls both forward motion and directional maneuvers. We successfully replicated several maneuvers including forward swimming, reversed motion, diving, station-keeping and vertical swimming. For each maneuver, a series of experiments were performed as a function of fin frequency, wavelength and traveling wave direction to measure swimming velocities, orientation angles and mean power consumption. In addition, three-dimensional flow fields were measured during forward swimming and station-keeping using volumetric particle image velocimetry (PIV). The efficiency for forward swimming was compared using three metrics: cost of transport, wave efficiency and Strouhal number. The results indicate that the cost of transport exhibits a V-shape trend with the minimum value at low swimming velocity. The robot can reach optimal wave efficiency and locomotor performance at a range of 0.2 to 0.4 St. Volumetric PIV data reveal the shed of vortex tubes generated by the fin during forward swimming and station keeping. For forward swimming, a series of vortex tubes are shed off the fin edge with a lateral and downward direction with respect to the longitudinal axis of the fin. For station keeping, flow measurements suggest that the vortex tubes are shed at the mid-section of the fin while the posterior and anterior segment of the vortex stay attached to the fin. These results agree with the previous vortex structures based on simulations and 2D PIV. The further development of this vessel with high maneuverability and station keeping performance can be used for oceanography, coastal exploration, defense, oil industry and other marine industries where operations are unsafe or impractical for divers or

The stress characteristics of plate-fin structures at the different operation parameters of LNG heat exchanger

Directory of Open Access Journals (Sweden)

Ma Hongqiang

2018-01-01

Full Text Available In this paper, the stresses of plate-fin structures at the different operation parameters were analyzed in actual operation process of LNG plate-fin heat exchanger based on finite element method and thermal elastic theory. Stress characteristics of plate-fin structures were investigated at the different operation parameters of that. The results show that the structural failure of plate-fin structures is mainly induced by the maximum shear stress at the brazing filler metal layer between plate and fin while by the maximum normal stress in the region of brazed joint near the fin side. And a crack would initiate in brazed joint near the fin side. The maximum normal stress is also main factor to result in the structural failure of plate-fin structures at the different temperature difference (between Natural Gas (NG and Mixture Refrigerant (MR, MR temperature and NG pressure of LNG heat exchanger. At the same time, the peak stresses obviously increase as the temperature difference, MR temperature and NG pressure increase. These results will provide some constructive instructions in the safe operation of LNG plate-fin heat exchanger in a large-scale LNG cold-box.

Experimental research on single phase convection heat transfer in micro-fin tube

International Nuclear Information System (INIS)

Fan Guangming; Sun Zhongning; Zhu Sheng

2011-01-01

An experimental investigation of heat transfer and flow resistance characteristics of single phase water in three micro-fin tubes with different fin height was conducted. At the same time, the efficiency of micro-fin tubes within the experimental scope was evaluated and the optimal working region was determined. Based on the experimental data in the optimal working region, correlations for predicting the heat transfer and flow resistance were also given by multiple regression method. The result indicates that the micro-fin tubes can greatly enhance the single-phase heat transfer in turbulent flow, and the increase of heat transfer coefficient is higher than the increase of flow resistance. The accuracy of the correlation is very high, of which the deviation from the experimental value is very small. (authors)

Mechanical Property Analysis in the Retracted Pin-Tool (RPT) Region of Friction Stir Welded (FSW) Aluminum Lithium 2195

Science.gov (United States)

Ding, R. Jeffrey; Oelgoetz, Peter A.

1999-01-01

The "Auto-Adjustable Pin Tool for Friction Stir Welding", was developed at The Marshall Space Flight Center to address process deficiencies unique to the FSW process. The auto-adjustable pin tool, also called the retractable pin-tool (R.PT) automatically withdraws the welding probe of the pin-tool into the pin-tool's shoulder. The primary function of the auto-adjustable pin-tool is to allow for keyhole closeout, necessary for circumferential welding and localized weld repair, and, automated pin-length adjustment for the welding of tapered material thickness. An overview of the RPT hardware is presented. The paper follows with studies conducted using the RPT. The RPT was used to simulate two capabilities; welding tapered material thickness and closing out the keyhole in a circumferential weld. The retracted pin-tool regions in aluminum- lithium 2195 friction stir weldments were studied through mechanical property testing and metallurgical sectioning. Correlation's can be =de between retractable pin-tool programmed parameters, process parameters, microstructure, and resulting weld quality.

Retraction notice to: "The Application of Symmetric Key Cryptographic Algorithms in Wireless Sensor Networks"

Science.gov (United States)

Si, Lingling; Ji, Zhigang; Wang, Zhihui

This article has been retracted: please see Elsevier Policy on Article Withdrawal. This article has been retracted at the request of the Publisher. The authors have plagiarized a paper that had already appeared in "Queen's 25th Biennial Symposium on Communications", page 168-172, print ISBN 978-1-4244-5709-0. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

Clinical experience of a new retractable barb needle for breast lesion localization: The first 60 cases

International Nuclear Information System (INIS)

Urrutia, E.J.; Hawkins, I.F.; Hawkins, M.C.; Meacham, M.A.; Bland, K.I.; Copelan, E.M. III.

1987-01-01

Recently there has been an increase in the request to the radiologists from surgeons to localize nonpalpable breast lesions suspicious for malignancy. Currently there are several needles used for this purpose. The authors present here a new retractable barb needle which consists of a coaxial system with a 20-gauge outer cannula and a 23-gauge inner cannula with a sharp stylus with a hook spring wire soldered to it. The main advantage of this needle over other systems is the ability of the barb to be retracted and the needle repositioned. Other advantages are the strong anchoring properties of the barb, permitting retraction by the surgeon and ending fear of dislodgement, breaking, or transection as experienced with other systems. This system also lowers the radiation exposure to the patients since only one confirmatory radiograph is necessary after optimal positioning of the needle as opposed to two with the most popular system used currently. The authors have done 60 localizations in 58 patients with no failures or major complications. The area in question was successfully sampled in all cases. The authors' referring surgeons prefer this needle over other commercially available types

Assessment of in vitro antifungal activity of preparation ''fin Candimis'' against Candida strains

Directory of Open Access Journals (Sweden)

Anna Głowacka

2013-12-01

Full Text Available The aim of the study was to assess the antifungal activity of preparation „fin Candimis” (oregano essential oil against yeast-like strains belonging to the genus Candida. During the investigation, there were used up nine Candida albicans strains and ten C. glabrata strains isolated from different clinical material, along with one C. albicans demonstration strain ATCC 90028. The oregano essential oil, utilized in the study, was obtained from fresh leaves of Origanum vulgare L. and bore a trade name „fin Candimis”. According to data yielded by its manufacturer, concentration of pure oregano essential oil in preparation „fin Candimis” totals up to 210 mg/ml. The susceptibility of the Candida strains to preparation „fin Candimis” was assessed by means of the disc-diffusion method, upon the Sabouraud solid medium (after a 24-hour incubation of the cultures at temperature of 37 degrees centigrade; the oregano essential oil had been diluted in 1 ml of DMSO, according to the geometrical progression. A measure of the antifungal activity of preparation „fin Candimis” was the minimal inhibitory concentration (MIC, in terms of the fungus growth. Preparation „fin Candimis” is capable of being applied in the prevention and treatment of candidiasis – alone, or as a natural adjunctive agent. The C. albicans strains are more susceptible to preparation „fin Candimis” in comparison to the C. glabrata ones.

Thermal management of electronics using phase change material based pin fin heat sinks

International Nuclear Information System (INIS)

Baby, R; Balaji, C

2012-01-01

This paper reports the results of an experimental study carried out to explore the thermal characteristics of phase change material based heat sinks for electronic equipment cooling. The phase change material (PCM) used in this study is n – eicosane. All heat sinks used in the present study are made of aluminium with dimensions of 80 × 62 mm 2 base with a height of 25 mm. Pin fins acts as the thermal conductivity enhancer (TCE) to improve the distribution of heat more uniformly as the thermal conductivity of the PCM is very low. A total of three different pin fin heat sink geometries with 33, 72 and 120 pin fins filled with phase change materials giving rise to 4%, 9% and 15% volume fractions of the TCE respectively were experimentally investigated. Baseline comparisons are done with a heat sink filled with PCM, without any fin. Studies are conducted for heat sinks on which a uniform heat load is applied at the bottom for the finned and unfinned cases. The effect of pin fins of different volume fractions with power levels ranging from 4 to 8 W corresponding to a heat flux range of 1. 59 to 3.17 kW/m 2 , was explored in this paper. The volume fraction of the PCM (PCM volume / (Total volume – fin volume)) is also varied as 0. 3, 0.6 and 1 to determine the effect of PCM volume on the overall performance of the electronic equipment.

Burnout in the boiling of water and freon-113 on tubes with annular fins

International Nuclear Information System (INIS)

Rubin, I.R.; Pul'kin, I.N.; Roizen, L.I.

1986-01-01

This paper presents the results of numerical calculations of burnout heat flux associated with the boiling of Freon-113 and water on an annular fin of constant thickness which have been approximated by simple analytical relations. These are used to calculate the critical burnout parameters of tubes with an annular fin assembly. The calculated data may be used for the analysis of tubes with an annular fin assembly over a wide range of variation of the thermophysical properties of the material and geometrical parameters of the fin assembly

Rotator cuff muscles lose responsiveness to anabolic steroids after tendon tear and musculotendinous retraction: an experimental study in sheep.

Science.gov (United States)

Gerber, Christian; Meyer, Dominik C; Von Rechenberg, Brigitte; Hoppeler, Hans; Frigg, Robert; Farshad, Mazda

2012-11-01

Long-standing rotator cuff tendon tearing is associated with retraction, loss of work capacity, irreversible fatty infiltration, and atrophy of the rotator cuff muscles. Although continuous musculotendinous relengthening can experimentally restore muscular architecture, restoration of atrophy and fatty infiltration is hitherto impossible. Continuous relengthening with pharmacological stimulation of muscle growth using an anabolic steroid or insulin-like growth factor (IGF) can reverse atrophy and fatty infiltration as well as improve the work capacity of chronically retracted rotator cuff muscles in sheep. Controlled laboratory study. Sixteen weeks after tenotomy of the infraspinatus (ISP) tendon, atrophy and fatty infiltration had developed in the retracted ISP muscle. The musculotendinous unit was continuously relengthened in 14 sheep during 6 weeks: Four sheep were treated without pharmacological stimulation, 4 with intramuscular administration of an anabolic steroid, and 6 with IGF before final repair and rehabilitation (12 weeks). Changes were documented by intraoperative measurements of muscle work capacity, histology, and computed tomography/magnetic resonance imaging. Musculotendinous relengthening by continuous traction resulted in gains of length ranging from 0.7 cm in the IGF group to 1.3 cm in the control group. Fatty infiltration progressed in all groups, and the muscle's cross-sectional area ranged from 71% to 74% of the contralateral side at sacrifice and did not show any differences between groups in weight, volume, histological composition, or work capability of the muscle. The contralateral muscles in the anabolic steroid group, however, showed significantly higher (mean ± standard deviation) muscle work capacity of 10 ± 0.9 N·m than the contralateral muscles of the control group (6.8 ± 2.4 N·m) (P muscle fiber area as well as by an unusual gain in the animals' weight after injection of the anabolic steroid. Subcutaneous continuous

Influence of the degree of thermal contact in fin and tube heat exchanger

DEFF Research Database (Denmark)

Singh, Shobhana; Sørensen, Kim; Condra, Thomas Joseph

2016-01-01

Present work aims to investigate the significance of thermal contact area between fins and tubes in a heat exchanger. The heat exchanger type selected for the study is a liquid-gas fin and tube heat exchanger. Four different cases namely I, II, III, and IV, based on a variable degree of thermal...... contact between fins and tubes are investigated. Case-I with 100% thermal contact area between the fin and tube is set as a reference to cases-II, III, and IV with a thermal contact area of approximately 70%, 50%, and 35%, respectively. Three-dimensional (3D) steady-state numerical models based on finite...... and to compare the performance of heat exchanger design in different cases. Comparative analysis indicates a significant influence of the degree of the thermal contact area between fin and tube on the overall performance. Case-I is found to have higher overall heat transfer coefficient of 47.332 W/(m2 K), higher...

Experimental Study on Cooling Heat Transfer of Supercritical Carbon Dioxide Inside Horizontal Micro-Fin Tubes

Science.gov (United States)

Kuwahara, Ken; Higashiiu, Shinya; Ito, Daisuke; Koyama, Shigeru

This paper deals with the experimental study on cooling heat transfer of supercritical carbon dioxide inside micro-fin tubes. The geometrical parameters in micro-fin tubes used in the present study are 6.02 mm in outer diameter, 4.76 mm to 5.11 mm in average inner diameter, 0.15 mm to 0.24 mm in fin height, 5 to 25 in helix angle, 46 to 52 in number of fins and 1.4 to 2.3 in area expansion ratio. Heat transfer coefficients were measured at 8-10 MPa in pressure, 360-690 kg/(m2•s) in mass velocity and 20-75 °C in CO2 temperature. The measured heat transfer coefficients of micro-fin tubes were 1.4 to 2 times higher than those of the smooth tube having 4.42 in inner diameter. The predicted heat transfer coefficients using the correlation equation, which was developed for single-phase turbulent fluid flow inside micro-fin-tubes, showed large deviations to the measured values. The new correlation to predict cooling heat transfer coefficient of supercritical carbon dioxide inside micro-fin tubes was developed taking into account the shape of fins based on experimental data empirically. This correlation equation agreed within ±20% of almost all of the experimental data.

Development of plate-fin heat exchanger for intermediate heat exchanger of high-temperature gas cooled reactor. Fabrication process, high-temperature strength and creep-fatigue life prediction of plate-fin structure made of Hastelloy X