• Title/Summary/Keyword: Wright

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Finite element modelling of the shear behaviour of profiled composite walls incorporating steel-concrete interaction

  • Anwar Hossain, K.M.;Wright, H.D.
    • Structural Engineering and Mechanics
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    • v.21 no.6
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    • pp.659-676
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    • 2005
  • The novel form of composite walling system consists of two skins of profiled steel sheeting with an in-fill of concrete. The behaviour of such walling under in-plane shear is important in order to utilise this system as shear elements in a steel framed building. Steel sheet-concrete interface governs composite action, overall behaviour and failure modes of such walls. This paper describes the finite element (FE) modelling of the shear behaviour of walls with particular emphasis on the simulation of steel-concrete interface. The modelling of complex non-linear steel-concrete interaction in composite walls is conducted by using different FE models. Four FE models are developed and characterized by their approaches to simulate steel-concrete interface behaviour allowing either full or partial composite action. Non-linear interface or joint elements are introduced between steel and concrete to simulate partial composite action that allows steel-concrete in-plane slip or out of plane separation. The properties of such interface/joint elements are optimised through extensive parametric FE analysis using experimental results to achieve reliable and accurate simulation of actual steel-concrete interaction in a wall. The performance of developed FE models is validated through small-scale model tests. FE models are found to simulate strength, stiffness and strain characteristics reasonably well. The performance of a model with joint elements connecting steel and concrete layers is found better than full composite (without interface or joint elements) and other models with interface elements. The proposed FE model can be used to simulate the shear behaviour of composite walls in practical situation.

Genetic Diversity and Population Genetic Structure of Cephalotaxus koreana in South Korea

  • Hong, Kyung Nak;Kim, Young Mi;Park, Yu Jin;Lee, Jei Wan
    • Korean Journal of Plant Resources
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    • v.27 no.6
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    • pp.660-670
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    • 2014
  • The Korean plum yew (Cephalotaxus koreana Nakai) is a shade-tolerant, coniferous shrub. The seeds have been used as a folk medicine in Korea, and an alkaloid extract (HTT) is known to have anticancer properties. We estimated the genetic diversity of 429 trees in 16 populations in South Korea using 194 polymorphic amplicons from seven combinations of AFLP primer-restriction enzymes. The average number of effective alleles and the percentage of polymorphic loci were 1.37 and 79.4%, respectively. Shannon's diversity index and the expected heterozygosity were 0.344 and 0.244, respectively. We divided 16 populations into four groups on the UPGMA dendrogram and the PCA biplot. The first two principal components explained 84% of the total genetic variation. Genetic differentiation between populations explained 14% of total genetic variation, and the remaining 86% came from difference between individuals within populations, as determined by an analysis of molecular variance (AMOVA). However, the genetic differentiation did not correlate with the geographic distance between populations from the Mantel test. The Bayesian statistics, which are comparable to Wright's $F_{ST}$ and Nei's $G_{ST}$, were ${\theta}^I=0.406$ and ${\theta}^{II}=0.172$, respectively. The population genetic diversity was slightly lower, and the strength of genetic differentiation was much weaker, than the average of those plants having similar life histories, as assessed using arbitrary marker systems. We discuss strategies for the genetic conservation of the plum yew in Korea.

Guided bone regeneration using demineralized allogenic bone matrix with calcium sulfate: case series

  • Kim, Young-Kyun;Lee, Ji-Young;Kim, Su-Gwan;Lim, Seung-Chul
    • The Journal of Advanced Prosthodontics
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    • v.5 no.2
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    • pp.167-171
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    • 2013
  • PURPOSE. The purpose of this case series was to evaluate the effect of guided bone regeneration using demineralized allogenic bone matrix with calcium sulfate. MATERIALS AND METHODS. Guided bone regeneration using Demineralized Allogenic Bone Matrix with Calcium Sulfate ($AlloMatrix^{TM}$, Wright. USA) was performed at the time of implant placement from February 2010 to April 2010. At the time of the second surgery, clinical evaluation of bone healing and histologic evaluation were performed. The study included 10 patients, and 23 implants were placed. The extent of bony defects around implants was determined by measuring the horizontal and vertical bone defects using a periodontal probe from the mesial, distal, buccal, and lingual sides and calculating the mean and standard deviation of these measurements. Wedge-shaped tissue samples were obtained from 3 patients and histologic examination was performed. RESULTS. In clinical evaluation, it was observed that horizontal bone defects were completely healed with new bones, and in the vertical bone defect area, 15.1% of the original defect area remained. In 3 patients, histological tests were performed, and 16.7-41.7% new bone formation was confirmed. Bone graft materials slowly underwent resorption over time. CONCLUSION. $AlloMatrix^{TM}$ is an allograft material that can be readily manipulated. It does not require the use of barrier membranes, and good bone regeneration can be achieved with time.

Development and validation of a non-linear k-ε model for flow over a full-scale building

  • Wright, N.G.;Easom, G.J.;Hoxey, R.J.
    • Wind and Structures
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    • v.4 no.3
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    • pp.177-196
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    • 2001
  • At present the most popular turbulence models used for engineering solutions to flow problems are the $k-{\varepsilon}$ and Reynolds stress models. The shortcoming of these models based on the isotropic eddy viscosity concept and Reynolds averaging in flow fields of the type found in the field of Wind Engineering are well documented. In view of these shortcomings this paper presents the implementation of a non-linear model and its evaluation for flow around a building. Tests were undertaken using the classical bluff body shape, a surface mounted cube, with orientations both normal and skewed at $45^{\circ}$ to the incident wind. Full-scale investigations have been undertaken at the Silsoe Research Institute with a 6 m surface mounted cube and a fetch of roughness height equal to 0.01 m. All tests were originally undertaken for a number of turbulence models including the standard, RNG and MMK $k-{\varepsilon}$ models and the differential stress model. The sensitivity of the CFD results to a number of solver parameters was tested. The accuracy of the turbulence model used was deduced by comparison to the full-scale predicted roof and wake recirculation zone lengths. Mean values of the predicted pressure coefficients were used to further validate the turbulence models. Preliminary comparisons have also been made with available published experimental and large eddy simulation data. Initial investigations suggested that a suitable turbulence model should be able to model the anisotropy of turbulent flow such as the Reynolds stress model whilst maintaining the ease of use and computational stability of the two equations models. Therefore development work concentrated on non-linear quadratic and cubic expansions of the Boussinesq eddy viscosity assumption. Comparisons of these with models based on an isotropic assumption are presented along with comparisons with measured data.

A Study on the Spatial Characteristics in the Residential Designs by Vilhelm Wohlert - Focusing on Program Composition, Spatialization, Multidimensional Experience - (빌헬름 볼러트의 주택 작품에 나타난 공간적 특성에 관한 연구 - 프로그램 구성, 공간구축, 다차원적 경험을 중심으로 -)

  • Kim, Jong-Jin
    • Korean Institute of Interior Design Journal
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    • v.21 no.3
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    • pp.3-10
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    • 2012
  • Vilhelm Wohlert is the Danish architect who designed Louisiana Museum of Modern Art near Copenhagen. Because of Louisiana Museum's popularity, Vilhelm Wohlert's name was started to be aware since 1990s. Although he is a well-known architect in Denmark, unfortunately his name is unknown in other countries. He designed various design projects from small scale furniture design to large scale museum and public projects. There are three programmatic categories in his architecture: exhibition programs including Louisiana Museum, residential program including private houses, and public programs including churches and schools. This thesis focuses on his residential design projects. Even though he designed a multi-family houses, Wohlert's house design consists of mainly one-off large private houses located in a nice natural environment. In chapter 3, the general history of his house projects was studied. Among them, the first exhibition house for Forum was explained more deeply to show Wohlert's early house design philosophy. In chapter 4, three built house projects were analyzed in detail. Analytical diagrams were used to show the key elements in the residential space. They are program composition, circulation, spatialization elements, final construction. His buildings have been compared with Alvar Aalto, Frank Lloyd Wright, and other Scandinavian architects. But there are some major differences that make Wohlert's design unique. In chapter 5, the case analysis results were summarized together to highlight the specific design characteristics found in Wohlert's residential design process. The universal spatial quality found in his residential projects can be applied in contemporary spatial designs.

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Effects of Zr-hydride distribution of irradiated Zircaloy-2 cladding in RIA-simulating pellet-clad mechanical interaction testing

  • Magnusson, Per;Alvarez-Holston, Anna-Maria;Ammon, Katja;Ledergerber, Guido;Nilsson, Marcus;Schrire, David;Nissen, Klaus;Wright, Jonathan
    • Nuclear Engineering and Technology
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    • v.50 no.2
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    • pp.246-252
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    • 2018
  • A series of simulated reactivity-initiated accident (RIA) tests on irradiated fully recrystallized boiling water reactor Zircaloy-2 cladding has been performed by means of the expansion-due-to-compression (EDC) test method. The EDC method reproduces fuel pellet-clad mechanical interaction (PCMI) conditions for the cladding during RIA transients with respect to temperature and loading rates by out-of-pile mechanical testing. The tested materials had a large variation in burnup and hydrogen content (up to 907 wppm). The results of the EDC tests showed variation in the PCMI resistance of claddings with similar burnup and hydrogen content, making it difficult to clearly identify ductile-to-brittle transition temperatures. The EDC-tested samples of the present and previous work were investigated by light optical and scanning electron microscopy to study the influence of factors such as azimuthal variation of the Zr-hydrides and the presence of hydride rims and radially oriented hydrides. Two main characteristics were identified in samples with low ductility with respect to hydrogen content and test temperature: hydride rims and radial hydrides at the cladding outer surface. Crack propagation and failure modes were also studied, showing two general modes of crack propagation depending on distribution and amount of radially oriented hydrides. It was concluded that the PCMI resistance of irradiated cladding under normal conditions with homogenously distributed circumferential hydrides is high, with good margin to the RIA failure limits. To further improve safety, focus should be on conditions causing nonfavorable hydride distribution, such as hydride reorientation and formation of hydride blisters at the cladding outer surface.

Anemia Screening, Prevalence, and Treatment in Pediatric Inflammatory Bowel Disease in the United States, 2010-2014

  • Miller, Steven D.;Cuffari, Carmelo;Akhuemonkhan, Eboselume;Guerrerio, Anthony L.;Lehmann, Harold;Hutfless, Susan
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.22 no.2
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    • pp.152-161
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    • 2019
  • Purpose: We examined the prevalence of anemia, annual screening for anemia, and treatment of anemia with iron among children with inflammatory bowel disease (IBD). Methods: A retrospective study of U.S. pediatric patients with IBD was performed in the MarketScan commercial claims database from 2010-2014. Children (ages 1-21) with at least two inpatient or outpatient encounters for IBD who had available lab and pharmacy data were included in the cohort. Anemia was defined using World Health Organization criteria. We used logistic regression to determine differences in screening, incident anemia, and treatment based on age at first IBD encounter and sex. Results: The cohort (n=2,446) included 1,560 Crohn's disease (CD) and 886 ulcerative colitis (UC). Approximately, 85% of CD and 81% of UC were screened for anemia. Among those screened, 51% with CD and 43% with UC had anemia. Only 24% of anemia patients with CD and 20% with UC were tested for iron deficiency; 85% were iron deficient. Intravenous (IV) iron was used to treat 4% of CD and 4% UC patients overall and 8% of those with anemia. Conclusion: At least 80% of children with IBD were screened for anemia, although most did not receive follow-up tests for iron deficiency. The 43%-50% prevalence of anemia was consistent with prior studies. Under-treatment with IV iron points to a potential target for quality improvement.

A HARMS-based heterogeneous human-robot team for gathering and collecting

  • Kim, Miae;Koh, Inseok;Jeon, Hyewon;Choi, Jiyeong;Min, Byung Cheol;Matson, Eric T.;Gallagher, John
    • Advances in robotics research
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    • v.2 no.3
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    • pp.201-217
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    • 2018
  • Agriculture production is a critical human intensive task, which takes place in all regions of the world. The process to grow and harvest crops is labor intensive in many countries due to the lack of automation and advanced technology. Much of the difficult, dangerous and dirty labor of crop production can be automated with intelligent and robotic platforms. We propose an intelligent, agent-oriented robotic team, which can enable the process of harvesting, gathering and collecting crops and fruits, of many types, from agricultural fields. This paper describes a novel robotic organization enabling humans, robots and agents to work together for automation of gathering and collection functions. The focus of the research is a model, called HARMS, which can enable Humans, software Agents, Robots, Machines and Sensors to work together indistinguishably. With this model, any capability-based human-like organization can be conceived and modeled, such as in manufacturing or agriculture. In this research, we model, design and implement a technology application of knowledge-based robot-to-robot and human-to-robot collaboration for an agricultural gathering and collection function. The gathering and collection functions were chosen as they are some of the most labor intensive and least automated processes in the process acquisition of agricultural products. The use of robotic organizations can reduce human labor and increase efficiency allowing people to focus on higher level tasks and minimizing the backbreaking tasks of agricultural production in the future. In this work, the HARMS model was applied to three different robotic instances and an integrated test was completed with satisfactory results that show the basic promise of this research.

Association of tumor differentiation grade and survival of women with squamous cell carcinoma of the uterine cervix

  • Matsuo, Koji;Mandelbaum, Rachel S.;Machida, Hiroko;Purushotham, Sanjay;Grubbs, Brendan H.;Roman, Lynda D.;Wright, Jason D.
    • Journal of Gynecologic Oncology
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    • v.29 no.6
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    • pp.91.1-91.12
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    • 2018
  • Objective: To examine the association between tumor grade and survival for women with squamous cervical cancer. Methods: This retrospective observational study utilized the Surveillance, Epidemiology, and End Result program data between 1983 and 2013 to examine women with squamous cervical cancer with known tumor differentiation grade. Multivariable analyses were performed to assess independent associations between tumor differentiation grade and survival. Results: A total of 31,536 women were identified including 15,175 (48.1%) with grade 3 tumors, 14,084 (44.7%) with grade 2 neoplasms and 2,277 (7.2%) with grade 1 tumors. Higher tumor grade was significantly associated with older age, higher stage disease, larger tumor size, and lymph node metastasis (all, p<0.001). In a multivariable analysis, grade 2 tumors (adjusted-hazard ratio [HR]=1.21; p<0.001) and grade 3 tumors (adjusted-HR=1.45; p<0.001) were independently associated with decreased cause-specific survival (CSS) compared to grade 1 tumors. Among the 7,429 women with stage II-III disease who received radiotherapy without surgical treatment, grade 3 tumors were independently associated with decreased CSS compared to grade 2 tumors (adjusted-HR=1.16; p<0.001). Among 4,045 women with node-negative stage I disease and tumor size ${\leq}4cm$ who underwent surgical treatment without radiotherapy, grade 2 tumors (adjusted-HR=2.54; p=0.028) and grade 3 tumors (adjusted-HR=4.48; p<0.001) were independently associated with decreased CSS compared to grade 1 tumors. Conclusion: Our study suggests that tumor differentiation grade may be a prognostic factor in women with squamous cervical cancer, particularly in early-stage disease. Higher tumor grade was associated with poorer survival.

Ectopic teeth with disparate migration: A literature review and new case series

  • Pallak Arora ;Madhu K. Nair ;Hui Liang ;Paras B. Patel ;John M. Wright;Mehrnaz Tahmasbi-Arashlow
    • Imaging Science in Dentistry
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    • v.53 no.3
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    • pp.229-238
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    • 2023
  • Purpose: Ectopic eruption can be defined as the emergence of a tooth in an abnormal location, where the tooth does not follow its typical eruption pathway. While ectopic eruption within the dentate region is well-documented in the literature, ectopic eruption in non-dentate regions is relatively rare. This study aimed to report 6 cases of ectopic teeth and present a systematic review of the English-language literature on ectopic teeth, emphasizing demographic characteristics, radiographic features, potential complications, and treatment options. Materials and Methods: A literature search was conducted using the PubMed, Medline, Web of Science, and Cochrane databases. The demographic data and radiographic findings of patients presenting with ectopic teeth were recorded. Results: The literature review yielded 61 cases of ectopic teeth, with patients ranging in age from 3 to 74 years. The findings from these previously reported cases demonstrated that the most common location for ectopic teeth was the maxillary sinus, which is consistent with this case series. The Pearson chi-square test was performed to evaluate the correlation between age and location of ectopic teeth, and the results were found to be statistically significant (P<0.05). However, no statistically significant relationship was observed between sex and the location of ectopic teeth. Conclusion: The distinct features of these cases warrant reporting. This study presents the first case of supernumerary teeth in the condyle without any associated pathosis. Another notable characteristic is the pre-eruptive resorption of 2 inverted supernumerary teeth ectopically located in the palate, which predisposes to sinus opacification.