48 CFR 1536.209 - Construction contracts with architect-engineer firms.

Science.gov (United States)

2010-10-01

... architect-engineer firms. 1536.209 Section 1536.209 Federal Acquisition Regulations System ENVIRONMENTAL PROTECTION AGENCY SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Special Aspects of Contracting for Construction 1536.209 Construction contracts with architect-engineer firms. (a...

48 CFR 36.209 - Construction contracts with architect-engineer firms.

Science.gov (United States)

2010-10-01

... with architect-engineer firms. 36.209 Section 36.209 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Special Aspects of Contracting for Construction 36.209 Construction contracts with architect-engineer firms. No...

48 CFR 636.209 - Construction contracts with architect-engineer firms.

Science.gov (United States)

2010-10-01

... with architect-engineer firms. 636.209 Section 636.209 Federal Acquisition Regulations System DEPARTMENT OF STATE SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Special Aspects of Contracting for Construction 636.209 Construction contracts with architect-engineer firms. The...

Modelling a Global EPCM (Engineering, Procurement and Construction Management Enterprise

Directory of Open Access Journals (Sweden)

Sekhar Chattopadhyay

2010-03-01

Full Text Available This paper investigates the applicability of enterprise architectures in the context of current business environment by examining the application of Purdue Enterprise Reference Architecture to WorleyParsons, a global engineering, procurement and construction management enterprise, under the backdrop of a similar study carried out on Fluor Daniel during mid-nineties of the last century. The outcome of this study recommends the need for new enterprise architecture, the People-Centric Enterprise Architecture that not only focuses on human dimension in modern enterprises as the central thread, but also includes more business characteristics of the enterprise other than engineerings.

48 CFR 952.236 - Construction and architect-engineer contracts.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Construction and architect-engineer contracts. 952.236 Section 952.236 Federal Acquisition Regulations System DEPARTMENT OF ENERGY... Construction and architect-engineer contracts. ...

Engineering Accomplishments in the Construction of NCSX

International Nuclear Information System (INIS)

G. H. Neilson; P.J. Heitzenroeder; B.E. Nelson; W.T. Reiersen; A. Brooks; T.G. Brown; J.H. Chrzanowski; M.J. Cole; F. Dahlgren; T. Dodson; L.E. Dudek; R.A. Ellis; H.M. Fan; P.J. Fogarty; K.D. Freudenberg; P.L. Goranson; J.H. Harris; M.R. Kalish; G. Labik; J.F. Lyon; N. Pomphrey; C.D. Priniski; S. Raftopoulos; D.J. Rej; W.R. Sands; R.T. Simmons; B.E. Stratton; R.L. Strykowsky; M.E. Viola; D.E. Williamson; M.C. Zarnstorff

2008-01-01

The National Compact Stellarator Experiment (NCSX) was designed to test a compact, quasiaxisymmetric stellarator configuration. Flexibility and accurate realization of its complex 3D geometry were key requirements affecting the design and construction. While the project was terminated before completing construction, there were significant engineering accomplishments in design, fabrication, and assembly. The design of the stellarator core device was completed. All of the modular coils, toroidal field coils, and vacuum vessel sectors were fabricated. Critical assembly steps were demonstrated. Engineering advances were made in the application of CAD modeling, structural analysis, and accurate fabrication of complex-shaped components and subassemblies. The engineering accomplishments of the project are summarized

Design Solutions for Sustainable Construction of Pre Engineered Steel Buildings

Directory of Open Access Journals (Sweden)

Muhammad Umair Saleem

2018-05-01

Full Text Available Sustainable construction of ecofriendly infrastructure has been the priority of worldwide researchers. The induction of modern technology in the steel manufacturing industry has enabled designers to get the desired control over the steel section shapes and profiles resulting in efficient use of construction material and manufacturing energy required to produce these materials. The current research study is focused on the optimization of steel building costs with the use of pre-engineered building construction technology. Construction of conventional steel buildings (CSB incorporates the use of hot rolled sections, which have uniform cross-section throughout the length. However, pre-engineered steel buildings (PEB utilize steel sections, which are tailored and profiled based on the required loading effects. In this research study, the performance of PEB steel frames in terms of optimum use of steel sections and its comparison with the conventional steel building is presented in detail. A series of PEB and CSB steel frames is selected and subjected to various loading conditions. Frames were analyzed using Finite Element Based analysis tool and design was performed using American Institute of Steel Construction design specifications. Comparison of the frames has been established in terms of frame weights, lateral displacements (sway and vertical displacements (deflection of the frames. The results have clearly indicated that PEB steel frames are not only the most economical solution due to lesser weight of construction but also have shown better performance compared to CSB frames.

Welding engineering manual for constructing engineers. Pt. 2

International Nuclear Information System (INIS)

Neumann, A.

1986-01-01

The manual is a real treasure trove of knowledge and experience for the statics expert, the constructing engineer, and the welding engineer, who have to do with design and dimensioning of welding engineering work for steel structures, bridges, boilers, vessels, and pipes. Many practical examples are given together with numerous data that provide helpful information for the task of technical and economic design and dimensioning. Determination of efficient and appropriate cross-sectional dimensions and materials is the main goal of the manual. Structural steel engineering and installations subject to monitoring and inspection such as boilers, pipings, pressure vessels, and nuclear installations are the subject fields dealt with in separate chapters. The dimensioning rules presented are based on the regulations and technical codes valid in the GDR and the FRG. The catalogue of technical rules of the FRG concerning structural steel engineering and installations as above are given in supplementary chapters. (orig./HP) [de

48 CFR 31.201-7 - Construction and architect-engineer contracts.

Science.gov (United States)

2010-10-01

...-engineer contracts. 31.201-7 Section 31.201-7 Federal Acquisition Regulations System FEDERAL ACQUISITION... Organizations 31.201-7 Construction and architect-engineer contracts. Specific principles and procedures for... architect-engineer contracts related to construction projects, are in 31.105. The applicability of these...

48 CFR 853.236 - Construction and architect-engineer contracts.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Construction and architect-engineer contracts. 853.236 Section 853.236 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS CLAUSES AND FORMS FORMS Prescription of Forms 853.236 Construction and architect-engineer...

Biopolitics problems of large-scale hydraulic engineering construction

International Nuclear Information System (INIS)

Romanenko, V.D.

1997-01-01

The XX century which will enter in a history as a century of large-scale hydraulic engineering constructions come to the finish. Only on the European continent 517 large reservoirs (more than 1000 million km 3 of water were detained, had been constructed for a period from 1901 till 1985. In the Danube basin a plenty for reservoirs of power stations, navigations, navigating sluices and other hydraulic engineering structures are constructed. Among them more than 40 especially large objects are located along the main bed of the river. A number of hydro-complexes such as Dnieper-Danube and Gabcikovo, Danube-Oder-Labe (project), Danube-Tissa, Danube-Adriatic Sea (project), Danube-Aegean Sea, Danube-Black Sea ones, are entered into operation or are in a stage of designing. Hydraulic engineering construction was especially heavily conducted in Ukraine. On its territory some large reservoirs on Dnieper and Yuzhny Bug were constructed, which have heavily changed the hydrological regime of the rivers. Summarised the results of river systems regulating in Ukraine one can be noted that more than 27 thousand ponds (3 km 3 per year), 1098 reservoirs of total volume 55 km 3 , 11 large channels of total length more than 2000 km and with productivity of 1000 m 2 /s have been created in Ukraine. Hydraulic engineering construction played an important role in development of the industry and agriculture, water-supply of the cities and settlements, in environmental effects, and maintenance of safe navigation in Danube, Dnieper and other rivers. In next part of the paper, the environmental changes after construction of the Karakum Channel on the Aral Sea in the Middle Asia are discussed

Optimization and control methods in industrial engineering and construction

CERN Document Server

Wang, Xiangyu

2014-01-01

This book presents recent advances in optimization and control methods with applications to industrial engineering and construction management. It consists of 15 chapters authored by recognized experts in a variety of fields including control and operation research, industrial engineering, and project management. Topics include numerical methods in unconstrained optimization, robust optimal control problems, set splitting problems, optimum confidence interval analysis, a monitoring networks optimization survey, distributed fault detection, nonferrous industrial optimization approaches, neural networks in traffic flows, economic scheduling of CCHP systems, a project scheduling optimization survey, lean and agile construction project management, practical construction projects in Hong Kong, dynamic project management, production control in PC4P, and target contracts optimization.   The book offers a valuable reference work for scientists, engineers, researchers and practitioners in industrial engineering and c...

Cryopreservation of tissue engineered constructs for bone.

Science.gov (United States)

Kofron, Michelle D; Opsitnick, Natalie C; Attawia, Mohamed A; Laurencin, Cato T

2003-11-01

The large-scale clinical use of tissue engineered constructs will require provisions for its mass availability and accessibility. Therefore, it is imperative to understand the effects of low temperature (-196 degrees C) on the tissue engineered biological system. Initial studies used samples of the osteoblast-like cell line (SaOS-2) adhered to a two-dimensional poly(lactide-co-glycolide) thin film (2D-PLAGA) or a three-dimensional poly(lactide-co-glycolide) sintered microsphere matrix (3D-PLAGA) designed for bone tissue engineering. Experimental samples were tested for their ability to maintain cell viability, following low temperature banking for one week, in solutions of the penetrating cryoprotective agents, dimethylsulfoxide (DMSO), ethylene glycol, and glycerol. Results indicated the DMSO solution yielded the greatest percent cell survival for SaOS-2 cells adhered to both the 2D- and 3D-PLAGA scaffolds; therefore, DMSO was used to cryopreserve mineralizing primary rabbit osteoblasts cells adhered to 2D-PLAGA matrices for 35 days. Results indicated retention of the extracellular matrix architecture as no statistically significant difference in the pre- and post-thaw mineralized structures was measured. Percent cell viability of the mineralized constructs following low temperature storage was approximately 50%. These are the first studies to address the issue of preservation techniques for tissue engineered constructs. The ability to successfully cryopreserve mineralized tissue engineered matrices for bone may offer an unlimited and readily available source of bone-like materials for orthopaedic applications.

The Strategy of Management Тraining in the Construction Engineering

Directory of Open Access Journals (Sweden)

Khripko Elena

2017-01-01

Full Text Available The operating efficiency of leaders in the construction industry is largely determined by the level of formation of managerial skills. Along with this, it is stated that the process of formation and development of managerial skills for leaders in the construction engineering is attended by a number of difficulties and frequently doesn’t make it past the threshold. This paper formulates a new approach in the formation of managerial skills of leaders in the construction engineering. The cross-sectoral assessment of managerial skills featuring the heads of the construction engineering and other industries, such as energy, metallurgy, showed low-performing managerial skills for the heads of the construction industry. The reasons of the formation of low-performing managerial skills in this article are referred to as peculiar features of organizational behavior in the construction engineering, in particular an imminent regression in the leader-follower system. Based on the results of the research conducted, the similarity of issues in regard to managerial skills in these areas is inherent in key differences in the formulation of priorities of corporate competencies.

Adoption of value engineering: an attribute study for construction

International Nuclear Information System (INIS)

Shaikh, P.

2015-01-01

For economic reasons, engineers are compelled to explore low cost methods in construction industry to reduce the overall cost of a project. Research studies have been conducted in this regard throughout the world and value engineering is one of such approaches. Its effective use and applications reduces the project cost without compromising the project quality. Project cost, and efficient design alternatives can be identified using this technique, which will ultimately reduce the overall project cost. Client satisfaction, project reliability and quality can also be improved by the application of value engineering. It is also used for improving managerial performance, project schedule and reduced risks in a project. It is a powerful tool used to identify problems and recommend solutions. This paper highlights the importance of value engineering in general and with specific perspective of Construction Industry in Pakistan. Questionnaire based survey has been conducted by construction managers (i.e. project engineers, construction engineers, project managers, architects, etc.) through online web based system, as a result, random data sampling is achieved. The attributes are mapped to obtain goals for the project. The data has been analyzed through reliability and linear regression using SPSS while Z-Score and Average Index are conducted using MS Excel. The results showed that there is ample need to apply such techniques in initial phases of any project to get project benefits. (author)

LOGISTICS RISK RESEARCH OF PREFABRICATED HOUSE CONSTRUCTION ENGINEERING BASED ON CREDIBILITY METHOD

Directory of Open Access Journals (Sweden)

Xiaoping Bai

2017-07-01

Full Text Available In recent years, the prefabricated house industry has rapid development,.Because of fewer suppliers, higher demand transport scheme and complex quality test, the risks of construction engineering logistics links are relatively high. Studying how to effectively evaluate the risks of construction engineering logistics links is significant. According to the characteristics of the prefabricated house construction engineering, we analyse the construction engineering logistics risks and use the combined weights method to determine the weight of indexes which contains both subjective and objective factors, to improve the scientific value and the validity of the assessment. Based on credibility measure method, a new logistics risk evaluation model in prefabricated housing is established to estimate the risk during making prefabricated house construction engineering. The presented model can avoid the subjectivity of selecting the membership function and solve the problem of how to comprehensively assess the construction engineering logistics risk in a certain extent.

Construction engineering inspection direct cost survey.

Science.gov (United States)

2014-07-01

The objective of the study was to provide a rationale to Georgia Department of Transportation : (GDOT) for Direct Costs in terms of salary and wages charged by qualified independent : contractors performing Construction Engineering Inspection (CEI) s...

76 FR 58155 - Defense Federal Acquisition Regulation Supplement; Construction and Architect-Engineer Services...

Science.gov (United States)

2011-09-20

... Federal Acquisition Regulation Supplement; Construction and Architect-Engineer Services Performance... performance evaluations for construction and architect-engineer services. DATES: Effective Date: September 20... past performance for construction and Architect- Engineer services. On April 19, 2011, DoD published a...

Reverse engineering of inductive fault current limiters

Energy Technology Data Exchange (ETDEWEB)

Pina, J M; Neves, M Ventim; Rodrigues, A L [Centre of Technology and Systems Faculdade de Ciencias e Tecnologia, Nova University of Lisbon Monte de Caparica, 2829-516 Caparica (Portugal); Suarez, P; Alvarez, A, E-mail: jmmp@fct.unl.p [' Benito Mahedero' Group of Electrical Applications of Superconductors Escuela de IngenierIas Industrials, University of Extremadura Avenida de Elvas s/n, 06006 Badajoz (Spain)

2010-06-01

The inductive fault current limiter is less compact and harder to scale to high voltage networks than the resistive one. Nevertheless, its simple construction and mechanical robustness make it attractive in low voltage grids. Thus, it might be an enabling technology for the advent of microgrids, low voltage networks with dispersed generation, controllable loads and energy storage. A new methodology for reverse engineering of inductive fault current limiters based on the independent analysis of iron cores and HTS cylinders is presented in this paper. Their electromagnetic characteristics are used to predict the devices' hysteresis loops and consequently their dynamic behavior. Previous models based on the separate analysis of the limiters' components were already derived, e.g. in transformer like equivalent models. Nevertheless, the assumptions usually made may limit these models' application, as shown in the paper. The proposed methodology obviates these limitations. Results are validated through simulations.

Reverse engineering of inductive fault current limiters

International Nuclear Information System (INIS)

Pina, J M; Neves, M Ventim; Rodrigues, A L; Suarez, P; Alvarez, A

2010-01-01

The inductive fault current limiter is less compact and harder to scale to high voltage networks than the resistive one. Nevertheless, its simple construction and mechanical robustness make it attractive in low voltage grids. Thus, it might be an enabling technology for the advent of microgrids, low voltage networks with dispersed generation, controllable loads and energy storage. A new methodology for reverse engineering of inductive fault current limiters based on the independent analysis of iron cores and HTS cylinders is presented in this paper. Their electromagnetic characteristics are used to predict the devices' hysteresis loops and consequently their dynamic behavior. Previous models based on the separate analysis of the limiters' components were already derived, e.g. in transformer like equivalent models. Nevertheless, the assumptions usually made may limit these models' application, as shown in the paper. The proposed methodology obviates these limitations. Results are validated through simulations.

48 CFR 53.236 - Construction and architect-engineer contracts.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Construction and architect-engineer contracts. 53.236 Section 53.236 Federal Acquisition Regulations System FEDERAL ACQUISITION...-engineer contracts. ...

Facile construction of a random protein domain insertion library using an engineered transposon.

Science.gov (United States)

Shah, Vandan; Pierre, Brennal; Kim, Jin Ryoun

2013-01-15

Insertional fusion between multiple protein domains represents a novel means of creating integrated functionalities. Currently, there is no robust guideline for selection of insertion sites ensuring the desired functional outcome of insertional fusion. Therefore, construction and testing of random domain insertion libraries, in which a host protein domain is randomly inserted into a guest protein domain, significantly benefit extensive exploration of sequence spaces for insertion sites. Short peptide residues are usually introduced between protein domains to alleviate structural conflicts, and the interdomain linker residues may affect the functional outcome of protein insertion complexes. Unfortunately, optimal control of interdomain linker residues is not always available in conventional methods used to construct random domain insertion libraries. Moreover, most conventional methods employ blunt-end rather than sticky-end ligation between host and guest DNA fragments, thus lowering library construction efficiency. Here, we report the facile construction of random domain insertion libraries using an engineered transposon. We show that random domain insertion with optimal control of interdomain linker residues was possible with our engineered transposon-based method. In addition, our method employs sticky-end rather than blunt-end ligation between host and guest DNA fragments, thus allowing for facile construction of relatively large sized libraries. Copyright © 2012 Elsevier Inc. All rights reserved.

Constructal Theory Of Design In Engineering And Nature

Directory of Open Access Journals (Sweden)

Adrian Bejan

2005-02-01

Full Text Available This is a brief introduction to an engineering theory on the origin and generation of geometric form in all flow systems: the animate, the inanimate and the engineered. The theory is named constructal, and is based on the thought that it is natural for currents to construct for themselves in time paths of greater flow access. It is shown that this process of flow path optimization can be reasoned on the basis of principle: the maximization of global performance subject to finite-size constraints. One example is the generation of tree-shaped flow patterns, as paths of least resistance between one point (source, sink and an infinity of points (area, volume, as in the circulatory, respiratory and nervous systems. An other is the generation of regular spacings in heat generating volumes, such as swarms of honeybees. The optimized tree-flow geometries account for allometric laws, e. g., the relationship between the total tube contact area and the body size, the proportionality between metabolic rate and body size raised to the power 3/4, the proportionality between breathing and heartbeating times and body size raised to the power 1/4, and the proportionality between the cruising speed of flying bodies (insects, birds, airplanes and body mass raised to the power 1/6. The optimized flow structures constitute robust designs, and robustness improves as the complexity of the system increases. Flow architectures that are more efficient look more natural.

[Purveyors of technology: provincial engineers and the construction of road infrastructure in Minas Gerais].

Science.gov (United States)

Barbosa, Lidiany Silva

2011-01-01

The article analyzes the role played by engineers in the construction of road infrastructure in Minas Gerais between the 1840s and 1880s. Building and providing regular maintenance for roads and bridges was a task carried out by the Minas Gerais provincial government, which since the 1830s had a specific agency assigned to designing, building, and maintaining public communication routes. Engineers were part of the agency from its inception, playing a significant role in designing projects and in the actual execution of certain works. The current study is grounded in administrative documentation in which the details of work progress are reported to the provincial government. The gathered records provide technical, administrative, and financial information, along with data on labor power and the agents engaged in construction works.

A puzzle assembly strategy for fabrication of large engineered cartilage tissue constructs.

Science.gov (United States)

Nover, Adam B; Jones, Brian K; Yu, William T; Donovan, Daniel S; Podolnick, Jeremy D; Cook, James L; Ateshian, Gerard A; Hung, Clark T

2016-03-21

Engineering of large articular cartilage tissue constructs remains a challenge as tissue growth is limited by nutrient diffusion. Here, a novel strategy is investigated, generating large constructs through the assembly of individually cultured, interlocking, smaller puzzle-shaped subunits. These constructs can be engineered consistently with more desirable mechanical and biochemical properties than larger constructs (~4-fold greater Young׳s modulus). A failure testing technique was developed to evaluate the physiologic functionality of constructs, which were cultured as individual subunits for 28 days, then assembled and cultured for an additional 21-35 days. Assembled puzzle constructs withstood large deformations (40-50% compressive strain) prior to failure. Their ability to withstand physiologic loads may be enhanced by increases in subunit strength and assembled culture time. A nude mouse model was utilized to show biocompatibility and fusion of assembled puzzle pieces in vivo. Overall, the technique offers a novel, effective approach to scaling up engineered tissues and may be combined with other techniques and/or applied to the engineering of other tissues. Future studies will aim to optimize this system in an effort to engineer and integrate robust subunits to fill large defects. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Research progress of co-culture system for constructing vascularized tissue engineered bone].

Science.gov (United States)

Fu, Weili; Xiang, Zhou

2014-02-01

To review the research progress of the co-culture system for constructing vascularized tissue engineered bone. The recent literature concerning the co-culture system for constructing vascularized tissue engineered bone was reviewed, including the selection of osteogenic and endothelial lineages, the design and surface modification of scaffolds, the models and dimensions of the co-culture system, the mechanism, the culture conditions, and their application progress. The construction of vascularized tissue engineered bone is the prerequisite for their survival and further clinical application in vivo. Mesenchymal stem cells (owning the excellent osteogenic potential) and endothelial progenitor cells (capable of directional differentiation into endothelial cell) are considered as attractive cell types for the co-culture system to construct vascularized tissue engineered bone. The culture conditions need to be further optimized. Furthermore, how to achieve the clinical goals of minimal invasion and autologous transplantation also need to be further studied. The strategy of the co-culture system for constructing vascularized tissue engineered bone would have a very broad prospects for clinical application in future.

48 CFR 836.209 - Construction contracts with architect-engineer firms.

Science.gov (United States)

2010-10-01

... with architect-engineer firms. 836.209 Section 836.209 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER...-engineer firms. (a) When the contracting officer considers it necessary or advantageous to award a contract...

Construction Site Environmental Impact in Civil Engineering Education

Science.gov (United States)

Teixeira, Jose M. Cardoso

2005-01-01

The environmental impact of construction activity has gained increasing importance in the last few years and become a key subject for civil engineering education. A survey of Portuguese higher education institutions shows that concern with this topic is mostly directed at the impact of large construction projects and especially focused on their…

Bi-project management in engineering complex industrial construction projects

NARCIS (Netherlands)

Velde, Robert R. van der; Donk, Dirk Pieter van

2000-01-01

Engineering large industrial construction projects is usually a complex task with several co-operating actors. This paper investigates such projects, characterised by two main actors: the owner of the installation (the client organisation) responsible for the engineering of the production process,

A Continuing Education Short Course and Engineering Curriculum to Accelerate Workforce Development in Wind Power Plant Design, Construction, and Operations

Energy Technology Data Exchange (ETDEWEB)

Tinjum, James [Univ. of Wisconsin, Madison, WI (United States)

2012-11-29

Significant advances in wind turbine technology and wind turbine power plant capabilities are appearing in the U.S. Sites that only 10 years ago might have been overlooked are being considered for build out. However, the development of a skilled workforce in the engineering fields and construction trades lags the potential market, especially if the industry is expected to site, design, construct, and operate sufficient wind power plant sites to meet the potential for 20% wind energy by 2030. A select few firms have penetrated the engineer-procure-construction (EPC) market of wind power plant construction. Competition and know-how in this market is vital to achieve cost-effective, design-construct solutions. The industry must produce or retrain engineers, contractors, and technicians to meet ambitious goals. Currently, few universities offer undergraduate or graduate classes that teach the basics in designing, building, and maintaining wind power plants that are safe, efficient, and productive.

Management Model for Evaluation and Selection of Engineering Equipment Suppliers for Construction Projects in Iraq

Directory of Open Access Journals (Sweden)

Kadhim Raheem Erzaij

2016-06-01

Full Text Available Engineering equipment is essential part in the construction project and usually manufactured with long lead times, large costs and special engineering requirements. Construction manager targets that equipment to be delivered in the site need date with the right quantity, appropriate cost and required quality, and this entails an efficient supplier can satisfy these targets. Selection of engineering equipment supplier is a crucial managerial process .it requires evaluation of multiple suppliers according to multiple criteria. This process is usually performed manually and based on just limited evaluation criteria, so better alternatives may be neglected. Three stages of survey comprised number of public and private companies in Iraqi construction sector were employed to identify main criteria and sub criteria for supplier selection and their priorities.The main criteria identified were quality of product, commercial aspect, delivery, reputation and position, and system quality . An effective technique in multiple criteria decision making (MCDM as analytical hierarchy process (AHP have been used to get importance weights of criteria based on experts judgment. Thereafter, a management software system for Evaluation and Selection of Engineering Equipment Suppliers (ESEES has been developed based on the results obtained from AHP. This model was validated in a case study at municipality of Baghdad involved actual cases of selection pumps suppliers for infrastructure projects .According to experts, this model can improve the current process followed in the supplier selection and aid decision makers to adopt better choices in the domain of selection engineering equipment suppliers.

Proposal for the increase of the contract amounts for LHC civil engineering construction and civil engineering consultancy contracts

CERN Document Server

2001-01-01

This document concerns the increase of the contract amounts for LHC civil engineering construction contracts and civil engineering consultancy contracts. The Finance Committee is invited to agree to the increase of the contract amounts with: - the joint venture TEERAG-ASDAG (AT), C. BARESEL (DE) and LOCHER (CH) for civil engineering construction, package 1, for a revised total amount of 91 500 000 Swiss francs, subject to revision; - the joint venture EDF (FR) and KNIGHT&PIESOLD (GB) for the provision of civil engineering consultancy services, package 1, for a revised total amount of 14 400 000 Swiss francs, subject to revision; - the joint venture TAYLOR WOODROW (GB), AMEC (GB) and SPIE BATIGNOLLES (FR) for civil engineering construction, package 3a, for a revised total amount of 118 000 000 Swiss francs, subject to revision; - the joint venture BROWN&ROOT (GB), INTECSA (ES) and HIDROTECNICA (PT) for the provision of civil engineering consultancy services, package 3, for a revised total amount of 14 ...

Current strategies in multiphasic scaffold design for osteochondral tissue engineering: A review.

Science.gov (United States)

Yousefi, Azizeh-Mitra; Hoque, Md Enamul; Prasad, Rangabhatala G S V; Uth, Nicholas

2015-07-01

The repair of osteochondral defects requires a tissue engineering approach that aims at mimicking the physiological properties and structure of two different tissues (cartilage and bone) using specifically designed scaffold-cell constructs. Biphasic and triphasic approaches utilize two or three different architectures, materials, or composites to produce a multilayered construct. This article gives an overview of some of the current strategies in multiphasic/gradient-based scaffold architectures and compositions for tissue engineering of osteochondral defects. In addition, the application of finite element analysis (FEA) in scaffold design and simulation of in vitro and in vivo cell growth outcomes has been briefly covered. FEA-based approaches can potentially be coupled with computer-assisted fabrication systems for controlled deposition and additive manufacturing of the simulated patterns. Finally, a summary of the existing challenges associated with the repair of osteochondral defects as well as some recommendations for future directions have been brought up in the concluding section of this article. © 2014 Wiley Periodicals, Inc.

New technologies in Islamic countries. Power engineering, transport, oil industry, machinery construction, building construction and information technologies problems

International Nuclear Information System (INIS)

Sharipova, N.S.

1999-01-01

The published proceedings contain brief presentations concerning new technologies in power engineering, transport, oil industry, machinery construction, building construction and information technologies presented to the International scientific and technical conference: New technologies in Islamic countries, which was organized within frame work of 6 General Assembly of Federation of engineering Institutes of Islamic countries (FEIIC). (author)

Projects of Iberdrola Engineering and Construction on the Flamanville 3 EPR

International Nuclear Information System (INIS)

Zornoza, J.; Dumas, H.; Sesma, J. L.; Cubian, B.; Diaz, J. I.

2013-01-01

Iberdrola Engineering and Construction is participating during the last 5 years in 5 projects on the Flamanville 3 EPR, both in the nuclear island and conventional island and the pump house. These projects represent a challenge from the technical point of view due to the high requirements applicable to the project because of the experience feedback of the operator EDF and of compliance with new regulations that have emerged since the completion of the last nuclear power station in France. This paper presents the description of these projects, as well as its current status. (Author)

Civil Engineering Construction of Underground Works

CERN Document Server

Rammer, H

1999-01-01

For the first time at CERN, new shafts and caverns will be excavated inside a surface building. The LHC civil engineering construction for the ATLAS experiment has been designed such that the experimental hall will be completed to the extent that it can provide a secure, weatherproof and sound insulated covering to the shaft excavation area. The construction of the two access shafts and the experimental cavern will follow and will be carried out inside the building. This unconventional method of working allows the excavation of the Molasse rock in the dry, which is essential for this type of rock, and ensures reduced environmental pollution by noise and dust. The paper will present the technical infrastructure required for this particular construction method, explain its advantages and disadvantages, and compare it with a conventional method of underground excavations to be used on the same work site for the construction of the service cavern.

Regeneration of the anterior cruciate ligament: Current strategies in tissue engineering

Science.gov (United States)

Nau, Thomas; Teuschl, Andreas

2015-01-01

Recent advancements in the field of musculoskeletal tissue engineering have raised an increasing interest in the regeneration of the anterior cruciate ligament (ACL). It is the aim of this article to review the current research efforts and highlight promising tissue engineering strategies. The four main components of tissue engineering also apply in several ACL regeneration research efforts. Scaffolds from biological materials, biodegradable polymers and composite materials are used. The main cell sources are mesenchymal stem cells and ACL fibroblasts. In addition, growth factors and mechanical stimuli are applied. So far, the regenerated ACL constructs have been tested in a few animal studies and the results are encouraging. The different strategies, from in vitro ACL regeneration in bioreactor systems to bio-enhanced repair and regeneration, are under constant development. We expect considerable progress in the near future that will result in a realistic option for ACL surgery soon. PMID:25621217

New technologies in Islamic countries. Power engineering, transport, oil industry, machinery construction, building construction and information technologies problems

International Nuclear Information System (INIS)

Sharipova, N.S.

1999-01-01

This issue contains papers, which reflect the most important achievements of new technologies in power engineering, transport, oil industry, machinery construction, building construction and information technologies presented to the International Scientific and Technical Conference: New technologies in Islamic countries, which was organized within frame work of 6 General Assembly of Federation of Engineering Institutes of Islamic Countries (FEIIC). (author)

Establishing Early Functional Perfusion and Structure in Tissue Engineered Cardiac Constructs.

Science.gov (United States)

Wang, Bo; Patnaik, Sourav S; Brazile, Bryn; Butler, J Ryan; Claude, Andrew; Zhang, Ge; Guan, Jianjun; Hong, Yi; Liao, Jun

2015-01-01

Myocardial infarction (MI) causes massive heart muscle death and remains a leading cause of death in the world. Cardiac tissue engineering aims to replace the infarcted tissues with functional engineered heart muscles or revitalize the infarcted heart by delivering cells, bioactive factors, and/or biomaterials. One major challenge of cardiac tissue engineering and regeneration is the establishment of functional perfusion and structure to achieve timely angiogenesis and effective vascularization, which are essential to the survival of thick implants and the integration of repaired tissue with host heart. In this paper, we review four major approaches to promoting angiogenesis and vascularization in cardiac tissue engineering and regeneration: delivery of pro-angiogenic factors/molecules, direct cell implantation/cell sheet grafting, fabrication of prevascularized cardiac constructs, and the use of bioreactors to promote angiogenesis and vascularization. We further provide a detailed review and discussion on the early perfusion design in nature-derived biomaterials, synthetic biodegradable polymers, tissue-derived acellular scaffolds/whole hearts, and hydrogel derived from extracellular matrix. A better understanding of the current approaches and their advantages, limitations, and hurdles could be useful for developing better materials for future clinical applications.

Improving Construction Process through Integration and Concurrent Engineering

Directory of Open Access Journals (Sweden)

Malik Khalfan

2012-11-01

Full Text Available In an increasingly competitive business environment, improvedtime-to-market, reduced production cost, quality of the productand customer involvement are rapidly becoming the key successfactors for any product development process. Consequently, mostorganisations are moving towards the adoption of latest technologyand new management concepts and philosophies such as totalquality management and concurrent engineering (CE to bringimprovement in their product development process. This paperdiscusses the adoption of integrated processes and CE withinthe construction industry to enable construction organisations toimprove their project development process. It also discusses aproposed integrated database model for the construction projects,which should enable the construction process to improve, becomemore effective and more efficient.

Current status of nuclear engineering education

International Nuclear Information System (INIS)

Palladino, N.J.

1975-01-01

The 65 colleges and universities offering undergraduate degrees in nuclear engineering and the 15 schools offering strong nuclear engineering options are, in general, doing a good job to meet the current spectrum of job opportunities. But, nuclear engineering programs are not producing enough graduates to meet growing demands. They currently receive little aid and support from their customers --industry and government--in the form of scholarships, grants, faculty research support, student thesis and project support, or student summer jobs. There is not enough interaction between industry and universities. Most nuclear engineering programs are geared too closely to the technology of the present family of reactors and too little to the future breeder reactors and controlled thermonuclear reactors. In addition, nuclear engineering programs attract too few women and members of minority ethnic groups. Further study of the reasons for this fact is needed so that effective corrective action can be taken. Faculty in nuclear engineering programs should assume greater initiative to provide attractive and objective nuclear energy electives for technical and nontechnical students in other disciplines to improve their technical understanding of the safety and environmental issues involved. More aggressive and persistent efforts must be made by nuclear engineering schools to obtain industry support and involvement in their programs

Increase of the contract amounts for LHC civil-engineering construction and civil-engineering consultancy contracts

CERN Document Server

2005-01-01

This document concerns the increase of the contract amounts for LHC civil-engineering construction and civil-engineering consultancy, Package 2. The Finance Committee is invited to take note of the increase of the contract amounts with: - the joint venture DRAGADOS (ES) and SELI (IT) for civil-engineering construction, LHC Package 2, for an amount of 28 087 000 Swiss francs, subject to revision, in the amount previously announced to Finance Committee (CERN/FC/4516) of 132 200 000 Swiss francs, subject to revision, bringing the total to a maximum amount of 160 287 000 Swiss francs, subject to revision. - the joint venture GIBB (GB), GEOCONSULT (AT) and SGI (CH) for the provision of civil-engineering consultancy services, LHC Package 2, for an amount of 900 000 Swiss francs, subject to revision, in the amount previously announced to Finance Committee of 13 800 000 Swiss francs, subject to revision, bringing the total to a maximum amount of 14 700 000 Swiss francs, subject to revision

Facilitating Industrial Placement in the Construction Engineering Curriculum

DEFF Research Database (Denmark)

Wandahl, Søren; Ussing, Lene Faber

2016-01-01

outset in the hypothesis that external effectiveness (industry readiness) is better in those modes of education that, at least in part, are based on the world of work itself, and several sources highlight the necessity of strong links between engineering education and industry. Hence, it becomes central......There is often a claim that there is a disconnection between theory and practice, which raises questions on student’s readiness for employment and the extent that higher education responds effectively to the evolving needs of the construction industry. Industrial placements schemes can facilitate...... student learning from construction practice whereby students can reflect on their learning experience at the university. The interplay between traditional engineering curriculum and the context-based learning is important for securing the right skills and competencies among the graduates. This paper takes...

Computational model-informed design and bioprinting of cell-patterned constructs for bone tissue engineering.

Science.gov (United States)

Carlier, Aurélie; Skvortsov, Gözde Akdeniz; Hafezi, Forough; Ferraris, Eleonora; Patterson, Jennifer; Koç, Bahattin; Van Oosterwyck, Hans

2016-05-17

Three-dimensional (3D) bioprinting is a rapidly advancing tissue engineering technology that holds great promise for the regeneration of several tissues, including bone. However, to generate a successful 3D bone tissue engineering construct, additional complexities should be taken into account such as nutrient and oxygen delivery, which is often insufficient after implantation in large bone defects. We propose that a well-designed tissue engineering construct, that is, an implant with a specific spatial pattern of cells in a matrix, will improve the healing outcome. By using a computational model of bone regeneration we show that particular cell patterns in tissue engineering constructs are able to enhance bone regeneration compared to uniform ones. We successfully bioprinted one of the most promising cell-gradient patterns by using cell-laden hydrogels with varying cell densities and observed a high cell viability for three days following the bioprinting process. In summary, we present a novel strategy for the biofabrication of bone tissue engineering constructs by designing cell-gradient patterns based on a computational model of bone regeneration, and successfully bioprinting the chosen design. This integrated approach may increase the success rate of implanted tissue engineering constructs for critical size bone defects and also can find a wider application in the biofabrication of other types of tissue engineering constructs.

Identifying Indicators Related to Constructs for Engineering Design Outcome

Science.gov (United States)

Wilhelmsen, Cheryl A.; Dixon, Raymond A.

2016-01-01

This study ranked constructs articulated by Childress and Rhodes (2008) and identified the key indicators for each construct as a starting point to explore what should be included on an instrument to measure the engineering design process and outcomes of students in high schools that use the PLTW and EbDTM curricula in Idaho. A case-study design…

Value engineering awareness study for sustainable construction in Malaysia

International Nuclear Information System (INIS)

Fathoni U; Zakaria C M; Rohayu C O

2013-01-01

Construction process has often been described as a highly complex process because of the number of disciplines involved during the conceptual, design and construction stage. With the emergence of latest technology and concern for environment, increasing attention in construction industry is given on sustainability. Balance in quality and sustainability has become a major challenge to the construction industry. This paper presents a study that has conducted to determine the acceptance and application of Value Engineering (VE) and Life Cycle Cost Analysis (LCCA) in Malaysia construction industry. A set of questionnaire have distributed to different practitioners in construction industry and the result has reflect the fact that the application of VE and LCCA are still very low.

Materials for construction and civil engineering science, processing, and design

CERN Document Server

Margarido, Fernanda

2015-01-01

This expansive volume presents the essential topics related to construction materials composition and their practical application in structures and civil installations. The book's diverse slate of expert authors assemble invaluable case examples and performance data on the most important groups of materials used in construction, highlighting aspects such as nomenclature, the properties, the manufacturing processes, the selection criteria, the products/applications, the life cycle and recyclability, and the normalization. Civil Engineering Materials: Science, Processing, and Design is ideal for practicing architects; civil, construction, and structural engineers, and serves as a comprehensive reference for students of these disciplines. This book also: ·       Provides a substantial and detailed overview of traditional materials used in structures and civil infrastructure ·       Discusses properties of natural and synthetic materials in construction and materials' manufacturing processes ·  �...

Methodology discourses as boundary work in the construction of engineering education.

Science.gov (United States)

Beddoes, Kacey

2014-04-01

Engineering education research is a new field that emerged in the social sciences over the past 10 years. This analysis of engineering education research demonstrates that methodology discourses have played a central role in the construction and development of the field of engineering education, and that they have done so primarily through boundary work. This article thus contributes to science and technology studies literature by examining the role of methodology discourses in an emerging social science field. I begin with an overview of engineering education research before situating the case within relevant bodies of literature on methodology discourses and boundary work. I then identify two methodology discourses--rigor and methodological diversity--and discuss how they contribute to the construction and development of engineering education research. The article concludes with a discussion of how the findings relate to prior research on methodology discourses and boundary work and implications for future research.

Recent Efforts and Experiments in the Construction of Aviation Engines

Science.gov (United States)

SCHWAGER

1920-01-01

It became evident during World War I that ever-increasing demands were being placed on the mean power of aircraft engines as a result of the increased on board equipment and the demands of aerial combat. The need was for increased climbing efficiency and climbing speed. The response to these demands has been in terms of lightweight construction and the adaptation of the aircraft engine to the requirements of its use. Discussed here are specific efforts to increase flying efficiency, such as reduction of the number of revolutions of the propeller from 1400 to about 900 r.p.m. through the use of a reduction gear, increasing piston velocity, locating two crankshafts in one gear box, and using the two-cycle stroke. Also discussed are improvements in the transformation of fuel energy into engine power, the raising of compression ratios, the use of super-compression with carburetors constructed for high altitudes, the use of turbo-compressors, rotary engines, and the use of variable pitch propellers.

An Investigation of Women Engineers in Non-Traditional Occupations in the Thai Construction Industry

Directory of Open Access Journals (Sweden)

Nuanthip Kaewsri

2011-06-01

Full Text Available For over a decade, the public and the private sectors have carried out research aimed at attracting women engineers to the construction industry and retaining them. However, studies on women engineers working in other types of construction-related businesses apart from contractor companies such as consultancies, developers, etc., have not been many. This paper aims to examine the experiences of women engineers in non-traditional careers and the implications for their turnover. A literature search on women’s careers in construction was performed in conjunction with semi-structured interviews with a sampling of 141 individuals. Results from three viewpoints, viz those of professional men and women engineers in contractor companies, and women engineers in non-contractor companies, were found to differ in many respects, including their opinions about career advancement, career path and the difficulties involved. It was also found that women engineers in contractor companies were much more affected by problems such as sexual harassment, work-life conflicts and equal opportunity than women engineers in non-contractor companies. Turnover rates of women engineers and their reasons for leaving were examined. Women engineers, particularly those in contractor companies, had to confront more barriers in non-traditional careers than their male counterparts.  Nonetheless, working in non-contractor companies provides a viable alternative for women engineers who want to have successful careers in the Thai construction industry.

Engineered skeletal muscle tissue for soft robotics: fabrication strategies, current applications, and future challenges.

Science.gov (United States)

Duffy, Rebecca M; Feinberg, Adam W

2014-01-01

Skeletal muscle is a scalable actuator system used throughout nature from the millimeter to meter length scales and over a wide range of frequencies and force regimes. This adaptability has spurred interest in using engineered skeletal muscle to power soft robotics devices and in biotechnology and medical applications. However, the challenges to doing this are similar to those facing the tissue engineering and regenerative medicine fields; specifically, how do we translate our understanding of myogenesis in vivo to the engineering of muscle constructs in vitro to achieve functional integration with devices. To do this researchers are developing a number of ways to engineer the cellular microenvironment to guide skeletal muscle tissue formation. This includes understanding the role of substrate stiffness and the mechanical environment, engineering the spatial organization of biochemical and physical cues to guide muscle alignment, and developing bioreactors for mechanical and electrical conditioning. Examples of engineered skeletal muscle that can potentially be used in soft robotics include 2D cantilever-based skeletal muscle actuators and 3D skeletal muscle tissues engineered using scaffolds or directed self-organization. Integration into devices has led to basic muscle-powered devices such as grippers and pumps as well as more sophisticated muscle-powered soft robots that walk and swim. Looking forward, current, and future challenges include identifying the best source of muscle precursor cells to expand and differentiate into myotubes, replacing cardiomyocytes with skeletal muscle tissue as the bio-actuator of choice for soft robots, and vascularization and innervation to enable control and nourishment of larger muscle tissue constructs. © 2013 Wiley Periodicals, Inc.

Monitoring sinew contraction during formation of tissue-engineered fibrin-based ligament constructs.

Science.gov (United States)

Paxton, Jennifer Z; Wudebwe, Uchena N G; Wang, Anqi; Woods, Daniel; Grover, Liam M

2012-08-01

The ability to study the gross morphological changes occurring during tissue formation is vital to producing tissue-engineered structures of clinically relevant dimensions in vitro. Here, we have used nondestructive methods of digital imaging and optical coherence tomography to monitor the early-stage formation and subsequent maturation of fibrin-based tissue-engineered ligament constructs. In addition, the effect of supplementation with essential promoters of collagen synthesis, ascorbic acid (AA) and proline (P), has been assessed. Contraction of the cell-seeded fibrin gel occurs unevenly within the first 5 days of culture around two fixed anchor points before forming a longitudinal ligament-like construct. AA+P supplementation accelerates gel contraction in the maturation phase of development, producing ligament-like constructs with a higher collagen content and distinct morphology to that of unsupplemented constructs. These studies highlight the importance of being able to control the methods of tissue formation and maturation in vitro to enable the production of tissue-engineered constructs with suitable replacement tissue characteristics for repair of clinical soft-tissue injuries.

Proceedings of the national seminar on advanced construction techniques and geotechnical engineering

International Nuclear Information System (INIS)

Partheeban, P.; Poornima, C.A.; Guru, V.

2015-02-01

The objective of this seminar is to emphasize the need for developing modern construction materials in the era of technology. It also provides a forum for National Research Scholars, Construction Specialists and Professionals, Planners, Faculty, PG and UG Students to discuss and evolve solutions for various difficulties faced during construction. Theme of seminar includes Geotechnical site Investigation, Ground improvement Techniques, Soil Dynamics, Geotechnical Earthquake Engineering, Geo- Environmental Engineering, Self Compacting Concrete, Geopolymer Concrete and Concrete Technology, Cost Effective Construction Techniques, Limit state performance state approach Elastic and Elasto-plastic behavior and Reduction of Corrosion in concrete using Chemical admixtures. Paper relevant to INIS are indexed separately

A leadership-as-practice perspective on design in architecture, engineering and construction projects: interaction analysis of a collaborative workshop

NARCIS (Netherlands)

Zerjav, Vedran; Hartmann, Timo; van Amstel, Frederick

2014-01-01

This paper proposes an alternative perspective on the role of leadership in the context of collaborative practices in architecture, engineering and construction design. While most of current leadership literature is focused on outstanding individuals with abilities to influence others, the aim of

Contracting Economics of Large Engineering and Construction Projects

NARCIS (Netherlands)

Berends, T.C.

2007-01-01

Large Engineering and Construction Projects (LECPs) form an important area of economic activity, covering a range of different artefacts. These projects have in common that they are massive undertakings, spanning long time periods and they involve large capital investments. Uncertainty and risk are

Study on evaluation of construction reliability for engineering project based on fuzzy language operator

Science.gov (United States)

Shi, Yu-Fang; Ma, Yi-Yi; Song, Ping-Ping

2018-03-01

System Reliability Theory is a research hotspot of management science and system engineering in recent years, and construction reliability is useful for quantitative evaluation of project management level. According to reliability theory and target system of engineering project management, the defination of construction reliability appears. Based on fuzzy mathematics theory and language operator, value space of construction reliability is divided into seven fuzzy subsets and correspondingly, seven membership function and fuzzy evaluation intervals are got with the operation of language operator, which provides the basis of corresponding method and parameter for the evaluation of construction reliability. This method is proved to be scientific and reasonable for construction condition and an useful attempt for theory and method research of engineering project system reliability.

Doublet III construction and engineering test

International Nuclear Information System (INIS)

Anon.

1979-01-01

Progress during FY-78 on the construction and operation of the Doublet III is reported. Detailed discussions about the installation and testing of various components and subsystems, including the B-coil, E-coil, F-coils and support structure, vacuum vessel, vacuum pumping system, limiter, thermal insulation blanket, control system, B-coil power system, E-coil power system, F-coil power system, and motor-generator, are presented. A brief review of the engineering test operation is given

STUDY OF ELABORATION OF CONSTRUCTION CRANKSHAFT PISTON OF AUTOMOBILE PNEUMATIC ENGINE

Directory of Open Access Journals (Sweden)

Voronkov, А.

2013-01-01

Full Text Available Expound are the results of study of elaration of construction of crankshaft 4-cylinder V-evocative piston pneumatic engine, which is made by conversion of serial internal-combustion engine 4Ч 7,6x6,6.

A novel bioprinting method and system for forming hybrid tissue engineering constructs.

Science.gov (United States)

Shanjani, Y; Pan, C C; Elomaa, L; Yang, Y

2015-12-18

Three dimensional (3D) bioprinting is a promising approach to form tissue engineering constructs (TECs) via positioning biomaterials, growth factors, and cells with controlled spatial distribution due to its layer-by-layer manufacturing nature. Hybrid TECs composed of relatively rigid porous scaffolds for structural and mechanical integrity and soft hydrogels for cell- and growth factor-loading have a tremendous potential to tissue regeneration under mechanical loading. However, despite excessive progress in the field, the current 3D bioprinting techniques and systems fall short in integration of such soft and rigid multifunctional components. Here we present a novel 3D hybrid bioprinting technology (Hybprinter) and its capability enabling integration of soft and rigid components for TECs. Hybprinter employs digital light processing-based stereolithography (DLP-SLA) and molten material extrusion techniques for soft and rigid materials, respectively. In this study, poly-ethylene glycol diacrylate (PEGDA) and poly-(ε-caprolactone) (PCL) were used as a model material for soft hydrogel and rigid scaffold, respectively. It was shown that geometrical accuracy, swelling ratio and mechanical properties of the hydrogel component can be tailored by DLP-SLA module. We have demonstrated the printability of variety of complex hybrid construct designs using Hybprinter technology and characterized the mechanical properties and functionality of such constructs. The compressive mechanical stiffness of a hybrid construct (90% hydrogel) was significantly higher than hydrogel itself (∼6 MPa versus 100 kPa). In addition, viability of cells incorporated within the bioprinted hybrid constructs was determined approximately 90%. Furthermore, a functionality of a hybrid construct composed of porous scaffold with an embedded hydrogel conduit was characterized for vascularized tissue engineering applications. High material diffusion and high cell viability in about 2.5 mm distance

Sustainable Construction for Urban Infill Development Using Engineered Massive Wood Panel Systems

Directory of Open Access Journals (Sweden)

Steffen Lehmann

2012-10-01

Full Text Available Prefabricated engineered solid wood panel construction systems can sequester and store CO2. Modular cross-laminated timber (CLT, also called cross-lam panels form the basis of low-carbon, engineered construction systems using solid wood panels that can be used to build residential infill developments of 10 storeys or higher. Multi-apartment buildings of 4 to 10 storeys constructed entirely in timber, such as recently in Europe, are innovative, but their social and cultural acceptance in Australia and North America is at this stage still uncertain. Future commercial utilisation is only possible if there is a user acceptance. The author is part of a research team that aims to study two problems: first models of urban infill; then focus on how the use of the CLT systems can play an important role in facilitating a more livable city with better models of infill housing. Wood is an important contemporary building resource due to its low embodied energy and unique attributes. The potential of prefabricated engineered solid wood panel systems, such as CLT, as a sustainable building material and system is only just being realised around the globe. Since timber is one of the few materials that has the capacity to store carbon in large quantities over a long period of time, solid wood panel construction offers the opportunity of carbon engineering, to turn buildings into ‘carbon sinks’. Thus some of the historically negative environmental impact of urban development and construction can be turned around with CLT construction on brownfield sites.

Potential and Benefits of Building Information Modeling (BIM) During Pre-Construction, Construction and Post Construction Stage

OpenAIRE

Aw Nien Wei; Md Azree Othuman Mydin

2017-01-01

The construction industry is the main economic support for all countries around the world in which continually adapting to meet competitive challenges around the global market. Nevertheless, the construction project is becoming much more complex and difficult to manage. This is because the construction project involves a large number of stakeholder, for example, the consultant companies, architects, engineers, building surveyors and quantity surveyors. The technology current...

Organizing the engineering basis of works during NPP construction

International Nuclear Information System (INIS)

Gorodinskij, Yu.Kh.; Finberg, L.K.; Shapiro, V.I.

1988-01-01

Experience in organization of the system of engineering basis of works during the Khmelnitskij NPP construction, aimed at providing the applicability of the software complex realized with a computer when solving the problems arising before the service of engineering basis of works, is described. Calculational complex for solving the problems on the engineering basis of works includes the SM-2420 processor, immediate access and external storages on MD with capacity not less than 1 and 60 Mbit correspondignly, terminal multiplexer, VTA 2000-15 video terminals, not less than 10 pieces of videotons and not less than two SM-6315 alphanumerical printers

The Role of the Military Construction Engineers in the Hybrid War

Science.gov (United States)

2015-06-12

an increase in the need for infrastructure. Military construction engineers were responsible for the NIKE construction program, storage sites for...has minimized the significance of geographical and political boundaries. Because of these facts, the NATO Bi-Strategic Command has assessed Hybrid

3D bioprinting and the current applications in tissue engineering.

Science.gov (United States)

Huang, Ying; Zhang, Xiao-Fei; Gao, Guifang; Yonezawa, Tomo; Cui, Xiaofeng

2017-08-01

Bioprinting as an enabling technology for tissue engineering possesses the promises to fabricate highly mimicked tissue or organs with digital control. As one of the biofabrication approaches, bioprinting has the advantages of high throughput and precise control of both scaffold and cells. Therefore, this technology is not only ideal for translational medicine but also for basic research applications. Bioprinting has already been widely applied to construct functional tissues such as vasculature, muscle, cartilage, and bone. In this review, the authors introduce the most popular techniques currently applied in bioprinting, as well as the various bioprinting processes. In addition, the composition of bioink including scaffolds and cells are described. Furthermore, the most current applications in organ and tissue bioprinting are introduced. The authors also discuss the challenges we are currently facing and the great potential of bioprinting. This technology has the capacity not only in complex tissue structure fabrication based on the converted medical images, but also as an efficient tool for drug discovery and preclinical testing. One of the most promising future advances of bioprinting is to develop a standard medical device with the capacity of treating patients directly on the repairing site, which requires the development of automation and robotic technology, as well as our further understanding of biomaterials and stem cell biology to integrate various printing mechanisms for multi-phasic tissue engineering. Copyright © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Vascularization of soft tissue engineering constructs

DEFF Research Database (Denmark)

Pimentel Carletto, Rodrigo

with mechanical properties in the range of soft tissues has not been fully achieved. My project focused on the fabrication and the active perfusion of hydrogel constructs with multi-dimensional vasculature and controlled mechanical properties targeting soft tissues. Specifically, the initial part of the research...... nanotechnology-based paradigm for engineering vascularised liver tissue for transplantation”) and the Danish National Research Foundation and Villum Foundation’s Center for Intelligent Drug delivery and sensing Using microcontainers and Nanomechanics (Danish National Research Foundation (DNRF122)....

Fibrin Gels Exhibit Improved Biological, Structural, and Mechanical Properties Compared with Collagen Gels in Cell-Based Tendon Tissue-Engineered Constructs

Science.gov (United States)

Dyment, Nathaniel A.; Lu, Yinhui; Rao, Marepalli; Shearn, Jason T.; Rowe, David W.; Kadler, Karl E.; Butler, David L.

2015-01-01

The prevalence of tendon and ligament injuries and inadequacies of current treatments is driving the need for alternative strategies such as tissue engineering. Fibrin and collagen biopolymers have been popular materials for creating tissue-engineered constructs (TECs), as they exhibit advantages of biocompatibility and flexibility in construct design. Unfortunately, a few studies have directly compared these materials for tendon and ligament applications. Therefore, this study aims at determining how collagen versus fibrin hydrogels affect the biological, structural, and mechanical properties of TECs during formation in vitro. Our findings show that tendon and ligament progenitor cells seeded in fibrin constructs exhibit improved tenogenic gene expression patterns compared with their collagen-based counterparts for approximately 14 days in culture. Fibrin-based constructs also exhibit improved cell-derived collagen alignment, increased linear modulus (2.2-fold greater) compared with collagen-based constructs. Cyclic tensile loading, which promotes the maturation of tendon constructs in a previous work, exhibits a material-dependent effect in this study. Fibrin constructs show trending reductions in mechanical, biological, and structural properties, whereas collagen constructs only show improved tenogenic expression in the presence of mechanical stimulation. These findings highlight that components of the mechanical stimulus (e.g., strain amplitude or time of initiation) need to be tailored to the material and cell type. Given the improvements in tenogenic expression, extracellular matrix organization, and material properties during static culture, in vitro findings presented here suggest that fibrin-based constructs may be a more suitable alternative to collagen-based constructs for tissue-engineered tendon/ligament repair. PMID:25266738

Fabrication of myogenic engineered tissue constructs.

Science.gov (United States)

Pacak, Christina A; Cowan, Douglas B

2009-05-01

Despite the fact that electronic pacemakers are life-saving medical devices, their long-term performance in pediatric patients can be problematic owing to the restrictions imposed by a child's small size and their inevitable growth. Consequently, there is a genuine need for innovative therapies designed specifically for pediatric patients with cardiac rhythm disorders. We propose that a conductive biological alternative consisting of a collagen-based matrix containing autologously-derived cells could better adapt to growth, reduce the need for recurrent surgeries, and greatly improve the quality of life for these patients. In the present study, we describe a procedure for incorporating primary skeletal myoblast cell cultures within a hydrogel matrix to fashion a surgically-implantable tissue construct that will serve as an electrical conduit between the upper and lower chambers of the heart. Ultimately, we anticipate using this type of engineered tissue to restore atrioventricular electrical conduction in children with complete heart block. In view of that, we isolate myoblasts from the skeletal muscles of neonatal Lewis rats and plate them onto laminin-coated tissue culture dishes using a modified version of established protocols. After one to two days, cultured cells are collected and mixed with antibiotics, type 1 collagen, Matrigel, and NaHCO(3). The result is a viscous, uniform solution that can be cast into a mold of nearly any shape and size. For our tissue constructs, we employ type 1 collagen isolated from fetal lamb skin using standard procedures. Once the tissue has solidified at 37 degrees C, culture media is carefully added to the plate until the construct is submerged. The engineered tissue is then allowed to further condense through dehydration for 2 more days, at which point it is ready for in vitro assessment or surgical-implantation.

Functional evaluation of artificial skeletal muscle tissue constructs fabricated by a magnetic force-based tissue engineering technique.

Science.gov (United States)

Yamamoto, Yasunori; Ito, Akira; Fujita, Hideaki; Nagamori, Eiji; Kawabe, Yoshinori; Kamihira, Masamichi

2011-01-01

Skeletal muscle tissue engineering is currently applied in a variety of research fields, including regenerative medicine, drug screening, and bioactuator development, all of which require the fabrication of biomimic and functional skeletal muscle tissues. In the present study, magnetite cationic liposomes were used to magnetically label C2C12 myoblast cells for the construction of three-dimensional artificial skeletal muscle tissues by an applied magnetic force. Skeletal muscle functions, such as biochemical and contractile properties, were evaluated for the artificial tissue constructs. Histological studies revealed that elongated and multinucleated myotubes were observed within the tissue. Expression of muscle-specific markers, such as myogenin, myosin heavy chain and tropomyosin, were detected in the tissue constructs by western blot analysis. Further, creatine kinase activity increased during differentiation. In response to electric pulses, the artificial tissue constructs contracted to generate a physical force (the maximum twitch force, 33.2 μN [1.06 mN/mm2]). Rheobase and chronaxie of the tissue were determined as 4.45 V and 0.72 ms, respectively. These results indicate that the artificial skeletal muscle tissue constructs fabricated in this study were physiologically functional and the data obtained for the evaluation of their functional properties may provide useful information for future skeletal muscle tissue engineering studies.

Construction project of Flamanville 3 NPP. The participation of Iberdrola engineering and Construction

International Nuclear Information System (INIS)

Diaz Prada, J. I.; Cubian, B.

2014-01-01

Iberdrola Engineering and Construction (IIC) leads several projects mini EPC for the EPR Flamanville 3 NPP for providing important for safety components and auxiliary systems in the pump house and in the turbine island. The realization of this new nuclear project has been a challenge from the technical and organizational perspective because the plant is the first of the new nuclear station (FDAKE) type EPR 1700 MWe series in a highly restrictive environment due to to the large number of particular requirements from the final customer and the meager degree of progress of the design to the date of commencement of construction. (Author)

ORNL engineering design and construction reengineering report

Energy Technology Data Exchange (ETDEWEB)

McNeese, L.E.

1998-01-01

A team composed of individuals representing research and development (R and D) divisions, infrastructure support organizations, and Department of Energy (DOE)-Oak Ridge Operations was chartered to reengineer the engineering, design, and construction (ED and C) process at Oak Ridge National Laboratory (ORNL). The team recognized that ED and C needs of both R and D customers and the ORNL infrastructure program have to be met to maintain a viable and competitive national laboratory. Their goal was to identify and recommend implementable best-in-class ED and C processes that will efficiently and cost-effectively support the ORNL R and D staff by being responsive to their programmatic and infrastructure needs. The team conducted process mapping of current and potential ED and C approaches, developed idealized versions of ED and C processes, and identified potential barriers to an efficient ED and C process. Eight subteams were assigned to gather information and to evaluate the significance of potential barriers through benchmarking, surveys, interviews, and reviews of key topical areas in order to determine whether the perceived barriers were real and important and whether they resulted from laws or regulations over which ORNL has no control.

Constructing an Efficient Self-Tuning Aircraft Engine Model for Control and Health Management Applications

Science.gov (United States)

Armstrong, Jeffrey B.; Simon, Donald L.

2012-01-01

Self-tuning aircraft engine models can be applied for control and health management applications. The self-tuning feature of these models minimizes the mismatch between any given engine and the underlying engineering model describing an engine family. This paper provides details of the construction of a self-tuning engine model centered on a piecewise linear Kalman filter design. Starting from a nonlinear transient aerothermal model, a piecewise linear representation is first extracted. The linearization procedure creates a database of trim vectors and state-space matrices that are subsequently scheduled for interpolation based on engine operating point. A series of steady-state Kalman gains can next be constructed from a reduced-order form of the piecewise linear model. Reduction of the piecewise linear model to an observable dimension with respect to available sensed engine measurements can be achieved using either a subset or an optimal linear combination of "health" parameters, which describe engine performance. The resulting piecewise linear Kalman filter is then implemented for faster-than-real-time processing of sensed engine measurements, generating outputs appropriate for trending engine performance, estimating both measured and unmeasured parameters for control purposes, and performing on-board gas-path fault diagnostics. Computational efficiency is achieved by designing multidimensional interpolation algorithms that exploit the shared scheduling of multiple trim vectors and system matrices. An example application illustrates the accuracy of a self-tuning piecewise linear Kalman filter model when applied to a nonlinear turbofan engine simulation. Additional discussions focus on the issue of transient response accuracy and the advantages of a piecewise linear Kalman filter in the context of validation and verification. The techniques described provide a framework for constructing efficient self-tuning aircraft engine models from complex nonlinear

Development of large engineered cartilage constructs from a small population of cells.

Science.gov (United States)

Brenner, Jillian M; Kunz, Manuela; Tse, Man Yat; Winterborn, Andrew; Bardana, Davide D; Pang, Stephen C; Waldman, Stephen D

2013-01-01

Confronted with articular cartilage's limited capacity for self-repair, joint resurfacing techniques offer an attractive treatment for damaged or diseased tissue. Although tissue engineered cartilage constructs can be created, a substantial number of cells are required to generate sufficient quantities of tissue for the repair of large defects. As routine cell expansion methods tend to elicit negative effects on chondrocyte function, we have developed an approach to generate phenotypically stable, large-sized engineered constructs (≥3 cm(2) ) directly from a small amount of donor tissue or cells (as little as 20,000 cells to generate a 3 cm(2) tissue construct). Using rabbit donor tissue, the bioreactor-cultivated constructs were hyaline-like in appearance and possessed a biochemical composition similar to native articular cartilage. Longer bioreactor cultivation times resulted in increased matrix deposition and improved mechanical properties determined over a 4 week period. Additionally, as the anatomy of the joint will need to be taken in account to effectively resurface large affected areas, we have also explored the possibility of generating constructs matched to the shape and surface geometry of a defect site through the use of rapid-prototyped defect tissue culture molds. Similar hyaline-like tissue constructs were developed that also possessed a high degree of shape correlation to the original defect mold. Future studies will be aimed at determining the effectiveness of this approach to the repair of cartilage defects in an animal model and the creation of large-sized osteochondral constructs. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

Engineered surface barriers for waste disposal sites: lysimeter facility design and construction

International Nuclear Information System (INIS)

Phillips, S.J.; Ruben, M.S.; Kirkham, R.R.

1988-01-01

A facility to evaluate performance of engineered surface carriers for confinement of buried wastes has been designed, constructed, and operations initiated. The Field Lysimeter Test Facility is located at the US Department of Energy's Hanford Site in Richland, Washington. The facility consists of 18 one-dimensional drainage and weighing lysimeters used to evaluate 7 replicated barrier treatments. Distinct layers of natural earth materials were used to construct layered soil and rock barriers in each lysimeter. These barrier designs are capable in principal of significantly reducing or precluding infiltration of meteoric water through barriers into underlying contaminated zones. This paper summarizes salient facility design and construction features used in testing of the Hanford Site's engineered surface barriers

Chemical Engineering Education - Current and Future Trends

DEFF Research Database (Denmark)

Gani, Rafiqul

topics (transport phenomena, separations, reaction engineering, etc.) must remain strong, should the applications that currently emphasize commodity chemicals also include new topics such as sustainability, and product design? In Europe, the European Federation of Chemical Engineering (EFCE) has taken...... has a product focus. With this shift of the chemical industry, what should be the curriculum of the chemical engineering degrees at the BSc- and MSc-levels, and, are the skill set of chemical engineers appropriate for this altered chemical industry? While the basic skill set, defined by the core...... a leading role to define the chemical engineering curriculum. The result has been a set of recommendations for the first (BSc), second (MSc) and third (PhD) cycle chemical engineering education aligned to the Bologna Process. They recommend that students studying towards bachelor and masters qualifications...

Additive manufacturing techniques for the production of tissue engineering constructs.

Science.gov (United States)

Mota, Carlos; Puppi, Dario; Chiellini, Federica; Chiellini, Emo

2015-03-01

'Additive manufacturing' (AM) refers to a class of manufacturing processes based on the building of a solid object from three-dimensional (3D) model data by joining materials, usually layer upon layer. Among the vast array of techniques developed for the production of tissue-engineering (TE) scaffolds, AM techniques are gaining great interest for their suitability in achieving complex shapes and microstructures with a high degree of automation, good accuracy and reproducibility. In addition, the possibility of rapidly producing tissue-engineered constructs meeting patient's specific requirements, in terms of tissue defect size and geometry as well as autologous biological features, makes them a powerful way of enhancing clinical routine procedures. This paper gives an extensive overview of different AM techniques classes (i.e. stereolithography, selective laser sintering, 3D printing, melt-extrusion-based techniques, solution/slurry extrusion-based techniques, and tissue and organ printing) employed for the development of tissue-engineered constructs made of different materials (i.e. polymeric, ceramic and composite, alone or in combination with bioactive agents), by highlighting their principles and technological solutions. Copyright © 2012 John Wiley & Sons, Ltd.

Construction of tissue-engineered small-diameter vascular grafts in fibrin scaffolds in 30 days.

Science.gov (United States)

Gui, Liqiong; Boyle, Michael J; Kamin, Yishai M; Huang, Angela H; Starcher, Barry C; Miller, Cheryl A; Vishnevetsky, Michael J; Niklason, Laura E

2014-05-01

Tissue-engineered small-diameter vascular grafts have been developed as a promising alternative to native veins or arteries for replacement therapy. However, there is still a crucial need to improve the current approaches to render the tissue-engineered blood vessels more favorable for clinical applications. A completely biological blood vessel (3-mm inner diameter) was constructed by culturing a 50:50 mixture of bovine smooth muscle cells (SMCs) with neonatal human dermal fibroblasts in fibrin gels. After 30 days of culture under pulsatile stretching, the engineered blood vessels demonstrated an average burst pressure of 913.3±150.1 mmHg (n=6), a suture retention (53.3±15.4 g) that is suitable for implantation, and a compliance (3.1%±2.5% per 100 mmHg) that is comparable to native vessels. These engineered grafts contained circumferentially aligned collagen fibers, microfibrils and elastic fibers, and differentiated SMCs, mimicking a native artery. These promising mechanical and biochemical properties were achieved in a very short culture time of 30 days, suggesting the potential of co-culturing SMCs with fibroblasts in fibrin gels to generate functional small-diameter vascular grafts for vascular reconstruction surgery.

Computer-aided dental prostheses construction using reverse engineering.

Science.gov (United States)

Solaberrieta, E; Minguez, R; Barrenetxea, L; Sierra, E; Etxaniz, O

2014-01-01

The implementation of computer-aided design/computer-aided manufacturing (CAD/CAM) systems with virtual articulators, which take into account the kinematics, constitutes a breakthrough in the construction of customised dental prostheses. This paper presents a multidisciplinary protocol involving CAM techniques to produce dental prostheses. This protocol includes a step-by-step procedure using innovative reverse engineering technologies to transform completely virtual design processes into customised prostheses. A special emphasis is placed on a novel method that permits a virtual location of the models. The complete workflow includes the optical scanning of the patient, the use of reverse engineering software and, if necessary, the use of rapid prototyping to produce CAD temporary prostheses.

Space construction engineering - A new career field

Science.gov (United States)

Hagler, T.

1979-01-01

Opportunities for engineers in the design and construction of future large space structures are outlined. Possible space structures for the 1980's include a large mirror to reflect sunlight to earth for night lighting, an antenna for a personal communications system, a deep space communications relay system and a large passive radiometer to measure soil moisture. Considerations in the design of such structures include the lack of gravity, allowing structures to be built with much less supporting weight, the cost of transportation to orbit, leading to the use of aluminum or composite materials stored on reels and attached to a beam builder, and the required surface accuracy in the presence of thermal stresses. Construction factors to consider include the use of astronauts and remote manipulators in assembly, both of which have been demonstrated to be feasible.

Construction Performance Optimization toward Green Building Premium Cost Based on Greenship Rating Tools Assessment with Value Engineering Method

Science.gov (United States)

Latief, Yusuf; Berawi, Mohammed Ali; Basten, Van; Riswanto; Budiman, Rachmat

2017-07-01

Green building concept becomes important in current building life cycle to mitigate environment issues. The purpose of this paper is to optimize building construction performance towards green building premium cost, achieving green building rating tools with optimizing life cycle cost. Therefore, this study helps building stakeholder determining building fixture to achieve green building certification target. Empirically the paper collects data of green building in the Indonesian construction industry such as green building fixture, initial cost, operational and maintenance cost, and certification score achievement. After that, using value engineering method optimized green building fixture based on building function and cost aspects. Findings indicate that construction performance optimization affected green building achievement with increasing energy and water efficiency factors and life cycle cost effectively especially chosen green building fixture.

Current Status of Engineering Education in America

Science.gov (United States)

Barr, Ronald E.

Many faculty believe that engineering education in America is at a crossroads and much change is needed. International competition in engineering and the global economy have major potential impact on the engineering workforce of the future. We must find ways to educate U.S. engineers to be competitive and creative contributors in the worldwide arena. Recent national reports are sounding the alarm that the U.S. is losing it leadership in technology and innovation, with consequences for economic prosperity and national security. The report Rising Above the Gathering Storm discusses this dilemma in detail and offers four recommendations to U.S. policymakers. The report Educating the Engineer of 2020 discusses new ways to prepare American engineers for the 21st Century. Furthermore, changes in ABET accreditation, along with new paradigms of teaching and new technology in the classroom, are changing the scholarship of engineering education. We must find ways to promote change in engineering faculty for this new opportunity in engineering educational scholarship. Future engineering students are now in K-12, which is becoming an increasingly diverse population that in the past has not been fully represented in engineering education. Current trends show disaffection for pursuing studies in science and engineering in the youth of our U.S. society. We must find new ways to portray engineering as an exciting and rewarding career, and certainly as an educational platform for professional careers beyond the baccalaureate degree.

Complex engineering objects construction using Multi-D innovative technology

International Nuclear Information System (INIS)

Agafonov, Alexey

2013-01-01

Multi-D technology is an integrated innovative project management system for a construction of complex engineering objects based on a construction process simulation using an intellectual 3D model. Multi-D technology includes: • The unified schedule of E+P+C; • The schedule of loading of human resources, machines & mechanisms; • The budget of expenses and the income integrated with the schedule; • 3D model; • Multi-D model; • Weekly-daily tasks (with 4th level schedules); • Control system of interaction of Customer-EPC(m) company - Contractors; • Change and configuration management system

VALUE-BASED APPROACH TO MANAGING CURRENT ASSETS OF CORPORATE CONSTRUCTION COMPANIES

Directory of Open Access Journals (Sweden)

Galyna Shapoval

2017-09-01

Full Text Available In modern conditions of management, the value of an enterprise becomes the main indicator, which is learned not only by scientists, but also by owners of enterprise and potential investors. Current assets take a very important place among the factors that affect the value of an enterprise, so management of current assets becomes more acute from the point of their impact on enterprise value. The purpose of the paper is to develop a system of value-based management of corporate construction companies’ current assets. The main tasks are: the study of current assets impact on the value of corporate construction companies, the definition of value-based approach to managing current assets of corporate enterprises and development of value-based management system of corporate construction companies’ current assets by elements. General scientific and special research methods were used while writing the work. Value-based management of current assets involves value-based management of the elements of current assets. The value-based inventory management includes the following stages of management: the assessment of reliability and choice of supplier according to the criterion of cash flow maximization, the classification of stocks in management accounting according to the rhythm of supply and the establishment of periodicity of supplies in accordance with the needs of the construction process. The value-based management of accounts receivable includes the following stages of management: assessment of the efficiency of investment of working capital into accounts receivable, the assessment of customers' loyalty and the definition of credit conditions and monitoring of receivables by construction and debt instruments. Value-based cash management involves determining the required level of cash to ensure the continuity of the construction process, assessing the effectiveness of cash use according to the criterion of maximizing cash flow, as well as budget

Evolutionary algorithms and metaheuristics in civil engineering and Construction management

CERN Document Server

Greiner, David

2015-01-01

This book focuses on civil and structural engineering and construction management applications. The contributions constitute modified, extended and improved versions of research presented at the  minisymposium organized by the editors at the ECCOMAS conference on this topic in Barcelona 2014.

Current Trends in Aerospace Engineering Education on Taiwan.

Science.gov (United States)

Hsieh, Sheng-Jii

A proposal for current trends in Aerospace Engineering Education on Taiwan has been drawn from the suggestions made after a national conference of "Workshop on Aerospace Engineering Education Reform." This workshop was held in January 18-20, 1998, at the Institute of Aeronautics and Astronautics, National Cheng Kung University, Tainan,…

LHC Civil Engineering Construction Contracts Cost Monitoring and Budget Forecasting

CERN Document Server

Skelton, K

2000-01-01

The Civil Engineering project for the LHC is estimated at 350 MCHF, of which about 316 MCHF is for the construction contracts. These contracts are based on a system of remeasurement whereby the consultant estimates the quantities required for the construction of each structure and the contractor commits himself to the unit price, which define the initial tender price. There are many factors that affect the final price for these contracts, from increases or decreases in quantities of the estimated amounts in the original bill of quantities to variations to the contract. This paper will look at how these factors change costs at the individual level of a structure to the overall costs of the contract. It will look at how the Civil Engineering Group monitors these changes to calculate cash flows and final costs and how this information is used as a basis for budget forecasts.

Problematising the `Career Academic' in UK construction and engineering education: does the system want what the system gets?

Science.gov (United States)

Pilcher, Nick; Forster, Alan; Tennant, Stuart; Murray, Mike; Craig, Nigel

2017-11-01

'Career Academics' are principally research-led, entering academia with limited or no industrial or practical experience. UK Higher Education Institutions welcome them for their potential to attain research grant funding and publish world-leading journal papers, ultimately enhancing institutional reputation. This polemical paper problematises the Career Academic around three areas: their institutional appeal; their impact on the student experience, team dynamics and broader academic functions; and current strategic policy to employ them. We also argue that recent UK Government teaching-focused initiatives will not address needs to employ practical academics, or 'Pracademics' in predominantly vocational Construction and Engineering Education. We generate questions for policy-makers, institutions and those implementing strategy. We argue that research is key, but partial rebalancing will achieve a diverse academic skill base to achieve contextualised construction and engineering education. In wider European contexts, the paper resonates with issues of academic 'drift' and provides reflection for others on the UK context.

Quality assurance and quality control of nuclear engineering during construction phase

International Nuclear Information System (INIS)

Zhang Zhihua; Deng Yue; Liu Yaoguang; Xu Xianqi; Zhou Shan; Qian Dazhi; Zhang Yang

2007-01-01

The quality assurance (QA) and quality control (QC) is a very important work in the nuclear engineering. This paper starts with how to establish quality assurance system of nuclear engineering construction phase, then introduces several experiments and techniques such as the implementation of quality assurance program, the quality assurance and quality control of contractors, the quality surveillance and control of supervisory companies, quality assurance audit and surveillance of builders. (authors)

Constructs and methods for genome editing and genetic engineering of fungi and protists

Science.gov (United States)

Hittinger, Christopher Todd; Alexander, William Gerald

2018-01-30

Provided herein are constructs for genome editing or genetic engineering in fungi or protists, methods of using the constructs and media for use in selecting cells. The construct include a polynucleotide encoding a thymidine kinase operably connected to a promoter, suitably a constitutive promoter; a polynucleotide encoding an endonuclease operably connected to an inducible promoter; and a recognition site for the endonuclease. The constructs may also include selectable markers for use in selecting recombinations.

Quality assurance during construction of civil engineering structures important to safety of nuclear facilities

International Nuclear Information System (INIS)

2011-11-01

The present manual is developed to deal with quality assurance aspect of civil engineering structures in a greater detail. This manual gives detail to develop QA plans specific to multifarious activities of civil engineering construction

The Stirling engine. Simply explained, easily constructed. 9. rev. and enl. ed.; Der Stirlingmotor. Einfach erklaert und leicht gebaut

Energy Technology Data Exchange (ETDEWEB)

Viebach, Dieter

2010-07-01

Subsequently to a easily comprehensively description of the function and characteristics of Stirling engines, the author of the book under consideration describes the construction of a model Stirling engine on the basis of clear construction drawings. A delicacy for experienced modelers: The 'amazing model', a miniature Stirling engine consisting of beverage cans, has been running with the warmth of the human hand. Even in this technically demanding model, the construction will be described accurately by detailed construction drawings.

Monitoring Bone Tissue Engineered (BTE) Constructs Based on the Shifting Metabolism of Differentiating Stem Cells.

Science.gov (United States)

Simmons, Aaron D; Sikavitsas, Vassilios I

2018-01-01

Ever-increasing demand for bone grafts necessitates the realization of clinical implementation of bone tissue engineered constructs. The predominant hurdle to implementation remains to be securing FDA approval, based on the lack of viable methods for the rigorous monitoring of said constructs. The study presented herein details a method for such monitoring based on the shifting metabolism of mesenchymal stem cells (MSCs) as they differentiate into osteoblasts. To that end, rat MSCs seeded on 85% porous spunbonded poly(L-lactic acid) scaffolds were cultured in flow perfusion bioreactors with baseline or osteoinductive media, and levels of key physio-metabolic markers (oxygen, glucose, osteoprotegerin, and osteocalcin) were monitored throughout culture. Comparison of these non-destructively obtained values and current standard destructive analyses demonstrated key trends useful for the concurrent real-time monitoring of construct cellularity and maturation. Principle among these is the elucidation of the ratio of the rates of oxygen uptake to glucose consumption as a powerful quality marker. This ratio, supported on a physiological basis, has been shown herein to be reliable in the determination of both construct maturation (defined as osteoblastic differentiation and accompanying mineralization) and construct cellularity. Supplementary monitoring of OPG and OCN are shown to provide further validation of such metrics.

Gene composer: database software for protein construct design, codon engineering, and gene synthesis.

Science.gov (United States)

Lorimer, Don; Raymond, Amy; Walchli, John; Mixon, Mark; Barrow, Adrienne; Wallace, Ellen; Grice, Rena; Burgin, Alex; Stewart, Lance

2009-04-21

To improve efficiency in high throughput protein structure determination, we have developed a database software package, Gene Composer, which facilitates the information-rich design of protein constructs and their codon engineered synthetic gene sequences. With its modular workflow design and numerous graphical user interfaces, Gene Composer enables researchers to perform all common bio-informatics steps used in modern structure guided protein engineering and synthetic gene engineering. An interactive Alignment Viewer allows the researcher to simultaneously visualize sequence conservation in the context of known protein secondary structure, ligand contacts, water contacts, crystal contacts, B-factors, solvent accessible area, residue property type and several other useful property views. The Construct Design Module enables the facile design of novel protein constructs with altered N- and C-termini, internal insertions or deletions, point mutations, and desired affinity tags. The modifications can be combined and permuted into multiple protein constructs, and then virtually cloned in silico into defined expression vectors. The Gene Design Module uses a protein-to-gene algorithm that automates the back-translation of a protein amino acid sequence into a codon engineered nucleic acid gene sequence according to a selected codon usage table with minimal codon usage threshold, defined G:C% content, and desired sequence features achieved through synonymous codon selection that is optimized for the intended expression system. The gene-to-oligo algorithm of the Gene Design Module plans out all of the required overlapping oligonucleotides and mutagenic primers needed to synthesize the desired gene constructs by PCR, and for physically cloning them into selected vectors by the most popular subcloning strategies. We present a complete description of Gene Composer functionality, and an efficient PCR-based synthetic gene assembly procedure with mis-match specific endonuclease

Gene Composer: database software for protein construct design, codon engineering, and gene synthesis

Directory of Open Access Journals (Sweden)

Mixon Mark

2009-04-01

Full Text Available Abstract Background To improve efficiency in high throughput protein structure determination, we have developed a database software package, Gene Composer, which facilitates the information-rich design of protein constructs and their codon engineered synthetic gene sequences. With its modular workflow design and numerous graphical user interfaces, Gene Composer enables researchers to perform all common bio-informatics steps used in modern structure guided protein engineering and synthetic gene engineering. Results An interactive Alignment Viewer allows the researcher to simultaneously visualize sequence conservation in the context of known protein secondary structure, ligand contacts, water contacts, crystal contacts, B-factors, solvent accessible area, residue property type and several other useful property views. The Construct Design Module enables the facile design of novel protein constructs with altered N- and C-termini, internal insertions or deletions, point mutations, and desired affinity tags. The modifications can be combined and permuted into multiple protein constructs, and then virtually cloned in silico into defined expression vectors. The Gene Design Module uses a protein-to-gene algorithm that automates the back-translation of a protein amino acid sequence into a codon engineered nucleic acid gene sequence according to a selected codon usage table with minimal codon usage threshold, defined G:C% content, and desired sequence features achieved through synonymous codon selection that is optimized for the intended expression system. The gene-to-oligo algorithm of the Gene Design Module plans out all of the required overlapping oligonucleotides and mutagenic primers needed to synthesize the desired gene constructs by PCR, and for physically cloning them into selected vectors by the most popular subcloning strategies. Conclusion We present a complete description of Gene Composer functionality, and an efficient PCR-based synthetic gene

Current-day matters of administration and law in the field of high-rise construction

Science.gov (United States)

Voskresenskaya, Elena; Snetkov, Vitaly; Tebryaev, Alexander

2018-03-01

The article touches upon main reasons for high-rise construction: increase in energy consumption and limited availability of site in the big cities of Russia. Increase in energy consumption is related with construction, transportation and applying of ventilation and air conditioning systems. Nowadays, there are developed a lot of design and engineer solutions, that include autonomous systems as well as passive methods with low energy consumption rate, which are interrelated with local climate conditions. Certain architectural solutions contribute to energy consumption decrease: building orientation with respect to the cardinal directions, taking into account the prevailing cold wind directions, maximum glazing of the southern facades and minimum glazing of the northern ones, what plays a big role in hard climate conditions. Limited availability of site for construction in the big cities resulted in rapid development of the high-rise construction, which today prevails in terms of quantitative indicators of civil engineering.

Engineering aspects of disruption current decay

International Nuclear Information System (INIS)

Murray, J.G.

1983-11-01

Engineering features associated with the configuration of a tokamak can affect the amount of energy that produces melting and damage to the limiters or internal wall surfaces as the result of a major disruption. During the current decay period of a major thermal disruption, the energy that can damage a wall or limiter comes from the external magnetic field. By providing a good conducting torus near the plasma and increasing the plasma circuit resistance, this magnetic energy (transferred by way of the plasma circuit) can be minimized. This report addresses engineering design features to reduce the energy deposited on the inner torus surface that produces melting of the structures

Singularities of construction of static war-hour meters alternating-current

Directory of Open Access Journals (Sweden)

М.О. Петрище

2004-04-01

Full Text Available  The analysis of construction of static war-hour meters is carried out which are founded on use of specialized tools, which are intended for measurement of a active energy. The shortages of such methods concerning a possibility of unauthorized takeoff of an electric energy are marked through improper phasing of a current. The method is offered which allows to construct static war-hour meters insensitive to improper phasing of a current.

A data-driven approach to reverse engineering customer engagement models: towards functional constructs.

Science.gov (United States)

de Vries, Natalie Jane; Carlson, Jamie; Moscato, Pablo

2014-01-01

Online consumer behavior in general and online customer engagement with brands in particular, has become a major focus of research activity fuelled by the exponential increase of interactive functions of the internet and social media platforms and applications. Current research in this area is mostly hypothesis-driven and much debate about the concept of Customer Engagement and its related constructs remains existent in the literature. In this paper, we aim to propose a novel methodology for reverse engineering a consumer behavior model for online customer engagement, based on a computational and data-driven perspective. This methodology could be generalized and prove useful for future research in the fields of consumer behaviors using questionnaire data or studies investigating other types of human behaviors. The method we propose contains five main stages; symbolic regression analysis, graph building, community detection, evaluation of results and finally, investigation of directed cycles and common feedback loops. The 'communities' of questionnaire items that emerge from our community detection method form possible 'functional constructs' inferred from data rather than assumed from literature and theory. Our results show consistent partitioning of questionnaire items into such 'functional constructs' suggesting the method proposed here could be adopted as a new data-driven way of human behavior modeling.

A data-driven approach to reverse engineering customer engagement models: towards functional constructs.

Directory of Open Access Journals (Sweden)

Natalie Jane de Vries

Full Text Available Online consumer behavior in general and online customer engagement with brands in particular, has become a major focus of research activity fuelled by the exponential increase of interactive functions of the internet and social media platforms and applications. Current research in this area is mostly hypothesis-driven and much debate about the concept of Customer Engagement and its related constructs remains existent in the literature. In this paper, we aim to propose a novel methodology for reverse engineering a consumer behavior model for online customer engagement, based on a computational and data-driven perspective. This methodology could be generalized and prove useful for future research in the fields of consumer behaviors using questionnaire data or studies investigating other types of human behaviors. The method we propose contains five main stages; symbolic regression analysis, graph building, community detection, evaluation of results and finally, investigation of directed cycles and common feedback loops. The 'communities' of questionnaire items that emerge from our community detection method form possible 'functional constructs' inferred from data rather than assumed from literature and theory. Our results show consistent partitioning of questionnaire items into such 'functional constructs' suggesting the method proposed here could be adopted as a new data-driven way of human behavior modeling.

Vascularization of soft tissue engineering constructs

DEFF Research Database (Denmark)

Pimentel Carletto, Rodrigo

nanotechnology-based paradigm for engineering vascularised liver tissue for transplantation”) and the Danish National Research Foundation and Villum Foundation’s Center for Intelligent Drug delivery and sensing Using microcontainers and Nanomechanics (Danish National Research Foundation (DNRF122).......Vascularization is recognized to be the biggest challenge for the fabrication of tissues and finally, organs in vitro. So far, several fabrication techniques have been proposed to create a perfusable vasculature within hydrogels, however, the vascularization and perfusion of hydrogels...... with mechanical properties in the range of soft tissues has not been fully achieved. My project focused on the fabrication and the active perfusion of hydrogel constructs with multi-dimensional vasculature and controlled mechanical properties targeting soft tissues. Specifically, the initial part of the research...

Use of engineered nanomaterials in the construction industry with specific emphasis on paints and their flows in construction and demolition waste in Switzerland.

Science.gov (United States)

Hincapié, Ingrid; Caballero-Guzman, Alejandro; Hiltbrunner, David; Nowack, Bernd

2015-09-01

One sector where the use of engineered nanomaterials (ENMs) is supposed to offer novel or improved functionalities is the construction industry. During the renovation or demolition of buildings, ENMs contained in former construction materials will enter recycling systems or become construction waste. Currently, information about ENM flows in these processes is insufficient. The potential for the release of ENMs from this waste into the environment is unknown, as are the environmental impacts. To evaluate whether there is currently any nano-relevant construction and demolition waste (C&DW) originating from buildings, we evaluated the sources and flows of ENMs in C&DW and identified their potential exposure pathways. A survey of business representatives of Swiss companies in this sector found that ENMs are mainly used in paints and cement. The most frequently used ENMs in the Swiss housing construction industry are nano-TiO2, nano-SiO2, nano-ZnO, and nano-Ag. Using a bottom-up, semi-quantitative approach, we estimated the flows of ENMs contained in paints along the product's life cycle from buildings to recycling and landfill. The flows of ENMs are determined by their associated flows of building materials. We estimated an annual amount of ENMs used in paints of 14t of TiO2, 12t of SiO2, 5t of ZnO, and 0.2t of Ag. The majority of ENMs contained in paints in Switzerland enter recycling systems (23t/y), a smaller amount is disposed directly in landfills (7t/y), and a tiny fraction of ENM waste is incinerated (0.01t/y). Our results allow a qualitative determination of the potential release of ENMs into technical or environmental compartments, with the highest potential release expected during recycling. Copyright © 2015 Elsevier Ltd. All rights reserved.

Civil engineering work

International Nuclear Information System (INIS)

Cousyn, Rene; Goubin, Jean.

1977-01-01

Although it does not require a specifically new technicality, the Civil Engineering site of a nuclear power plant is a complex work. Considering as an example the power plant currently in construction at Tricastin, the authors describe the main Civil Engineering work and task organization applied to carry it out [fr

Evolutionary, Unconscious Design Support for the Architectural, Engineering and Construction Industry

NARCIS (Netherlands)

Van de Ruitenbeek, H.K.M.

2012-01-01

The Architecture, Engineering and Construction (AEC) industry is a complex system in which carpenters, structural designers, architects, modellers, cost estimators, planners, politicians and many others act apart together in project-specific virtual enterprises. There is a large amount of actors, an

Current status of construction of nuclear power plants No. 7, No. 8 in Korea

International Nuclear Information System (INIS)

Sug, S.H.

1979-01-01

The up-to-date accomplishment and future work in the construction of nuclear power plants in Korea are outlined. The scope of the construction project of the No. 7 and No. 8 power plants, selection of the suppliers of the main instruments, assessment of the planning, architecture, engineering, construction fund, procurement of nuclear fuel, and the necessities of home production of various nuclear materials are briefly summarized. (author)

Morphological changes in paraurethral area after introduction of tissue engineering construct on the basis of adipose tissue stromal cells.

Science.gov (United States)

Makarov, A V; Arutyunyan, I V; Bol'shakova, G B; Volkov, A V; Gol'dshtein, D V

2009-10-01

We studied morphological changes in the paraurethral area of Wistar rats after introduction of tissue engineering constructs on the basis of multipotent mesenchymal stem cells and gelatin sponge. The tissue engineering construct containing autologous culture of the stromal fraction of the adipose tissue was most effective. After introduction of this construct we observed more rapid degradation of the construct matrix and more intensive formation of collagen fibers.

Growth factor stimulation improves the structure and properties of scaffold-free engineered auricular cartilage constructs.

Directory of Open Access Journals (Sweden)

Renata G Rosa

Full Text Available The reconstruction of the external ear to correct congenital deformities or repair following trauma remains a significant challenge in reconstructive surgery. Previously, we have developed a novel approach to create scaffold-free, tissue engineering elastic cartilage constructs directly from a small population of donor cells. Although the developed constructs appeared to adopt the structural appearance of native auricular cartilage, the constructs displayed limited expression and poor localization of elastin. In the present study, the effect of growth factor supplementation (insulin, IGF-1, or TGF-β1 was investigated to stimulate elastogenesis as well as to improve overall tissue formation. Using rabbit auricular chondrocytes, bioreactor-cultivated constructs supplemented with either insulin or IGF-1 displayed increased deposition of cartilaginous ECM, improved mechanical properties, and thicknesses comparable to native auricular cartilage after 4 weeks of growth. Similarly, growth factor supplementation resulted in increased expression and improved localization of elastin, primarily restricted within the cartilaginous region of the tissue construct. Additional studies were conducted to determine whether scaffold-free engineered auricular cartilage constructs could be developed in the 3D shape of the external ear. Isolated auricular chondrocytes were grown in rapid-prototyped tissue culture molds with additional insulin or IGF-1 supplementation during bioreactor cultivation. Using this approach, the developed tissue constructs were flexible and had a 3D shape in very good agreement to the culture mold (average error <400 µm. While scaffold-free, engineered auricular cartilage constructs can be created with both the appropriate tissue structure and 3D shape of the external ear, future studies will be aimed assessing potential changes in construct shape and properties after subcutaneous implantation.

Construction and design of solid-propellant rocket engines. Konstruktsiia i proektirovanie raketnykh dvigatelei tverdogo topliva

Energy Technology Data Exchange (ETDEWEB)

Fakhrutdinov, I.K.; Kotel' nikov, A.V.

1987-01-01

Methods for assessing the durability of different components of solid-propellant rocket engines are presented. The following aspects of engine development are discussed: task formulation, parameter calculation, construction scheme selection, materials, and durability assessment. 45 references.

Engineering and construction projects for oil and gas processing facilities: Contracting, uncertainty and the economics of information

International Nuclear Information System (INIS)

Berends, Kees

2007-01-01

The amount of oil and gas processing capacity required to meet demand during the next 20 years is more than twice the amount realised during the last decades. Engineering and Construction contractors (ECs) play a key role in the development and implementation of Large Engineering and Construction Projects (LECPs) for these facilities. We examine the characteristics of LECPs, demand and supply of the contracting market and the strategies traditionally adopted by owners to contract out the development and implementation of these projects to ECs. We demonstrate that these traditional strategies are not longer effective, in the current 'sellers market', to mitigate the oligopolistic economic inefficiencies. As the 'overheating' of the contracting market is expected to continue for a considerable period of time, alternative contracting strategies are required. Contract theory, particularly the economics of information on LECPs, indicates how alternative contracting strategies can be used to overcome economic inefficiencies. The effective use of these alternative strategies requires increased owner involvement and their effectiveness is contingent upon owner competency and ECs acting as the owner's agent rather than its adversary. This will require an organisational and behavioural change process for both owners and ECs

CONSIDERATION REGARDING CURRENT ASSETS IN THE CONSTRUCTION ENTITIES

Directory of Open Access Journals (Sweden)

Laura Adriana COJOCARU (ALIONESCU

2014-06-01

Full Text Available Accounting for current assets mainly aims to obtain useful information on the management of their best in order to make management decisions. Counting efficiency of these assets, their importance, provides improved performance of the entity. In this paper we want to study the degree of implementation of policies and accounting treatments on the current assets in the specific construction economic entities, the problems of implementation and thus better addressing their theoretical and procedural to improve the information provided by financial statements. Due to the importance of proper conduct of business owned entities, accounting current assets should result in optimal and efficient control of current assets.

Constructing Learning-by-Doing Pedagogical Model for Delivering 21st Century Engineering Education

Directory of Open Access Journals (Sweden)

Ghassan Frache

2018-01-01

Full Text Available The United Arab Emirates (UAE is dedicated to establishing the best teaching and learning environment for students and staff across all higher education institutions. To heed this call, the engineering division adopted the Learning-by-Doing (LBD pedagogical philosophy for 21st Century education at the heart of its strategic directions. This study intends to explore how LBD is understood and practiced in UAE colleges and how 21st Century skills can be explicitly incorporated into its engineering curriculum by using constructive alignment as a pattern for instructional design. This work intends to investigate the general question: “What constructively aligned Learning-by-Doing pedagogical model, with the incorporation of 21st Century skills, needs to be developed to effectively teach and prepare engineering students at the Higher College of Technology, UAE for successful long-term employment in the global working economy?”. Using mixed method research design and input from its major stakeholders, student survey questionnaires, engineering instructors and dean structured interviews, overt class observation and syllabi examination have all been utilized for data triangulation. In conclusion, the study developed a collaborative LBD model tailor-fitted to the institution’s engineering program and to UAE’s culture.

Design Guide for Selection and Specification of Kevlar Rope for Ocean Engineering and Construction.

Science.gov (United States)

1976-07-01

public rtoieco cnd sol . It i Idim .buttm Is ul"rnimi.. OCEAN ENGINEERING AND CONSTRUCTION PROJECT OFFICE CHESAPEAKE DIVISION NAVAL FACILITIES ENGINEERING...be to have no more than one layer. This is impractical for oceano - graphic purposes. Assuming a need to spooi many layers of rope under tension

CARTILAGE CONSTRUCTS ENGINEERED FROM CHONDROCYTES OVEREXPRESSING IGF-I IMPROVE THE REPAIR OF OSTEOCHONDRAL DEFECTS IN A RABBIT MODEL

Science.gov (United States)

Madry, Henning; Kaul, Gunter; Zurakowski, David; Vunjak-Novakovic, Gordana; Cucchiarini, Magali

2015-01-01

Tissue engineering combined with gene therapy is a promising approach for promoting articular cartilage repair. Here, we tested the hypothesis that engineered cartilage with chondrocytes over expressing a human insulin-like growth factor I (IGF-I) gene can enhance the repair of osteochondral defects, in a manner dependent on the duration of cultivation. Genetically modified chondrocytes were cultured on biodegradable polyglycolic acid scaffolds in dynamic flow rotating bioreactors for either 10 or 28 d. The resulting cartilaginous constructs were implanted into osteochondral defects in rabbit knee joints. After 28 weeks of in vivo implantation, immunoreactivity to ß-gal was detectable in the repair tissue of defects that received lacZ constructs. Engineered cartilaginous constructs based on IGF-I-over expressing chondrocytes markedly improved osteochondral repair compared with control (lacZ) constructs. Moreover, IGF-I constructs cultivated for 28 d in vitro significantly promoted osteochondral repair vis-à-vis similar constructs cultivated for 10 d, leading to significantly decreased osteoarthritic changes in the cartilage adjacent to the defects. Hence, the combination of spatially defined overexpression of human IGF-I within a tissue-engineered construct and prolonged bioreactor cultivation resulted in most enhanced articular cartilage repair and reduction of osteoarthritic changes in the cartilage adjacent to the defect. Such genetically enhanced tissue engineering provides a versatile tool to evaluate potential therapeutic genes in vivo and to improve our comprehension of the development of the repair tissue within articular cartilage defects. Insights gained with additional exploration using this model may lead to more effective treatment options for acute cartilage defects. PMID:23588785

Cartilage constructs engineered from chondrocytes overexpressing IGF-I improve the repair of osteochondral defects in a rabbit model

Directory of Open Access Journals (Sweden)

H Madry

2013-04-01

Full Text Available Tissue engineering combined with gene therapy is a promising approach for promoting articular cartilage repair. Here, we tested the hypothesis that engineered cartilage with chondrocytes overexpressing a human insulin-like growth factor I (IGF-I gene can enhance the repair of osteochondral defects, in a manner dependent on the duration of cultivation. Genetically modified chondrocytes were cultured on biodegradable polyglycolic acid scaffolds in dynamic flow rotating bioreactors for either 10 or 28 d. The resulting cartilaginous constructs were implanted into osteochondral defects in rabbit knee joints. After 28 weeks of in vivo implantation, immunoreactivity to ß-gal was detectable in the repair tissue of defects that received lacZ constructs. Engineered cartilaginous constructs based on IGF-I-overexpressing chondrocytes markedly improved osteochondral repair compared with control (lacZ constructs. Moreover, IGF-I constructs cultivated for 28 d in vitro significantly promoted osteochondral repair vis-à-vis similar constructs cultivated for 10 d, leading to significantly decreased osteoarthritic changes in the cartilage adjacent to the defects. Hence, the combination of spatially defined overexpression of human IGF-I within a tissue-engineered construct and prolonged bioreactor cultivation resulted in most enhanced articular cartilage repair and reduction of osteoarthritic changes in the cartilage adjacent to the defect. Such genetically enhanced tissue engineering provides a versatile tool to evaluate potential therapeutic genes in vivo and to improve our comprehension of the development of the repair tissue within articular cartilage defects. Insights gained with additional exploration using this model may lead to more effective treatment options for acute cartilage defects.

Nanostructured 3D Constructs Based on Chitosan and Chondroitin Sulphate Multilayers for Cartilage Tissue Engineering

NARCIS (Netherlands)

Silva, J.M.; Georgi, Nicole; Costa, R.; Sher, P.; Reis, R L; van Blitterswijk, Clemens; Karperien, Hermanus Bernardus Johannes; Mano, J.F.

2013-01-01

Nanostructured three-dimensional constructs combining layer-by-layer technology (LbL) and template leaching were processed and evaluated as possible support structures for cartilage tissue engineering. Multilayered constructs were formed by depositing the polyelectrolytes chitosan (CHT) and

New CMS detectors under construction at CERN

CERN Multimedia

Katarina Anthony

2012-01-01

While the LHC will play the starring role in the 2013/2014 Long Shutdown (LS1), the break will also be a chance for its experiments to upgrade their detectors. CMS will be expanding its current muon detection systems, fitting 72 new cathode strip chambers (CSC) and 144 new resistive plate chambers (RPC) to the endcaps of the detector. These new chambers are currently under construction in Building 904.   CMS engineers install side panels on a CSC detector in Building 904. "The original RPC and CSC detectors were constructed in bits and pieces around the world," says Armando Lanaro, CSC construction co-ordinator. "But for the construction of these additional chambers, we decided to unify the assembly and testing into a single facility at CERN. There, CMS technicians, engineers and physicists are taking raw materials and transforming them into installation-ready detectors.” This new facility can be found in Building 904. Once the assembly site for the strai...

Involving construction in the preliminary engineering process

International Nuclear Information System (INIS)

Mahoney, D.T. Jr.; Boccieri, S.V. Jr.

1994-01-01

With today's high cost associated with modifications in nuclear power plants, it is imperative that the authors continue to investigate ways to cut costs but at the same time improve efficiency and reduce radiation exposure to those directly associated with the implementation of modifications. The success associated with involving construction in the preliminary engineering process will not only cut costs and improve efficiency but will establish a Team Building concept to provide accountability to all those associated with the implementation of the task. This form of partnering focuses on the solutions rather than highlighting the difficulties. This paper will demonstrate techniques to implement such ideas and provide examples to corroborate actual successes already achieved

The interplay between tissue growth and scaffold degradation in engineered tissue constructs

KAUST Repository

O’Dea, R. D.

2012-09-18

In vitro tissue engineering is emerging as a potential tool to meet the high demand for replacement tissue, caused by the increased incidence of tissue degeneration and damage. A key challenge in this field is ensuring that the mechanical properties of the engineered tissue are appropriate for the in vivo environment. Achieving this goal will require detailed understanding of the interplay between cell proliferation, extracellular matrix (ECM) deposition and scaffold degradation. In this paper, we use a mathematical model (based upon a multiphase continuum framework) to investigate the interplay between tissue growth and scaffold degradation during tissue construct evolution in vitro. Our model accommodates a cell population and culture medium, modelled as viscous fluids, together with a porous scaffold and ECM deposited by the cells, represented as rigid porous materials. We focus on tissue growth within a perfusion bioreactor system, and investigate how the predicted tissue composition is altered under the influence of (1) differential interactions between cells and the supporting scaffold and their associated ECM, (2) scaffold degradation, and (3) mechanotransduction-regulated cell proliferation and ECM deposition. Numerical simulation of the model equations reveals that scaffold heterogeneity typical of that obtained from μCT scans of tissue engineering scaffolds can lead to significant variation in the flow-induced mechanical stimuli experienced by cells seeded in the scaffold. This leads to strong heterogeneity in the deposition of ECM. Furthermore, preferential adherence of cells to the ECM in favour of the artificial scaffold appears to have no significant influence on the eventual construct composition; adherence of cells to these supporting structures does, however, lead to cell and ECM distributions which mimic and exaggerate the heterogeneity of the underlying scaffold. Such phenomena have important ramifications for the mechanical integrity of

Selecting, engineering and constructing drilling sites at the Geysers geothermal field. Geysers chinetsu ryoiki ni okeru kussaku shikichi no sentei engineering kochiku

Energy Technology Data Exchange (ETDEWEB)

1993-04-01

This paper describes some examples of selection, engineering and construction of drilling sites at the Geysers geothermal field in the northern district of California State. Steep landform, thin-layered soil and violent rainfall create unstable conditions bringing about numerous landslide in the field. Selection of a well drilling site appropriate in such conditions is started by analyzing the aerial photographs by technical staff. After site selection, prospecting and soil test are conducted and a working plan in the well site is decided to prepare engineering drawings. In the construction, land preparation, the open-cutting of base-line trench, etc. are carried out. The base-line trench is a large and sufficiently deep one which is open-cut to the front end or the middle of the bottom part of the well plateau. The final construction work is to build a leading casing for interpolating cementing. The well site construction in the Geysers geothermal field is done in consideration of protecting human life, health and properties. 1 fig.

Potential and Benefits of Building Information Modeling (BIM During Pre-Construction, Construction and Post Construction Stage

Directory of Open Access Journals (Sweden)

Aw Nien Wei

2017-11-01

Full Text Available The construction industry is the main economic support for all countries around the world in which continually adapting to meet competitive challenges around the global market. Nevertheless, the construction project is becoming much more complex and difficult to manage. This is because the construction project involves a large number of stakeholder, for example, the consultant companies, architects, engineers, building surveyors and quantity surveyors. The technology currently used in the construction industry is the AutoCAD (Automatic computeraided design. AutoCAD is a commercial software application for 2D and 3D computer-aided design (CAD and drafting develop by Autodesk. Generally, all the drawing design from Autocad will be exchanged among the stakeholder in the form of paper. Information exchanged among them mostly involves a lot of documents and drawings. This practice creates errors because of documents and drawings are mostly in a paper-based format that is not properly managed which results in miscommunication among them. Having wrong information in the construction process could hinder the productivity of projects because in a construction project information is one of the important construction materials. Building Information Modeling (BIM is one of the newly software in the architecture, engineering, and construction (AEC industries to ensure all parties receive the right information. BIM technology is also an intelligent model of a building constructed digitally in the way of 3D. The software will generate model containing the information needed to support the construction, fabrication, and procurement activities that needed to realize the building. This paper will discuss on potential and benefits of BIM during pre-construction stage, construction stage and during post construction stage

Engineered barriers: current status

International Nuclear Information System (INIS)

Atkinson, A.; Marsh, G.P.

1988-01-01

This report summarises the current state of research relevant to assessing the performance of engineered barriers made of steel and concrete in radioactive waste repositories. The objective of these barriers is to contain the radionuclides within them by providing both physical and chemical impediment to their release. The physical barriers are of most value for highly soluble isotopes with relatively short half-lives (eg 137 Cs), since they can provide containment until a large fraction of the activity has decayed. In addition they can facilitate retrievability for some period after disposal. The chemical barriers operate by beneficial conditioning of the near field groundwater and providing sites for sorption of radionuclides. Both of these reduce the aqueous concentration of radionuclides in the near field. (author)

Savannah River Plant engineering, design, and construction history of ``S`` projects and other work, January 1961--December 1964. Volume 2

Energy Technology Data Exchange (ETDEWEB)

1970-03-01

The work described in this volume of ``S`` Projects History is an extension of the type of work described in Volume I. E.I. du Pont de flemours & Company had entered into Contract AT (07-2)-l with the United States Atomic Energy Commission to develop, design, construct, install, and operate facilities to produce heavy water, fissionable materials, and related products. Under this contract,, Du Pont constructed and operated the Savannah River Plant. The engineering, design, and construction for most of the larger ``S`` projects was performed by the Engineering DeDartment. For some of the large and many of the smaller projects the Engineering Department was responsible only for the construction because the Atomic Energy Division (AED) of the Explosives Department handled the other phases. The Engineering Department Costruction Division also performed the physical work for many of the plant work orders. This volume includes a general description of the Du Pont Engineering Department activities pertaining to the engineering, design, and construction of the ``S`` projects at the Savannah River Plant; brief summaries of the projects and principal work requests; and supplementary informaticn on a few subjects in Volume I for which final data was not available at the closing date. Projects and other plant engineering work which were handled entirely by the Explosives Department -- AED are not included in this history.

[Construction of injectable tissue engineered nucleus pulposus in vitro].

Science.gov (United States)

Tian, Huake; Wang, Jian; Chen, Chao; Liu, Jie; Zhou, Yue

2009-02-01

To investigate the feasibility of using thermo-sensitive chitosan hydrogen as a scaffold to construct tissue engineered injectable nucleus pulposus (NP). Three-month-old neonatal New Zealand rabbits (male or female) weighing 150-200 g were selected to isolate and culture NP cells. The thermo-sensitive chitosan hydrogel scaffold was made of chitosan, disodium beta-glycerophosphate and hydroxyethyl cellulose. Its physical properties and gross condition were observed. The tissue engineered NP was constructed by compounding the scaffold and rabbit NP cells. Then, the viability of NP cells in the chitosan hydrogel was observed 2 days after compound culture and the growth condition of NP cells on the scaffold was observed by SEM 7 days after compound culture. NP cells went through histology and immunohistochemistry detection and their secretion of aggrecan and expression of Col II mRNA were analyzed by RT-PCR 21 days after compound culture. The thermo-sensitive chitosan hydrogel was liquid at room temperature and solidified into gel at 37 degrees C (15 minutes) due to crosslinking reaction. Acridine orange-propidium iodide staining showed that the viability rate of NP cells in chitosan hydrogel was above 90%. Scanning electron microscope observation demonstrated that the NP cells were distributed in the reticulate scaffold, with ECM on their surfaces. The results of HE, toluidine blue, safranin O and histology and immunohistochemistry staining confirmed that the NP cells in chitosan hydrogel were capable of producing ECM. RT-PCR results showed that the secretion of Col II and aggrecan mRNA in NP cells cultured three-dimensionally by chitosan hydrogen scaffold were 0.631 +/- 0.064 and 0.832 +/- 0.052, respectively, showing more strengths of producing matrix than that of monolayer culture (0.528 +/- 0.039, 0.773 +/- 0.046) with a significant difference (P compound culture, and may be a potential NP cells carrier for tissue engineered NP.

Hybrid printing of mechanically and biologically improved constructs for cartilage tissue engineering applications

International Nuclear Information System (INIS)

Xu Tao; Binder, Kyle W; Albanna, Mohammad Z; Dice, Dennis; Zhao Weixin; Yoo, James J; Atala, Anthony

2013-01-01

Bioprinting is an emerging technique used to fabricate viable, 3D tissue constructs through the precise deposition of cells and hydrogels in a layer-by-layer fashion. Despite the ability to mimic the native properties of tissue, printed 3D constructs that are composed of naturally-derived biomaterials still lack structural integrity and adequate mechanical properties for use in vivo, thus limiting their development for use in load-bearing tissue engineering applications, such as cartilage. Fabrication of viable constructs using a novel multi-head deposition system provides the ability to combine synthetic polymers, which have higher mechanical strength than natural materials, with the favorable environment for cell growth provided by traditional naturally-derived hydrogels. However, the complexity and high cost associated with constructing the required robotic system hamper the widespread application of this approach. Moreover, the scaffolds fabricated by these robotic systems often lack flexibility, which further restrict their applications. To address these limitations, advanced fabrication techniques are necessary to generate complex constructs with controlled architectures and adequate mechanical properties. In this study, we describe the construction of a hybrid inkjet printing/electrospinning system that can be used to fabricate viable tissues for cartilage tissue engineering applications. Electrospinning of polycaprolactone fibers was alternated with inkjet printing of rabbit elastic chondrocytes suspended in a fibrin–collagen hydrogel in order to fabricate a five-layer tissue construct of 1 mm thickness. The chondrocytes survived within the printed hybrid construct with more than 80% viability one week after printing. In addition, the cells proliferated and maintained their basic biological properties within the printed layered constructs. Furthermore, the fabricated constructs formed cartilage-like tissues both in vitro and in vivo as evidenced by the

Eddy Current Assessment of Engineered Components Containing Nanofibers

Science.gov (United States)

Ko, Ray T.; Hoppe, Wally; Pierce, Jenny

2009-03-01

The eddy current approach has been used to assess engineered components containing nanofibers. Five specimens with different programmed defects were fabricated. A 4-point collinear probe was used to verify the electrical resistivity of each specimen. The liftoff component of the eddy current signal was used to test two extreme cases with different nano contents. Additional eddy current measurements were also used in detecting a missing nano layer simulating a manufacturing process error. The results of this assessment suggest that eddy current liftoff measurement can be a useful tool in evaluating the electrical properties of materials containing nanofibers.

Oxygen gradients in tissue-engineered PEGT/PBT cartilaginous constructs: Measurement and modeling

NARCIS (Netherlands)

Malda, J.; Rouwkema, Jeroen; Martens, D.E.; le Comte, EP; Kooy, F.K.; Tramper, J.; van Blitterswijk, Clemens; Riesle, J.U.

2004-01-01

The supply of oxygen within three-dimensional tissue-engineered (TE) cartilage polymer constructs is mainly by diffusion. Oxygen consumption by cells results in gradients in the oxygen concentration. The aims of this study were, firstly, to identify the gradients within TE cartilage polymer

Oxygen gradients in tissue-engineered PEGT/PBT cartilaginous constructs: measurement and modeling

NARCIS (Netherlands)

Malda, J.; Rouwkema, J.; Martens, D.E.; Paul le Comte, E.; Kooy, F.K.; Tramper, J.; Blitterswijk, van C.A.; Riesle, J.

2004-01-01

The supply of oxygen within three-dimensional tissue-engineered (TE) cartilage polymer constructs is mainly by diffusion. Oxygen consumption by cells results in gradients in the oxygen concentration. The aims of this study were, firstly, to identify the gradients within TE: cartilage polymer

Chitosan-based scaffolds for the support of smooth muscle constructs in intestinal tissue engineering

Science.gov (United States)

Zakhem, Elie; Raghavan, Shreya; Gilmont, Robert R; Bitar, Khalil N

2012-01-01

Intestinal tissue engineering is an emerging field due to a growing demand for intestinal lengthening and replacement procedures secondary to massive resections of the bowel. Here, we demonstrate the potential use of a chitosan/collagen scaffold as a 3D matrix to support the bioengineered circular muscle constructs maintain their physiological functionality. We investigated the biocompatibility of chitosan by growing rabbit colonic circular smooth muscle cells (RCSMCs) on chitosan-coated plates. The cells maintained their spindle-like morphology and preserved their smooth muscle phenotypic markers. We manufactured tubular scaffolds with central openings composed of chitosan and collagen in a 1:1 ratio. Concentrically-aligned 3D circular muscle constructs were bioengineered using fibrin-based hydrogel seeded with RCSMCs. The constructs were placed around the scaffold for 2 weeks, after which they were taken off and tested for their physiological functionality. The muscle constructs contracted in response to Acetylcholine (Ach) and potassium chloride (KCl) and they relaxed in response to vasoactive intestinal peptide (VIP). These results demonstrate that chitosan is a biomaterial possibly suitable for intestinal tissue engineering applications. PMID:22483012

Barriers to the Uptake of Concurrent Engineering in the Nigerian Construction Industry

OpenAIRE

Aniekwu, Nathaniel Anny; Igboanugo, Anthony C.

2012-01-01

It is the consensus of scholars that the productivity of the construction industry is very low when compared with other industries. Concurrent Engineering (CE), which has a primary goal of reducing the total time from designing a product to releasing it into the market, while creating better designs as well, has been identified as one of the concepts that has yielded effective adaptation in the construction industry. An exploratory survey was used to identify 63 variables with the capacity to...

Design and Construction of Variable Direct Current Speed Drive ...

African Journals Online (AJOL)

controlled rectifiers from the viewpoint of simplicity and cost effectiveness to act as power converter and controller. Design and construction of constituent circuits such as acceleration/deceleration, speed and current amplifier and the trigger ...

Current Hitachi knowledge engineering systems: an overview

Energy Technology Data Exchange (ETDEWEB)

Masui, S; Maeda, A; Masuishi, T [Hitachi, Ltd., Tokyo (Japan)

1992-02-01

In order to bring the knowledge engineering technology up to the practical phase, Hitachi has provided several knowledge engineering system products, including expert system building tools, knowledge acquisition tools, and many kinds of stand-alone and build-in expert systems in both the business and process control fields. In this review article, an overview of Hitachi{prime}s recent knowledge systems is described, which includes a trend analysis on recent market recognition. In addition, to introduce the Hitachi{prime}s current activities, a new product, a user interface building tool, and a new method of tuning fuzzy membership functions using a neuro-computing algorithm are also described. Furthermore, it is pointed out that not only practical tools and methodologies, but also a practical development team, including a planning section, a cooperating expert, a user section, and experienced knowledge engineers, is needed to achieve practical expert systems. 20 refs., 10 figs., 1 tab.

An analysis of extended entity relationship constructs extraction in database reverse engineering approaches

International Nuclear Information System (INIS)

Jilani, M.A.; Aziz, A.; Hussain, T.

2008-01-01

Database reverse Engineering is technique used for transforming relational schema into a conceptual schema for finding and fixing design flaw for maintaining and re-engineering database systems for the integration of database system with another and migration of a database system from one platform to another. We studied the approaches from year 1993 to 2006 to find out which EER construct cannot be retrieved by most of the DBRE approaches so that they can be retrieved in the future. For each EER construct that can be retrieved by using a given DBRE approach. We show whether they are retrieved without user involvement (automatically). Partial user involvement (semi-automatically) or full user involvement (manually). We also discuss the relevant advantages and limitations of each DBRE technique considered in this paper. (author)

Public health engineering education in India: current scenario, opportunities and challenges.

Science.gov (United States)

Hussain, Mohammad Akhtar; Sharma, Kavya; Zodpey, Sanjay

2011-01-01

Public health engineering can play an important and significant role in solving environmental health issues. In order to confront public health challenges emerging out of environmental problems we need adequately trained public health engineers / environmental engineers. Considering the current burden of disease attributable to environmental factors and expansion in scope of applications of public health / environmental engineering science, it is essential to understand the present scenario of teaching, training and capacity building programs in these areas. Against this background the present research was carried out to know the current teaching and training programs in public health engineering and related disciplines in India and to understand the potential opportunities and challenges available. A systematic, predefined approach was used to collect and assemble the data related to various teaching and training programs in public health engineering / environmental engineering in India. Public health engineering / environmental engineering education and training in the country is mainly offered through engineering institutions, as pre-service and in-service training. Pre-service programs include diploma, degree (graduate) and post-graduate courses affiliated to various state technical boards, institutes and universities, whereas in-service training is mainly provided by Government of India recognized engineering and public health training institutes. Though trainees of these programs acquire skills related to engineering sciences, they significantly lack in public health skills. The teaching and training of public health engineering / environmental engineering is limited as a part of public health programs (MD Community Medicine, MPH, DPH) in India. There is need for developing teaching and training of public health engineering or environmental engineering as an interdisciplinary subject. Public health institutes can play an important and significant role in this

Engineered cartilaginous tubes for tracheal tissue replacement via self-assembly and fusion of human mesenchymal stem cell constructs.

Science.gov (United States)

Dikina, Anna D; Strobel, Hannah A; Lai, Bradley P; Rolle, Marsha W; Alsberg, Eben

2015-06-01

There is a critical need to engineer a neotrachea because currently there are no long-term treatments for tracheal stenoses affecting large portions of the airway. In this work, a modular tracheal tissue replacement strategy was developed. High-cell density, scaffold-free human mesenchymal stem cell-derived cartilaginous rings and tubes were successfully generated through employment of custom designed culture wells and a ring-to-tube assembly system. Furthermore, incorporation of transforming growth factor-β1-delivering gelatin microspheres into the engineered tissues enhanced chondrogenesis with regard to tissue size and matrix production and distribution in the ring- and tube-shaped constructs, as well as luminal rigidity of the tubes. Importantly, all engineered tissues had similar or improved biomechanical properties compared to rat tracheas, which suggests they could be transplanted into a small animal model for airway defects. The modular, bottom up approach used to grow stem cell-based cartilaginous tubes in this report is a promising platform to engineer complex organs (e.g., trachea), with control over tissue size and geometry, and has the potential to be used to generate autologous tissue implants for human clinical applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

Tissue-engineered cartilaginous constructs for the treatment of caprine cartilage defects, including distribution of laminin and type IV collagen.

Science.gov (United States)

Jeng, Lily; Hsu, Hu-Ping; Spector, Myron

2013-10-01

The purpose of this study was the immunohistochemical evaluation of (1) cartilage tissue-engineered constructs; and (2) the tissue filling cartilage defects in a goat model into which the constructs were implanted, particularly for the presence of the basement membrane molecules, laminin and type IV collagen. Basement membrane molecules are localized to the pericellular matrix in normal adult articular cartilage, but have not been examined in tissue-engineered constructs cultured in vitro or in tissue filling cartilage defects into which the constructs were implanted. Cartilaginous constructs were engineered in vitro using caprine chondrocyte-seeded type II collagen scaffolds. Autologous constructs were implanted into 4-mm-diameter defects created to the tidemark in the trochlear groove in the knee joints of skeletally mature goats. Eight weeks after implantation, the animals were sacrificed. Constructs underwent immunohistochemical and histomorphometric evaluation. Widespread staining for the two basement membrane molecules was observed throughout the extracellular matrix of in vitro and in vivo samples in a distribution unlike that previously reported for cartilage. At sacrifice, 70% of the defect site was filled with reparative tissue, which consisted largely of fibrous tissue and some fibrocartilage, with over 70% of the reparative tissue bonded to the adjacent host tissue. A novel finding of this study was the observation of laminin and type IV collagen in in vitro engineered cartilaginous constructs and in vivo cartilage repair samples from defects into which the constructs were implanted, as well as in normal caprine articular cartilage. Future work is needed to elucidate the role of basement membrane molecules during cartilage repair and regeneration.

Conformity Assessment as a Tool for Organizational Learning in Large Engineering and Construction Projects

Directory of Open Access Journals (Sweden)

Luciano Assalim

2013-05-01

Full Text Available For the successful realization of large engineering and construction projects (LECPs, a systemic organizational learning framework for institutional cooperation is critical. Due to the long project life-cycle of LECPs, this is particularly important for this kind of project. The objective of this paper is to analyze to what extent the conformity assessment of LECPs, carried out under Engineering, Procurement and Construction management (EPCm services, can be used as a tool for organizational learning and cooperation between typical stakeholders (project owners, engineering contractors, EPC contractors; subcontractors and certification bodies. The research, from which this paper emanates, was based on a case study concerning LECPs in an oil and gas company in Brazil. Based on its results, we suggest that the proposed organizational learning framework, supported by the conformity assessment rationale, constitutes an important management tool that can be disseminated in other organizational contexts where conformity assessments of LECPs take place.

A Novel Strategy to Engineer Pre-Vascularized Full-Length Dental Pulp-like Tissue Constructs.

Science.gov (United States)

Athirasala, Avathamsa; Lins, Fernanda; Tahayeri, Anthony; Hinds, Monica; Smith, Anthony J; Sedgley, Christine; Ferracane, Jack; Bertassoni, Luiz E

2017-06-12

The requirement for immediate vascularization of engineered dental pulp poses a major hurdle towards successful implementation of pulp regeneration as an effective therapeutic strategy for root canal therapy, especially in adult teeth. Here, we demonstrate a novel strategy to engineer pre-vascularized, cell-laden hydrogel pulp-like tissue constructs in full-length root canals for dental pulp regeneration. We utilized gelatin methacryloyl (GelMA) hydrogels with tunable physical and mechanical properties to determine the microenvironmental conditions (microstructure, degradation, swelling and elastic modulus) that enhanced viability, spreading and proliferation of encapsulated odontoblast-like cells (OD21), and the formation of endothelial monolayers by endothelial colony forming cells (ECFCs). GelMA hydrogels with higher polymer concentration (15% w/v) and stiffness enhanced OD21 cell viability, spreading and proliferation, as well as endothelial cell spreading and monolayer formation. We then fabricated pre-vascularized, full-length, dental pulp-like tissue constructs by dispensing OD21 cell-laden GelMA hydrogel prepolymer in root canals of extracted teeth and fabricating 500 µm channels throughout the root canals. ECFCs seeded into the microchannels successfully formed monolayers and underwent angiogenic sprouting within 7 days in culture. In summary, the proposed approach is a simple and effective strategy for engineering of pre-vascularized dental pulp constructs offering potentially beneficial translational outcomes.

A modular approach to creating large engineered cartilage surfaces.

Science.gov (United States)

Ford, Audrey C; Chui, Wan Fung; Zeng, Anne Y; Nandy, Aditya; Liebenberg, Ellen; Carraro, Carlo; Kazakia, Galateia; Alliston, Tamara; O'Connell, Grace D

2018-01-23

Native articular cartilage has limited capacity to repair itself from focal defects or osteoarthritis. Tissue engineering has provided a promising biological treatment strategy that is currently being evaluated in clinical trials. However, current approaches in translating these techniques to developing large engineered tissues remains a significant challenge. In this study, we present a method for developing large-scale engineered cartilage surfaces through modular fabrication. Modular Engineered Tissue Surfaces (METS) uses the well-known, but largely under-utilized self-adhesion properties of de novo tissue to create large scaffolds with nutrient channels. Compressive mechanical properties were evaluated throughout METS specimens, and the tensile mechanical strength of the bonds between attached constructs was evaluated over time. Raman spectroscopy, biochemical assays, and histology were performed to investigate matrix distribution. Results showed that by Day 14, stable connections had formed between the constructs in the METS samples. By Day 21, bonds were robust enough to form a rigid sheet and continued to increase in size and strength over time. Compressive mechanical properties and glycosaminoglycan (GAG) content of METS and individual constructs increased significantly over time. The METS technique builds on established tissue engineering accomplishments of developing constructs with GAG composition and compressive properties approaching native cartilage. This study demonstrated that modular fabrication is a viable technique for creating large-scale engineered cartilage, which can be broadly applied to many tissue engineering applications and construct geometries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dam construction as an engineering solution for water supply problem : environmental thrusts

Energy Technology Data Exchange (ETDEWEB)

Hosseini, A.H. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering

2004-09-01

Water supply management and the potential impacts associated with engineering practices in water supply systems were examined. Global aspects of increasing water demand were presented and compared with populations, urbanization and water demand. Engineering practices in waterworks developments such as dam construction, river intakes, infiltration galleries, wells, boreholes and adits were also discussed. Construction of large dams and the problems associated with damming the rivers were studied as large dams generally have substantial impacts on rivers, watersheds and aquatic ecosystems, leading to the irreversible loss of species populations and ecosystems. These problems include negative impacts on the terrestrial ecosystem, greenhouse gas emissions from reservoirs due to decaying vegetation and carbon inflows from the catchment, changes in flow regimes, trapping of sediments and nutrients behind a dam, blocking migration of aquatic organisms, as well as negative impacts on flood plain ecosystems and fisheries. In addition, a case study, on the environmental impacts associated with damming in Three Gorges Valley in China was presented. 9 refs., 8 figs.

Combined protein construct and synthetic gene engineering for heterologous protein expression and crystallization using Gene Composer

Directory of Open Access Journals (Sweden)

Walchli John

2009-04-01

Full Text Available Abstract Background With the goal of improving yield and success rates of heterologous protein production for structural studies we have developed the database and algorithm software package Gene Composer. This freely available electronic tool facilitates the information-rich design of protein constructs and their engineered synthetic gene sequences, as detailed in the accompanying manuscript. Results In this report, we compare heterologous protein expression levels from native sequences to that of codon engineered synthetic gene constructs designed by Gene Composer. A test set of proteins including a human kinase (P38α, viral polymerase (HCV NS5B, and bacterial structural protein (FtsZ were expressed in both E. coli and a cell-free wheat germ translation system. We also compare the protein expression levels in E. coli for a set of 11 different proteins with greatly varied G:C content and codon bias. Conclusion The results consistently demonstrate that protein yields from codon engineered Gene Composer designs are as good as or better than those achieved from the synonymous native genes. Moreover, structure guided N- and C-terminal deletion constructs designed with the aid of Gene Composer can lead to greater success in gene to structure work as exemplified by the X-ray crystallographic structure determination of FtsZ from Bacillus subtilis. These results validate the Gene Composer algorithms, and suggest that using a combination of synthetic gene and protein construct engineering tools can improve the economics of gene to structure research.

The method of using current regulations and standards in designing management and technologies of construction

Directory of Open Access Journals (Sweden)

Sinenko Sergey

2017-01-01

Full Text Available Economic efficiency of using funds in construction of buildings and structures begins from an effective, proper design, which is based on modern, cutting-edge, advanced equipment, streamlined organization and process solutions of construction operations. In the light of this it is considered application of “Self-Organization and Technology of Building” multifunctional software package capable of solving various engineering tasks on designing management of construction operations in accordance with the applicable rules and regulations in view of using software for automatic generation of workflow. Implementing this software in the construction management processes may help to solve management tasks at the construction site.

Engineering Parameters in Bioreactor's Design: A Critical Aspect in Tissue Engineering

Science.gov (United States)

Amoabediny, Ghassem; Pouran, Behdad; Tabesh, Hadi; Shokrgozar, Mohammad Ali; Haghighipour, Nooshin; Khatibi, Nahid; Mottaghy, Khosrow; Zandieh-Doulabi, Behrouz

2013-01-01

Bioreactors are important inevitable part of any tissue engineering (TE) strategy as they aid the construction of three-dimensional functional tissues. Since the ultimate aim of a bioreactor is to create a biological product, the engineering parameters, for example, internal and external mass transfer, fluid velocity, shear stress, electrical current distribution, and so forth, are worth to be thoroughly investigated. The effects of such engineering parameters on biological cultures have been addressed in only a few preceding studies. Furthermore, it would be highly inefficient to determine the optimal engineering parameters by trial and error method. A solution is provided by emerging modeling and computational tools and by analyzing oxygen, carbon dioxide, and nutrient and metabolism waste material transports, which can simulate and predict the experimental results. Discovering the optimal engineering parameters is crucial not only to reduce the cost and time of experiments, but also to enhance efficacy and functionality of the tissue construct. This review intends to provide an inclusive package of the engineering parameters together with their calculation procedure in addition to the modeling techniques in TE bioreactors. PMID:24000327

Engineering parameters in bioreactor's design: a critical aspect in tissue engineering.

Science.gov (United States)

Salehi-Nik, Nasim; Amoabediny, Ghassem; Pouran, Behdad; Tabesh, Hadi; Shokrgozar, Mohammad Ali; Haghighipour, Nooshin; Khatibi, Nahid; Anisi, Fatemeh; Mottaghy, Khosrow; Zandieh-Doulabi, Behrouz

2013-01-01

Bioreactors are important inevitable part of any tissue engineering (TE) strategy as they aid the construction of three-dimensional functional tissues. Since the ultimate aim of a bioreactor is to create a biological product, the engineering parameters, for example, internal and external mass transfer, fluid velocity, shear stress, electrical current distribution, and so forth, are worth to be thoroughly investigated. The effects of such engineering parameters on biological cultures have been addressed in only a few preceding studies. Furthermore, it would be highly inefficient to determine the optimal engineering parameters by trial and error method. A solution is provided by emerging modeling and computational tools and by analyzing oxygen, carbon dioxide, and nutrient and metabolism waste material transports, which can simulate and predict the experimental results. Discovering the optimal engineering parameters is crucial not only to reduce the cost and time of experiments, but also to enhance efficacy and functionality of the tissue construct. This review intends to provide an inclusive package of the engineering parameters together with their calculation procedure in addition to the modeling techniques in TE bioreactors.

Constructing engineers through practice: Gendered features of learning and identity development

Science.gov (United States)

Tonso, Karen L.

How do women and men student engineers develop an engineering identity (a sense of belonging, or not), while practicing "actual" engineering? What are the influences of gender, learning and knowledge, relations of power, and conceptions of equality on cultural identity development? I studied these issues in reform-minded engineering design classes, courses organized around teaching students communications, teamwork, and practical engineering. Engineering-student cultural identity categories revealed a status hierarchy, predicated on meeting "academic" criteria for excellence, and the almost total exclusion of women. While working as an engineering colleague on five student teams (three first-year and two senior) and attending their design classes, I documented how cultural identities were made evident and constructed in students' practical engineering. Design projects promoted linking academic knowledge with real-world situations, sharing responsibilities and trusting colleagues, communicating engineering knowledge to technical and non-technical members of business communities, and addressing gaps in students' knowledge. With a curriculum analysis and survey of students' perceptions of the differences between design and conventional courses, I embedded the design classes in the wider campus and found that: (1) Engineering education conferred prestige, power, and well-paying jobs on students who performed "academic" engineering, while failing to adequately encourage "actual" engineering practices. High-status student engineers were the least likely to perform "actual" engineering in design teams. (2) Engineering education advanced an ideology that encouraged its practitioners to consider men's privilege and women's invisibility normal. By making "acting like men act" the standards to which engineering students must conform, women learned to put up with oppressive treatment. Women's accepting their own mistreatment and hiding their womanhood became a condition of

Chemical Reaction Engineering: Current Status and Future Directions.

Science.gov (United States)

Dudukovic, M. P.

1987-01-01

Describes Chemical Reaction Engineering (CRE) as the discipline that quantifies the interplay of transport phenomena and kinetics in relating reactor performance to operating conditions and input variables. Addresses the current status of CRE in both academic and industrial settings and outlines future trends. (TW)

Current situation and countermeasures of port logistics park information construction

Directory of Open Access Journals (Sweden)

Zhen Liu

2013-03-01

Full Text Available Purpose: Improve work efficiency of logistics park department, and drive the economy of the park and its surrounding areas. Design/methodology/approach: Analyze the information development situation and existent questions of current national logistics park, and design proper scheme to meet the demand of port logistics park. Findings: Proposed an information construction implementation plan using technology of the Internet of things which can be applied to port logistics park. Designed a scheme for the park information construction and explained the system's implementation strategy and implementation steps. Practical implications: The proposed construction program is particularly suitable for the northwest port logistics parks in China, and also has reference function to other logistics park construction. Originality/value: Group the information construction of the logistics park into four levels, three types of users, and two requirements. The scheme is innovative and comprehensive, which can ensure the development of port logistics park.

Evolutionary, Unconscious Design Support for the Architectural, Engineering and Construction Industry

OpenAIRE

Van de Ruitenbeek, H.K.M.

2012-01-01

The Architecture, Engineering and Construction (AEC) industry is a complex system in which carpenters, structural designers, architects, modellers, cost estimators, planners, politicians and many others act apart together in project-specific virtual enterprises. There is a large amount of actors, an overwhelming number of ongoing processes, distributed, decentralised organisations and a variety of projects. This complicates efficient communication and supply chain integration which, according...

Engineering Parameters in Bioreactor’s Design: A Critical Aspect in Tissue Engineering

Directory of Open Access Journals (Sweden)

Nasim Salehi-Nik

2013-01-01

Full Text Available Bioreactors are important inevitable part of any tissue engineering (TE strategy as they aid the construction of three-dimensional functional tissues. Since the ultimate aim of a bioreactor is to create a biological product, the engineering parameters, for example, internal and external mass transfer, fluid velocity, shear stress, electrical current distribution, and so forth, are worth to be thoroughly investigated. The effects of such engineering parameters on biological cultures have been addressed in only a few preceding studies. Furthermore, it would be highly inefficient to determine the optimal engineering parameters by trial and error method. A solution is provided by emerging modeling and computational tools and by analyzing oxygen, carbon dioxide, and nutrient and metabolism waste material transports, which can simulate and predict the experimental results. Discovering the optimal engineering parameters is crucial not only to reduce the cost and time of experiments, but also to enhance efficacy and functionality of the tissue construct. This review intends to provide an inclusive package of the engineering parameters together with their calculation procedure in addition to the modeling techniques in TE bioreactors.

Production of anthocyanins in metabolically engineered microorganisms: Current status and perspectives

Directory of Open Access Journals (Sweden)

Jian Zha

2017-12-01

Full Text Available Microbial production of plant-derived natural products by engineered microorganisms has achieved great success thanks to large extend to metabolic engineering and synthetic biology. Anthocyanins, the water-soluble colored pigments found in terrestrial plants that are responsible for the red, blue and purple coloration of many flowers and fruits, are extensively used in food and cosmetics industry; however, their current supply heavily relies on complex extraction from plant-based materials. A promising alternative is their sustainable production in metabolically engineered microbes. Here, we review the recent progress on anthocyanin biosynthesis in engineered bacteria, with a special focus on the systematic engineering modifications such as selection and engineering of biosynthetic enzymes, engineering of transportation, regulation of UDP-glucose supply, as well as process optimization. These promising engineering strategies will facilitate successful microbial production of anthocyanins in industry in the near future.

Final Report on the Audit of Architect-Engineer Contracting at the Officer in Charge of Construction, Naval Facilities Engineering Command Contracts, Mediterranean, Madrid, Spain

Science.gov (United States)

1990-11-30

This is our final report on the audit of Architect-Engineer Contracting for the Officer in Charge of Construction, Naval Facilities Engineering...Command Contracts, Mediterranean, for your information and use. This is the fourth in a series of reports issued as part of the audit of architect-engineer...A-E) contracting. The Contract Management Directorate made the audit from August 1989 through July 1990. When we expanded the audit scope to include

An antibody based approach for multi-coloring osteogenic and chondrogenic proteins in tissue engineered constructs.

Science.gov (United States)

Leferink, Anne M; Reis, Diogo Santos; van Blitterswijk, Clemens A; Moroni, Lorenzo

2018-04-11

When tissue engineering strategies rely on the combination of three-dimensional (3D) polymeric or ceramic scaffolds with cells to culture implantable tissue constructs in vitro, it is desirable to monitor tissue growth and cell fate to be able to more rationally predict the quality and success of the construct upon implantation. Such a 3D construct is often referred to as a 'black-box' since the properties of the scaffolds material limit the applicability of most imaging modalities to assess important construct parameters. These parameters include the number of cells, the amount and type of tissue formed and the distribution of cells and tissue throughout the construct. Immunolabeling enables the spatial and temporal identification of multiple tissue types within one scaffold without the need to sacrifice the construct. In this report, we concisely review the applicability of antibodies (Abs) and their conjugation chemistries in tissue engineered constructs. With some preliminary experiments, we show an efficient conjugation strategy to couple extracellular matrix Abs to fluorophores. The conjugated probes proved to be effective in determining the presence of collagen type I and type II on electrospun and additive manufactured 3D scaffolds seeded with adult human bone marrow derived mesenchymal stromal cells. The conjugation chemistry applied in our proof of concept study is expected to be applicable in the coupling of any other fluorophore or particle to the Abs. This could ultimately lead to a library of probes to permit high-contrast imaging by several imaging modalities.

Growth Factor Stimulation Improves the Structure and Properties of Scaffold-Free Engineered Auricular Cartilage Constructs

Science.gov (United States)

Rosa, Renata G.; Joazeiro, Paulo P.; Bianco, Juares; Kunz, Manuela; Weber, Joanna F.; Waldman, Stephen D.

2014-01-01

The reconstruction of the external ear to correct congenital deformities or repair following trauma remains a significant challenge in reconstructive surgery. Previously, we have developed a novel approach to create scaffold-free, tissue engineering elastic cartilage constructs directly from a small population of donor cells. Although the developed constructs appeared to adopt the structural appearance of native auricular cartilage, the constructs displayed limited expression and poor localization of elastin. In the present study, the effect of growth factor supplementation (insulin, IGF-1, or TGF-β1) was investigated to stimulate elastogenesis as well as to improve overall tissue formation. Using rabbit auricular chondrocytes, bioreactor-cultivated constructs supplemented with either insulin or IGF-1 displayed increased deposition of cartilaginous ECM, improved mechanical properties, and thicknesses comparable to native auricular cartilage after 4 weeks of growth. Similarly, growth factor supplementation resulted in increased expression and improved localization of elastin, primarily restricted within the cartilaginous region of the tissue construct. Additional studies were conducted to determine whether scaffold-free engineered auricular cartilage constructs could be developed in the 3D shape of the external ear. Isolated auricular chondrocytes were grown in rapid-prototyped tissue culture molds with additional insulin or IGF-1 supplementation during bioreactor cultivation. Using this approach, the developed tissue constructs were flexible and had a 3D shape in very good agreement to the culture mold (average error tissue structure and 3D shape of the external ear, future studies will be aimed assessing potential changes in construct shape and properties after subcutaneous implantation. PMID:25126941

Textile Technologies and Tissue Engineering: A Path Towards Organ Weaving

Science.gov (United States)

Akbari, Mohsen; Tamayol, Ali; Bagherifard, Sara; Serex, Ludovic; Mostafalu, Pooria; Faramarzi, Negar; Mohammadi, Mohammad Hossein

2016-01-01

Textile technologies have recently attracted great attention as potential biofabrication tools for engineering tissue constructs. Using current textile technologies, fibrous structures can be designed and engineered to attain the required properties that are demanded by different tissue engineering applications. Several key parameters such as physiochemical characteristics of fibers, pore size and mechanical properties of the fabrics play important role in the effective use of textile technologies in tissue engineering. This review summarizes the current advances in the manufacturing of biofunctional fibers. Different textile methods such as knitting, weaving, and braiding are discussed and their current applications in tissue engineering are highlighted. PMID:26924450

Bone tissue engineering with human mesenchymal stem cell sheets constructed using magnetite nanoparticles and magnetic force.

Science.gov (United States)

Shimizu, Kazunori; Ito, Akira; Yoshida, Tatsuro; Yamada, Yoichi; Ueda, Minoru; Honda, Hiroyuki

2007-08-01

An in vitro reconstruction of three-dimensional (3D) tissues without the use of scaffolds may be an alternative strategy for tissue engineering. We have developed a novel tissue engineering strategy, termed magnetic force-based tissue engineering (Mag-TE), in which magnetite cationic liposomes (MCLs) with a positive charge at the liposomal surface, and magnetic force were used to construct 3D tissue without scaffolds. In this study, human mesenchymal stem cells (MSCs) magnetically labeled with MCLs were seeded onto an ultra-low attachment culture surface, and a magnet (4000 G) was placed on the reverse side. The MSCs formed multilayered sheet-like structures after a 24-h culture period. MSCs in the sheets constructed by Mag-TE maintained an in vitro ability to differentiate into osteoblasts, adipocytes, or chondrocytes after a 21-day culture period using each induction medium. Using an electromagnet, MSC sheets constructed by Mag-TE were harvested and transplanted into the bone defect in the crania of nude rats. Histological observation revealed that new bone surrounded by osteoblast-like cells was formed in the defect area 14 days after transplantation with MSC sheets, whereas no bone formation was observed in control rats without the transplant. These results indicated that Mag-TE could be used for the transplantation of MSC sheets using magnetite nanoparticles and magnetic force, providing novel methodology for bone tissue engineering.

Three-Dimensional Engineered Bone–Ligament–Bone Constructs for Anterior Cruciate Ligament Replacement

Science.gov (United States)

Ma, Jinjin; Smietana, Michael J.; Kostrominova, Tatiana Y.; Wojtys, Edward M.; Larkin, Lisa M.

2012-01-01

The anterior cruciate ligament (ACL), a major stabilizer of the knee, is commonly injured. Because of its intrinsic poor healing ability, a torn ACL is usually reconstructed by a graft. We developed a multi-phasic, or bone–ligament–bone, tissue-engineered construct for ACL grafts using bone marrow stromal cells and sheep as a model system. After 6 months in vivo, the constructs increased in cross section and exhibited a well-organized microstructure, native bone integration, a functional enthesis, vascularization, innervation, increased collagen content, and structural alignment. The constructs increased in stiffness to 52% of the tangent modulus and 95% of the geometric stiffness of native ACL. The viscoelastic response of the explants was virtually indistinguishable from that of adult ACL. These results suggest that our constructs after implantation can obtain physiologically relevant structural and functional characteristics comparable to those of adult ACL. They present a viable option for ACL replacement. PMID:21902608

Current challenges for education of nuclear engineers. Beyond nuclear basics

Energy Technology Data Exchange (ETDEWEB)

Schoenfelder, Christian [AREVA GmbH, Offenbach (Germany). Training Center

2014-07-15

In past decades, curricula for the education of nuclear engineers (either as a major or minor subject) have been well established all over the world. However, from the point of view of a nuclear supplier, recent experiences in large and complex new build as well as modernization projects have shown that important competences required in these projects were not addressed during the education of young graduates. Consequently, in the past nuclear industry has been obliged to either accept long periods for job familiarization, or to develop and implement various dedicated internal training measures. Although the topics normally addressed in nuclear engineering education (like neutron and reactor physics, nuclear materials or thermohydraulics and the associated calculation methods) build up important competences, this paper shows that the current status of nuclear applications requires adaptations of educational curricula. As a conclusion, when academic nuclear engineering curricula start taking into account current competence needs in nuclear industry, it will be for the benefit of the current and future generation of nuclear engineers. They will be better prepared for their future job positions and career perspectives, especially on an international level. The recommendations presented should not only be of importance for the nuclear fission field, but also for the fusion community. Here, the Horizon 2020 Roadmap to Fusion as published in 2012 now is focusing on ITER and on a longer-term development of fusion technology for a future demonstration reactor DEMO. The very challenging work program is leading to a strong need for exactly those skills that are described in this article.

Current challenges for education of nuclear engineers. Beyond nuclear basics

International Nuclear Information System (INIS)

Schoenfelder, Christian

2014-01-01

In past decades, curricula for the education of nuclear engineers (either as a major or minor subject) have been well established all over the world. However, from the point of view of a nuclear supplier, recent experiences in large and complex new build as well as modernization projects have shown that important competences required in these projects were not addressed during the education of young graduates. Consequently, in the past nuclear industry has been obliged to either accept long periods for job familiarization, or to develop and implement various dedicated internal training measures. Although the topics normally addressed in nuclear engineering education (like neutron and reactor physics, nuclear materials or thermohydraulics and the associated calculation methods) build up important competences, this paper shows that the current status of nuclear applications requires adaptations of educational curricula. As a conclusion, when academic nuclear engineering curricula start taking into account current competence needs in nuclear industry, it will be for the benefit of the current and future generation of nuclear engineers. They will be better prepared for their future job positions and career perspectives, especially on an international level. The recommendations presented should not only be of importance for the nuclear fission field, but also for the fusion community. Here, the Horizon 2020 Roadmap to Fusion as published in 2012 now is focusing on ITER and on a longer-term development of fusion technology for a future demonstration reactor DEMO. The very challenging work program is leading to a strong need for exactly those skills that are described in this article.

The potential of 3-dimensional construct engineered from poly(lactic-co-glycolic acid)/fibrin hybrid scaffold seeded with bone marrow mesenchymal stem cells for in vitro cartilage tissue engineering.

Science.gov (United States)

Abdul Rahman, Rozlin; Mohamad Sukri, Norhamiza; Md Nazir, Noorhidayah; Ahmad Radzi, Muhammad Aa'zamuddin; Zulkifly, Ahmad Hafiz; Che Ahmad, Aminudin; Hashi, Abdurezak Abdulahi; Abdul Rahman, Suzanah; Sha'ban, Munirah

2015-08-01

Articular cartilage is well known for its simple uniqueness of avascular and aneural structure that has limited capacity to heal itself when injured. The use of three dimensional construct in tissue engineering holds great potential in regenerating cartilage defects. This study evaluated the in vitro cartilaginous tissue formation using rabbit's bone marrow mesenchymal stem cells (BMSCs)-seeded onto poly(lactic-co-glycolic acid) PLGA/fibrin and PLGA scaffolds. The in vitro cartilaginous engineered constructs were evaluated by gross inspection, histology, cell proliferation, gene expression and sulphated glycosaminoglycan (sGAG) production at week 1, 2 and 3. After 3 weeks of culture, the PLGA/fibrin construct demonstrated gross features similar to the native tissue with smooth, firm and glistening appearance, superior histoarchitectural and better cartilaginous extracellular matrix compound in concert with the positive glycosaminoglycan accumulation on Alcian blue. Significantly higher cell proliferation in PLGA/fibrin construct was noted at day-7, day-14 and day-21 (ptissue engineered cartilage. Copyright © 2015 Elsevier Ltd. All rights reserved.

Tough and flexible CNT-polymeric hybrid scaffolds for engineering cardiac constructs.

Science.gov (United States)

Kharaziha, Mahshid; Shin, Su Ryon; Nikkhah, Mehdi; Topkaya, Seda Nur; Masoumi, Nafiseh; Annabi, Nasim; Dokmeci, Mehmet R; Khademhosseini, Ali

2014-08-01

In the past few years, a considerable amount of effort has been devoted toward the development of biomimetic scaffolds for cardiac tissue engineering. However, most of the previous scaffolds have been electrically insulating or lacked the structural and mechanical robustness to engineer cardiac tissue constructs with suitable electrophysiological functions. Here, we developed tough and flexible hybrid scaffolds with enhanced electrical properties composed of carbon nanotubes (CNTs) embedded aligned poly(glycerol sebacate):gelatin (PG) electrospun nanofibers. Incorporation of varying concentrations of CNTs from 0 to 1.5% within the PG nanofibrous scaffolds (CNT-PG scaffolds) notably enhanced fiber alignment and improved the electrical conductivity and toughness of the scaffolds while maintaining the viability, retention, alignment, and contractile activities of cardiomyocytes (CMs) seeded on the scaffolds. The resulting CNT-PG scaffolds resulted in stronger spontaneous and synchronous beating behavior (3.5-fold lower excitation threshold and 2.8-fold higher maximum capture rate) compared to those cultured on PG scaffold. Overall, our findings demonstrated that aligned CNT-PG scaffold exhibited superior mechanical properties with enhanced CM beating properties. It is envisioned that the proposed hybrid scaffolds can be useful for generating cardiac tissue constructs with improved organization and maturation. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Construction of a capsular tissue-engineered ureteral stent seeded with autologous urothelial cells].

Science.gov (United States)

Tan, Haisong; Fu, Weijun; Li, Jianqiang; Wang, Zhongxin; Li, Gang; Ma, Xin; Dong, Jun; Gao, Jiangping; Wang, Xiaoxiong; Zhang, Xu

2013-01-01

To investigate the feasibility of constructing a capsular poly L-lactic acid (PLLA) ureteral stent seeded with autologous urothelial cells using tissue engineering methods. The capsular ureteral stent was constructed by subcutaneously embedding PLLA ureteral stent in the back of beagles for 3 weeks to induce the formation of connective tissue on the surfaces. After decellularization of the stent, the expanded autologous urothelial cells were seeded on the stent. The surface structure and cell adhesion of the stent were observed using HE staining, scanning electron microscope (SEM) and immunocytochemical staining. MTT assay was used to evaluate urothelial cell proliferation on the capsular PLLA ureteral stent and on circumferential small intestinal submucosa graft. HE staining and VIII factor immunohistochemistry revealed numerous capillaries in the connective tissue encapsulating the stent without obvious local inflammatory response. The results of SEM and immunocytochemical staining showed that the capsule contained rich collagenic fibers forming three-dimensional structures, and the seeded autologous urothelial cells could adhere and well aligned on the surface. MTT assay showed normal growth of the cells on the stent as compared with the cells grown on circumferential small intestinal submucosa graft. The capsular PLLA ureteral stent allows adhesion and proliferation of autologous urothelial cells and shows a potential in applications of constructing tissue-engineered ureter.

ABB.-Combustion Engineering's Experience in Nuclear Power Plant Engineering and Construction in Korea

International Nuclear Information System (INIS)

Veris, James W.

1992-01-01

The Yonggwang Nuclear Project is a milestone project for the Korean Nuclear Industry. The Project has the two objectives of obtaining self-reliance in all aspects of nuclear technology and of constructing two modern nuclear power plants under the leadership of Korean companies acting as prime contractors. ABB.-Combustion Engineering 1000 MW System 80+ TM was chosen in 1987 as the NSLS design to meet these two objectives. This paper summarizers the significant experiences and lessons learned through the first four years of the Project as well as identifying implications for such future projects. The unique challenges of the project are identified and an evaluation of the experiences in the technology, self-reliance program and in the design and manufacturing processes will be made

Tissue Engineering: Current Strategies and Future Directions

OpenAIRE

Olson, Jennifer L.; Atala, Anthony; Yoo, James J.

2011-01-01

Novel therapies resulting from regenerative medicine and tissue engineering technology may offer new hope for patients with injuries, end-stage organ failure, or other clinical issues. Currently, patients with diseased and injured organs are often treated with transplanted organs. However, there is a shortage of donor organs that is worsening yearly as the population ages and as the number of new cases of organ failure increases. Scientists in the field of regenerative medicine and tissue eng...

Regenerative endodontics as a tissue engineering approach: past, current and future.

Science.gov (United States)

Malhotra, Neeraj; Mala, Kundabala

2012-12-01

With the reported startling statistics of high incidence of tooth decay and tooth loss, the current interest is focused on the development of alternate dental tissue replacement therapies. This has led to the application of dental tissue engineering as a clinically relevant method for the regeneration of dental tissues and generation of bioengineered whole tooth. Although, tissue engineering approach requires the three main key elements of stem cells, scaffold and morphogens, a conductive environment (fourth element) is equally important for successful engineering of any tissue and/or organ. The applications of this science has evolved continuously in dentistry, beginning from the application of Ca(OH)(2) in vital pulp therapy to the development of a fully functional bioengineered tooth (mice). Thus, with advances in basic research, recent reports and studies have shown successful application of tissue engineering in the field of dentistry. However, certain practical obstacles are yet to be overcome before dental tissue regeneration can be applied as evidence-based approach in clinics. The article highlights on the past achievements, current developments and future prospects of tissue engineering and regenerative therapy in the field of endodontics and bioengineered teeth (bioteeth). © 2012 The Authors. Australian Endodontic Journal © 2012 Australian Society of Endodontology.

Textile Technologies and Tissue Engineering: A Path Toward Organ Weaving.

Science.gov (United States)

Akbari, Mohsen; Tamayol, Ali; Bagherifard, Sara; Serex, Ludovic; Mostafalu, Pooria; Faramarzi, Negar; Mohammadi, Mohammad Hossein; Khademhosseini, Ali

2016-04-06

Textile technologies have recently attracted great attention as potential biofabrication tools for engineering tissue constructs. Using current textile technologies, fibrous structures can be designed and engineered to attain the required properties that are demanded by different tissue engineering applications. Several key parameters such as physiochemical characteristics of fibers, microarchitecture, and mechanical properties of the fabrics play important roles in the effective use of textile technologies in tissue engineering. This review summarizes the current advances in the manufacturing of biofunctional fibers. Different textile methods such as knitting, weaving, and braiding are discussed and their current applications in tissue engineering are highlighted. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pattern of Bone Generation after Irradiation in Vascularized Tissue Engineered Constructs.

Science.gov (United States)

Eweida, Ahmad; Fathi, Ibrahim; Eltawila, Ahmed M; Elsherif, Ahmad M; Elkerm, Yasser; Harhaus, Leila; Kneser, Ulrich; Sakr, Mahmoud F

2018-02-01

 Regenerative medicine modalities provide promising alternatives to conventional reconstruction techniques but are still deficient after malignant tumor excision or irradiation due to defective vascularization.  We investigated the pattern of bone formation in axially vascularized tissue engineering constructs (AVTECs) after irradiation in a study that mimics the clinical scenario after head and neck cancer. Heterotopic bone generation was induced in a subcutaneously implanted AVTEC in the thigh of six male New Zealand rabbits. The tissue construct was made up of Nanobone (Artoss GmbH; Rostock, Germany) granules mixed with autogenous bone marrow and 80 μL of bone morphogenic protein-2 at a concentration of 1.5 μg/μL. An arteriovenous loop was created microsurgically between the saphenous vessels and implanted in the core of the construct to induce axial vascularization. The constructs were subjected to external beam irradiation on postoperative day 20 with a single dose of 15 Gy. The constructs were removed 20 days after irradiation and subjected to histological and immunohistochemical analysis for vascularization, bone formation, apoptosis, and cellular proliferation.  The vascularized constructs showed homogenous vascularization and bone formation both in their central and peripheral regions. Although vascularity, proliferation, and apoptosis were similar between central and peripheral regions of the constructs, significantly more bone was formed in the central regions of the constructs.  The study shows for the first time the pattern of bone formation in AVTECs after irradiation using doses comparable to those applied after head and neck cancer. Axial vascularization probably enhances the osteoinductive properties in the central regions of AVTECs after irradiation. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

E-COCOMO: The Extended COst Constructive MOdel for Cleanroom Software Engineering

Directory of Open Access Journals (Sweden)

Hitesh KUMAR SHARMA

2014-02-01

Full Text Available Mistakes create rework. Rework takes time and increases costs. The traditional software engineering methodology defines the ratio of Design:Code:Test as 40:20:40. As we can easily see that 40% time and efforts are used in testing phase in traditional approach, that means we have to perform rework again if we found some bugs in testing phase. This rework is being performed after Design and code phase. This rework will increase the cost exponentially. The cleanroom software engineering methodology controls the exponential growth in cost by removing this rework. It says that "do the work correct in first attempt and move to next phase after getting the proof of correctness". This new approach minimized the rework and reduces the cost in the exponential ratio. Due to the removal of testing phase, the COCOMO (COst COnstructive MOdel used for the traditional engineering is not directly applicable in cleanroom software engineering. The traditional cost drivers used for traditional COCOMO needs to be revised. We have proposed the Extended version of COCOMO (i.e. E-COCOMO in which we have incorporated some new cost drivers. This paper explains the proposed E-COCOMO and the detailed description of proposed new cost driver.

Plant cell engineering: current research, application and future prospects

International Nuclear Information System (INIS)

Wang Xunqing; Liu Luxiang

2008-01-01

This paper reviewed the current status of basic research in plant cell engineering, highlighted the application of embryo culture, double haploid (DH) technology, protoplast culture and somatic hybridization, somaclonal variation, rapid propagation, and bio-products production of plant-origin, and t he prospects. (authors)

Causes of delays on Construction Projects in Kuwait according to opinion of engineers working in Kuwait

OpenAIRE

Naser S. Almutairi

2016-01-01

This paper presents an investigation into analysis of the causes of delays on Construction Projects in Kuwait according to opinion of engineers working in Kuwait. This is achieved through identification of the major causes of delays in the construction industry as reported in literature and using a questionnaire survey to collect the views of the various key players in the Kuwaiti construction industry. The data is analyzed and the views of the groups surveyed discussed and the relative impor...

Safety risk assessment for vertical concrete formwork activities in civil engineering construction.

Science.gov (United States)

López-Arquillos, Antonio; Rubio-Romero, Juan Carlos; Gibb, Alistair G F; Gambatese, John A

2014-01-01

The construction sector has one of the worst occupational health and safety records in Europe. Of all construction tasks, formwork activities are associated with a high frequency of accidents and injuries. This paper presents an investigation of the activities and related safety risks present in vertical formwork for in-situ concrete construction in the civil engineering sector. Using the methodology of staticized groups, twelve activities and ten safety risks were identified and validated by experts. Every safety risk identified in this manner was quantified for each activity using binary methodology according to the frequency and severity scales developed in prior research. A panel of experts was selected according to the relevant literature on staticized groups. The results obtained show that the activities with the highest risk in vertical formwork tasks are: Plumbing and leveling of forms, cutting of material, handling materials with cranes, and climbing or descending ladders. The most dangerous health and safety risks detected were falls from height, cutting and overexertion. The research findings provide construction practitioners with further evidence of the hazardous activities associated with concrete formwork construction and a starting point for targeting worker health and safety programmes.

The Development of Precise Engineering Surveying Technology

Directory of Open Access Journals (Sweden)

LI Guangyun

2017-10-01

Full Text Available With the construction of big science projects in China, the precise engineering surveying technology developed rapidly in the 21th century. Firstly, the paper summarized up the current development situation for the precise engineering surveying instrument and theory. Then the three typical cases of the precise engineering surveying practice such as accelerator alignment, industry measurement and high-speed railway surveying technology are focused.

Engineered barriers: current status 1989

International Nuclear Information System (INIS)

Atkinson, A.; Marsh, G.B.

1989-06-01

This report summarises the current state of research relevant to assessing the performance of engineered barriers made of steel and concrete in radioactive waste repositories. The objective of these barriers is to contain substantially the radionuclides within them by providing both physical and chemical impediment to their release. The physical barriers are of most value for highly soluble isotopes with relatively short half-lives (eg 137 Cs), since they can provide a measure of containment until a large fraction of the activity has decayed. In addition they can facilitate retrievability for some period after disposal. The chemical barriers operate by beneficial conditioning of the near field groundwater and providing sites for sorption of radionuclides. Both of these reduce the aqueous concentration of radionuclides in the near field. (author)

Tool for Benchmarking BIM Performance of Design Engineering and Construction Firms in The Netherlands

NARCIS (Netherlands)

Sebastian, R.; Berlo, L. van

2010-01-01

Building information modelling (BIM) is becoming more and more important to manage complex communication and information sharing processes in collaborative building projects. A growing number of design, engineering and construction firms have made attempts to adopt BIM to enhance their services and

Providing solutions to engineering problems

International Nuclear Information System (INIS)

Connop, R.P.P.

1991-01-01

BNFL has acquired unique experience over a period of 40 years in specifying, designing and constructing spent fuel reprocessing and associated waste management plant. This experience is currently used to support a pound 5.5 billion capital investment programme. This paper reviews a number of engineering problems and their solutions to highlight BNFL experience in providing comprehensive specification, design and engineering and project management services. (author)

Engineering drag currents in Coulomb coupled quantum dots

Science.gov (United States)

Lim, Jong Soo; Sánchez, David; López, Rosa

2018-02-01

The Coulomb drag phenomenon in a Coulomb-coupled double quantum dot system is revisited with a simple model that highlights the importance of simultaneous tunneling of electrons. Previously, cotunneling effects on the drag current in mesoscopic setups have been reported both theoretically and experimentally. However, in both cases the sequential tunneling contribution to the drag current was always present unless the drag level position were too far away from resonance. Here, we consider the case of very large Coulomb interaction between the dots, whereby the drag current needs to be assisted by cotunneling events. As a consequence, a quantum coherent drag effect takes place. Further, we demonstrate that by properly engineering the tunneling probabilities using band tailoring it is possible to control the sign of the drag and drive currents, allowing them to flow in parallel or antiparallel directions. We also show that the drag current can be manipulated by varying the drag gate potential and is thus governed by electron- or hole-like transport.

Advancing Integrated STEM Learning through Engineering Design: Sixth-Grade Students' Design and Construction of Earthquake Resistant Buildings

Science.gov (United States)

English, Lyn D.; King, Donna; Smeed, Joanna

2017-01-01

As part of a 3-year longitudinal study, 136 sixth-grade students completed an engineering-based problem on earthquakes involving integrated STEM learning. Students employed engineering design processes and STEM disciplinary knowledge to plan, sketch, then construct a building designed to withstand earthquake damage, taking into account a number of…

Management and integration of engineering and construction activities: Lessons learned from the AP1000R nuclear power plant China project

International Nuclear Information System (INIS)

McCullough, M. C.; Ebeling-Koning, D.; Evans, M. C.

2012-01-01

The lessons learned during the early phase of design engineering and construction activities for the AP1000 China Project can be applied to any project involving multiple disciplines and multiple organizations. Implementation of a first-of-a-kind design to directly support construction activities utilizing resources assigned to design development and design delivery creates challenges with prioritization of activities, successful closure of issues, and communication between site organizations and the home office. To ensure successful implementation, teams were assigned and developed to directly support construction activities including prioritization of activities, site communication and ensuring closure of site emergent issues. By developing these teams, the organization is better suited to meet the demands of the construction schedule while continuing with design evolution of a standard plant and engineering delivery for multiple projects. For a successful project, proper resource utilization and prioritization are key for overcoming obstacles and ensuring success of the engineering organization. (authors)

Engineering America's Current and Future Space Transportation Systems: 50 Years of Systems Engineering Innovation for Sustainable Exploration

Science.gov (United States)

Dmbacher, Daniel L.; Lyles, Garry M.; McConnaughey, Paul

2008-01-01

Over the past 50 years, the National Aeronautics and Space Administration (NASA) has delivered space transportation solutions for America's complex missions, ranging from scientific payloads that expand knowledge, such as the Hubble Space Telescope, to astronauts and lunar rovers destined for voyages to the Moon. Currently, the venerable Space Shuttle, which has been in service since 1981, provides the United States' (U.S.) capability for both crew and heavy cargo to low-Earth orbit to' construct the International Space Station, before the Shuttle is retired in 2010. In the next decade, NASA will replace this system with a duo of launch vehicles: the Ares I Crew Launch Vehicle and the Ares V Cargo Launch Vehicle (Figure 1). The goals for this new system include increased safety and reliability coupled with lower operations costs that promote sustainable space exploration for decades to come. The Ares I will loft the Orion Crew Exploration Vehicle, while the heavy-lift Ares V will carry the Altair Lunar Lander and the equipment and supplies needed to construct a lunar outpost for a new generation of human and robotic space pioneers. This paper will provide details of the in-house systems engineering and vehicle integration work now being performed for the Ares I and planned for the Ares V. It will give an overview of the Ares I system-level test activities, such as the ground vibration testing that will be conducted in the Marshall Center's Dynamic Test Stand to verify the integrated vehicle stack's structural integrity and to validate computer modeling and simulation (Figure 2), as well as the main propulsion test article analysis to be conducted in the Static Test Stand. These activities also will help prove and refine mission concepts of operation, while supporting the spectrum of design and development work being performed by Marshall's Engineering Directorate, ranging from launch vehicles and lunar rovers to scientific spacecraft and associated experiments

Analysis on Key Points of Construction and Management of Municipal Landscape Engineering

Science.gov (United States)

Liang, Mingxia; Fei, Cheng

2018-02-01

At present, China has made great efforts to promote the construction of ecological civilization and promote the development of ecological protection and environmental construction. It has important practical significance to maintain the ecological balance and environmental quality of our country. Especially with the gradual improvement in people’s awareness of environmental protection, so that the green of the city also put forward higher requirements at the same time with the rising of the level of urbanization. In the process of urban landscape construction, the rational planning of urban landscaping involves a lot of subject knowledge. In the green process, we should fully consider the system of urban development and construction in China, based on the design of urban development and long-term planning of the landscaping project. In addition, we must also consider the traditional layout of the city area and the physical and geographical situation and so on, to enhance the objective and scientific nature of urban landscape. Therefore, it is of great practical significance to ensure the quality of landscaping in the effective management of municipal landscape engineering.

Hybrid cellular automaton modeling of nutrient modulated cell growth in tissue engineering constructs.

Science.gov (United States)

Chung, C A; Lin, Tze-Hung; Chen, Shih-Di; Huang, Hsing-I

2010-01-21

Mathematic models help interpret experimental results and accelerate tissue engineering developments. We develop in this paper a hybrid cellular automata model that combines the differential nutrient transport equation to investigate the nutrient limited cell construct development for cartilage tissue engineering. Individual cell behaviors of migration, contact inhibition and cell collision, coupled with the cell proliferation regulated by oxygen concentration were carefully studied. Simplified two-dimensional simulations were performed. Using this model, we investigated the influence of cell migration speed on the overall cell growth within in vitro cell scaffolds. It was found that intense cell motility can enhance initial cell growth rates. However, since cell growth is also significantly modulated by the nutrient contents, intense cell motility with conventional uniform cell seeding method may lead to declined cell growth in the final time because concentrated cell population has been growing around the scaffold periphery to block the nutrient transport from outside culture media. Therefore, homogeneous cell seeding may not be a good way of gaining large and uniform cell densities for the final results. We then compared cell growth in scaffolds with various seeding modes, and proposed a seeding mode with cells initially residing in the middle area of the scaffold that may efficiently reduce the nutrient blockage and result in a better cell amount and uniform cell distribution for tissue engineering construct developments.

Engineering Ethics Education : Its Necessity, Objectives, Methods, Current State, and Challenges

Science.gov (United States)

Fudano, Jun

The importance of engineering ethics education has become widely recognized in the industrialized countries including Japan. This paper examines the background against which engineering ethics education is required, and reviews its objectives, methods, and challenges, as well as its current state. In pointing out important issues associated with the apparent acceptance and quantitative development of ethics education, especially after the establishment of the Japan Accreditation Board for Engineering Education in 1999, the author stresses that the most serious problem is the lack of common understanding on the objectives of engineering ethics education. As a strategy to improve the situation, the so-called “Ethics-across-the-Curriculum” approach is introduced. The author also claims that business/organization ethics which is consistent with engineering ethics should be promoted in Japan.

Engineering and training simulators: A combined approach for nuclear plant construction projects

International Nuclear Information System (INIS)

Harnois, Olivier; Gain, Pascal; Bartak, Jan; Gathmann, Ralf

2007-01-01

Full text: Simulation technologies have always been widely used on nuclear applications, but with a clear division between engineering application, using highly validated code run in batch mode, and training purpose where real time computation is a mandatory requirement. Thanks to the flexibility of modern simulation technology and the increased performance of computers, it becomes now possible to develop Nuclear Power plant simulators that can be used both for engineering and training purposes. In the last years, the revival of nuclear industry raised a number of new construction or plant finishing projects in which the application of this combined approach would result in decisive improvement on plant construction lead times, better project control and cost optimizations. The simulator development is to be executed in a step-wise approach, scheduled in parallel with the plant design and construction phases. During a first step, the simulator will model the plant nuclear island systems plus the corresponding instrumentation and control, specific malfunctions and local commands. It can then be used for engineering activities defining and validating the plant operating strategies in case of incidents or accidents. The Simulator executive Station and Operator Station will be in prototype version with an interface imagery enabling monitoring and control of the simulator. Availability of such simulation platform leads to a significant increase in efficiency of the engineering works, the possibility to validate basic design hypotheses and detect defects and conflicts early. The second phase will consist in the fully detailed simulation of Main Control Room plant supervision and control MMI, taking into account I and C control loops detailed design improvement, while having sufficient fidelity in order to be suitable for the future operator training. Its use will enable the engineering units not only to specify and validate normal, incident and accident detailed plant

APPLIED ORGANIZATION OF CONSTRUCTION

Directory of Open Access Journals (Sweden)

Kievskiy Leonid Vladimirovich

2017-03-01

Full Text Available Applied disciplines in the sphere of construction which are engaged in the solution of vital macroeconomical problems (the general trend of development of these disciplines is the expansion of problematics and mutual integration are considered. Construction organization characteristic at the present stage as a systems engineering discipline covering the investment process of creation of real estate items, is given. The main source of current research trends for applied sciences (socio-economic development forecasts, regional and local programs is determined. Interpenetration and integration of various fields of knowledge exemplified by the current interindustry problem of blocks renovation organization of existing development, is demonstrated. Mathematical model of wave construction (for the period of deployment is proposed. Nature of dependence of the total duration of renovation on the limit of annual input and coefficient of renovation, is established. Overall structure of the Moscow region housing market is presented, and approaches to definition of effective demand are proposed.

Evaluation of Current Assessment Methods in Engineering Entrepreneurship Education

Science.gov (United States)

Purzer, Senay; Fila, Nicholas; Nataraja, Kavin

2016-01-01

Quality assessment is an essential component of education that allows educators to support student learning and improve educational programs. The purpose of this study is to evaluate the current state of assessment in engineering entrepreneurship education. We identified 52 assessment instruments covered in 29 journal articles and conference…

Current opportunities and challenges in skeletal muscle tissue engineering

NARCIS (Netherlands)

Koning, Merel; Harmsen, Martin C; van Luyn, Marja J A; Werker, Paul M N

The purpose of this article is to give a concise review of the current state of the art in tissue engineering (TE) of skeletal muscle and the opportunities and challenges for future clinical applicability. The endogenous progenitor cells of skeletal muscle, i.e. satellite cells, show a high

Qualitative Knowledge Construction for Engineering Systems: Extending the Design Structure Matrix Methodology in Scope and Procedure

National Research Council Canada - National Science Library

Bartolomei, Jason E

2007-01-01

...), by providing a dynamic, end-to-end representation of an engineering system. In support of this contribution, a new research methodology is presented called Qualitative Knowledge Construction (QKC...

Continuous Identification of a Four-Stroke SI Engine

DEFF Research Database (Denmark)

Melgaard, Henrik; Hendricks, Elbert; Madsen, Henrik

1990-01-01

Compact engine models often consist of a set of nonlinear differential equations which predict the time development of the mean value of the engine state variables (and perhaps some internal variables): such models are sometimes called mean value engine models. Currently a great deal of attention...... and Maximum Likelihood estimation). These techniques have been applied to a four cylinder SI engine. The results include an identification of the most important parameters and time constants of the engine. These are of interest for the construction of engine simulation models, for control studies...... is focused on constructing such continuous time models and on finding their parameters. This paper shows, that it is possible to identify an engine model from a linearized version of a mean value model for a CFI four-cycle spark ignition (SI) engine. Such an approach is useful because it preserves a physical...

Proteomic profiling of tissue-engineered blood vessel walls constructed by adipose-derived stem cells.

Science.gov (United States)

Wang, Chen; Guo, Fangfang; Zhou, Heng; Zhang, Yun; Xiao, Zhigang; Cui, Lei

2013-02-01

Adipose-derived stem cells (ASCs) can differentiate into smooth muscle cells and have been engineered into elastic small diameter blood vessel walls in vitro. However, the mechanisms involved in the development of three-dimensional (3D) vascular tissue remain poorly understood. The present study analyzed protein expression profiles of engineered blood vessel walls constructed by human ASCs using methods of two-dimensional gel electrophoresis (2DE) and mass spectrometry (MS). These results were compared to normal arterial walls. A total of 1701±15 and 1265±26 protein spots from normal and engineered blood vessel wall extractions were detected by 2DE, respectively. A total of 20 spots with at least 2.0-fold changes in expression were identified, and 38 differently expressed proteins were identified by 2D electrophoresis and ion trap MS. These proteins were classified into seven functional categories: cellular organization, energy, signaling pathway, enzyme, anchored protein, cell apoptosis/defense, and others. These results demonstrated that 2DE, followed by ion trap MS, could be successfully utilized to characterize the proteome of vascular tissue, including tissue-engineered vessels. The method could also be employed to achieve a better understanding of differentiated smooth muscle protein expression in vitro. These results provide a basis for comparative studies of protein expression in vascular smooth muscles of different origin and could provide a better understanding of the mechanisms of action needed for constructing blood vessels that exhibit properties consistent with normal blood vessels.

Construct validity-Current issues and recommendations for future hand hygiene research.

Science.gov (United States)

Neo, Jun Rong Jeffrey

2017-05-01

Health care-associated infection is a leading cause of morbidity and mortality. Hand hygiene is widely regarded as an effective prevention strategy. Often, hand hygiene research is designed and conducted by health care practitioners who may lack formal training in research methods, particularly in the area of social science. In a research context, a construct is a concept that can be measured or observed in some way. A construct can be directly or indirectly measured. For example, height can be directly measured by centimeters, whereas depression can be indirectly measured by a scale of 20 items. Every construct needs to be operationalized by measure(s) to make it a variable. Hence, construct validity refers to the degree of fit between the construct of interest and its operational measure. However, issues with construct validity often weaken the translation from construct to measure(s). This article will (1) describe the common threats to construct validity pertaining to hand hygiene research, (2) identify practical limitations in current research design, and (3) provide recommendations to improve construct validity in future hand hygiene research. By understanding how construct validity may affect hand hygiene research design, there is great potential to improve the validity of future hand hygiene research findings. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

An adaptive algorithm for performance assessment of construction project management with respect to resilience engineering and job security

Directory of Open Access Journals (Sweden)

P. Hashemi

2018-01-01

Full Text Available Construction sites are accident-prone locations and therefore safety management plays an im-portant role in these workplaces. This study presents an adaptive algorithm for performance as-sessment of project management with respect to resilience engineering and job security in a large construction site. The required data are collected using questionnaires in a large construction site. The presented algorithm is composed of radial basis function (RBF, artificial neural networks multi-layer perceptron (ANN-MLP, and statistical tests. The results indicate that preparedness, fault-tolerance, and flexibility are the most effective factors on overall efficiency. Moreover, job security and resilience engineering have similar statistical impacts on overall system efficiency. The results are verified and validated by the proposed algorithm.

Reduced analysis and confirmatory research on co-adaptability theoretical solution to conflicting events in construction engineering projects

Institute of Scientific and Technical Information of China (English)

无

2010-01-01

The co-adaptability theoretical solution to conflicting events in construction engineering projects has three problems. First, the transformation of constraint conditions of theoretical solution is very difficult in practical engineering applications; second, some coefficients are difficult to be determined; third, there are overfull circular arithmetic operations involved in it. To resolve these problems, a new method to reduce the theoretical solution complications is proposed. By analyzing the operating mechanism of theoretical solution model, redundancies in the theoretical solution can be eliminated, and the ISM mapping with the co-adaptability solution can be set up. Based on this approach, a procedure to solve practical conflicting events in construction projects is established by replacing characteristic variables with mathematic variables. The research results show that the procedure can replace the co-adaptability theoretical solution effectively and solve practical conflicting events in construction projects.

Micrometer scale guidance of mesenchymal stem cells to form structurally oriented large-scale tissue engineered cartilage.

Science.gov (United States)

Chou, Chih-Ling; Rivera, Alexander L; Williams, Valencia; Welter, Jean F; Mansour, Joseph M; Drazba, Judith A; Sakai, Takao; Baskaran, Harihara

2017-09-15

Current clinical methods to treat articular cartilage lesions provide temporary relief of the symptoms but fail to permanently restore the damaged tissue. Tissue engineering, using mesenchymal stem cells (MSCs) combined with scaffolds and bioactive factors, is viewed as a promising method for repairing cartilage injuries. However, current tissue engineered constructs display inferior mechanical properties compared to native articular cartilage, which could be attributed to the lack of structural organization of the extracellular matrix (ECM) of these engineered constructs in comparison to the highly oriented structure of articular cartilage ECM. We previously showed that we can guide MSCs undergoing chondrogenesis to align using microscale guidance channels on the surface of a two-dimensional (2-D) collagen scaffold, which resulted in the deposition of aligned ECM within the channels and enhanced mechanical properties of the constructs. In this study, we developed a technique to roll 2-D collagen scaffolds containing MSCs within guidance channels in order to produce a large-scale, three-dimensional (3-D) tissue engineered cartilage constructs with enhanced mechanical properties compared to current constructs. After rolling the MSC-scaffold constructs into a 3-D cylindrical structure, the constructs were cultured for 21days under chondrogenic culture conditions. The microstructure architecture and mechanical properties of the constructs were evaluated using imaging and compressive testing. Histology and immunohistochemistry of the constructs showed extensive glycosaminoglycan (GAG) and collagen type II deposition. Second harmonic generation imaging and Picrosirius red staining indicated alignment of neo-collagen fibers within the guidance channels of the constructs. Mechanical testing indicated that constructs containing the guidance channels displayed enhanced compressive properties compared to control constructs without these channels. In conclusion, using a novel

Construction of helium engineering demonstration loop (HENDEL M+A) for VHTR

International Nuclear Information System (INIS)

Shimomura, Saneaki; Tanaka, Toshiyuki; Nakano, Tadasuke

1983-01-01

The mother and adapter sections of the large structural component demonstration test loop, alias Helium Engineering Demonstration Loop, for the multipurpose, high temperature gas-cooled experimental reactor were completed in March, 1982. This facility was constructed by Fuji Electric Co., Ltd. and Kawasaki Heavy Industries Ltd. as the main contractors, and by the cooperation with Mitsubishi Heavy Industries Ltd. and Ishikawajima Harima Heavy Industries Co., Ltd. The HENDEL M+A is the testing facility of the largest scale in the world, which can handle 1000 deg C, 40 kgf/cm 2 G helium at a half flow rate of one core cooling loop of the experimental reactor. With the HENDEL M+A, the demonstration tests of fuel assembly stacks, in-core structures, large flow rate and high temperature equipment are planned. The HENDEL M+A comprises two mother loops, an adapter loop, and common auxiliary systems fon measurement and control (In), refining (Mp), makeup (Mu) and cooling water (Uc). The construction and function of such main equipment as a heater, circulators and internally insulated piping are described. The progress of the construction and the main experience during the construction, the process of operation and the performance are reported. (Kako, I.)

Application of 3D CADDS model to design and engineering for constructability improvement

International Nuclear Information System (INIS)

Cho, U.Y.; Park, C.C.; Choy, E.

1998-01-01

The use of three dimensional (3D) computer-aided design and drafting system (CADDS) model along with the associated information management system in engineering phases of large projects is well established and yielding significant improvements in project cost, schedule and quality. The information contained in these models can also be utilized in plant construction site for construction schedule review, installation procedure review, interference check, and visual communication tool to the utility owner when the visual and spatial information contained in the 3D models is integrated with other plant information. This paper will describe the application of 3D models and the associated databases in the construction process of CANDU HWR heavy water reactors. Some examples on the use of 3D CADD models in CANDU projects will be presented

Innovations in nuclear concrete constructions

International Nuclear Information System (INIS)

Tatum, C.B.

1983-01-01

The technical requirements and scope of concrete work on nuclear projects present significant engineering and construction challenges. These demands represent the extremes in many areas of construction operations. In meeting these challenges, engineering and construction forces have developed several innovations which can be beneficially applied to other types of construction. Innovative approaches in the general categories of engineering scope, construction input to engineering, work planning, special methods and techniques, and satisfaction of quality assurance requirements are given in this paper. The transfer of this technology to other segments of the construction industry will improve overall performance by avoiding the problem areas encountered on nuclear projects

Bioactive glass 13-93 as a subchondral substrate for tissue-engineered osteochondral constructs: a pilot study.

Science.gov (United States)

Jayabalan, Prakash; Tan, Andrea R; Rahaman, Mohammed N; Bal, B Sonny; Hung, Clark T; Cook, James L

2011-10-01

Replacement of diseased areas of the joint with tissue-engineered osteochondral grafts has shown potential in the treatment of osteoarthritis. Bioactive glasses are candidates for the osseous analog of these grafts. (1) Does Bioactive Glass 13-93 (BG 13-93) as a subchondral substrate improve collagen and glycosaminoglycan production in a tissue-engineered cartilage layer? (2) Does BG 13-93 as a culture medium supplement increase the collagen and glycosaminoglycan production and improve the mechanical properties in a tissue-engineered cartilage layer? In Study 1, bioactive glass samples (n = 4) were attached to a chondrocyte-seeded agarose layer to form an osteochondral construct, cultured for 6 weeks, and compared to controls. In Study 2, bioactive glass samples (n = 5) were cocultured with cell-seeded agarose for 6 weeks. The cell-seeded agarose layer was exposed to BG 13-93 either continuously or for the first or last 2 weeks in culture or had no exposure. Osteochondral constructs with a BG 13-93 base had improved glycosaminoglycan deposition but less collagen II content. Agarose scaffolds that had a temporal exposure to BG 13-93 within the culture medium had improved mechanical and biochemical properties compared to continuous or no exposure. When used as a subchondral substrate, BG 13-93 did not improve biochemical properties compared to controls. However, as a culture medium supplement, BG 13-93 improved the biochemical and mechanical properties of a tissue-engineered cartilage layer. BG 13-93 may not be suitable in osteochondral constructs but could have potential as a medium supplement for neocartilage formation.

Analogy and construction of meaning in science teaching physics for engineering students

Directory of Open Access Journals (Sweden)

Thamara FAGÚNDEZ ZAMBRANO

2011-12-01

Full Text Available Normal 0 21 false false false ES X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} An analogy can be interpreted as a structured mapping between two domains, one called domain-domain and another named source-goal. This is one of functions can play an analogy, and this function we are interested in this work to analyze how specific an analogy involved in construction and justification of new knowledge. The research finds about the use of analogies as a teaching resource are three teachers experienced in college physics classes. More specifically on the role of that resource in the construction of scientific knowledge and its contribution the teaching and learning of college-level physics and general training of the engineering student. The context of the study is Faculty of Engineering, University of Carabobo, Venezuela. The approach methodology is qualitative. This is a descriptive-interpretative cases study.  Analysis and results to identify and classify analogies by use given by teachers and their contribution to the construction of meaning scientists. Implications for improving teaching practice are extracted

Regeneration of skull bones in adult rabbits after implantation of commercial osteoinductive materials and transplantation of a tissue-engineering construct.

Science.gov (United States)

Volkov, A V; Alekseeva, I S; Kulakov, A A; Gol'dshtein, D V; Shustrov, S A; Shuraev, A I; Arutyunyan, I V; Bukharova, T B; Rzhaninova, A A; Bol'shakova, G B; Grigor'yan, A S

2010-10-01

We performed a comparative study of reparative osteogenesis in rabbits with experimental critical defects of the parietal bones after implantation of commercial osteoinductive materials "Biomatrix", "Osteomatrix", "BioOss" in combination with platelet-rich plasma and transplantation of a tissue-engineering construct on the basis of autogenic multipotent stromal cells from the adipose tissue predifferentiated in osteogenic direction. It was found that experimental reparative osteogenesis is insufficiently stimulated by implantation materials and full-thickness trepanation holes were not completely closed. After transplantation of the studied tissue-engineering construct, the defect was filled with full-length bone regenerate (in the center of the regenerate and from the maternal bone) in contrast to control and reference groups, where the bone tissue was formed only on the side of the maternal bone. On day 120 after transplantation of the tissue-engineering construct, the percent of newly-formed bone tissue in the regenerate was 24% (the total percent of bone tissue in the regenerate was 39%), which attested to active incomplete regenerative process in contrast to control and reference groups. Thus, the study demonstrated effective regeneration of the critical defects of the parietal bones in rabbits 120 days after transplantation of the tissue-engineering construct in contrast to commercial osteoplastic materials for directed bone regeneration.

SWITCH: a dynamic CRISPR tool for genome engineering and metabolic pathway control for cell factory construction in Saccharomyces cerevisiae.

Science.gov (United States)

Vanegas, Katherina García; Lehka, Beata Joanna; Mortensen, Uffe Hasbro

2017-02-08

The yeast Saccharomyces cerevisiae is increasingly used as a cell factory. However, cell factory construction time is a major obstacle towards using yeast for bio-production. Hence, tools to speed up cell factory construction are desirable. In this study, we have developed a new Cas9/dCas9 based system, SWITCH, which allows Saccharomyces cerevisiae strains to iteratively alternate between a genetic engineering state and a pathway control state. Since Cas9 induced recombination events are crucial for SWITCH efficiency, we first developed a technique TAPE, which we have successfully used to address protospacer efficiency. As proof of concept of the use of SWITCH in cell factory construction, we have exploited the genetic engineering state of a SWITCH strain to insert the five genes necessary for naringenin production. Next, the naringenin cell factory was switched to the pathway control state where production was optimized by downregulating an essential gene TSC13, hence, reducing formation of a byproduct. We have successfully integrated two CRISPR tools, one for genetic engineering and one for pathway control, into one system and successfully used it for cell factory construction.

A Novel Pulsatile Bioreactor for Mechanical Stimulation of Tissue Engineered Cardiac Constructs

Directory of Open Access Journals (Sweden)

Günther Eissner

2011-07-01

Full Text Available After myocardial infarction, the implantation of stem cell seeded scaffolds on the ischemic zone represents a promising strategy for restoration of heart function. However, mechanical integrity and functionality of tissue engineered constructs need to be determined prior to implantation. Therefore, in this study a novel pulsatile bioreactor mimicking the myocardial contraction was developed to analyze the behavior of mesenchymal stem cells derived from umbilical cord tissue (UCMSC colonized on titanium-coated polytetrafluorethylene scaffolds to friction stress. The design of the bioreactor enables a simple handling and defined mechanical forces on three seeded scaffolds at physiological conditions. The compact system made of acrylic glass, Teflon®, silicone, and stainless steel allows the comparison of different media, cells and scaffolds. The bioreactor can be gas sterilized and actuated in a standard incubator. Macroscopic observations and pressure-measurements showed a uniformly sinusoidal pulsation, indicating that the bioreactor performed well. Preliminary experiments to determine the adherence rate and morphology of UCMSC after mechanical loadings showed an almost confluent cellular coating without damage on the cell surface. In summary, the bioreactor is an adequate tool for the mechanical stress of seeded scaffolds and offers dynamic stimuli for pre-conditioning of cardiac tissue engineered constructs in vitro.

Management and integration of engineering and construction activities: Lessons learned from the AP1000{sup R} nuclear power plant China project

Energy Technology Data Exchange (ETDEWEB)

McCullough, M. C.; Ebeling-Koning, D.; Evans, M. C. [Westinghouse Electric Company LLC, 1000 Westinghouse Drive, Cranberry Township, PA 16066 (United States)

2012-07-01

The lessons learned during the early phase of design engineering and construction activities for the AP1000 China Project can be applied to any project involving multiple disciplines and multiple organizations. Implementation of a first-of-a-kind design to directly support construction activities utilizing resources assigned to design development and design delivery creates challenges with prioritization of activities, successful closure of issues, and communication between site organizations and the home office. To ensure successful implementation, teams were assigned and developed to directly support construction activities including prioritization of activities, site communication and ensuring closure of site emergent issues. By developing these teams, the organization is better suited to meet the demands of the construction schedule while continuing with design evolution of a standard plant and engineering delivery for multiple projects. For a successful project, proper resource utilization and prioritization are key for overcoming obstacles and ensuring success of the engineering organization. (authors)

Methods for constructing exact solutions of partial differential equations mathematical and analytical techniques with applications to engineering

CERN Document Server

Meleshko, Sergey V

2005-01-01

Differential equations, especially nonlinear, present the most effective way for describing complex physical processes. Methods for constructing exact solutions of differential equations play an important role in applied mathematics and mechanics. This book aims to provide scientists, engineers and students with an easy-to-follow, but comprehensive, description of the methods for constructing exact solutions of differential equations.

Construction of Engineering Education Program based on the Alumni's Evaluation of the Educational Outcome

Science.gov (United States)

Tsukamoto, Takehiko; Nishizawa, Hitoshi

The Department of Electrical and Electronic Engineering in Toyota National College of Technology has put great emphasis on fundamental subjects, such as “electrical and electronic circuit" and “electromagnetism" more than 40 years. On the other hand, several issues of our college were clarified by the alumni's evaluation of the educational outcome in 2002. The most serious issue was low achievement of English and Social education. The alumni of all generation are dissatisfied with their low skill in English communication. As a part of the educational reforms, our department has constructed a new engineering education program focusing on fundamental ability. We introduced many problem-based-learning experiments and the compulsory subjects such as “English communication for electrical engineers" and “Engineering Ethics" into this program. Great educative results are obtained by these improvements. As a typical example, the scores of all 2nd grade students of advanced engineering course in TOEIC tests became 450 points or more. Our program has been authorized by JABEE since 2004.

Development of a construct-based risk assessment framework for genetic engineered crops.

Science.gov (United States)

Beker, M P; Boari, P; Burachik, M; Cuadrado, V; Junco, M; Lede, S; Lema, M A; Lewi, D; Maggi, A; Meoniz, I; Noé, G; Roca, C; Robredo, C; Rubinstein, C; Vicien, C; Whelan, A

2016-10-01

Experience gained in the risk assessment (RA) of genetically engineered (GE) crops since their first experimental introductions in the early nineties, has increased the level of familiarity with these breeding methodologies and has motivated several agencies and expert groups worldwide to revisit the scientific criteria underlying the RA process. Along these lines, the need to engage in a scientific discussion for the case of GE crops transformed with similar constructs was recently identified in Argentina. In response to this need, the Argentine branch of the International Life Sciences Institute (ILSI Argentina) convened a tripartite working group to discuss a science-based evaluation approach for transformation events developed with genetic constructs which are identical or similar to those used in previously evaluated or approved GE crops. This discussion considered new transformation events within the same or different species and covered both environmental and food safety aspects. A construct similarity concept was defined, considering the biological function of the introduced genes. Factors like environmental and dietary exposure, familiarity with both the crop and the trait as well as the crop biology, were identified as key to inform a construct-based RA process.

Wood construction codes issues in the United States

Science.gov (United States)

Douglas R. Rammer

2006-01-01

The current wood construction codes find their origin in the 1935 Wood Handbook: Wood as an Engineering Material published by the USDA Forest Service. Many of the current design recommendations can be traced back to statements from this book. Since this time a series of development both historical and recent has led to a multi-layered system for use of wood products in...

The influence of construct scale on the composition and functional properties of cartilaginous tissues engineered using bone marrow-derived mesenchymal stem cells.

Science.gov (United States)

Buckley, Conor T; Meyer, Eric G; Kelly, Daniel J

2012-02-01

Engineering cartilaginous tissue of a scale necessary to treat defects observed clinically is a well-documented challenge in the field of cartilage tissue engineering. The objective of this study was to determine how the composition and mechanical properties of cartilaginous tissues that are engineered by using bone marrow-derived mesenchymal stem cells (MSCs) depend on the scale of the construct. Porcine bone marrow-derived MSCs were encapsulated in agarose hydrogels, and constructs of different cylindrical geometries (Ø4×1.5 mm; Ø5×3 mm; Ø6×4.5 mm; Ø8×4.5 mm) were fabricated and maintained in a chemically defined serum-free medium supplemented with transforming growth factor-β3 for 42 days. Total sulfated glycosaminoglycan (sGAG) accumulation by day 42 increased from 0.14% w/w to 0.88% w/w as the construct geometry increased from Ø4×1.5 to Ø8×4.5 mm, with collagen accumulation increasing from 0.31% w/w to 1.62% w/w. This led to an increase in the dynamic modulus from 90.81 to 327.51 kPa as the engineered tissue increased in scale from Ø4×1.5 to Ø8×4.5 mm. By decreasing the external oxygen tension from 20% to 5%, it was possible to achieve these higher levels of mechanical functionality in the smaller engineered tissues. Constructs were then sectioned into smaller subregions to quantify the spatial accumulation of extracellular matrix components, and a model of oxygen diffusion and consumption was used to predict spatial gradients in oxygen concentration throughout the construct. sGAG accumulation was always highest in regions where oxygen concentration was predicted to be lowest. In addition, as the size of the engineered construct increased, different regions of the construct preferentially supported either sGAG or collagen accumulation, thus suggesting that gradients in regulatory factors other than oxygen were playing a role in determining levels of collagen synthesis. The identification of such factors and the means to control their

Barriers to the Uptake of Concurrent Engineering in the Nigerian Construction Industry

Directory of Open Access Journals (Sweden)

Nathaniel Anny Aniekwu

2012-12-01

engineering and also to compute the Kendall’s coefficient of concordance, which assess the levels of agreement among the judges on the consistency of the rankings. A Kendall’s coefficient of concordance of W=0.57365 was recorded. A lack of awareness emerged as the most important barrier against the integration of this concept into the Nigerian construction industry. The top five variables are all human factors that can be ameliorated by proper education.

Current and Future Research Directions in Requirements Engineering

Science.gov (United States)

Cheng, Betty H. C.; Atlee, Joanne M.

In this paper, we review current requirements engineering (RE) research and identify future research directions suggested by emerging software needs. First, we overview the state of the art in RE research. The research is considered with respect to technologies developed to address specific requirements tasks, such as elicitation, modeling, and analysis. Such a review enables us to identify mature areas of research, as well as areas that warrant further investigation. Next, we review several strategies for performing and extending RE research results, to help delineate the scope of future research directions. Finally, we highlight what we consider to be the “hot” current and future research topics, which aim to address RE needs for emerging systems of the future.

The effect of PEGT/PBT scaffold architecture on oxygen gradients in tissue engineered cartilaginous constructs

NARCIS (Netherlands)

Malda, J.; Woodfield, T.B.F.; van der Vloodt, F.; Kooy, F.K.; Martens, D.E.; Tramper, J.C.; van Blitterswijk, Clemens; Riesle, J.U.

2004-01-01

Repair of articular cartilage defects using tissue engineered constructs composed of a scaffold and cultured autologous cells holds promise for future treatments. However, nutrient limitation (e.g. oxygen) has been suggested as a cause of the onset of chondrogenesis solely within the peripheral

Magnetic resonance microscopy for monitoring osteogenesis in tissue-engineered construct in vitro

Energy Technology Data Exchange (ETDEWEB)

Xu Huihui [Bioengineering Department (MC 063), University of Illinois at Chicago, 851 South Morgan Street, Chicago, IL 60607-7052 (United States); Othman, Shadi F [Bioengineering Department (MC 063), University of Illinois at Chicago, 851 South Morgan Street, Chicago, IL 60607-7052 (United States); Hong Liu [Bioengineering Department (MC 063), University of Illinois at Chicago, 851 South Morgan Street, Chicago, IL 60607-7052 (United States); Peptan, Ioana A [Bioengineering Department (MC 063), University of Illinois at Chicago, 851 South Morgan Street, Chicago, IL 60607-7052 (United States); Magin, Richard L [Bioengineering Department (MC 063), University of Illinois at Chicago, 851 South Morgan Street, Chicago, IL 60607-7052 (United States)

2006-02-07

Magnetic resonance microscopy (MRM) is used to monitor osteogenesis in tissue-engineered constructs. Measurements of the developing tissue's MR relaxation times (T{sub 1} and T{sub 2}), apparent diffusion coefficient (ADC) and elastic shear modulus were conducted over a 4-week growth period using an 11.74 T Bruker spectrometer with an imaging probe adapted for MR elastography (MRE). Both the relaxation times and the ADC show a statistically significant decrease after only one week of tissue development while the tissue stiffness increases progressively during the first two weeks of in vitro growth. The measured MR parameters are correlated with histologically monitored osteogenic tissue development. This study shows that MRM can provide quantitative data with which to characterize the growth and development of tissue-engineered bone.

The application of micro UAV in construction project

Science.gov (United States)

Kaamin, Masiri; Razali, Siti Nooraiin Mohd; Ahmad, Nor Farah Atiqah; Bukari, Saifullizan Mohd; Ngadiman, Norhayati; Kadir, Aslila Abd; Hamid, Nor Baizura

2017-10-01

In every outstanding construction project, there is definitely have an effective construction management. Construction management allows a construction project to be implemented according to plan. Every construction project must have a progress development works that is usually created by the site engineer. Documenting the progress of works is one of the requirements in construction management. In a progress report it is necessarily have a visual image as an evidence. The conventional method used for photographing on the construction site is by using common digital camera which is has few setback comparing to Micro Unmanned Aerial Vehicles (UAV). Besides, site engineer always have a current issues involving limitation of monitoring on high reach point and entire view of the construction site. The purpose of this paper is to provide a concise review of Micro UAV technology in monitoring the progress on construction site through visualization approach. The aims of this study are to replace the conventional method of photographing on construction site using Micro UAV which can portray the whole view of the building, especially on high reach point and allows to produce better images, videos and 3D model and also facilitating site engineer to monitor works in progress. The Micro UAV was flown around the building construction according to the Ground Control Points (GCPs) to capture images and record videos. The images taken from Micro UAV have been processed generate 3D model and were analysed to visualize the building construction as well as monitoring the construction progress work and provides immediate reliable data for project estimation. It has been proven that by using Micro UAV, a better images and videos can give a better overview of the construction site and monitor any defects on high reach point building structures. Not to be forgotten, with Micro UAV the construction site progress is more efficiently tracked and kept on the schedule.

Construction control for earth and rockfill dams. Technical engineering and design guides as adapted from the U.S. Army Corps of Engineers, No. 27

International Nuclear Information System (INIS)

1999-01-01

This manual outlines the key components that will ensure the safety and performance of these dams, including competent and adequate supervision, careful inspection and control testing. Detailed chapters cover every aspect of foundation and abutment treatment, field organization and responsibility, borrow areas and quarries, earth-fill and rockfill construction, and miscellaneous construction features such as river diversion, stage construction and service bridge pier foundations. Useful appendices contain methods for relating field density data to desired or specified values, field compaction control data, detailed information on instruments used in earth and rockfill dam construction and lists of required and related publications, as well as a bibliography. This detailed and useful manual is an essential information source for engineers and constructors

Facilitating Constructive Alignment in Power Systems Engineering Education Using Free and Open-Source Software

Science.gov (United States)

Vanfretti, L.; Milano, F.

2012-01-01

This paper describes how the use of free and open-source software (FOSS) can facilitate the application of constructive alignment theory in power systems engineering education by enabling the deep learning approach in power system analysis courses. With this aim, this paper describes the authors' approach in using the Power System Analysis Toolbox…

Preclinical study of mouse pluripotent parthenogenetic embryonic stem cell derivatives for the construction of tissue-engineered skin equivalent.

Science.gov (United States)

Rao, Yang; Cui, Jihong; Yin, Lu; Liu, Wei; Liu, Wenguang; Sun, Mei; Yan, Xingrong; Wang, Ling; Chen, Fulin

2016-10-22

Embryonic stem cell (ESC) derivatives hold great promise for the construction of tissue-engineered skin equivalents (TESE). However, harvesting of ESCs destroys viable embryos and may lead to political and ethical concerns over their application. In the current study, we directed mouse parthenogenetic embryonic stem cells (pESCs) to differentiate into fibroblasts, constructed TESE, and evaluated its function in vivo. The stemness marker expression and the pluripotent differentiation ability of pESCs were tested. After embryoid body (EB) formation and adherence culture, mesenchymal stem cells (MSCs) were enriched and directed to differentiate into fibroblastic lineage. Characteristics of derived fibroblasts were assessed by quantitative real-time PCR and ELISA. Functional ability of the constructed TESE was tested by a mouse skin defects repair model. Mouse pESCs expressed stemness marker and could form teratoma containing three germ layers. MSCs could be enriched from outgrowths of EBs and directed to differentiate into fibroblastic lineage. These cells express a high level of growth factors including FGF, EGF, VEGF, TGF, PDGF, and IGF1, similar to those of ESC-derived fibroblasts and mouse fibroblasts. Seeded into collagen gels, the fibroblasts derived from pESCs could form TESE. Mouse skin defects could be successfully repaired 15 days after transplantation of TESE constructed by fibroblasts derived from pESCs. pESCs could be induced to differentiate into fibroblastic lineage, which could be applied to the construction of TESE and skin defect repair. Particularly, pESC derivatives avoid the limitations of political and ethical concerns, and provide a promising source for regenerative medicine.

The healing of bony defects by cell-free collagen-based scaffolds compared to stem cell-seeded tissue engineered constructs.

LENUS (Irish Health Repository)

Lyons, Frank G

2010-12-01

One of the key challenges in tissue engineering is to understand the host response to scaffolds and engineered constructs. We present a study in which two collagen-based scaffolds developed for bone repair: a collagen-glycosaminoglycan (CG) and biomimetic collagen-calcium phosphate (CCP) scaffold, are evaluated in rat cranial defects, both cell-free and when cultured with MSCs prior to implantation. The results demonstrate that both cell-free scaffolds showed excellent healing relative to the empty defect controls and somewhat surprisingly, to the tissue engineered (MSC-seeded) constructs. Immunological analysis of the healing response showed higher M1 macrophage activity in the cell-seeded scaffolds. However, when the M2 macrophage response was analysed, both groups (MSC-seeded and non-seeded scaffolds) showed significant activity of these cells which are associated with an immunomodulatory and tissue remodelling response. Interestingly, the location of this response was confined to the construct periphery, where a capsule had formed, in the MSC-seeded groups as opposed to areas of new bone formation in the non-seeded groups. This suggests that matrix deposited by MSCs during in vitro culture may adversely affect healing by acting as a barrier to macrophage-led remodelling when implanted in vivo. This study thus improves our understanding of host response in bone tissue engineering.

Ion currents in diesel engines

OpenAIRE

Rao, Rahul

2017-01-01

This thesis documents an experimental and modelling investigation into ion formation in diesel engines, its uses in the field of engine performance and emissions prediction and the mechanisms by which these uses are made possible. Ion sensors have been employed in engines for a variety of purposes, including estimation of air-fuel ratio, start of combustion and in-cylinder pressure, detection of knock, misfire and combustion resonance, prediction of soot formation, and control of spark ...

Point-form electrodynamics and the construction of conserved current operators

International Nuclear Information System (INIS)

Klink, W.H.

2003-01-01

A general procedure for constructing conserved electromagnetic current operators in the presence of hadronic interactions is given. The four-momentum operator in point-form relativistic quantum mechanics is written as the sum of hadronic, photon, and electromagnetic four-momentum operators, where the electromagnetic four-momentum operator is generated from a vertex operator, in which a conserved current operator is contracted with the four-vector potential operator. The current operator is the sum of free, dynamically determined and model-dependent operators. The dynamically determined current operator is formed form a free current operator and the interacting hadronic four-momentum operator, in such a way that the sum of free and dynamically determined current operators is conserved with respect to the hadronic interactions. The model-dependent operator is a many-body current operator, formed as the commutator of an antisymmetric operator with the hadronic four-momentum operator. It is shown that such an operator is also conserved with respect to the hadronic interactions and also does not renormalize the charge. Refs. 9 (author)

Engineering Cardiac Muscle Tissue: A Maturating Field of Research.

Science.gov (United States)

Weinberger, Florian; Mannhardt, Ingra; Eschenhagen, Thomas

2017-04-28

Twenty years after the initial description of a tissue engineered construct, 3-dimensional human cardiac tissues of different kinds are now generated routinely in many laboratories. Advances in stem cell biology and engineering allow for the generation of constructs that come close to recapitulating the complex structure of heart muscle and might, therefore, be amenable to industrial (eg, drug screening) and clinical (eg, cardiac repair) applications. Whether the more physiological structure of 3-dimensional constructs provides a relevant advantage over standard 2-dimensional cell culture has yet to be shown in head-to-head-comparisons. The present article gives an overview on current strategies of cardiac tissue engineering with a focus on different hydrogel methods and discusses perspectives and challenges for necessary steps toward the real-life application of cardiac tissue engineering for disease modeling, drug development, and cardiac repair. © 2017 American Heart Association, Inc.

Human Factors Engineering: Current Practices and Development Needs in Finland

Energy Technology Data Exchange (ETDEWEB)

Savioja, Paula; Norros, Leena; Liinasuo, Marja; Laarni, Jari [VTT Technical Research Centre of Finland, Finland (Finland)

2011-08-15

This paper describes initial findings from a study concerning the practices and development needs of Human Factors Engineering (HFE) in Finland. HFE is increasing in importance as the Radiation and Nuclear Safety Authority Finland (STUK) is renewing the regulatory guidelines and the intention is to include requirements concerning HFE. The motivation for the paper is to discover how HFE is conducted currently in order to envision what should be aimed at when modifying requirements for design practices. In an interview with STUK it was discovered that current HFE practices encompass mainly activities related to control room modifications and as such namely verification and validation of new designs. The adoption of the entire HFE process in design and modification projects requires changes that include better integration of technical and Human Factors Engineering approaches. Boundary objects that mediate between different design disciplines are needed in order to enforce the stronger integration. Concept of operations (CONOPS) is suggested as a such boundary object.

Projects of Iberdrola Engineering and Construction on the Flamanville 3 EPR; Proyectos de Iberdrola Ingenieria y construccion en el EPR de Flamanville 3

Energy Technology Data Exchange (ETDEWEB)

Zornoza, J.; Dumas, H.; Sesma, J. L.; Cubian, B.; Diaz, J. I.

2013-06-01

Iberdrola Engineering and Construction is participating during the last 5 years in 5 projects on the Flamanville 3 EPR, both in the nuclear island and conventional island and the pump house. These projects represent a challenge from the technical point of view due to the high requirements applicable to the project because of the experience feedback of the operator EDF and of compliance with new regulations that have emerged since the completion of the last nuclear power station in France. This paper presents the description of these projects, as well as its current status. (Author)

Protein engineering for metabolic engineering: current and next-generation tools

Science.gov (United States)

Marcheschi, Ryan J.; Gronenberg, Luisa S.; Liao, James C.

2014-01-01

Protein engineering in the context of metabolic engineering is increasingly important to the field of industrial biotechnology. As the demand for biologically-produced food, fuels, chemicals, food additives, and pharmaceuticals continues to grow, the ability to design and modify proteins to accomplish new functions will be required to meet the high productivity demands for the metabolism of engineered organisms. This article reviews advances of selecting, modeling, and engineering proteins to improve or alter their activity. Some of the methods have only recently been developed for general use and are just beginning to find greater application in the metabolic engineering community. We also discuss methods of generating random and targeted diversity in proteins to generate mutant libraries for analysis. Recent uses of these techniques to alter cofactor use, produce non-natural amino acids, alcohols, and carboxylic acids, and alter organism phenotypes are presented and discussed as examples of the successful engineering of proteins for metabolic engineering purposes. PMID:23589443

Building information modelling review with potential applications in tunnel engineering of China

Science.gov (United States)

Zhou, Weihong; Qin, Haiyang; Qiu, Junling; Fan, Haobo; Lai, Jinxing; Wang, Ke; Wang, Lixin

2017-08-01

Building information modelling (BIM) can be applied to tunnel engineering to address a number of problems, including complex structure, extensive design, long construction cycle and increased security risks. To promote the development of tunnel engineering in China, this paper combines actual cases, including the Xingu mountain tunnel and the Shigu Mountain tunnel, to systematically analyse BIM applications in tunnel engineering in China. The results indicate that BIM technology in tunnel engineering is currently mainly applied during the design stage rather than during construction and operation stages. The application of BIM technology in tunnel engineering covers many problems, such as a lack of standards, incompatibility of different software, disorganized management, complex combination with GIS (Geographic Information System), low utilization rate and poor awareness. In this study, through summary of related research results and engineering cases, suggestions are introduced and an outlook for the BIM application in tunnel engineering in China is presented, which provides guidance for design optimization, construction standards and later operation maintenance.

Current distribution and enhancement of the engineering critical current density in multifilament Bi-2223 tapes

DEFF Research Database (Denmark)

Wang, W.G.; Jensen, M.B.; Kindl, B.

2000-01-01

The spatial distribution of the critical current density (Jc) and engineering critical current density (Je) along the tape width direction was studied by a cutting technique on Bi-2223 multifilamentary tapes. In general, an increase of Jc towards the centre of the tape was measured. We attribute...... microstructure with a great amount of secondary phases. Local variation of Jc was measured within the centre segment of the tape. This indicates the influence of other factors on Jc, such as filament shape, connectivity of the filaments, and sausaging. Enhancement of Je has been pursued in which average Je of 12...

Detonation Jet Engine. Part 2--Construction Features

Science.gov (United States)

Bulat, Pavel V.; Volkov, Konstantin N.

2016-01-01

We present the most relevant works on jet engine design that utilize thermodynamic cycle of detonative combustion. Detonation engines of various concepts, pulse detonation, rotational and engine with stationary detonation wave, are reviewed. Main trends in detonation engine development are discussed. The most important works that carried out…

Current Students | College of Engineering & Applied Science

Science.gov (United States)

Electrical Engineering Instructional Laboratories Student Resources Industrial & Manufacturing Engineering Industrial & Manufacturing Engineering Academic Programs Industrial & Manufacturing Engineering Major Industrial & Manufacturing Engineering Minor Industrial & Manufacturing Engineering

An Analytical Reverse Engineering of IELTS Listening Tasks for a Construct Model

OpenAIRE

Masood Khalili Sabet; Hamid Reza Babaee Bormanaki

2017-01-01

The study reported here was concerned with the issue of reverse engineering of language test items as it relates to the identification of the language constructs underlying listening tasks of LELTS test. In this regard, the IELTS examination papers, from IELTS 1 to IELTS 10 were compiled as a corpus for the analysis. Tasks were analyzed using a taxonomic frame work adopted from Moore, Morton and price (2012), that was originally adapted from Weir and Urquhart (1998), with a focus on two dimen...

Engineering zonal cartilage through bioprinting collagen type II hydrogel constructs with biomimetic chondrocyte density gradient.

Science.gov (United States)

Ren, Xiang; Wang, Fuyou; Chen, Cheng; Gong, Xiaoyuan; Yin, Li; Yang, Liu

2016-07-20

Cartilage tissue engineering is a promising approach for repairing and regenerating cartilage tissue. To date, attempts have been made to construct zonal cartilage that mimics the cartilaginous matrix in different zones. However, little attention has been paid to the chondrocyte density gradient within the articular cartilage. We hypothesized that the chondrocyte density gradient plays an important role in forming the zonal distribution of extracellular matrix (ECM). In this study, collagen type II hydrogel/chondrocyte constructs were fabricated using a bioprinter. Three groups were created according to the total cell seeding density in collagen type II pre-gel: Group A, 2 × 10(7) cells/mL; Group B, 1 × 10(7) cells/mL; and Group C, 0.5 × 10(7) cells/mL. Each group included two types of construct: one with a biomimetic chondrocyte density gradient and the other with a single cell density. The constructs were cultured in vitro and harvested at 0, 1, 2, and 3 weeks for cell viability testing, reverse-transcription quantitative PCR (RT-qPCR), biochemical assays, and histological analysis. We found that total ECM production was positively correlated with the total cell density in the early culture stage, that the cell density gradient distribution resulted in a gradient distribution of ECM, and that the chondrocytes' biosynthetic ability was affected by both the total cell density and the cell distribution pattern. Our results suggested that zonal engineered cartilage could be fabricated by bioprinting collagen type II hydrogel constructs with a biomimetic cell density gradient. Both the total cell density and the cell distribution pattern should be optimized to achieve synergistic biological effects.

Restoration of limited defects of the cartilage with the use of cell-engineered constructs

Directory of Open Access Journals (Sweden)

S. A. Gerasimov

2017-01-01

Full Text Available Aim: to develop a three-dimensional composite cell-engineered constructs (CEC for restoration of limited defects of the cartilage in experiment.Materials and methods. To create a cell-engineered constructs (CEC, were used collagenic carriers: «Chondro Gide» impermeable bilayer membrane and «Osteoplast» permeable matrix. A comparative study of their cytotoxic and adhesion properties was made in vitro. Chondroplastic potential of prepared CECs based on collagenous matrices with allogeneic mesenchymal stem cells (MSC of the rabbit bone marrow grown on their surface was assessed in vivo. A cylindrical defect of the cartilage of the medial femoral condyle 3.3 mm in diameter at a depth of 1.5 mm was formed on both rabbit feet. Laboratory animals were divided into 3 groups: control group; Experiment 1 group with Chondro Gide used as the MSC carrier within CEC; Experiment 2 group using Osteoplast matrix. Upon experiment completion, a morphometric and histomorphologic research of tissue specimens was made. For statistical evaluation of the results a defect region recovery factor (RF was offered and used. Results. After a 6-month observation period the control group showed partial recovery of the defect region with the recovery factor (RF of 0.62 ± 0.06. The RF in Experiment 1 group equalled to 0.79 ± 0.07, Experiment 2 group revealed RF at the level of 0.88 ± 0.02. Statistical analysis of the research results shows that the use of CEC used in Experiment 2 group reduces a relative risk of therapeutic failures by 92.9%, and absolute risk – by 43.3% as compared to Experiment 1 group. Histomorphologic research data are indicative of a hyaline cartilage formation in the central defect zone, which is partially close to the intact cartilage to the maximum with zonality marked.Conclusion. Results of the research of the developed three-dimension cell-engineered constructs consisting of mesenchymal stem cells of the bone marrow grown on the Osteoplast

A new construction technique for tissue-engineered heart valves using the self-assembly method.

Science.gov (United States)

Tremblay, Catherine; Ruel, Jean; Bourget, Jean-Michel; Laterreur, Véronique; Vallières, Karine; Tondreau, Maxime Y; Lacroix, Dan; Germain, Lucie; Auger, François A

2014-11-01

Tissue engineering appears as a promising option to create new heart valve substitutes able to overcome the serious drawbacks encountered with mechanical substitutes or tissue valves. The objective of this article is to present the construction method of a new entirely biological stentless aortic valve using the self-assembly method and also a first assessment of its behavior in a bioreactor when exposed to a pulsatile flow. A thick tissue was created by stacking several fibroblast sheets produced with the self-assembly technique. Different sets of custom-made templates were designed to confer to the thick tissue a three-dimensional (3D) shape similar to that of a native aortic valve. The construction of the valve was divided in two sequential steps. The first step was the installation of the thick tissue in a flat preshaping template followed by a 4-week maturation period. The second step was the actual cylindrical 3D forming of the valve. The microscopic tissue structure was assessed using histological cross sections stained with Masson's Trichrome and Picrosirius Red. The thick tissue remained uniformly populated with cells throughout the construction steps and the dense extracellular matrix presented corrugated fibers of collagen. This first prototype of tissue-engineered heart valve was installed in a bioreactor to assess its capacity to sustain a light pulsatile flow at a frequency of 0.5 Hz. Under the light pulsed flow, it was observed that the leaflets opened and closed according to the flow variations. This study demonstrates that the self-assembly method is a viable option for the construction of complex 3D shapes, such as heart valves, with an entirely biological material.

A comparison of current Naval Facilities Engineering Command field office staffing methods, state staffing methods and the construction industry institutes owner contractor work structure

OpenAIRE

Monreal, Michael

2001-01-01

CIVINS (Civilian Institutions) Thesis document This report was generated by accepting a report topic contained in a list of topics on the Civil Engineer Corps Graduate School Information web page. The topic request and description is noted as follows: Topic. How to Measure Staffing Requirements in ROICC offices and Other Acquisition Functions with a description. Description: We base current staffing requirements on history and only adjust from what we have used in the past years. It is sus...

Construction and evaluation of urinary bladder bioreactor for urologic tissue-engineering purposes.

LENUS (Irish Health Repository)

Davis, Niall F

2012-01-31

OBJECTIVE: To design and construct a urinary bladder bioreactor for urologic tissue-engineering purposes and to compare the viability and proliferative activity of cell-seeded extracellular matrix scaffolds cultured in the bioreactor with conventional static growth conditions. MATERIALS AND METHODS: A urinary bladder bioreactor was designed and constructed to replicate physiologic bladder dynamics. The bioreactor mimicked the filling pressures of the human bladder by way of a cyclical low-delivery pressure regulator. In addition, cell growth was evaluated by culturing human urothelial cells (UCs) on porcine extracellular matrix scaffolds in the bioreactor and in static growth conditions for 5 consecutive days. The attachment, viability, and proliferative potential were assessed and compared with quantitative viability indicators and by fluorescent markers for intracellular esterase activity and plasma membrane integrity. Scaffold integrity was characterized with scanning electron microscopy and 4\\

Toshiba's developments on construction techniques of nuclear power plants

International Nuclear Information System (INIS)

Hayashi, Y.; Itoh, N.

1987-01-01

Reliable and economic energy supplies are fundamental requirements of energy policies in Japan. To accomplish these needs, nuclear power plants are being increased in Japan. In recent years, construction cost increases and schedule extensions have affected the capital cost of nuclear energy, compared with fossil power plants, due to lower costs of oil and coal. On the other hand, several severe regulations have been applied to nuclear power plant designs. High-quality and cooperative engineering and harmonized design of equipment and parts are strongly required. Therefore, reduced construction costs and scheduling, as well as higher quality and reliability, are the most important items for nuclear industry. Toshiba has developed new construction techniques, as well as design and engineering tools for control and management, that demonstrate the positive results achieved in the shorter construction period of 1100-MW(electric) nuclear power plants. The normal construction period so far is 64 months, whereas the current construction period is 52 months. (New construction techniques are partially applied). In future years, the construction period will be lowered to 48 months. (New construction techniques are fully applied). A construction period is defined as time from the start of rock inspection to the start of commercial operation

Management for Construction Materials and Control of Construction Waste in Construction Industry: A Review

OpenAIRE

A. A. Gulghane; Prof P. V. Khandve

2015-01-01

In recent treads a wide range of building materials is available for the construction of civil engineering structures. The total cost of materials may be up to 60% or more of the total cost incurred in construction project dependent upon the type of project. Effective construction materials management is a key to success for a construction project. Construction waste is another serious problem in construction industry. A large and various types of construction waste with different...

Tissue Equivalents Based on Cell-Seeded Biodegradable Microfluidic Constructs

Directory of Open Access Journals (Sweden)

Sarah L. Tao

2010-03-01

Full Text Available One of the principal challenges in the field of tissue engineering and regenerative medicine is the formation of functional microvascular networks capable of sustaining tissue constructs. Complex tissues and vital organs require a means to support oxygen and nutrient transport during the development of constructs both prior to and after host integration, and current approaches have not demonstrated robust solutions to this challenge. Here, we present a technology platform encompassing the design, construction, cell seeding and functional evaluation of tissue equivalents for wound healing and other clinical applications. These tissue equivalents are comprised of biodegradable microfluidic scaffolds lined with microvascular cells and designed to replicate microenvironmental cues necessary to generate and sustain cell populations to replace dermal and/or epidermal tissues lost due to trauma or disease. Initial results demonstrate that these biodegradable microfluidic devices promote cell adherence and support basic cell functions. These systems represent a promising pathway towards highly integrated three-dimensional engineered tissue constructs for a wide range of clinical applications.

Building information modelling (BIM) after ten years: Malaysian construction players’ perception of BIM

Science.gov (United States)

Latiffi, A. Ahmad; Brahim, J.; Fathi, M. S.

2017-08-01

Building Information Modelling (BIM) concept has expanded widely in many countries for more than a decade with its role of improving current practices in construction projects. However, the understanding of BIM differs among construction players, depending on how construction players utilize the concept in their projects. Therefore, this paper aims to explore the understanding of BIM concept among construction players in the Malaysian construction industry. A literature review on BIM concept and semi-structured interviews with construction players in BIM such as client, civil and structural (C&S) engineer and mechanical and electrical (M&E) engineer, quantity surveyor (QS), contractor, facilities manager and BIM consultant have been conducted in order to achieve this study’s the aim. The results show that the understanding of BIM concept among the construction players is limited to BIM as a process and technology. It is important for the construction players to improve their understanding of BIM as it can be used to enhance performance and productivity of construction projects.

Constructed Wetlands

Science.gov (United States)

these systems can improve water quality, engineers and scientists construct systems that replicate the functions of natural wetlands. Constructed wetlands are treatment systems that use natural processes

Current progress of targetron technology: development, improvement and application in metabolic engineering.

Science.gov (United States)

Liu, Ya-Jun; Zhang, Jie; Cui, Gu-Zhen; Cui, Qiu

2015-06-01

Targetrons are mobile group II introns that can recognize their DNA target sites by base-pairing RNA-DNA interactions with the aid of site-specific binding reverse transcriptases. Targetron technology stands out from recently developed gene targeting methods because of the flexibility, feasibility, and efficiency, and is particularly suitable for the genetic engineering of difficult microorganisms, including cellulolytic bacteria that are considered promising candidates for biomass conversion via consolidated bioprocessing. Along with the development of the thermotargetron method for thermophiles, targetron technology becomes increasingly important for the metabolic engineering of industrial microorganisms aiming at biofuel/chemical production. To summarize the current progress of targetron technology and provide new insights on the use of the technology, this paper reviews the retrohoming mechanisms of both mesophilic and thermophilic targetron methods based on various group II introns, investigates the improvement of targetron tools for high target efficiency and specificity, and discusses the current applications in the metabolic engineering for bacterial producers. Although there are still intellectual property and technical restrictions in targetron applications, we propose that targetron technology will contribute to both biochemistry research and the metabolic engineering for industrial productions. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Textile Technologies and Tissue Engineering: A Path Towards Organ Weaving

OpenAIRE

Akbari, Mohsen; Tamayol, Ali; Bagherifard, Sara; Serex, Ludovic; Mostafalu, Pooria; Faramarzi, Negar; Mohammadi, Mohammad Hossein; Khademhosseini, Ali

2016-01-01

Textile technologies have recently attracted great attention as potential biofabrication tools for engineering tissue constructs. Using current textile technologies, fibrous structures can be designed and engineered to attain the required properties that are demanded by different tissue engineering applications. Several key parameters such as physiochemical characteristics of fibers, pore size and mechanical properties of the fabrics play important role in the effective use of textile technol...

CD34/CD133 enriched bone marrow progenitor cells promote neovascularization of tissue engineered constructs in vivo

Directory of Open Access Journals (Sweden)

Marietta Herrmann

2014-11-01

We demonstrate that this population of cells, isolated in a clinically relevant manner and cultured with autologous growth factors readily promoted neovascularization in tissue engineered constructs in vivo enabling a potential translation into the clinic.

Structural health monitoring and lifecycle-management for civil engineering constructions in power plants and industrial facilities; Zustandsueberwachung und Lebensdauermanagement von baulichen Einrichtungen in Kraftwerken und Industrieanlagen

Energy Technology Data Exchange (ETDEWEB)

Lehnen, Dieter; Demmer, Martin; Pfister, Tobias [ZERNA Planen und Pruefen GmbH, Bochum (Germany)

2013-09-01

In contrast to other fields of engineering, structural health monitoring and lifecycle management for civil engineering constructions in power plants and industrial facilities have to be developed yet. The necessity of this development immediately arises from the building regulations law with its extensive set of regulations as well as from economic constraints. Approaches and methods of structural health monitoring and lifecycle management for civil engineering constructions in power plants and industrial facilities could be improved intensively during recent years. The paper focuses on practical examples that show the necessity of comprehensive and strategic structural health monitoring in conjunction with lifecycle management for civil engineering constructions in power plants and industrial facilities unambiguously und clear. (orig.)

Videogame Construction by Engineering Students for Understanding Modelling Processes: The Case of Simulating Water Behaviour

Science.gov (United States)

Pretelín-Ricárdez, Angel; Sacristán, Ana Isabel

2015-01-01

We present some results of an ongoing research project where university engineering students were asked to construct videogames involving the use of physical systems models. The objective is to help them identify and understand the elements and concepts involved in the modelling process. That is, we use game design as a constructionist approach…

Pathway Construction in Corynebacterium glutamicum and Strain Engineering To Produce Rare Sugars from Glycerol.

Science.gov (United States)

Yang, Jiangang; Zhu, Yueming; Men, Yan; Sun, Shangshang; Zeng, Yan; Zhang, Ying; Sun, Yuanxia; Ma, Yanhe

2016-12-21

Rare sugars are valuable natural products widely used in pharmaceutical and food industries. In this study, we expected to synthesize rare ketoses from abundant glycerol using dihydroxyacetone phosphate (DHAP)-dependent aldolases. First, a new glycerol assimilation pathway was constructed to synthesize DHAP. The enzymes which convert glycerol to 3-hydroxypropionaldehyde and l-glyceraldehyde were selected, and their corresponding aldehyde synthesis pathways were constructed in vivo. Four aldol pathways based on different aldolases and phosphorylase were gathered. Next, three pathways were assembled and the resulting strains synthesized 5-deoxypsicose, 5-deoxysorbose, and 5-deoxyfructose from glucose and glycerol and produce l-fructose, l-tagatose, l-sorbose, and l-psicose with glycerol as the only carbon source. To achieve higher product titer and yield, the recombinant strains were further engineered and fermentation conditions were optimized. Fed-batch culture of engineered strains obtained 38.1 g/L 5-deoxypsicose with a yield of 0.91 ± 0.04 mol product per mol of glycerol and synthesized 20.8 g/L l-fructose, 10.3 g/L l-tagatose, 1.2 g/L l-sorbose, and 0.95 g/L l-psicose.

The development of the collagen fibre network in tissue-engineered cartilage constructs in vivo. Engineered cartilage reorganises fibre network

Directory of Open Access Journals (Sweden)

H Paetzold

2012-04-01

Full Text Available For long term durability of tissue-engineered cartilage implanted in vivo, the development of the collagen fibre network orientation is essential as well as the distribution of collagen, since expanded chondrocytes are known to synthesise collagen type I. Typically, these properties differ strongly between native and tissue-engineered cartilage. Nonetheless, the clinical results of a pilot study with implanted tissue-engineered cartilage in pigs were surprisingly good. The purpose of this study was therefore to analyse if the structure and composition of the artificial cartilage tissue changes in the first 52 weeks after implantation. Thus, collagen network orientation and collagen type distribution in tissue-engineered cartilage-carrier-constructs implanted in the knee joints of Göttinger minipigs for 2, 26 or 52 weeks have been further investigated by processing digitised microscopy images of histological sections. The comparison to native cartilage demonstrated that fibre orientation over the cartilage depth has a clear tendency towards native cartilage with increasing time of implantation. After 2 weeks, the collagen fibres of the superficial zone were oriented parallel to the articular surface with little anisotropy present in the middle and deep zones. Overall, fibre orientation and collagen distribution within the implants were less homogenous than in native cartilage tissue. Despite a relatively low number of specimens, the consistent observation of a continuous approximation to native tissue is very promising and suggests that it may not be necessary to engineer the perfect tissue for implantation but rather to provide an intermediate solution to help the body to heal itself.

Plasmid DNA transfection using magnetite cationic liposomes for construction of multilayered gene-engineered cell sheet.

Science.gov (United States)

Ino, Kosuke; Kawasumi, Tamayo; Ito, Akira; Honda, Hiroyuki

2008-05-01

Modification of cellular functions by overexpression of genes is being increasingly practiced for tissue engineering. In the present study, we investigated whether transfection efficiency could be enhanced by magnetofection that involves the use of plasmid DNA (pDNA)/magnetite cationic liposomes (MCLs) complexes (pDNA/MCL) and magnetic force. The transfection efficiencies of the magnetofection technique by pDNA/MCL in fibroblasts and keratinocytes using reporter genes were 36- and 10-fold higher, respectively, than those of a lipofection technique by cationic liposomes. Moreover, in vitro construction of three-dimensional (3D) tissues is an important challenge. We recently proposed a novel technique termed "magnetic force-based tissue engineering" (Mag-TE) to produce 3D tissues. Since the fibroblasts after magnetofection incorporated both magnetite nanoparticles and pDNA, we investigated whether multilayered heterotypic cell sheets expressing transgene could be fabricated by Mag-TE. First, the fibroblasts were seeded onto an ultra-low attachment culture plate. When a magnet was placed under the plate, the cells accumulated at the bottom of the culture plate. After 24 h of culture, the transgene-expressing cells formed a multilayered cell sheet-like structure. These results indicated that MCLs are a potent biomanipulation tool for both gene transfer and 3D tissue construction, suggesting that these techniques are useful for tissue engineering. Copyright 2007 Wiley Periodicals, Inc.

Crosstalk between Substrates and Rho-Associated Kinase Inhibitors in Cryopreservation of Tissue-Engineered Constructs

Directory of Open Access Journals (Sweden)

Arindam Bit

2017-01-01

Full Text Available It is documented that human mesenchymal stem cells (hMSCs can be differentiated into various types of cells to present a tool for tissue engineering and regenerative medicine. Thus, the preservation of stem cells is a crucial factor for their effective long-term storage that further facilitates their continuous supply and transportation for application in regenerative medicine. Cryopreservation is the most important, practicable, and the only established mechanism for long-term preservation of cells, tissues, and organs, and engineered tissues; thus, it is the key step for the improvement of tissue engineering. A significant portion of MSCs loses cellular viability while freeze-thawing, which represents an important technical limitation to achieving sufficient viable cell numbers for maximum efficacy. Several natural and synthetic materials are extensively used as substrates for tissue engineering constructs and cryopreservation because they promote cell attachment and proliferation. Rho-associated kinase (ROCK inhibitors can improve the physiological function and postthaw viability of cryopreserved MSCs. This review proposes a crosstalk between substrate topology and interaction of cells with ROCK inhibitors. It is shown that incorporation of ionic nanoparticles in the presence of an external electrical field improves the generation of ROCK inhibitors to safeguard cellular viability for the enhanced cryopreservation of engineered tissues.

Possibilities of Monitoring the Technical Condition of the Combustion Engine with Starter Load Current

Directory of Open Access Journals (Sweden)

Michal Jukl

2014-01-01

Full Text Available This article deals with the verification of relations between the electric current of engine starter and tightness of the combustion chamber and the possibility of its use for the evaluation of the state in terms of engine wear. Engine wear is closely related to the quality of fuel combustion and also with the amount of produced harmful emissions. On this basis, it would be possible to extend the technical requirements of the protocol OBD to include the indirect control of engine wear. To meet the objectives set out above measurement was carried out by a petrol engine, which was located in the vehicle Škoda Felicia Combi GLX 1.3 The whole measurement was divided into several parts. The first measurement was carried out on the abovementioned motor without simulating leakage. The second measurement was performed when the leakage of one cylinder was simulated. Simulated leakage was conducted at removing the spark plugs. Other measurements simulated “mild” leak of the whole engine – all cylinders. Leakage was implemented by loosing all the spark plugs about 8 turns against full tightening with the appropriate torque. The last, fourth measurement simulates a “large” leaks of engine cylinders. This leakage was induced by removing all the spark plugs from all cylinders. As the measurement results showed leakage of one cylinder, and also the whole engine is reflected not only in the individual amplitude of the starter current, but also the shape of the entire curve.

Chiral measurements with the Fixed-Point Dirac operator and construction of chiral currents

International Nuclear Information System (INIS)

Hasenfratz, P.; Hauswirth, S.; Holland, K.; Joerg, T.; Niedermayer, F.

2002-01-01

In this preliminary study, we examine the chiral properties of the parametrized Fixed-Point Dirac operator D FP , see how to improve its chirality via the Overlap construction, measure the renormalized quark condensate Σ-circumflex and the topological susceptibility χ t , and investigate local chirality of near zero modes of the Dirac operator. We also give a general construction of chiral currents and densities for chiral lattice actions

Genetically engineered multivalent single chain antibody constructs for cancer therapy

International Nuclear Information System (INIS)

Surinder Batra

2006-01-01

increase its tumor: normal tissue ratio for improved therapeutic index, we engineered a variety antibody constructs. These constructs were evaluated using novel approaches like special radionuclides, pretargeting and optimization. Due to the smaller size, the engineered antibody molecules should penetrate better throughout a tumor mass, with less dose heterogeneity, than is the case with intact IgG. Multivalent scFvs with an appropriate radionuclide, therefore, hold promising prospects for cancer therapy and clinical imaging in MAb-based radiopharmaceuticals. In addition, the human anti-mouse antibodies (HAMA) responses in patients against antibody-based therapy are usually directed against the immunoglobulin constant regions; however, anti-idiotypic responses can also be detected. The HAMA responses reduce the efficacy of treatment by removing the circulating antibody molecules, fragments, and possibly scFvs by altering the pharmacokinetic properties of the antibody. HAMA responses against divalent IgG, divalent Ig fragments, and possibly multimeric scFvs could cause immune complex formation with hypersensitivity or allergic reactions that could be harmful to patients. The use of small molecules, such as scFvs (monomeric as well as multimeric), with their shorter biological half-lives and the lack of the constant regions and humanized variable (binding regions) performed in our studies should reduce the development of HAMA. The generation of humanized and fully human scFvs should further reduce the development of HAMA. Specific accomplishments on the project are the production of large amounts of recombinant antibodies as they are required in large amounts for cancer diagnosis and therapy. A variety of single-chain Fv (scFv) constructs were engineered for the desired pharmacokinetic properties. Tetrameric and dimeric scFvs showed a two-fold advantage: (1) there was a considerable gain in avidity as compared to smaller fragments, and (2) the biological half-life was more

A review of factors influencing underground construction quality and the performance of engineered features

International Nuclear Information System (INIS)

Talbot, R.; Moy, D.; Breeds, C.D.; Kostelec, C.M.; Emsley, S.J.; Shuttle, D.; Cutler, J.; Hedman, T.; Carlsson, A.

1992-01-01

This report describes research to identify and rank the factors that should be considered for an assessment of the radioactive containment capability of repository engineered features. Containment is to be achieved through the use of multiple barriers to radionuclide movement, including the waste, waste container, repository structures and backfill, and repository seals. A review of the literature is used to identify radionuclide mobilisation and transport processes for the anticipated environmental conditions, and to compile a data base of repository design features, functional requirements, and design objectives. For selected design components, the report identifies alternative designs and factors contributing to design, focusing on the requirements for a design process, design specifications, construction requirements, and quality assurance requirements for the both design and construction. Existing practice in large, underground civil construction projects is used as a part of comparison, in conjunction with reported performance assessments, to determine those areas in which the repository developer will need to provide additional data, justification, and documentation prior to construction to ensure that performance requirements can be achieved. (Author)

The Design, Construction, and Experimental Evaluation of a Compact Thermoacoustic-Stirling Engine Generator for Use in a micro-CHP Appliance

Science.gov (United States)

Wilcox, Douglas A., Jr.

Micro combined heat and power or micro-CHP is the simultaneous generation of useful heat and electricity on a residential scale. The heat and electricity are produced at the point of use, avoiding the distribution losses associated with a centralized power plant. These appliances combine a conventional gas-fired condensing boiler with an electric power module capable of generating electricity from the heat of combustion. Currently, the leading power modules for micro-CHP appliances are free-piston Stirling engines (FPSEs) which can generate 1050 watts of electricity at a thermal-to-electric efficiency of 26%.[1] These external combustion engines have been under development for the last 25 years, with FPSE micro-CHP appliances only recently being introduced to the commercial market. Publications by developers assert unlimited service life and high efficiency, with low noise and emissions; but despite these claims, the actual reliability and cost of manufacturing has prevented their successful mass-market adoption. A Thermoacoustic-Stirling Engine Generator or TaSEG is one possible alternative to FPSE's. A TaSEG uses a thermoacoustic engine, or acoustic heat engine, which can efficiently convert high temperature heat into acoustic power while maintaining a simple design with fewer moving parts than traditional FPSE's. This simpler engine is coupled to an electrodynamic alternator capable of converting acoustic power into electricity. This thesis outlines the design, construction, and experimental evaluation of a TaSEG which is appropriate for integration with a gas burner inside of a residential micro- CHP appliance. The design methodology is discussed, focusing on how changes in the geometry affected the predicted performance. Details of its construction are given and the performance of the TaSEG is then outlined. The TaSEG can deliver 132 watts of electrical output power to an electric load with an overall measured thermal-to-electric (first law) efficiency of eta

Sustainable Construction Supply Chains through Synchronized Production Planning and Control in Engineer-to-Order Enterprises

Directory of Open Access Journals (Sweden)

Patrick Dallasega

2017-10-01

Full Text Available Sustainability in the supply chain is becoming more and more important for industrial enterprises in different sectors. This research article focuses on construction supply chains (CSCs in the Engineer-to-Order (ETO industry, where every product is almost unique based on specific customer needs and requirements. The development of methods and approaches for more sustainable supply chain management in construction is becoming even more important. Engineering, fabrication of parts and their installation on-site are not always well synchronized in ETO supply chains. The results of such supply chains are long lead times, inefficient material transport and high and uncontrolled levels of work-in-progress (WIP. This article describes a conceptual approach to synchronize demand on-site with supply in manufacturing using the CONstant Work In Progress (ConWIP concept from Lean Management to achieve Just-in-Time (JIT supply. As a result, sustainable supply chains in ETO enterprises, with optimizations from an economic, ecological and social point of view, can be designed. The approach has been validated in an industrial case study.

48 CFR 227.7107-1 - Architectural designs and data clauses for architect-engineer or construction contracts.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Architectural designs and... construction involving architect-engineer services, is to obtain a unique architectural design of a building, a... CONTRACTING REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS Rights in Technical Data 227.7107-1 Architectural...

Wood products used in constructing conservation and development projects by the Corps of Engineers in the United States, 1962 and 1978

Science.gov (United States)

W. H. Reid; D. B. McKeever

Estimates of the amounts of wood products used in constructing civil conservation and development projects by the Corps of Engineers in the United States are presented for the years 1962 and 1978. Amounts of lumber, laminated lumber, poles and piling, and plywood used in construction are stratified by five construction categories, and three types of uses. Estimates of...

Flexible metabolic pathway construction using modular and divisible selection gene regulators

DEFF Research Database (Denmark)

Rugbjerg, Peter; Myling-Petersen, Nils; Sommer, Morten Otto Alexander

2015-01-01

Genetic selections are important to biological engineering. Although selectable traits are limited,currently each trait only permits simultaneous introduction of a single DNA fragment. Complex pathwayand strain construction however depends on rapid, combinatorial introduction of many genes thaten...

Concept document of the repository-based software engineering program: A constructive appraisal

Science.gov (United States)

1992-01-01

A constructive appraisal of the Concept Document of the Repository-Based Software Engineering Program is provided. The Concept Document is designed to provide an overview of the Repository-Based Software Engineering (RBSE) Program. The Document should be brief and provide the context for reading subsequent requirements and product specifications. That is, all requirements to be developed should be traceable to the Concept Document. Applied Expertise's analysis of the Document was directed toward assuring that: (1) the Executive Summary provides a clear, concise, and comprehensive overview of the Concept (rewrite as necessary); (2) the sections of the Document make best use of the NASA 'Data Item Description' for concept documents; (3) the information contained in the Document provides a foundation for subsequent requirements; and (4) the document adequately: identifies the problem being addressed; articulates RBSE's specific role; specifies the unique aspects of the program; and identifies the nature and extent of the program's users.

Countermeasures for China’s Ecological Environment Construction in Land Reclamation

Institute of Scientific and Technical Information of China (English)

Chen; LI; Xinfeng; LIU; Zhe; PENG; Tao; SI; Lingfeng; KONG

2013-01-01

Basic situation of the current ecological environment construction in land consolidation and rehabilitation of China is introduced. The related advanced experience abroad is summarized from mainly four aspects, namely policy, system as well as subject development, planning guidance, design method of project planning and engineering study, and practical countermeasures to China’s ecological environment construction in land reclamation are proposed. In terms of policy, system and subject, relevant regulations, policies and system construction should be strengthened and the framework of policy, system and subject development in ecological landscape construction of China’s land reclamation should be proposed, integrating ecological environment construction into land reclamation. At the level of strategic planning, the spatial layout and construction key points of green infrastructure in land reclamation of "urban multi-functional developing region, eastern economic developed region, central modern agricultural region and northwestern ecological fragile region" should be achieved. At the level of project planning design, ecological principles, sustainable landscape design principles and vernacular landscape design methods are to be integrated into the planning procedure to form operable technique regulations or introductions. At the level of engineering design, engineering technique system, standards and regulations of ditches, roads, forests and channels with local distinctions should be formulated according to the characters and strategic demands of urbanization, industrialization, agriculture modernization and ecological environment preservation in different regions.

Study on construction technology for repository

International Nuclear Information System (INIS)

Tanai, Kenji; Iwasa, Kengo; Hasegawa, Hiroshi; Miura, Kazuhiko; Okutsu, Kazuo; Kobayashi, Masaaki

1999-11-01

established and integrated through the construction of an underground research laboratory and of engineering technologies that are currently in the planning stages. Once a site is selected, an optimized integrated construction system suitable to the detailed geological environment conditions and the specification of each tunnel (shape, dimensions) will be selected. (author)

Engineering Critical Current Density Improvement in Ag- Bi-2223 Tapes

DEFF Research Database (Denmark)

Wang, W. G.; Seifi, Behrouz; Eriksen, Morten

2000-01-01

Ag alloy sheathed Bi-2223 multifilament tapes were produced by the powder-in-tube method. Engineering critical current density improvement has been achieved through both enhancement of critical current density by control of the thermal behavior of oxide powder and by an increase of the filling...... factor of the tapes. Phase evolution at initial sintering stage has been studied by a quench experiment in Ag-Bi-2223 tapes. The content, texture, and microstructure of various phases were determined by XRD and SEM. A novel process approach has been invented in which square wire was chosen rather than...

High field, low current operation of engineering test reactors

International Nuclear Information System (INIS)

Schwartz, J.; Cohn, D.R.; Bromberg, L.; Williams, J.E.C.

1987-06-01

Steady state engineering test reactors with high field, low current operation are investigated and compared to high current, lower field concepts. Illustrative high field ETR parameters are R = 3 m, α ∼ 0.5 m, B ∼ 10 T, β = 2.2% and I = 4 MA. For similar wall loading the fusion power of an illustrative high field, low current concept could be about 50% that of a lower field device like TIBER II. This reduction could lead to a 50% decrease in tritium consumption, resulting in a substantial decrease in operating cost. Furthermore, high field operation could lead to substantially reduced current drive requirements and cost. A reduction in current drive source power on the order of 40 to 50 MW may be attainable relative to a lower field, high current design like TIBER II implying a possible cost savings on the order of $200 M. If current drive is less efficient than assumed, the savings could be even greater. Through larger β/sub p/ and aspect ratio, greater prospects for bootstrap current operation also exist. Further savings would be obtained from the reduced size of the first wall/blanket/shield system. The effects of high fields on magnet costs are very dependent on technological assumptions. Further improvements in the future may lie with advances in superconducting and structural materials

Engineering endostatin-producing cartilaginous constructs for cartilage repair using nonviral transfection of chondrocyte-seeded and mesenchymal-stem-cell-seeded collagen scaffolds.

Science.gov (United States)

Jeng, Lily; Olsen, Bjorn R; Spector, Myron

2010-10-01

Although there is widespread recognition of the importance of angiogenesis in tissue repair, there is little work on the inhibition of angiogenesis in the context of tissue engineering of naturally avascular tissues, like articular cartilage. The objective was to engineer a collagen-scaffold-based cartilaginous construct overexpressing a potent antiangiogenic factor, endostatin, using nonviral transfection. Endostatin-plasmid-supplemented collagen scaffolds were seeded with mesenchymal stem cells and chondrocytes and cultured for 20–22 days. The effects of the following variables on endostatin expression and chondrogenesis were examined: collagen scaffold material, method of nonviral vector incorporation, plasmid load, culture medium, and oxygen tension. An increase and peak of endostatin protein was observed during the first week of culture, followed by a decrease to low levels, suggesting that overexpression of endostatin could be sustained for several days using the nonviral vector. The amount of endostatin produced was tunable with the external factors. Chondrogenesis was observed in the engineered constructs cultured in chondrogenic medium at the 3-week time point, demonstrating that endostatin did not inhibit the chondrogenic potential of mesenchymal stem cells or the general viability of the cells. The ability to engineer endostatin-expressing cartilaginous constructs will be of value for future work exercising regulatory control of angiogenesis in cartilage repair.

Current earthquake engineering practice for Japanese nuclear power plants

International Nuclear Information System (INIS)

Hofmayer, C.H.; Park, Y.J.; Costello, J.F.

1992-01-01

This paper provides a brief overview of seismic research being conducted in Japan and describes USNRC efforts to understand Japanese seismic practice. Current earthquake engineering practice for Japanese nuclear power plants is descried in JEAG 4601-1987, ''Technical Guidelines for Aseismic Design of Nuclear Power Plants.'' The USNRC has sponsored BNL to translate this document into English. Efforts are underway to study and understand JEAG 4601-1987 and make the translation more readily available in the United States

Modularization for ground engineering construction in the Anyue Gasfield, Sichuan Basin, with the designed annual gas processing capacity of six billion m3

Directory of Open Access Journals (Sweden)

Chaoming Chen

2016-12-01

Full Text Available In the Anyue Gasfield, Sichuan Basin, the Lower Cambrian Longwangmiao Fm gas reservoir in Moxi Block has enormous natural gas reserves, and it is a typical three-high (high temperature, high pressure, and high flow rate sour gas field. Its ground engineering project (with the designed gas processing capacity of 60 × 108 m3/a is characterized by high processing rate of each unit, complex process control, large construction load, restricted construction site and tight schedule. Based on the traditional engineering construction mode, however, it is difficult to complete the project design and construction within 16 months. In view of this, the design concept of unit large-scale modularization was introduced to implement “normalized design, scale purchase, factory-like prefabrication and modularized construction” and develop the modularization technology of large-scale surface engineering construction. This modularization technology is performed as follows. First, the modularized units are laid out reasonably according to the technological process. Second, the layout of modularized units is usually superimposed in the multi-layer framework. Third, those equipments with the same or similar operational modes, medium properties, functional characteristics and installation requirements are concentrated in the pattern of a module. Fourth, escape passageway is specially set up. Fifth, room for installation, maintenance and repair of large equipments is reserved. And sixth, transportation and hoisting requirements of modules are taken into consideration sufficiently. This technology is contributive to the improvement of design quality, effective shortening of design period, reduction of field working load, decrease of safety management risk of on-site installation, increase of production efficiency, conservation of land occupation and diminishment of construction investment. It plays a reference role in the modularized construction of surface

An impedance method for spatial sensing of 3D cell constructs – towards applications in tissue engineering

DEFF Research Database (Denmark)

Canali, Chiara; Mazzoni, Chiara; Larsen, Layla Bashir

2015-01-01

) cells were encapsulated in gelatin to form artificial 3D cell constructs and detected when placed in different positions inside large gelatin scaffolds. Taken together, these results open new perspectives for impedance-based sensing technologies for non-invasive monitoring in tissue engineering...

Enhanced nutrient transport improves the depth-dependent properties of tri-layered engineered cartilage constructs with zonal co-culture of chondrocytes and MSCs.

Science.gov (United States)

Kim, Minwook; Farrell, Megan J; Steinberg, David R; Burdick, Jason A; Mauck, Robert L

2017-08-01

Biomimetic design in cartilage tissue engineering is a challenge given the complexity of the native tissue. While numerous studies have generated constructs with near-native bulk properties, recapitulating the depth-dependent features of native tissue remains a challenge. Furthermore, limitations in nutrient transport and matrix accumulation in engineered constructs hinders maturation within the central core of large constructs. To overcome these limitations, we fabricated tri-layered constructs that recapitulate the depth-dependent cellular organization and functional properties of native tissue using zonally derived chondrocytes co-cultured with MSCs. We also introduced porous hollow fibers (HFs) and HFs/cotton threads to enhance nutrient transport. Our results showed that tri-layered constructs with depth-dependent organization and properties could be fabricated. The addition of HFs or HFs/threads improved matrix accumulation in the central core region. With HF/threads, the local modulus in the deep region of tri-layered constructs nearly matched that of native tissue, though the properties in the central regions remained lower. These constructs reproduced the zonal organization and depth-dependent properties of native tissue, and demonstrate that a layer-by-layer fabrication scheme holds promise for the biomimetic repair of focal cartilage defects. Articular cartilage is a highly organized tissue driven by zonal heterogeneity of cells, extracellular matrix proteins and fibril orientations, resulting in depth-dependent mechanical properties. Therefore, the recapitulation of the functional properties of native cartilage in a tissue engineered construct requires such a biomimetic design of the morphological organization, and this has remained a challenge in cartilage tissue engineering. This study demonstrates that a layer-by-layer fabrication scheme, including co-cultures of zone-specific articular CHs and MSCs, can reproduce the depth-dependent characteristics

Structural Learning Theory: Current Status and New Perspectives.

Science.gov (United States)

Scandura, Joseph M.

2001-01-01

Presents the current status and new perspectives on the Structured Learning Theory (SLT), with special consideration given to how SLT has been influenced by recent research in software engineering. Topics include theoretical constructs; content domains; structural analysis; cognition; assessing behavior potential; and teaching and learning issues,…

Bioreactors as Engineering Support to Treat Cardiac Muscle and Vascular Disease

Directory of Open Access Journals (Sweden)

Diana Massai

2013-01-01

Full Text Available Cardiovascular disease is the leading cause of morbidity and mortality in the Western World. The inability of fully differentiated, load-bearing cardiovascular tissues to in vivo regenerate and the limitations of the current treatment therapies greatly motivate the efforts of cardiovascular tissue engineering to become an effective clinical strategy for injured heart and vessels. For the effective production of organized and functional cardiovascular engineered constructs in vitro, a suitable dynamic environment is essential, and can be achieved and maintained within bioreactors. Bioreactors are technological devices that, while monitoring and controlling the culture environment and stimulating the construct, attempt to mimic the physiological milieu. In this study, a review of the current state of the art of bioreactor solutions for cardiovascular tissue engineering is presented, with emphasis on bioreactors and biophysical stimuli adopted for investigating the mechanisms influencing cardiovascular tissue development, and for eventually generating suitable cardiovascular tissue replacements.

Mechanical evaluation of a tissue-engineered zone of calcification in a bone–hydrogel osteochondral construct

Science.gov (United States)

Hollenstein, Jérôme; Terrier, Alexandre; Cory, Esther; Chen, Albert C.; Sah, Robert L.; Pioletti, Dominique P.

2016-01-01

The objective of this study was to test the hypothesis that mechanical properties of artificial osteochondral constructs can be improved by a tissue-engineered zone of calcification (teZCC) at the bone–hydrogel interface. Experimental push-off tests were performed on osteochondral constructs with or without a teZCC. In parallel, a numerical model of the osteochondral defect treatment was developed and validated against experimental results. Experimental results showed that the shear strength at the bone–hydrogel interface increased by 100% with the teZCC. Numerical predictions of the osteochondral defect treatment showed that the shear stress at the bone–hydrogel interface was reduced with the teZCC. We conclude that a teZCC in osteochondral constructs can provide two improvements. First, it increases the strength of the bone–hydrogel interface and second, it reduces the stress at this interface. PMID:23706035

Reactor engineering and engineered reactor safety in France

International Nuclear Information System (INIS)

1987-01-01

The proceedings give the full text of the lectures held by acknowledged French experts at the KTG Seminar in Mainz on March 10, 1987, all dealing with the leading topic of the current status of reactor engineering and development in France. Although the basic engineering principles and construction lines as well as the safety philosophy are the same in France as in West Germany, there have been distinctive developments over many years in the two countries that by now are not well known even among experts in this field, and hence cannot be properly assessed. Non-availability of relevant surveys or other type of literature in the German language reviewing the French developments is another factor that hitherto was a handicap to mutual exchange of information. The seminar was intended to close this gap. The proceedings should be read by all those in West Germany who wish to be informed about the developments in reactor engineering and reactor safety in France. (orig./DG) [de

South Carolina School Facilities Planning and Construction Guide.

Science.gov (United States)

South Carolina State Dept. of Education, Columbia. Office of School Planning and Building.

This publication, the result of a review of state school construction regulations, was developed for the purpose of providing an up-to-date guide on current laws, regulations, and the technology of the building profession. It is intended for architects and engineers as well as for school superintendents and boards of trustees, all of whom are…

CONSTRUCTION OF AN INSTRUMENT OF VOCATIONAL PREFERENCES FOR ENGINEERING CAREERS: THE IPVI INVENTORY

Directory of Open Access Journals (Sweden)

CARLOS E. ZERPA

2007-11-01

Full Text Available The main purpose of this work is to present the construction process and the most important psychometrical properties of a vocational preference test which we hope will prove to be a useful tool to help future engineering students make vocational decisions. The test may help to clarify the possible options within the general areas of study, according to the different specializations available. Originally, the IPVI included 14 subscales that corresponded to thesame number of engineering specializations offered in a Venezuelan university. The factorial structure underlying local data was studied through a sample of 174 engineering students, males and females, between 16 and 24 years old, via a factorial analysis of the consistency of the instrument and each subscale through Cronbach Alpha coefficient. An analysis of the main components was carried out and a new version of seven categories was made which was administrated to a sample of 456 students of both sexes, of ages between 16 and 25, from an important Venezuelan higher education institution. The factors found support the proposed dimensions in the second study. Some psychometric properties and implications for vocational counseling will be discussed.

Engineering graphics theoretical foundations of engineering geometry for design

CERN Document Server

Brailov, Aleksandr Yurievich

2016-01-01

This professional treatise on engineering graphics emphasizes engineering geometry as the theoretical foundation for communication of design ideas with real world structures and products. It considers each theoretical notion of engineering geometry as a complex solution of direct- and inverse-problems of descriptive geometry and each solution of basic engineering problems presented is accompanied by construction of biunique two- and three-dimension models of geometrical images. The book explains the universal structure of formal algorithms of the solutions of positional, metric, and axonometric problems, as well as the solutions of problems of construction in developing a curvilinear surface. The book further characterizes and explains the added laws of projective connections to facilitate construction of geometrical images in any of eight octants. Laws of projective connections allow constructing the complex drawing of a geometrical image in the American system of measurement and the European system of measu...

Tissue-engineered bone constructed in a bioreactor for repairing critical-sized bone defects in sheep.

Science.gov (United States)

Li, Deqiang; Li, Ming; Liu, Peilai; Zhang, Yuankai; Lu, Jianxi; Li, Jianmin

2014-11-01

Repair of bone defects, particularly critical-sized bone defects, is a considerable challenge in orthopaedics. Tissue-engineered bones provide an effective approach. However, previous studies mainly focused on the repair of bone defects in small animals. For better clinical application, repairing critical-sized bone defects in large animals must be studied. This study investigated the effect of a tissue-engineered bone for repairing critical-sized bone defect in sheep. A tissue-engineered bone was constructed by culturing bone marrow mesenchymal-stem-cell-derived osteoblast cells seeded in a porous β-tricalcium phosphate ceramic (β-TCP) scaffold in a perfusion bioreactor. A critical-sized bone defect in sheep was repaired with the tissue-engineered bone. At the eighth and 16th week after the implantation of the tissue-engineered bone, X-ray examination and histological analysis were performed to evaluate the defect. The bone defect with only the β-TCP scaffold served as the control. X-ray showed that the bone defect was successfully repaired 16 weeks after implantation of the tissue-engineered bone; histological sections showed that a sufficient volume of new bones formed in β-TCP 16 weeks after implantation. Eight and 16 weeks after implantation, the volume of new bones that formed in the tissue-engineered bone group was more than that in the β-TCP scaffold group (P bone improved osteogenesis in vivo and enhanced the ability to repair critical-sized bone defects in large animals.

Biphasic Finite Element Modeling Reconciles Mechanical Properties of Tissue-Engineered Cartilage Constructs Across Testing Platforms.

Science.gov (United States)

Meloni, Gregory R; Fisher, Matthew B; Stoeckl, Brendan D; Dodge, George R; Mauck, Robert L

2017-07-01

Cartilage tissue engineering is emerging as a promising treatment for osteoarthritis, and the field has progressed toward utilizing large animal models for proof of concept and preclinical studies. Mechanical testing of the regenerative tissue is an essential outcome for functional evaluation. However, testing modalities and constitutive frameworks used to evaluate in vitro grown samples differ substantially from those used to evaluate in vivo derived samples. To address this, we developed finite element (FE) models (using FEBio) of unconfined compression and indentation testing, modalities commonly used for such samples. We determined the model sensitivity to tissue radius and subchondral bone modulus, as well as its ability to estimate material parameters using the built-in parameter optimization tool in FEBio. We then sequentially tested agarose gels of 4%, 6%, 8%, and 10% weight/weight using a custom indentation platform, followed by unconfined compression. Similarly, we evaluated the ability of the model to generate material parameters for living constructs by evaluating engineered cartilage. Juvenile bovine mesenchymal stem cells were seeded (2 × 10 7 cells/mL) in 1% weight/volume hyaluronic acid hydrogels and cultured in a chondrogenic medium for 3, 6, and 9 weeks. Samples were planed and tested sequentially in indentation and unconfined compression. The model successfully completed parameter optimization routines for each testing modality for both acellular and cell-based constructs. Traditional outcome measures and the FE-derived outcomes showed significant changes in material properties during the maturation of engineered cartilage tissue, capturing dynamic changes in functional tissue mechanics. These outcomes were significantly correlated with one another, establishing this FE modeling approach as a singular method for the evaluation of functional engineered and native tissue regeneration, both in vitro and in vivo.

Construction management at the SP-100 ground engineering system test site

International Nuclear Information System (INIS)

Burchell, G.P.; Wilson, L.R.

1991-01-01

Contractors under the U.S. Department of Energy management have implemented a comprehensive approach to the management of design and construction of the complex facility modifications at the SP-100 Ground Engineering System Test Site on the Hanford Reservation. The SP-100 Test Site employs a multi-organizational integrated management approach with clearly defined responsibilities to assure success. This approach allows for thorough planning and analysis before the project kick off, thus minimizing the number and magnitude of problems which arise during the course of the project. When combined with a comprehensive cost and schedule/project management reporting system the problems which do occur are recognized early enough to assure timely intervention and resolution

Key features and progress of the KSTAR tokamak engineering

International Nuclear Information System (INIS)

Bak, J.S.; Choi, C.H.; Oh, Y.K.

2003-01-01

Substantial progress of the KSTAR tokamak engineering has been made on major tokamak structures, superconducting magnets, in-vessel components, diagnostic system, heating system, and power supplies. The engineering design has been elaborated to the extent necessary to allow a realistic assessment of its feasibility, performance, and cost. The prototype fabrication has been carried out to establish the reliable fabrication technologies and to confirm the validation of analyses employed for the KSTAR design. The completion of experimental building with beneficial occupancy for machine assembly was accomplished in Sep. 2002. The construction of special utility such as cryo-plant, de-ionized water-cooling system, and main power station will begin upon completion of building construction. The commissioning, construction, fabrication, and assembly of the whole facility will be going on by the end of 2005. This paper describes the main design features and engineering progress of the KSTAR tokamak, and elaborates the work currently underway. (author)

Software engineering the current practice

CERN Document Server

Rajlich, Vaclav

2011-01-01

INTRODUCTION History of Software EngineeringSoftware PropertiesOrigins of SoftwareBirth of Software EngineeringThird Paradigm: Iterative ApproachSoftware Life Span ModelsStaged ModelVariants of Staged ModelSoftware Technologies Programming Languages and CompilersObject-Oriented TechnologyVersion Control SystemSoftware ModelsClass DiagramsUML Activity DiagramsClass Dependency Graphs and ContractsSOFTWARE CHANGEIntroduction to Software ChangeCharacteristics of Software ChangePhases of Software ChangeRequirements and Their ElicitationRequirements Analysis and Change InitiationConcepts and Concept

Silk: a potential medium for tissue engineering.

Science.gov (United States)

Sobajo, Cassandra; Behzad, Farhad; Yuan, Xue-Feng; Bayat, Ardeshir

2008-01-01

Human skin is a complex bilayered organ that serves as a protective barrier against the environment. The loss of integrity of skin by traumatic experiences such as burns and ulcers may result in considerable disability or ultimately death. Therefore, in skin injuries, adequate dermal substitutes are among primary care targets, aimed at replacing the structural and functional properties of native skin. To date, there are very few single application tissue-engineered dermal constructs fulfilling this criterion. Silk produced by the domestic silkworm, Bombyx mori, has a long history of use in medicine. It has recently been increasingly investigated as a promising biomaterial for dermal constructs. Silk contains 2 fibrous proteins, sericin and fibroin. Each one exhibits unique mechanical and biological properties. Comprehensive review of randomized-controlled trials investigating current dermal constructs and the structures and properties of silk-based constructs on wound healing. This review revealed that silk-fibroin is regarded as the most promising biomaterial, providing options for the construction of tissue-engineered skin. The research available indicates that silk fibroin is a suitable biomaterial scaffold for the provision of adequate dermal constructs.

A Study on Nonconformance and Construction Method Improvement for Nuclear Power Plant

International Nuclear Information System (INIS)

Kim, Jong Yeob; Roh, Myung Sub

2014-01-01

Advanced power reactor was developed by domestic technology, and finally exported to abroad. In order to place the current nuclear power industrial base, construction has played a big role. Without magnificent construction technology, it would have been impossible to get a safe nuclear power plant on time and in budget. Construction industry occupies very large portion of the economy in South Korea and it has been a core of South Korea's economic growth. With a competitive construction industry and advanced nuclear power plant construction know-how, South Korea could provide safe and reliable nuclear power plants in domestic and world. However there are many repairs and number of corrective actions are in actual construction. Thus, this paper suggested the result of nonconformance and construction method improvement for nuclear power plant. Constructional engineering is a kind of science that has a variety of disciplines including structure, geology, mechanical equipment and other fields. Thus, the development of constructional engineering is closely associated with experience from failure and application advanced construction method. The recent experience in nuclear power plants construction has shown that those improved methods are fully applicable and can help shorten the construction schedule. The future of nuclear power plant construction seems to be more encouraged, even though it has many obstacles

Design, engineering, and construction of photosynthetic microbial cell factories for renewable solar fuel production.

Science.gov (United States)

Lindblad, Peter; Lindberg, Pia; Oliveira, Paulo; Stensjö, Karin; Heidorn, Thorsten

2012-01-01

There is an urgent need to develop sustainable solutions to convert solar energy into energy carriers used in the society. In addition to solar cells generating electricity, there are several options to generate solar fuels. This paper outlines and discusses the design and engineering of photosynthetic microbial systems for the generation of renewable solar fuels, with a focus on cyanobacteria. Cyanobacteria are prokaryotic microorganisms with the same type of photosynthesis as higher plants. Native and engineered cyanobacteria have been used by us and others as model systems to examine, demonstrate, and develop photobiological H(2) production. More recently, the production of carbon-containing solar fuels like ethanol, butanol, and isoprene have been demonstrated. We are using a synthetic biology approach to develop efficient photosynthetic microbial cell factories for direct generation of biofuels from solar energy. Present progress and advances in the design, engineering, and construction of such cyanobacterial cells for the generation of a portfolio of solar fuels, e.g., hydrogen, alcohols, and isoprene, are presented and discussed. Possibilities and challenges when introducing and using synthetic biology are highlighted.

Design, Engineering, and Construction of Photosynthetic Microbial Cell Factories for Renewable Solar Fuel Production

Energy Technology Data Exchange (ETDEWEB)

Lindblad, Peter; Lindberg, Pia; Stensjoe, Karin (Photochemistry and Molecular Science, Dept. of Chemistry-Aangstroem Laboratory, Uppsala Univ., Uppsala (Sweden)), E-mail: Peter.Lindblad@kemi.uu.se; Oliveira, Paulo (Instituto de Biologia Molecular e Celular, Porto (Portugal)); Heidorn, Thorsten (Bioforsk-Norwegian Inst. for Agricultural and Environmental Research, Aas Oslo, (Norway))

2012-03-15

There is an urgent need to develop sustainable solutions to convert solar energy into energy carriers used in the society. In addition to solar cells generating electricity, there are several options to generate solar fuels. This paper outlines and discusses the design and engineering of photosynthetic microbial systems for the generation of renewable solar fuels, with a focus on cyanobacteria. Cyanobacteria are prokaryotic microorganisms with the same type of photosynthesis as higher plants. Native and engineered cyanobacteria have been used by us and others as model systems to examine, demonstrate, and develop photobiological H{sub 2} production. More recently, the production of carbon-containing solar fuels like ethanol, butanol, and isoprene have been demonstrated. We are using a synthetic biology approach to develop efficient photosynthetic microbial cell factories for direct generation of biofuels from solar energy. Present progress and advances in the design, engineering, and construction of such cyanobacterial cells for the generation of a portfolio of solar fuels, e.g., hydrogen, alcohols, and isoprene, are presented and discussed. Possibilities and challenges when introducing and using synthetic biology are highlighted

Tissue engineered vascular grafts: Origins, development, and current strategies for clinical application.

Science.gov (United States)

Benrashid, Ehsan; McCoy, Christopher C; Youngwirth, Linda M; Kim, Jina; Manson, Roberto J; Otto, James C; Lawson, Jeffrey H

2016-04-15

Since the development of a dependable and durable synthetic non-autogenous vascular conduit in the mid-twentieth century, the field of vascular surgery has experienced tremendous growth. Concomitant with this growth, development in the field of bioengineering and the development of different tissue engineering techniques have expanded the armamentarium of the surgeon for treating a variety of complex cardiovascular diseases. The recent development of completely tissue engineered vascular conduits that can be implanted for clinical application is a particularly exciting development in this field. With the rapid advances in the field of tissue engineering, the great hope of the surgeon remains that this conduit will function like a true blood vessel with an intact endothelial layer, with the ability to respond to endogenous vasoactive compounds. Eventually, these engineered tissues may have the potential to supplant older organic but not truly biologic technologies, which are used currently. Copyright © 2015 Elsevier Inc. All rights reserved.

Knowledge Management Practice in Two Australian Architecture-Engineering-Construction (AEC Companies

Directory of Open Access Journals (Sweden)

Patrick Zou

2012-11-01

Full Text Available Knowledge management (KM could be described as a management system that supports the creation, sharing and retrieving of valued information, expertise and insight within and across communities of people and related organizations using information and communication technologies and hence it is a combination of the effective application of information technlogy and management of human resources. KM is becoming a core competitive factor in construction operations. This paper presents the results of two case studies of KM practices in large AEC (architecture, engineering and construction companies through desk-top study and semi-structured interviews. The results indicate that implementing KM in AEC companies leads to competitive advantages and improved decision-making, problem solving and business performance. The results also indicateed that while technology plays an important role, top management commitment, total employee involvement, performance assessment and the culture of knowledge-learning and sharing must be considered when implementing KM. Therefore it is suggested that the implementation of KM should incorporate the company's vision, work processes, technology and culture, to improve the ability of knowledge creating, capturing, sharing, retrieving and ultimately, to improve the company's competitive advantage, decision making, problem solving and innovation.

Dynamic culture of a thermosensitive collagen hydrogel as an extracellular matrix improves the construction of tissue-engineered peripheral nerve.

Science.gov (United States)

Huang, Lanfeng; Li, Rui; Liu, Wanguo; Dai, Jin; Du, Zhenwu; Wang, Xiaonan; Ma, Jianchao; Zhao, Jinsong

2014-07-15

Tissue engineering technologies offer new treatment strategies for the repair of peripheral nerve injury, but cell loss between seeding and adhesion to the scaffold remains inevitable. A thermosensitive collagen hydrogel was used as an extracellular matrix in this study and combined with bone marrow mesenchymal stem cells to construct tissue-engineered peripheral nerve composites in vitro. Dynamic culture was performed at an oscillating frequency of 0.5 Hz and 35° swing angle above and below the horizontal plane. The results demonstrated that bone marrow mesenchymal stem cells formed membrane-like structures around the poly-L-lactic acid scaffolds and exhibited regular alignment on the composite surface. Collagen was used to fill in the pores, and seeded cells adhered onto the poly-L-lactic acid fibers. The DNA content of the bone marrow mesenchymal stem cells was higher in the composites constructed with a thermosensitive collagen hydrogel compared with that in collagen I scaffold controls. The cellular DNA content was also higher in the thermosensitive collagen hydrogel composites constructed with the thermosensitive collagen hydrogel in dynamic culture than that in static culture. These results indicate that tissue-engineered composites formed with thermosensitive collagen hydrogel in dynamic culture can maintain larger numbers of seeded cells by avoiding cell loss during the initial adhesion stage. Moreover, seeded cells were distributed throughout the material.

Eddy current testing for blade edge micro cracks of aircraft engine

Science.gov (United States)

Zhang, Wei-min; Xu, Min-dong; Gao, Xuan-yi; Jin, Xin; Qin, Feng

2017-10-01

Based on the problems of low detection efficiency in the micro cracks detection of aircraft engine blades, a differential excitation eddy current testing system was designed and developed. The function and the working principle of the system were described, the problems which contained the manufacture method of simulated cracks, signal generating, signal processing and the signal display method were described. The detection test was carried out by taking a certain model aircraft engine blade with simulated cracks as a tested specimen. The test data was processed by digital low-pass filter in the computer and the crack signals of time domain display and Lissajous figure display were acquired. By comparing the test results, it is verified that Lissajous figure display shows better performance compared to time domain display when the crack angle is small. The test results show that the eddy current testing system designed in this paper is feasible to detect the micro cracks on the aeroengine blade and can effectively improve the detection efficiency of micro cracks in the practical detection work.

The in vivo characteristics of genetically engineered divalent and tetravalent single-chain antibody constructs

International Nuclear Information System (INIS)

Wittel, Uwe A.; Jain, Maneesh; Goel, Apollina; Chauhan, Subhash C.; Colcher, David; Batra, Surinder K.

2005-01-01

Engineered multivalent single-chain Fv (scFv) constructs have been demonstrated to exhibit rapid blood clearance and better tumor penetration. To understand the short plasma half-life of multivalent single-chain antibody fragments, the pharmacokinetic properties of covalent dimeric scFv [sc(Fv) 2 ], noncovalent tetrameric scFv {[sc(Fv) 2 ] 2 } and IgG of MAb CC49 were examined. The scFvs displayed an ability to form higher molecular aggregates in vivo. A specific proteolytic cleavage of the linker sequence of the covalent dimeric or a deterioration of the noncovalent association of the dimeric scFv into tetravalent scFv constructs was not observed. In conclusion, sc(Fv) 2 and [sc(Fv) 2 ] 2 are stable in vivo and have significant potential for diagnostic and therapeutic applications

Current status of a decommissioning project in the Enrichment Engineering Facility. Results in the second-half of the fiscal year of 2014

International Nuclear Information System (INIS)

Matsumoto, Takashi; Hayashibara, Kenichi; Ishimori, Yuu; Mita, Yutaka; Kakiya, Hideyoshi; Takahashi, Nobuo

2016-11-01

The Enrichment Engineering Facility of the Ningyo-toge Environmental Engineering Center was constructed in order to establish the technological basis of plant engineering for uranium enrichment in Japan. Uranium enrichment tests, using natural and reprocessed uranium, were carried out from 1979 to 1989 with two operation units in the facility. According to the decommissioning plan of the facility, UF 6 handling equipment and supplemental equipment in these plants are intended to be dismantled by 2019 in order to make vacant spaces for future projects use, for example, inventory investigation, precipitation treatment, etc. This report shows the current state of the decommissioning project in the second-half of the fiscal year of 2014, with indicating its schedule, procedure, situation, results, and so on. The dismantled materials generated amounted to 69 mesh containers and 191 drums, and the secondary waste generated amounted to 1,585.7 kg during the half year. In the fiscal year of 2014, the project was carried out according to the plan. The dismantled materials generated amounted to 153,938.1 kg as the whole of this period, and 36,343 kg from among them was treated as non-radioactive materials. (author)

In vivo structural and cellular remodeling of engineered bone-ligament-bone constructs used for anterior cruciate ligament reconstruction in sheep.

Science.gov (United States)

Florida, Shelby E; VanDusen, Keith W; Mahalingam, Vasudevan D; Schlientz, Aleesa J; Wojtys, Edward M; Wellik, Deneen M; Larkin, Lisa M

2016-11-01

Anterior cruciate ligament (ACL) ruptures rank among the most prevalent and costly sports-related injuries. Current tendon grafts used for ACL reconstruction are limited by suboptimal biomechanical properties. We have addressed these issues by engineering multiphasic bone-ligament-bone (BLB) constructs that develop structural and mechanical properties similar to native ACL. The purpose of this study was to examine the acute remodeling process that occurs as the BLB grafts advance toward the adult ligament phenotype in vivo. Thus, we implanted BLB constructs fabricated from male cells into female host sheep and allowed 3, 7, 14, or 28 days (n = 4 at each time point) for recovery. To address whether or not graft-derived cells were even necessary, a subset of BLB constructs (n = 3) were acellularized, implanted, and allowed 28 days for recovery. At each recovery time point, the following histological analyses were performed: picrosirius red staining to assess collagen alignment and immunohistochemistry to assess both graft development and host immune response. Polymerase chain reaction (PCR) analysis, performed on every explanted BLB, was used to detect the presence of graft-derived male cells remaining in the constructs and/or migration into surrounding host tissue. The analysis of the PCR and histology samples revealed a rapid migration of host-derived macrophages and neutrophils into the graft at 3 days, followed by increased collagen density and alignment, vascularization, innervation, and near complete repopulation of the graft with host cells within 28 days. This study provides a greater understanding of the processes of ligament regeneration in our BLB constructs as they remodel toward the adult ligament phenotype.

A Resilience Engineering Approach for Sustainable Safety in Green Construction

Directory of Open Access Journals (Sweden)

Lucio V. Rosa

2017-12-01

Full Text Available Sustainable construction is a complex endeavour, involving various stakeholders and resulting in situations that are incompletely described or underspecified. Traditional risk assessment methods require a detailed description of the system and safety, focusing on undesirable outcomes, losses, incidents and accidents. Developing this principle, this research describes a new way to deal with risk assessment in the green construction industry using a resilience engineering method based on the functional resonanceanalysis method and analytic hierarchy process methodologies. The functional resonance analysis method defines a systemic framework to model complex systems based on combinations of function variabilities during normal work. Therefore, to quantify the outcomes for risk assessment, this method was used together with the analytic hierarchy process in a case study during the modernisation work on the Maracanã stadium in Rio de Janeiro. The results of this case study demonstrate that the combined utilisation of the functional resonance analysis method and analytic hierarchy process can be utilised to recognise situations where developments could potentially be without control, which enables this to be used as a basis for performing indicators or a monitoring system. Furthermore, this combined technique can be used to assess and quantify the performance variabilities that may lead to occupational or environmental accidents, and provide new recommendations about how work processes should function, minimising production losses, incidents and accidents.

Skin equivalent tissue-engineered construct: co-cultured fibroblasts/ keratinocytes on 3D matrices of sericin hope cocoons.

Directory of Open Access Journals (Sweden)

Sunita Nayak

Full Text Available The development of effective and alternative tissue-engineered skin replacements to autografts, allografts and xenografts has became a clinical requirement due to the problems related to source of donor tissue and the perceived risk of disease transmission. In the present study 3D tissue engineered construct of sericin is developed using co-culture of keratinocytes on the upper surface of the fabricated matrices and with fibroblasts on lower surface. Sericin is obtained from "Sericin Hope" silkworm of Bombyx mori mutant and is extracted from cocoons by autoclave. Porous sericin matrices are prepared by freeze dried method using genipin as crosslinker. The matrices are characterized biochemically and biophysically. The cell proliferation and viability of co-cultured fibroblasts and keratinocytes on matrices for at least 28 days are observed by live/dead assay, Alamar blue assay, and by dual fluorescent staining. The growth of the fibroblasts and keratinocytes in co-culture is correlated with the expression level of TGF-β, b-FGF and IL-8 in the cultured supernatants by enzyme-linked immunosorbent assay. The histological analysis further demonstrates a multi-layered stratified epidermal layer of uninhibited keratinocytes in co-cultured constructs. Presence of involucrin, collagen IV and the fibroblast surface protein in immuno-histochemical stained sections of co-cultured matrices indicates the significance of paracrine signaling between keratinocytes and fibroblasts in the expression of extracellular matrix protein for dermal repair. No significant amount of pro inflammatory cytokines (TNF-α, IL-1β and nitric oxide production are evidenced when macrophages grown on the sericin matrices. The results all together depict the potentiality of sericin 3D matrices as skin equivalent tissue engineered construct in wound repair.

Global engineering

International Nuclear Information System (INIS)

Plass, L.

2001-01-01

This article considers the challenges posed by the declining orders in the plant engineering and contracting business in Germany, the need to remain competitive, and essential preconditions for mastering the challenge. The change in engineering approach is illustrated by the building of a methanol plant in Argentina by Lurgi with the basic engineering completed in Frankfurt with involvement of key personnel from Poland, completely engineered subsystems from a Brazilian subsupplier, and detailed engineering work in Frankfurt. The production of methanol from natural gas using the LurgiMega/Methanol process is used as a typical example of the industrial plant construction sector. The prerequisites for successful global engineering are listed, and error costs in plant construction, possible savings, and process intensification are discussed

Engineering design of a high-temperature superconductor current lead

International Nuclear Information System (INIS)

Niemann, R.C.; Cha, Y.S.; Hull, J.R.; Daugherty, M.A.; Buckles, W.E.

1993-01-01

As part of the US Department of Energy's Superconductivity Pilot Center Program, Argonne National Laboratory and Superconductivity, Inc., are developing high-temperature superconductor (HTS) current leads suitable for application to superconducting magnetic energy storage systems. The principal objective of the development program is to design, construct, and evaluate the performance of HTS current leads suitable for near-term applications. Supporting objectives are to (1) develop performance criteria; (2) develop a detailed design; (3) analyze performance; (4) gain manufacturing experience in the areas of materials and components procurement, fabrication and assembly, quality assurance, and cost; (5) measure performance of critical components and the overall assembly; (6) identify design uncertainties and develop a program for their study; and (7) develop application-acceptance criteria

Engineering design of a high-temperature superconductor current lead

Science.gov (United States)

Niemann, R. C.; Cha, Y. S.; Hull, J. R.; Daugherty, M. A.; Buckles, W. E.

As part of the US Department of Energy's Superconductivity Pilot Center Program, Argonne National Laboratory and Superconductivity, Inc., are developing high-temperature superconductor (HTS) current leads suitable for application to superconducting magnetic energy storage systems. The principal objective of the development program is to design, construct, and evaluate the performance of HTS current leads suitable for near-term applications. Supporting objectives are to (1) develop performance criteria; (2) develop a detailed design; (3) analyze performance; (4) gain manufacturing experience in the areas of materials and components procurement, fabrication and assembly, quality assurance, and cost; (5) measure performance of critical components and the overall assembly; (6) identify design uncertainties and develop a program for their study; and (7) develop application-acceptance criteria.

MOOC construction and application in professional degree postgraduate education: taking Introduction to Engineering Optics as an example

Science.gov (United States)

Hu, Feng; Zhou, Jin-peng; Wang, Xing-shu

2017-08-01

Aiming at the deficiency of the traditional postgraduate education mode for professional degree, such as the conflict between work and study, restricted supply and demand and poor efficiency of course teaching, the emergence of Massive Open Online Course (MOOC) which has large scale, online and open features can make up for the shortage of traditional professional degree postgraduate education mode by introducing MOOC teaching mode. However, it is still a fangle to integrate MOOC into the traditional postgraduate education for professional degree and there are no standard methods for reference in the construction of MOOC courses as well as the corresponding evaluations. In this paper, the construction method and practical experience of MOOC courses for professional degree postgraduate education are discussed in details, based on the MOOC course of Introduction to Engineering Optics. Firstly, the principle of MOOC course contents for professional degree postgraduate education is introduced from the aspects of students' demand, MOOC features and practical applications. Secondly, the optimization of MOOC teaching mode is discussed in order to improve the teaching quality and learning efficiency. Thirdly, in order to overcome the deficiency of current MOOC examination schemes, a novel MOOC evaluation scheme is proposed which is capable of assessing students' learning attitude as well as their ability and performance differences. Finally, a practical summary is given about how to integrate the MOOC teaching mode into the postgraduate education for professional degree, including the constructions of teaching team, course system as well as other factors. From the paper, we can conclude that the integration of MOOC teaching mode into the postgraduate education for professional degree will improve the teaching quality and efficiency.

Development of multilayer constructs for tissue engineering

NARCIS (Netherlands)

Bettahalli, N. M. S.; Groen, N.; Steg, H.; Unadkat, H.; de Boer, J.; van Blitterswijk, C. A.; Wessling, M.; Stamatialis, D.

The rapidly developing field of tissue engineering produces living substitutes that restore, maintain or improve the function of tissues or organs. In contrast to standard therapies, the engineered products become integrated within the patient, affording a potentially permanent and specific cure of

Development of multilayer constructs for tissue engineering

NARCIS (Netherlands)

Bettahalli Narasimha, M.S.; Groen, N.; Steg, H.; Unadkat, H.V.; de Boer, Jan; van Blitterswijk, Clemens; Wessling, Matthias; Stamatialis, Dimitrios

2014-01-01

The rapidly developing field of tissue engineering produces living substitutes that restore, maintain or improve the function of tissues or organs. In contrast to standard therapies, the engineered products become integrated within the patient, affording a potentially permanent and specific cure of

Application and Mechanics Analysis of Multi-Function Construction Platforms in Prefabricated-Concrete Construction

Science.gov (United States)

Wang, Meihua; Li, Rongshuai; Zhang, Wenze

2017-11-01

Multi-function construction platforms (MCPs) as an “old construction technology, new application” of the building facade construction equipment, its efforts to reduce labour intensity, improve labour productivity, ensure construction safety, shorten the duration of construction and other aspects of the effect are significant. In this study, the functional analysis of the multi-function construction platforms is carried out in the construction of the assembly building. Based on the general finite element software ANSYS, the static calculation and dynamic characteristics analysis of the MCPs structure are analysed, the simplified finite element model is constructed, and the selection of the unit, the processing and solution of boundary are under discussion and research. The maximum deformation value, the maximum stress value and the structural dynamic characteristic model are obtained. The dangerous parts of the platform structure are analysed, too. Multiple types of MCPs under engineering construction conditions are calculated, so as to put forward the rationalization suggestions for engineering application of the MCPs.

A study of competence in mathematics and mechanics in an engineering curriculum

Science.gov (United States)

Munns, Andrew

2017-11-01

Professional bodies expect engineers to show competence in both mathematics and engineering topics such as mechanics, using their abilities in both of these to solve problems. Yet within engineering programmes there is a phenomenon known as 'The Mathematics Problem', with students not demonstrating understanding of the subject. This paper will suggest that students are constructing different concept images in engineering and mathematics, based on their perception of either the use or exchange-value for the topics. Using a mixed methods approach, the paper compares 10 different types of concept image constructed by students, which suggests that familiar procedural images are preferred in mathematics. In contrast strategic and conceptual images develop for mechanics throughout the years of the programme, implying that different forms of competence are being constructed by students between the two subjects. The paper argues that this difference is attributed to the perceived use-value of mechanics in the career of the engineer, compared to the exchange-value associated with mathematics. Questions are raised about the relevance of current definitions of competence given that some routine mathematical operations previously performed by engineers are now being replaced by technology, in the new world of work.

3-D bioprinting technologies in tissue engineering and regenerative medicine: Current and future trends

Directory of Open Access Journals (Sweden)

Elliot S. Bishop

2017-12-01

Full Text Available Advances in three-dimensional (3D printing have increased feasibility towards the synthesis of living tissues. Known as 3D bioprinting, this technology involves the precise layering of cells, biologic scaffolds, and growth factors with the goal of creating bioidentical tissue for a variety of uses. Early successes have demonstrated distinct advantages over conventional tissue engineering strategies. Not surprisingly, there are current challenges to address before 3D bioprinting becomes clinically relevant. Here we provide an overview of 3D bioprinting technology and discuss key advances, clinical applications, and current limitations. While 3D bioprinting is a relatively novel tissue engineering strategy, it holds great potential to play a key role in personalized medicine.

A Review of Three-Dimensional Printing in Tissue Engineering.

Science.gov (United States)

Sears, Nick A; Seshadri, Dhruv R; Dhavalikar, Prachi S; Cosgriff-Hernandez, Elizabeth

2016-08-01

Recent advances in three-dimensional (3D) printing technologies have led to a rapid expansion of applications from the creation of anatomical training models for complex surgical procedures to the printing of tissue engineering constructs. In addition to achieving the macroscale geometry of organs and tissues, a print layer thickness as small as 20 μm allows for reproduction of the microarchitectures of bone and other tissues. Techniques with even higher precision are currently being investigated to enable reproduction of smaller tissue features such as hepatic lobules. Current research in tissue engineering focuses on the development of compatible methods (printers) and materials (bioinks) that are capable of producing biomimetic scaffolds. In this review, an overview of current 3D printing techniques used in tissue engineering is provided with an emphasis on the printing mechanism and the resultant scaffold characteristics. Current practical challenges and technical limitations are emphasized and future trends of bioprinting are discussed.

Tensile loading modulates bone marrow stromal cell differentiation and the development of engineered fibrocartilage constructs.

Science.gov (United States)

Connelly, John T; Vanderploeg, Eric J; Mouw, Janna K; Wilson, Christopher G; Levenston, Marc E

2010-06-01

Mesenchymal progenitors such as bone marrow stromal cells (BMSCs) are an attractive cell source for fibrocartilage tissue engineering, but the types or combinations of signals required to promote fibrochondrocyte-specific differentiation remain unclear. The present study investigated the influences of cyclic tensile loading on the chondrogenesis of BMSCs and the development of engineered fibrocartilage. Cyclic tensile displacements (10%, 1 Hz) were applied to BMSC-seeded fibrin constructs for short (24 h) or extended (1-2 weeks) periods using a custom loading system. At early stages of chondrogenesis, 24 h of cyclic tension stimulated both protein and proteoglycan synthesis, but at later stages, tension increased protein synthesis only. One week of intermittent cyclic tension significantly increased the total sulfated glycosaminoglycan and collagen contents in the constructs, but these differences were lost after 2 weeks of loading. Constraining the gels during the extended culture periods prevented contraction of the fibrin matrix, induced collagen fiber alignment, and increased sulfated glycosaminoglycan release to the media. Cyclic tension specifically stimulated collagen I mRNA expression and protein synthesis, but had no effect on collagen II, aggrecan, or osteocalcin mRNA levels. Overall, these studies suggest that the combination of chondrogenic stimuli and tensile loading promotes fibrochondrocyte-like differentiation of BMSCs and has the potential to direct fibrocartilage development in vitro.

A revisit on the current practice of dispute resolution and ADR in the Malaysian construction industry

Directory of Open Access Journals (Sweden)

Mohd Suhaimi Mohd Danuri

2012-06-01

Full Text Available The current dispute resolution procedures available in the Malaysian construction industry are mainly litigation and arbitration. In addition, the alternative dispute resolutions (ADR, namely mediation and adjudication, have also been introduced as the other methods for resolving disputes. The objective of this study is to examine the current practice of dispute resolution and ADR available in the Malaysian construction industry. The aim of this paper is two-fold: to report the current practice of dispute resolution and ADR, and identify the attributes of successful implementation of both mechanisms based on the perceptions of the Malaysian construction industry players. From the jurisprudence point of view, this study looks into the law as it is, in relation to the current practice of dispute resolution and ADR, by showing how those findings can be used to explain why improvement is needed to promote a successful and well received dispute resolution and ADR, and what lessons can be learnt, towards the formulation of a more viable methods for the Malaysian construction industry. NVivo software has been used to manage and organise the complete interview transcripts and facilitate the data analysis process for this study. Literature review reveals a continuous development of dispute resolution and ADR in the Malaysian construction industry, while, globally the industry has not only embraced ADR but also spearheaded the development of innovative forms of dispute avoidance mechanism. The findings of interviews show that locally, apart from litigation, the common types of ADR are arbitration, mediation and ad hoc mechanism. The findings also lead to the discovery of the following attributes: faster, less procedural, cost effective and enforceable; regulation and government's support; professionalism and ethic; training; and facility, that may promote a successful implementation of dispute resolution and ADR in Malaysia.

Transformation of Malaysian Construction Industry with Building Information Modelling (BIM

Directory of Open Access Journals (Sweden)

Latiffi Aryani Ahmad

2016-01-01

Full Text Available Building Information Modelling (BIM is a revolution of technology and a process that transformed the way building is planned, designed, analysed, constructed and managed. The revolution of technology and process could increase the quality of construction projects. The knowledge of BIM has been expanding in many countries including Malaysia. Since its inception, the use of BIM has broadened up widely with different purposes. The aims of this paper is to investigate the BIM implementation and uses in Malaysian construction projects. The methodologies adopted for structuring this paper are by using literature review and semi-structured interview with construction players that have experienced and being involved in projects using BIM. The purpose of literature review is to illustrate on the pervious research on the subject matter. Meanwhile, the purpose of interviews is to explore the involvement of construction players, years of experience in projects using BIM and BIM uses in construction projects. The findings revealed that BIM has been implemented in Malaysia since 2007 by various construction players, which are client, architect, C&S engineer, M&E engineer, QS, contractor, facilities manager and BIM consultant. The findings also revealed that BIM is used for project’ visualisation, improving project design, detecting design clashes, quantity take off and operation and maintenance. Further work will be focused on the current practices of construction players in projects using BIM.

Chaos as a psychological construct: historical roots, principal findings, and current growth directions.

Science.gov (United States)

Guastello, Stephen J

2009-07-01

The landmarks in the use of chaos and related constructs in psychology were entwined with the growing use of other nonlinear dynamical constructs, especially catastrophes and self-organization. The growth in substantive applications of chaos in psychology is partially related to the development of methodologies that work within the constraints of psychological data. The psychological literature includes rigorous theory with testable propositions, lighter-weight metaphorical uses of the construct, and colloquial uses of "chaos" with no particular theoretical intent. The current state of the chaos construct and supporting empirical research in psychological theory is summarized in neuroscience, psychophysics, psychomotor skill and other learning phenomena, clinical and abnormal psychology, and group dynamics and organizational behavior. Trends indicate that human systems do not remain chaotic indefinitely; they eventually self-organize, and the concept of the complex adaptive system has become prominent. Chaotic turbulence is generally higher in healthy systems compared to unhealthy systems, although opposite appears true in mood disorders. Group dynamics research shows trends consistent with the complex adaptive system, whereas organizational behavior lags behind in empirical studies relative to the quantity of its theory. Future directions for research involving the chaos construct and other nonlinear dynamics are outlined.

Integration and framing between system engineering, enterprise engineering and whole of society

CSIR Research Space (South Africa)

Erasmus, Louwrence D

2017-07-01

Full Text Available with the semantic theoretical constructs of systems levels of Boulding’s General Systems Theory. The construct of systems hierarchy levels addresses the progression from complicated engineered levels to the complexity of human interaction with engineered... predicates in: • A theory of the systems engineering process (Doeben-Henisch, et al., 2008) (Erasmus & Doeben-Henisch, 2011a) • A theory of systems engineering management (SEMBASE) (Erasmus & Doeben-Henisch, 2011b). In the structuralist programme...

Carbon-Nanotube-Embedded Hydrogel Sheets for Engineering Cardiac Constructs and Bioactuators

Science.gov (United States)

Shin, Su Ryon; Jung, Sung Mi; Zalabany, Momen; Kim, Keekyoung; Zorlutuna, Pinar; Kim, Sang bok; Nikkhah, Mehdi; Khabiry, Masoud; Azize, Mohamed; Kong, Jing; Wan, Kai-tak; Palacios, Tomas; Dokmeci, Mehmet R.; Bae, Hojae; Tang, Xiaowu (Shirley); Khademhosseini, Ali

2013-01-01

We engineered functional cardiac patches by seeding neonatal rat cardiomyocytes onto carbon nanotube (CNT) incorporated photocrosslinkable gelatin methacrylate (GelMA) hydrogel. The resulting cardiac constructs showed excellent mechanical integrity and advanced electrophysiological functions. Specifically, myocardial tissues cultured on 50 μm thick CNT-GelMA showed 3 times higher spontaneous synchronous beating rates and 85% lower excitation threshold, compared to those cultured on pristine GelMA hydrogels. Our results indicate that the electrically conductive and nanofibrous networks formed by CNTs within a porous gelatin framework is the key characteristics of CNT-GelMA leading to improved cardiac cell adhesion, organization, and cell-cell coupling. Centimeter-scale patches were released from glass substrates to form 3D biohybrid actuators, which showed controllable linear cyclic contraction/extension, pumping, and swimming actuations. In addition, we demonstrate for the first time that cardiac tissues cultured on CNT-GelMA resist damage by a model cardiac inhibitor as well as a cytotoxic compound. Therefore, incorporation of CNTs into gelatin, and potentially other biomaterials, could be useful in creating multifunctional cardiac scaffolds for both therapeutic purposes and in vitro studies. These hybrid materials could also be used for neuron and other muscle cells to create tissue constructs with improved organization, electroactivity, and mechanical integrity. PMID:23363247

Constructing Integrable High-pressure Full-current Free-boundary Stellarator Magnetohydrodynamic Equilibrium Solutions

International Nuclear Information System (INIS)

Hudson, S.R.; Monticello, D.A.; Reiman, A.H.; Strickler, D.J.; Hirshman, S.P.; Ku, L-P; Lazarus, E.; Brooks, A.; Zarnstorff, M.C.; Boozer, A.H.; Fu, G-Y.; Neilson, G.H.

2003-01-01

For the (non-axisymmetric) stellarator class of plasma confinement devices to be feasible candidates for fusion power stations it is essential that, to a good approximation, the magnetic field lines lie on nested flux surfaces; however, the inherent lack of a continuous symmetry implies that magnetic islands responsible for breaking the smooth topology of the flux surfaces are guaranteed to exist. Thus, the suppression of magnetic islands is a critical issue for stellarator design, particularly for small aspect ratio devices. Pfirsch-Schluter currents, diamagnetic currents, and resonant coil fields contribute to the formation of magnetic islands, and the challenge is to design the plasma and coils such that these effects cancel. Magnetic islands in free-boundary high-pressure full-current stellarator magnetohydrodynamic equilibria are suppressed using a procedure based on the Princeton Iterative Equilibrium Solver [Reiman and Greenside, Comp. Phys. Comm. 43 (1986) 157] which iterate s the equilibrium equations to obtain the plasma equilibrium. At each iteration, changes to a Fourier representation of the coil geometry are made to cancel resonant fields produced by the plasma. The changes are constrained to preserve certain measures of engineering acceptability and to preserve the stability of ideal kink modes. As the iterations continue, the coil geometry and the plasma simultaneously converge to an equilibrium in which the island content is negligible, the plasma is stable to ideal kink modes, and the coils satisfy engineering constraints. The method is applied to a candidate plasma and coil design for the National Compact Stellarator Experiment [Reiman, et al., Phys. Plasmas 8 (May 2001) 2083

Constructing integrable high-pressure full-current free-boundary stellarator magnetohydrodynamic equilibrium solutions

International Nuclear Information System (INIS)

Hudson, S.R.; Monticello, D.A.; Reiman, A.H.

2003-01-01

For the (non-axisymmetric) stellarator class of plasma confinement devices to be feasible candidates for fusion power stations it is essential that, to a good approximation, the magnetic field lines lie on nested flux surfaces; however, the inherent lack of a continuous symmetry implies that magnetic islands responsible for breaking the smooth topology of the flux surfaces are guaranteed to exist. Thus, the suppression of magnetic islands is a critical issue for stellarator design, particularly for small aspect ratio devices. Pfirsch-Schlueter currents, diamagnetic currents and resonant coil fields contribute to the formation of magnetic islands, and the challenge is to design the plasma and coils such that these effects cancel. Magnetic islands in free-boundary high-pressure full-current stellarator magnetohydrodynamic equilibria are suppressed using a procedure based on the Princeton Iterative Equilibrium Solver (Reiman and Greenside 1986 Comput. Phys. Commun. 43 157) which iterates the equilibrium equations to obtain the plasma equilibrium. At each iteration, changes to a Fourier representation of the coil geometry are made to cancel resonant fields produced by the plasma. The changes are constrained to preserve certain measures of engineering acceptability and to preserve the stability of ideal kink modes. As the iterations continue, the coil geometry and the plasma simultaneously converge to an equilibrium in which the island content is negligible, the plasma is stable to ideal kink modes, and the coils satisfy engineering constraints. The method is applied to a candidate plasma and coil design for the National Compact Stellarator eXperiment (Reiman et al 2001 Phys. Plasma 8 2083). (author)

Construction of an Engineer's Notebook Rubric

Science.gov (United States)

Kelley, Todd R.

2014-01-01

It is evident that there is a need for assessment instruments that measure design and engineering design skills, knowledge, and ways of design thinking. These student assessments must be authentic to engineering design practices and measure key elements of the engineering design process. Kelley (2011) presented a rationale to include…

Construction Management.

Science.gov (United States)

Abbott, James F.

This article provides a detailed discussion of a team approach to building that involves a construction manager, an architect, and a contractor. Bidding methods are outlined; the major components in construction management -- value engineering and fast track scheduling -- and the use of performance specifications are discussed. The construction…

Dual-fuel natural gas/diesel engines: Technology, performance, and emissions

Science.gov (United States)

Turner, S. H.; Weaver, C. S.

1994-11-01

An investigation of current dual-fuel natural gas/diesel engine design, performance, and emissions was conducted. The most pressing technological problems associated with dual-fuel engine use were identified along with potential solutions. It was concluded that dual-fuel engines can achieve low NO(sub x) and particulate emissions while retaining fuel-efficiency and BMEP levels comparable to those of diesel engines. The investigation also examined the potential economic impact of dual-fuel engines in diesel-electric locomotives, marine vessels, farm equipment, construction, mining, and industrial equipment, and stand-alone electricity generation systems. Recommendations for further additional funding to support research, development, and demonstration in these applications were then presented.

Synthetic constructs in/for the environment: managing the interplay between natural and engineered Biology.

Science.gov (United States)

Schmidt, Markus; de Lorenzo, Víctor

2012-07-16

The plausible release of deeply engineered or even entirely synthetic/artificial microorganisms raises the issue of their intentional (e.g. bioremediation) or accidental interaction with the Environment. Containment systems designed in the 1980s-1990s for limiting the spread of genetically engineered bacteria and their recombinant traits are still applicable to contemporary Synthetic Biology constructs. Yet, the ease of DNA synthesis and the uncertainty on how non-natural properties and strains could interplay with the existing biological word poses yet again the challenge of designing safe and efficacious firewalls to curtail possible interactions. Such barriers may include xeno-nucleic acids (XNAs) instead of DNA as information-bearing molecules, rewriting the genetic code to make it non-understandable by the existing gene expression machineries, and/or making growth dependent on xenobiotic chemicals. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Construction and performance tests of Helium Engineering Demonstration Loop (HENDEL) for VHTR

International Nuclear Information System (INIS)

Hishida, M.; Tanaka, T.; Shimomura, H.; Sanokawa, K.

1984-01-01

A helium engineering demonstration loop (HENDEL) was constructed and operated in JAERI in order to develop the high-temperature key components of an experimental very high temperature gas cooled reactor, like fuel stack, in-core reactor structure, hot gas duct, intermediate heat exchanger. Performance tests as well as demonstration of integrity are carried out with large-size or actual-size models of key components. The key components to be tested in HENDEL are: fuel stack and control rod; core supporting structure, or bottom structure of rector core exposed to direct impingement of high temperature core outlet flow; reactor internal components and structure; high temperature components in heat removal system (primary and secondary cooling systems)

Vascular and micro-environmental influences on MSC-coral hydroxyapatite construct-based bone tissue engineering.

Science.gov (United States)

Cai, Lei; Wang, Qian; Gu, Congmin; Wu, Jingguo; Wang, Jian; Kang, Ning; Hu, Jiewei; Xie, Fang; Yan, Li; Liu, Xia; Cao, Yilin; Xiao, Ran

2011-11-01

Bone tissue engineering (BTE) has been demonstrated an effective approach to generate bone tissue and repair bone defect in ectopic and orthotopic sites. The strategy of using a prevascularized tissue-engineered bone grafts (TEBG) fabricated ectopically to repair bone defects, which is called live bone graft surgery, has not been reported. And the quantitative advantages of vascularization and osteogenic environment in promoting engineered bone formation have not been defined yet. In the current study we generated a tissue engineered bone flap with a vascular pedicle of saphenous arteriovenous in which an organized vascular network was observed after 4 weeks implantation, and followed by a successful repaire of fibular defect in beagle dogs. Besides, after a 9 months long term observation of engineered bone formation in ectopic and orthotopic sites, four CHA (coral hydroxyapatite) scaffold groups were evaluated by CT (computed tomography) analysis. By the comparison of bone formation and scaffold degradation between different groups, the influences of vascularization and micro-environment on tissue engineered bone were quantitatively analyzed. The results showed that in the first 3 months vascularization improved engineered bone formation by 2 times of non-vascular group and bone defect micro-environment improved it by 3 times of ectopic group, and the CHA-scaffold degradation was accelerated as well. Copyright © 2011 Elsevier Ltd. All rights reserved.

Development of scaffold-free elastic cartilaginous constructs with structural similarities to auricular cartilage.

Science.gov (United States)

Giardini-Rosa, Renata; Joazeiro, Paulo P; Thomas, Kathryn; Collavino, Kristina; Weber, Joanna; Waldman, Stephen D

2014-03-01

External ear reconstruction with autologous cartilage still remains one of the most difficult problems in the fields of plastic and reconstructive surgery. As the absence of tissue vascularization limits the ability to stimulate new tissue growth, relatively few surgical approaches are currently available (alloplastic implants or sculpted autologous cartilage grafts) to repair or reconstruct the auricle (or pinna) as a result of traumatic loss or congenital absence (e.g., microtia). Alternatively, tissue engineering can offer the potential to grow autogenous cartilage suitable for implantation. While tissue-engineered auricle cartilage constructs can be created, a substantial number of cells are required to generate sufficient quantities of tissue for reconstruction. Similarly, as routine cell expansion can elicit negative effects on chondrocyte function, we have developed an approach to generate large-sized engineered auricle constructs (≥3 cm(2)) directly from a small population of donor cells (20,000-40,000 cells/construct). Using rabbit donor cells, the developed bioreactor-cultivated constructs adopted structural-like characteristics similar to native auricular cartilage, including the development of distinct cartilaginous and perichondrium-like regions. Both alterations in media composition and seeding density had profound effects on the formation of engineered elastic tissue constructs in terms of cellularity, extracellular matrix accumulation, and tissue structure. Higher seeding densities and media containing sodium bicarbonate produced tissue constructs that were closer to the native tissue in terms of structure and composition. Future studies will be aimed at improving the accumulation of specific tissue constituents and determining the clinical effectiveness of this approach using a reconstructive animal model.

Engineered phages for electronics.

Science.gov (United States)

Cui, Yue

2016-11-15

Phages are traditionally widely studied in biology and chemistry. In recent years, engineered phages have attracted significant attentions for functionalization or construction of electronic devices, due to their specific binding, catalytic, nucleating or electronic properties. To apply the engineered phages in electronics, these are a number of interesting questions: how to engineer phages for electronics? How are the engineered phages characterized? How to assemble materials with engineered phages? How are the engineered phages micro or nanopatterned? What are the strategies to construct electronics devices with engineered phages? This review will highlight the early attempts to address these questions and explore the fundamental and practical aspects of engineered phages in electronics, including the approaches for selection or expression of specific peptides on phage coat proteins, characterization of engineered phages in electronics, assembly of electronic materials, patterning of engineered phages, and construction of electronic devices. It provides the methodologies and opens up ex-cit-ing op-por-tu-ni-ties for the development of a variety of new electronic materials and devices based on engineered phages for future applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Digital fabrication in architecture, engineering and construction

CERN Document Server

Caneparo, Luca

2014-01-01

Digital technologies are changing the relationship between design and construction: with computer models, CAD/CAM, and prototyping, designers can gain direct control of building and construction processes. The ability to digitally model designs, and thus to use those models directly in the context of production, creates a synthesis between design and construction in keeping with the tradition of the close relationship between design and craftsmanship, between the quality of the design and the rules of the craft. The evolution of the culture of design and construction is the underlying theme of this book. The aim is to discuss the direction that innovation is now taking, with a particular focus on today’s cutting-edge architectures. The method addresses the ways in which different societies have dealt with the issues of their age regarding design and construction, the different contributions provided by various techniques, and with them the meanings expressed by the architecture. As building design using dig...

Development of support tools for efficient construction of dynamic simulation program for engineering systems

International Nuclear Information System (INIS)

Gofuku, Akio

1993-01-01

In this study, two support tools are developed for construction of a dynamic simulation program for engineering systems (especially nuclear systems) by combining software modules. These are (1) a sub-system to support the module selection suitable for dynamic simulation and (2) a graphical user interface to support visual construction of simulation programs. The support tools are designed to be independent on the conception of software modules (data communication methods between modules). In the module selection sub-system of item 1, a module is characterized beforehand by keywords for several criteria. The similarity between the characteristic of requested module by users and that of registered modules in the module library is estimated by a weighted average of similarity indexes for criteria. In the module selection sub-system, the weights are flexibly extracted from users by applying the analytic hierarchy process. The graphical user interface helps users to specify both calling order of modules and data transfer between two modules. The availability of the support tools is evaluated by several sample problems of module selection and dynamic simulation model construction. The support tools will be a strong tool for the efficient usage of software modules. (author)

On how to do construction management communications engineering

Institute of Scientific and Technical Information of China (English)

Zhang Zhi

2014-01-01

In the communication construction projects, improving the efectivenes of project management is an important part of the quality asurance program. The efectivenes of the communication and construction project management is afected by many factors. Therefore, the discusion of communication construction project management efectivenes is good for improving the quality of projects of great significance. This paper analyzes the characteristics and problems of communication construction projects, reflecting the importance of project management; then discused the factors afecting the efectivenes of project management; finaly targeted to improve the communication of construction project management efectivenes propose specific methods to ensure communication quality of construction projects.

Supplementation of exogenous adenosine 5'-triphosphate enhances mechanical properties of 3D cell-agarose constructs for cartilage tissue engineering.

Science.gov (United States)

Gadjanski, Ivana; Yodmuang, Supansa; Spiller, Kara; Bhumiratana, Sarindr; Vunjak-Novakovic, Gordana

2013-10-01

Formation of tissue-engineered cartilage is greatly enhanced by mechanical stimulation. However, direct mechanical stimulation is not always a suitable method, and the utilization of mechanisms underlying mechanotransduction might allow for a highly effective and less aggressive alternate means of stimulation. In particular, the purinergic, adenosine 5'-triphosphate (ATP)-mediated signaling pathway is strongly implicated in mechanotransduction within the articular cartilage. We investigated the effects of transient and continuous exogenous ATP supplementation on mechanical properties of cartilaginous constructs engineered using bovine chondrocytes and human mesenchymal stem cells (hMSCs) encapsulated in an agarose hydrogel. For both cell types, we have observed significant increases in equilibrium and dynamic compressive moduli after transient ATP treatment applied in the fourth week of cultivation. Continuous ATP treatment over 4 weeks of culture only slightly improved the mechanical properties of the constructs, without major changes in the total glycosaminoglycan (GAG) and collagen content. Structure-function analyses showed that transiently ATP-treated constructs, and in particular those based on hMSCs, had the highest level of correlation between compositional and mechanical properties. Transiently treated groups showed intense staining of the territorial matrix for GAGs and collagen type II. These results indicate that transient ATP treatment can improve functional mechanical properties of cartilaginous constructs based on chondrogenic cells and agarose hydrogels, possibly by improving the structural organization of the bulk phase and territorial extracellular matrix (ECM), that is, by increasing correlation slopes between the content of the ECM components (GAG, collagen) and mechanical properties of the construct.

Construction Sector (NAICS 23)

Science.gov (United States)

Find environmental regulatory information for the construction sector, including the construction of buildings or engineering projects. This includes RCRA information for hazardous waste, refrigeration compliance, asbestos, effluent guidelines & lead laws

Radio-frequency-assisted current startup in the Fusion Engineering Device

International Nuclear Information System (INIS)

Borowski, S.K.; Kammash, T.; Martin Peng, Y.K.

1984-01-01

Auxiliary radio-frequency (RF) heating of electrons before and during the current rise phase of a large tokamak, such as the Fusion Engineering Device (FED) (R 0 = 4.8 m, a = 1.3 m, sigma = 1.6, B(R 0 ) = 3.62 T), is examined as a means of reducing both the initiation loop voltage and resistive flux expenditure during startup. Prior to current initiation, 1 to 2 MW of electron cyclotron resonance heating power at about90 GHz is used to create a small volume of high conductivity plasma (T /sub e/ approx. = 100 eV, n /sub e/ approx. = 10 19 m -3 ) near the upper hybrid resonance (UHR) region. This plasma conditioning, referred to as preheating, permits a small radius (a 0 approx. = 0.2 to 0.4 m) current channel to be established with a relatively low initial loop voltage (less than or equal to 25 V as opposed to about 100 V without rf assist). During the subsequent plasma expansion and current rise phase, a combination of rf heating (up to 5 MW) and linear current ramping leads to a substantial savings in voltseconds by (a) minimizing the resistive flux consumption and (b) producing broad current density profiles. (With such broad profiles, the internal flux requirements are maintained at or near the flat profile limit.)

The effect of mechanical stimulation on the maturation of TDSCs-poly(L-lactide-co-e-caprolactone)/collagen scaffold constructs for tendon tissue engineering.

Science.gov (United States)

Xu, Yuan; Dong, Shiwu; Zhou, Qiang; Mo, Xiumei; Song, Lei; Hou, Tianyong; Wu, Jinglei; Li, Songtao; Li, Yudong; Li, Pei; Gan, Yibo; Xu, Jianzhong

2014-03-01

Mechanical stimulation plays an important role in the development and remodeling of tendons. Tendon-derived stem cells (TDSCs) are an attractive cell source for tendon injury and tendon tissue engineering. However, these cells have not yet been fully explored for tendon tissue engineering application, and there is also lack of understanding to the effect of mechanical stimulation on the maturation of TDSCs-scaffold construct for tendon tissue engineering. In this study, we assessed the efficacy of TDSCs in a poly(L-lactide-co-ε-caprolactone)/collagen (P(LLA-CL)/Col) scaffold under mechanical stimulation for tendon tissue engineering both in vitro and in vivo, and evaluated the utility of the transplanted TDSCs-scaffold construct to promote rabbit patellar tendon defect regeneration. TDSCs displayed good proliferation and positive expressed tendon-related extracellular matrix (ECM) genes and proteins under mechanical stimulation in vitro. After implanting into the nude mice, the fluorescence imaging indicated that TDSCs had long-term survival, and the macroscopic evaluation, histology and immunohistochemistry examinations showed high-quality neo-tendon formation under mechanical stimulation in vivo. Furthermore, the histology, immunohistochemistry, collagen content assay and biomechanical testing data indicated that dynamically cultured TDSCs-scaffold construct could significantly contributed to tendon regeneration in a rabbit patellar tendon window defect model. TDSCs have significant potential to be used as seeded cells in the development of tissue-engineered tendons, which can be successfully fabricated through seeding of TDSCs in a P(LLA-CL)/Col scaffold followed by mechanical stimulation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Nanostructured 3D constructs based on chitosan and chondroitin sulphate multilayers for cartilage tissue engineering.

Directory of Open Access Journals (Sweden)

Joana M Silva

Full Text Available Nanostructured three-dimensional constructs combining layer-by-layer technology (LbL and template leaching were processed and evaluated as possible support structures for cartilage tissue engineering. Multilayered constructs were formed by depositing the polyelectrolytes chitosan (CHT and chondroitin sulphate (CS on either bidimensional glass surfaces or 3D packet of paraffin spheres. 2D CHT/CS multi-layered constructs proved to support the attachment and proliferation of bovine chondrocytes (BCH. The technology was transposed to 3D level and CHT/CS multi-layered hierarchical scaffolds were retrieved after paraffin leaching. The obtained nanostructured 3D constructs had a high porosity and water uptake capacity of about 300%. Dynamical mechanical analysis (DMA showed the viscoelastic nature of the scaffolds. Cellular tests were performed with the culture of BCH and multipotent bone marrow derived stromal cells (hMSCs up to 21 days in chondrogenic differentiation media. Together with scanning electronic microscopy analysis, viability tests and DNA quantification, our results clearly showed that cells attached, proliferated and were metabolically active over the entire scaffold. Cartilaginous extracellular matrix (ECM formation was further assessed and results showed that GAG secretion occurred indicating the maintenance of the chondrogenic phenotype and the chondrogenic differentiation of hMSCs.

Nanostructured 3D constructs based on chitosan and chondroitin sulphate multilayers for cartilage tissue engineering.

Science.gov (United States)

Silva, Joana M; Georgi, Nicole; Costa, Rui; Sher, Praveen; Reis, Rui L; Van Blitterswijk, Clemens A; Karperien, Marcel; Mano, João F

2013-01-01

Nanostructured three-dimensional constructs combining layer-by-layer technology (LbL) and template leaching were processed and evaluated as possible support structures for cartilage tissue engineering. Multilayered constructs were formed by depositing the polyelectrolytes chitosan (CHT) and chondroitin sulphate (CS) on either bidimensional glass surfaces or 3D packet of paraffin spheres. 2D CHT/CS multi-layered constructs proved to support the attachment and proliferation of bovine chondrocytes (BCH). The technology was transposed to 3D level and CHT/CS multi-layered hierarchical scaffolds were retrieved after paraffin leaching. The obtained nanostructured 3D constructs had a high porosity and water uptake capacity of about 300%. Dynamical mechanical analysis (DMA) showed the viscoelastic nature of the scaffolds. Cellular tests were performed with the culture of BCH and multipotent bone marrow derived stromal cells (hMSCs) up to 21 days in chondrogenic differentiation media. Together with scanning electronic microscopy analysis, viability tests and DNA quantification, our results clearly showed that cells attached, proliferated and were metabolically active over the entire scaffold. Cartilaginous extracellular matrix (ECM) formation was further assessed and results showed that GAG secretion occurred indicating the maintenance of the chondrogenic phenotype and the chondrogenic differentiation of hMSCs.

Activities of the Center for Space Construction

Science.gov (United States)

1993-01-01

The Center for Space Construction (CSC) at the University of Colorado at Boulder is one of eight University Space Engineering Research Centers established by NASA in 1988. The mission of the center is to conduct research into space technology and to directly contribute to space engineering education. The center reports to the Department of Aerospace Engineering Sciences and resides in the College of Engineering and Applied Science. The college has a long and successful track record of cultivating multi-disciplinary research and education programs. The Center for Space Construction is prominent evidence of this record. At the inception of CSC, the center was primarily founded on the need for research on in-space construction of large space systems like space stations and interplanetary space vehicles. The scope of CSC's research has now evolved to include the design and construction of all spacecraft, large and small. Within this broadened scope, our research projects seek to impact the underlying technological basis for such spacecraft as remote sensing satellites, communication satellites, and other special purpose spacecraft, as well as the technological basis for large space platforms. The center's research focuses on three areas: spacecraft structures, spacecraft operations and control, and regolith and surface systems. In the area of spacecraft structures, our current emphasis is on concepts and modeling of deployable structures, analysis of inflatable structures, structural damage detection algorithms, and composite materials for lightweight structures. In the area of spacecraft operations and control, we are continuing our previous efforts in process control of in-orbit structural assembly. In addition, we have begun two new efforts in formal approach to spacecraft flight software systems design and adaptive attitude control systems. In the area of regolith and surface systems, we are continuing the work of characterizing the physical properties of lunar

A Study of Current Trends and Issues Related to Technical/Engineering Design Graphics.

Science.gov (United States)

Clark, Aaron C.; Scales Alice

2000-01-01

Presents results from a survey of engineering design graphics educators who responded to questions related to current trends and issues in the profession of graphics education. Concludes that there is a clear trend in institutions towards the teaching of constraint-based modeling and computer-aided manufacturing. (Author/YDS)

Modeling the fate and end-of-life phase of engineered nanomaterials in the Japanese construction sector.

Science.gov (United States)

Suzuki, Shinya; Part, Florian; Matsufuji, Yasushi; Huber-Humer, Marion

2018-02-01

To date construction materials that contain engineered nanomaterials (ENMs) are available at the markets, but at the same time very little is known about their environmental fate. Therefore, this study aimed at modeling the potential fate of ENMs by using the example of the Japanese construction sector and by conducting a dynamic material flow analysis. Expert interviews and national reports revealed that about 3920-4660 tons of ENMs are annually used for construction materials in Japan. Nanoscale TiO 2 , SiO 2 , Al 2 O 3 and carbon black have already been applied for decades to wall paints, road markings or concrete. The dynamic material flow model indicates that in 2016 about 95% of ENMs, which have been used since their year of market penetration, remained in buildings, whereas only 5% ended up in the Japanese waste management system or were diffusely released into the environment. Considering the current Japanese waste management system, ENMs were predicted to end up in recycled materials (40-47%) or in landfills (36-41%). It was estimated that only a small proportion was used in agriculture (5-7%, as ENM-containing sewage sludges) or was diffusely released into soils, surface waters or the atmosphere (5-19%). The results indicate that ENM release predominantly depend on their specific applications and characteristics. The model also highlights the importance of adequate collection and treatment of ENM-containing wastes. In future, similar dynamic flow models for other countries should consider, inasmuch as available, historical data on ENM production (e.g. like declaration reports that are annually published by relevant public authorities or associations), as such input data is very important regarding data reliability in order to decrease uncertainties and to continuously improve model accuracy. In addition, more environmental monitoring studies that aim at the quantification of ENM release and inadvertent transfer, particularly triggered by waste treatment

Careers in Construction: Construction Industry Series: Student Manual and Instructor's Guide.

Science.gov (United States)

Texas Education Agency, Austin. Dept. of Occupational Education and Technology.

The guide for instructors of construction occupations provides instructional suggestions and informational sources for structuring an exploratory program. The program is divided into the following blocks, representing different experiences in construction: (1) wood; (2) finishing; (3) engineering, support, and management services; (4) metal; (5)…

In vitro engineering of fibrocartilage using CDMP1 induced dermal fibroblasts and polyglycolide.

Science.gov (United States)

Zhao, Guiqing; Yin, Shuo; Liu, Guangpeng; Cen, Lian; Sun, Jian; Zhou, Heng; Liu, Wei; Cui, Lei; Cao, Yilin

2009-07-01

This study was designed to explore the feasibility of using cartilage-derived morphogenetic protein-1 (CDMP1) induced dermal fibroblasts (DFs) as seed cells and polyglycolide (PGA) as scaffold for fibrocartilage engineering. DFs isolated from canine were expanded and seeded on PGA scaffold to fabricate cell/scaffold constructs which were cultured with or without CDMP1. Proliferation and differentiation of DFs in different constructs were determined by DNA assay and glycosaminoglycan (GAG) production. Histological and immunohistochemical staining of the constructs after being in vitro cultured for 4 and 6 weeks were carried out to observe the fibrocartilage formation condition. The fibrocartilage-specific gene expression by cells in the constructs was analyzed by real-time PCR. It was shown that in the presence of CDMP1 the proliferation and GAG synthesis of DFs were significantly enhanced compared to those without CDMP1. Fibrocartilage-like tissue was formed in the CDMP1 induced construct after being cultured for 4 weeks, and it became more matured at 6 weeks as stronger staining for GAG and higher gene expression of collagen type II was observed. Since only weak staining for GAG and collagen type II was observed for the construct engineered without CDMP1, the induction effect on the fibrocartilage engineering can be ascertained when using DFs as seed cells. Furthermore, the potential of using DFs as seed cells to engineer fibrocartilage is substantiated and further study on using the engineered tissue to repair fibrocartilage defects is currently ongoing in our group.

Changing priorities of codes and standards -- quality engineering: Experiences in plant construction, maintenance, and operation

International Nuclear Information System (INIS)

Antony, D.D.; Suleski, P.F.; Meier, J.C.

1994-01-01

Application of the ASME Code across various fossil and nuclear plants necessitates a Company approach adapted by unique status of each plant. This arises from State Statutes, Federal Regulations and consideration of each plant's as-built history over a broad time frame of design, construction and operation. Additionally, the National Board Inspection Code accompanies Minnesota Statutes for plants owned by Northern States Power Company. This paper addresses some key points on NSP's use of ASME Code as a principal mechanical standard in plant design, construction and operation. A primary resource facilitating review of Code provisions is accurate status on current plant configuration. As plant design changes arise, the Code Edition/Addenda of original construction and installed upgrades or replacements are considered against available options allowed by current standards and dialog with the Jurisdictional Authority. Consistent with the overall goal of safe and reliable plant operation, there are numerous Code details and future needs to be addressed in concert with expected plant economics and planned outages for implementation. The discussion begins in the late 60's with new construction of Monticello and Prairie Island (both nuclear), through Sherburne County Units 1 through 3 (fossil), and their changes, replacements or repairs as operating plants

Multifactorial Optimization of Contrast-Enhanced Nanofocus Computed Tomography for Quantitative Analysis of Neo-Tissue Formation in Tissue Engineering Constructs.

Directory of Open Access Journals (Sweden)

Maarten Sonnaert

Full Text Available To progress the fields of tissue engineering (TE and regenerative medicine, development of quantitative methods for non-invasive three dimensional characterization of engineered constructs (i.e. cells/tissue combined with scaffolds becomes essential. In this study, we have defined the most optimal staining conditions for contrast-enhanced nanofocus computed tomography for three dimensional visualization and quantitative analysis of in vitro engineered neo-tissue (i.e. extracellular matrix containing cells in perfusion bioreactor-developed Ti6Al4V constructs. A fractional factorial 'design of experiments' approach was used to elucidate the influence of the staining time and concentration of two contrast agents (Hexabrix and phosphotungstic acid and the neo-tissue volume on the image contrast and dataset quality. Additionally, the neo-tissue shrinkage that was induced by phosphotungstic acid staining was quantified to determine the operating window within which this contrast agent can be accurately applied. For Hexabrix the staining concentration was the main parameter influencing image contrast and dataset quality. Using phosphotungstic acid the staining concentration had a significant influence on the image contrast while both staining concentration and neo-tissue volume had an influence on the dataset quality. The use of high concentrations of phosphotungstic acid did however introduce significant shrinkage of the neo-tissue indicating that, despite sub-optimal image contrast, low concentrations of this staining agent should be used to enable quantitative analysis. To conclude, design of experiments allowed us to define the most optimal staining conditions for contrast-enhanced nanofocus computed tomography to be used as a routine screening tool of neo-tissue formation in Ti6Al4V constructs, transforming it into a robust three dimensional quality control methodology.

Treatment of Ligament Constructs with Exercise-conditioned Serum: A Translational Tissue Engineering Model.

Science.gov (United States)

Lee-Barthel, Ann; Baar, Keith; West, Daniel W D

2017-06-11

In vitro experiments are essential to understand biological mechanisms; however, the gap between monolayer tissue culture and human physiology is large, and translation of findings is often poor. Thus, there is ample opportunity for alternative experimental approaches. Here we present an approach in which human cells are isolated from human anterior cruciate ligament tissue remnants, expanded in culture, and used to form engineered ligaments. Exercise alters the biochemical milieu in the blood such that the function of many tissues, organs and bodily processes are improved. In this experiment, ligament construct culture media was supplemented with experimental human serum that has been 'conditioned' by exercise. Thus the intervention is more biologically relevant since an experimental tissue is exposed to the full endogenous biochemical milieu, including binding proteins and adjunct compounds that may be altered in tandem with the activity of an unknown agent of interest. After treatment, engineered ligaments can be analyzed for mechanical function, collagen content, morphology, and cellular biochemistry. Overall, there are four major advantages versus traditional monolayer culture and animal models, of the physiological model of ligament tissue that is presented here. First, ligament constructs are three-dimensional, allowing for mechanical properties (i.e., function) such as ultimate tensile stress, maximal tensile load, and modulus, to be quantified. Second, the enthesis, the interface between boney and sinew elements, can be examined in detail and within functional context. Third, preparing media with post-exercise serum allows for the effects of the exercise-induced biochemical milieu, which is responsible for the wide range of health benefits of exercise, to be investigated in an unbiased manner. Finally, this experimental model advances scientific research in a humane and ethical manner by replacing the use of animals, a core mandate of the National

Evaluation of environmental management resources (ISO 14001) at civil engineering construction worksites: a case study of the community of Madrid.

Science.gov (United States)

Rodríguez, Gracia; Alegre, Francisco Javier; Martínez, Germán

2011-07-01

In recent years, significant advances have been made in business organization and management. The growing demands of clients as well as the globalization of world markets are among the many factors that have led to the establishment of systems of quality control and environmental management as a competitive strategy for businesses. When compared to other professional sectors, the construction sector has been slower to respond to environmental problems and to adopt Environmental Management Systems (EMS). In the world today the ISO 14001 standard is currently the main frame of reference used by construction companies to implement this type of management system. This article presents the results of a general study regarding the evaluation of the application of the ISO 14001 standard at civil engineering construction worksites in the Community of Madrid (Spain), specifically pertaining to requirement 4.4.1, Resources, roles, responsibilities, and authority. According to requirement 4.4.1, company executives should appoint people responsible for implementing the EMS and also specify their responsibilities and functions. The personnel designated for supervising environmental work should also have sufficient authority to establish and maintain the EMS. The results obtained were the following: - EMS supervisors did not generally possess adequate training and solid experience in construction work and in the environment. Furthermore, supervisors were usually forced to combine their environmental work with other tasks, which made their job even more difficult. - Generally speaking, supervisors were not given sufficient authority and autonomy because productivity at the construction site had priority over environmental management. This was due to the fact that the company management did not have a respectful attitude toward the environment, nor was the management actively involved in the establishment of the EMS. - Insufficient resources were allocated to the Environmental

The cell engineering construction and function evaluation of multi-layer biochip dialyzer.

Science.gov (United States)

Zhu, Wen; Li, Jiwei; Liu, Jianfeng

2013-10-01

We report the fabrication and function evaluation of multi-layer biochip dialyzer. Such device may potentially be applied to the wearable hemodialysis systems. By merging the advantages of microfluidic chip technology with cell engineering, both functions of glomerular filtration and renal tubule physiological activity are integrated in the same device. This device is designed into a laminated structure, in which the chip number of the superimposed layer can be arbitrarily tailored in accordance with the requirements of dialysis capacity. We propose that such structure can overcome the obstacles of large size and detached structure of the traditional hollow fiber dialyzer. To construct this multilayer biochips dialyzer, two types of dialyzer device with two-layered and six-layered chips are assembled, respectively. Cell adhesion and proliferation on three different dialysis membrane materials under static and dynamic conditions are investigated and compared. The filtration capability, re-absorption function and excrete ammonia function of the resulting multi-layer biochip dialyzer are evaluated. The results reveal that the constructed device can perform higher filtration efficiency and also play a role of renal tubule. This methodology may be useful in developing "scaling down" artificial kidneys that can act as wearable or even implantable hemodialysis systems.

Current Therapeutic Strategies for Adipose Tissue Defects/Repair Using Engineered Biomaterials and Biomolecule Formulations

Directory of Open Access Journals (Sweden)

Christopher M. Mahoney

2018-05-01

Full Text Available Tissue engineered scaffolds for adipose restoration/repair has significantly evolved in recent years. Patients requiring soft tissue reconstruction, caused by defects or pathology, require biomaterials that will restore void volume with new functional tissue. The gold standard of autologous fat grafting (AFG is not a reliable option. This review focuses on the latest therapeutic strategies for the treatment of adipose tissue defects using biomolecule formulations and delivery, and specifically engineered biomaterials. Additionally, the clinical need for reliable off-the-shelf therapies, animal models, and challenges facing current technologies are discussed.

Current Therapeutic Strategies for Adipose Tissue Defects/Repair Using Engineered Biomaterials and Biomolecule Formulations.

Science.gov (United States)

Mahoney, Christopher M; Imbarlina, Cayla; Yates, Cecelia C; Marra, Kacey G

2018-01-01

Tissue engineered scaffolds for adipose restoration/repair has significantly evolved in recent years. Patients requiring soft tissue reconstruction, caused by defects or pathology, require biomaterials that will restore void volume with new functional tissue. The gold standard of autologous fat grafting (AFG) is not a reliable option. This review focuses on the latest therapeutic strategies for the treatment of adipose tissue defects using biomolecule formulations and delivery, and specifically engineered biomaterials. Additionally, the clinical need for reliable off-the-shelf therapies, animal models, and challenges facing current technologies are discussed.

Engineering Geodesy - Definition and Core Competencies

Science.gov (United States)

Kuhlmann, Heiner; Schwieger, Volker; Wieser, Andreas; Niemeier, Wolfgang

2014-11-01

This article summarises discussions concerning the definition of "engineering geodesy" within the German Geodetic Commission. It is noted that engineering geodesy by means of its tasks, methods and characteristics is an application-oriented science whose research questions often arise from observed phenomena or from unsolved practical problems. In particular it is characterised by the professional handling of geometry-related problems in a cost-effective manner that includes comprehensive quality assessment at all phases of the problem solution - from planning through measurement to data processing and interpretation. The current methodical developments are primarily characterised by the increasing integration of the measurement and analysis into challenging construction, production and monitoring processes as well as by the transition to spatially continuous methods. A modern definition of engineering geodesy is proposed at the end of this article.

Engineering tubular bone using mesenchymal stem cell sheets and coral particles

Energy Technology Data Exchange (ETDEWEB)

Geng, Wenxin [Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, No.229 North Taibai Road, Xi’an 710069 (China); Ma, Dongyang [Department of Oral and Maxillofacial Surgery, Lanzhou General Hospital, Lanzhou Command of PLA, BinHe 333 South Road, Lanzhou 730052 (China); Yan, Xingrong; Liu, Liangqi; Cui, Jihong; Xie, Xin; Li, Hongmin [Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, No.229 North Taibai Road, Xi’an 710069 (China); Chen, Fulin, E-mail: chenfl@nwu.edu.cn [Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, No.229 North Taibai Road, Xi’an 710069 (China)

2013-04-19

Highlights: • We developed a novel engineering strategy to solve the limitations of bone grafts. • We fabricated tubular constructs using cell sheets and coral particles. • The composite constructs showed high radiological density and compressive strength. • These characteristics were similar to those of native bone. -- Abstract: The development of bone tissue engineering has provided new solutions for bone defects. However, the cell-scaffold-based approaches currently in use have several limitations, including low cell seeding rates and poor bone formation capacity. In the present study, we developed a novel strategy to engineer bone grafts using mesenchymal stem cell sheets and coral particles. Rabbit bone marrow mesenchymal stem cells were continuously cultured to form a cell sheet with osteogenic potential and coral particles were integrated into the sheet. The composite sheet was then wrapped around a cylindrical mandrel to fabricate a tubular construct. The resultant tubular construct was cultured in a spinner-flask bioreactor and subsequently implanted into a subcutaneous pocket in a nude mouse for assessment of its histological characteristics, radiological density and mechanical property. A similar construct assembled from a cell sheet alone acted as a control. In vitro observations demonstrated that the composite construct maintained its tubular shape, and exhibited higher radiological density, compressive strength and greater extracellular matrix deposition than did the control construct. In vivo experiments further revealed that new bone formed ectopically on the composite constructs, so that the 8-week explants of the composite sheets displayed radiological density similar to that of native bone. These results indicate that the strategy of using a combination of a cell sheet and coral particles has great potential for bone tissue engineering and repairing bone defects.

Engineering tubular bone using mesenchymal stem cell sheets and coral particles

International Nuclear Information System (INIS)

Geng, Wenxin; Ma, Dongyang; Yan, Xingrong; Liu, Liangqi; Cui, Jihong; Xie, Xin; Li, Hongmin; Chen, Fulin

2013-01-01

Highlights: • We developed a novel engineering strategy to solve the limitations of bone grafts. • We fabricated tubular constructs using cell sheets and coral particles. • The composite constructs showed high radiological density and compressive strength. • These characteristics were similar to those of native bone. -- Abstract: The development of bone tissue engineering has provided new solutions for bone defects. However, the cell-scaffold-based approaches currently in use have several limitations, including low cell seeding rates and poor bone formation capacity. In the present study, we developed a novel strategy to engineer bone grafts using mesenchymal stem cell sheets and coral particles. Rabbit bone marrow mesenchymal stem cells were continuously cultured to form a cell sheet with osteogenic potential and coral particles were integrated into the sheet. The composite sheet was then wrapped around a cylindrical mandrel to fabricate a tubular construct. The resultant tubular construct was cultured in a spinner-flask bioreactor and subsequently implanted into a subcutaneous pocket in a nude mouse for assessment of its histological characteristics, radiological density and mechanical property. A similar construct assembled from a cell sheet alone acted as a control. In vitro observations demonstrated that the composite construct maintained its tubular shape, and exhibited higher radiological density, compressive strength and greater extracellular matrix deposition than did the control construct. In vivo experiments further revealed that new bone formed ectopically on the composite constructs, so that the 8-week explants of the composite sheets displayed radiological density similar to that of native bone. These results indicate that the strategy of using a combination of a cell sheet and coral particles has great potential for bone tissue engineering and repairing bone defects

Naturally Engineered Maturation of Cardiomyocytes

Directory of Open Access Journals (Sweden)

Gaetano J. Scuderi

2017-05-01

Full Text Available Ischemic heart disease remains one of the most prominent causes of mortalities worldwide with heart transplantation being the gold-standard treatment option. However, due to the major limitations associated with heart transplants, such as an inadequate supply and heart rejection, there remains a significant clinical need for a viable cardiac regenerative therapy to restore native myocardial function. Over the course of the previous several decades, researchers have made prominent advances in the field of cardiac regeneration with the creation of in vitro human pluripotent stem cell-derived cardiomyocyte tissue engineered constructs. However, these engineered constructs exhibit a functionally immature, disorganized, fetal-like phenotype that is not equivalent physiologically to native adult cardiac tissue. Due to this major limitation, many recent studies have investigated approaches to improve pluripotent stem cell-derived cardiomyocyte maturation to close this large functionality gap between engineered and native cardiac tissue. This review integrates the natural developmental mechanisms of cardiomyocyte structural and functional maturation. The variety of ways researchers have attempted to improve cardiomyocyte maturation in vitro by mimicking natural development, known as natural engineering, is readily discussed. The main focus of this review involves the synergistic role of electrical and mechanical stimulation, extracellular matrix interactions, and non-cardiomyocyte interactions in facilitating cardiomyocyte maturation. Overall, even with these current natural engineering approaches, pluripotent stem cell-derived cardiomyocytes within three-dimensional engineered heart tissue still remain mostly within the early to late fetal stages of cardiomyocyte maturity. Therefore, although the end goal is to achieve adult phenotypic maturity, more emphasis must be placed on elucidating how the in vivo fetal microenvironment drives cardiomyocyte

Construction Management for Conventional Facilities of Proton Accelerator

International Nuclear Information System (INIS)

Kim, Jun Yeon; Cho, Jin Sam; Lee, Jae Sang

2008-05-01

Proton Engineering Frontier Project, puts its aim to building 100MeV 20mA linear proton accelerator which is national facility for NT, BT, IT, and future technologies, expected to boost up the national industry competitiveness. This R and D, Construction Management is in charge of the supportive works as site selection, architecture and engineering of conventional facilities, and overall construction management. The major goals of this work are as follows: At first, architecture and engineering of conventional facilities. Second, construction management, audit and inspection on construction of conventional facilities. Lastly, cooperation with the project host organization for adjusting technical issues of overall construction. In this research, We reviewed the basic design and made a detail design of conventional facilities. Preparation for construction license, site improvement and access road construction is fulfilled. Also, we made the technical support for project host as follows : selection of project host organization and host site selection, construction technical work for project host organization and procedure management

Current Status of Tissue Engineering in the Management of Severe Hypospadias

Directory of Open Access Journals (Sweden)

Tariq O. Abbas

2018-01-01

Full Text Available Hypospadias, characterized by misplacement of the urinary meatus in the lower side of the penis, is a frequent birth defect in male children. Because of the huge variation in the anatomic presentation of hypospadias, no single urethroplasty procedure is suitable for all situations. Hence, many surgical techniques have emerged to address the shortage of tissues required to bridge the gap in the urethra particularly in the severe forms of hypospadias. However, the rate of postoperative complications of currently available surgical procedures reaches up to one-fourth of the patients having severe hypospadias. Moreover, these urethroplasty techniques are technically demanding and require considerable surgical experience. These limitations have fueled the development of novel tissue engineering techniques that aim to simplify the surgical procedures and to reduce the rate of complications. Several types of biomaterials have been considered for urethral repair, including synthetic and natural polymers, which in some cases have been seeded with cells prior to implantation. These methods have been tested in preclinical and clinical studies, with variable degrees of success. This review describes the different urethral tissue engineering methodologies, with focus on the approaches used for the treatment of hypospadias. At present, despite many significant advances, the search for a suitable tissue engineering approach for use in routine clinical applications continues.

Constructing integrable full-pressure full-current free-boundary stellarator magnetohydrodynamic equilibrium solutions

International Nuclear Information System (INIS)

Hudson, S.R.

2002-01-01

For stellarators to be feasible candidates for fusion power stations it is essential that the magnetic field lines lie on nested flux surfaces; however, the lack of a continuous symmetry implies that magnetic islands, caused by Pfirsch-Schlueter currents, diamagnetic currents and resonant coil fields, are guaranteed to exist. The challenge is to design the plasma and coils such that these effects cancel. Magnetic islands in free-boundary full-pressure full-current stellarator magnetohydrodynamic equilibria are suppressed using a procedure based on the PIES code [Comp. Phys. Comm., 43:157, 1986] which iterates the equilibrium equations to obtain the plasma equilibrium. At each iteration, changes to a Fourier representation of the coil geometry are made to cancel resonant fields produced by the plasma. The changes are constrained to lie in the nullspace of certain measures of engineering acceptability and kink stability. As the iterations continue, the coil geometry and the plasma simultaneously converge to an equilibrium in which the island content is negligible. The method is applied to a candidate plasma and coil design for NCSX [Phys. Plas., 7:1911, 2000]. (author)

Method Engineering: Engineering of Information Systems Development Methods and Tools

NARCIS (Netherlands)

Brinkkemper, J.N.; Brinkkemper, Sjaak

1996-01-01

This paper proposes the term method engineering for the research field of the construction of information systems development methods and tools. Some research issues in method engineering are identified. One major research topic in method engineering is discussed in depth: situational methods, i.e.

A Study of Second-Year Engineering Students' Alternative Conceptions about Electric Potential, Current Intensity and Ohm's Law

Science.gov (United States)

Periago, M. Cristina; Bohigas, Xavier

2005-01-01

The aim of this research was to evaluate and analyse second-year industrial engineering and chemical engineering students prior knowledge of conceptual aspects of "circuit theory". Specifically, we focused on the basic concepts of electric potential and current intensity and on the fundamental relationship between them as expressed by Ohm's law.…

Data-driven technology for engineering systems health management design approach, feature construction, fault diagnosis, prognosis, fusion and decisions

CERN Document Server

Niu, Gang

2017-01-01

This book introduces condition-based maintenance (CBM)/data-driven prognostics and health management (PHM) in detail, first explaining the PHM design approach from a systems engineering perspective, then summarizing and elaborating on the data-driven methodology for feature construction, as well as feature-based fault diagnosis and prognosis. The book includes a wealth of illustrations and tables to help explain the algorithms, as well as practical examples showing how to use this tool to solve situations for which analytic solutions are poorly suited. It equips readers to apply the concepts discussed in order to analyze and solve a variety of problems in PHM system design, feature construction, fault diagnosis and prognosis.

Assessment of post-implantation integration of engineered tissues using fluorescence lifetime spectroscopy

Science.gov (United States)

Elahi, Sakib F.; Lee, Seung Y.; Lloyd, William R.; Chen, Leng-Chun; Kuo, Shiuhyang; Zhou, Ying; Kim, Hyungjin M.; Kennedy, Robert; Marcelo, Cynthia; Feinberg, Stephen E.; Mycek, Mary-Ann

2018-02-01

Clinical translation of engineered tissue constructs requires noninvasive methods to assess construct health and viability after implantation in patients. However, current practices to monitor post-implantation construct integration are either qualitative (visual assessment) or destructive (tissue histology). As label-free fluorescence lifetime sensing can noninvasively characterize pre-implantation construct viability, we employed a handheld fluorescence lifetime spectroscopy probe to quantitatively and noninvasively assess tissue constructs that were implanted in a murine model. We designed the system to be suitable for intravital measurements: portability, localization with precise maneuverability, and rapid data acquisition. Our model tissue constructs were manufactured from primary human cells to simulate patient variability and were stressed to create a range of health states. Secreted amounts of three cytokines that relate to cellular viability were measured in vitro to assess pre-implantation construct health. In vivo optical sensing assessed tissue integration of constructs at one-week and three-weeks post-implantation. At one-week post-implantation, optical parameters correlated with in vitro pre-implantation secretion levels of all three cytokines (p clinical optical diagnostic tools based on label-free fluorescence lifetime sensing of endogenous tissue fluorophores could noninvasively monitor post-implantation integration of engineered tissues.

Mechanisms Engineering Test Loop - Phase 1 Status Report

Energy Technology Data Exchange (ETDEWEB)

Kultgen, D. [Argonne National Lab. (ANL), Argonne, IL (United States); Grandy, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Hvasta, M. [Argonne National Lab. (ANL), Argonne, IL (United States); Lisowski, D. [Argonne National Lab. (ANL), Argonne, IL (United States); Toter, W. [Argonne National Lab. (ANL), Argonne, IL (United States); Borowski, A. [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-09-01

This report documents the current status of the Mechanisms Engineering Test Loop (METL) as of the end of FY2016. Currently, METL is in Phase I of its design and construction. Once operational, the METL facility will test small to intermediate-scale components and systems in order to develop advanced liquid metal technologies. Testing different components in METL is essential for the future of advanced fast reactors as it will provide invaluable performance data and reduce the risk of failures during plant operation.

Confirmation tests of construction method and initial performance quality for low permeable engineered barrier in side part of radioactive waste disposal facilities

International Nuclear Information System (INIS)

Yamada, Atsuo; Chijimatsu, Masakazu; Akiyama, Yoshihiro; Komine, Hideo; Iizuka, Atsushi

2016-01-01

As for the low permeable layer, important functions are expected as an engineered barrier of radioactive waste disposal for low-level waste with comparatively high radiation levels. On examining the construction methods of this low permeable layer, it is important to confirm the possibility of the construction in the conditions similar to the actual constructed conditions with a true scale size. Therefore, the construction examination for the side part of the low permeable layer by bentonite and the performance check test of the low permeable layer were carried out. The result of the construction examination showed that the possibility of the construction were confirmed, and the result of performance check test showed that it was possible to ensure the required performance of the low permeable layer, such as hydraulic conductivity. (author)

Numerical calculation of hydrodynamic characteristics of tidal currents for submarine excavation engineering in coastal area

Directory of Open Access Journals (Sweden)

Jian-hua Li

2016-04-01

Full Text Available In coastal areas with complicated flow movement, deposition and scour readily occur in submarine excavation projects. In this study, a small-scale model, with a high resolution in the vertical direction, was used to simulate the tidal current around a submarine excavation project. The finite volume method was used to solve Navier-Stokes equations and the Reynolds stress transport equation, and the entire process of the tidal current was simulated with unstructured meshes, generated in the irregular shape area, and structured meshes, generated in other water areas. The meshes near the bottom and free surface were densified with a minimum layer thickness of 0.05 m. The volume of fluid method was used to track the free surface, the volume fraction of cells on the upstream boundary was obtained from the volume fraction of adjacent cells, and that on the downstream boundary was determined by the water level process. The numerical results agree with the observed data, and some conclusions can be drawn: after the foundation trench excavation, the flow velocity decreases quite a bit through the foundation trench, with reverse flow occurring on the lee slope in the foundation trench; the swirling flow impedes inflow, leading to the occurrence of dammed water above the foundation trench; the turbulent motion is stronger during ebbing than in other tidal stages, the range with the maximum value of turbulent viscosity, occurring on the south side of the foundation trench at maximum ebbing, is greater than those in other tidal stages in a tidal cycle, and the maximum value of Reynolds shear stress occurs on the south side of the foundation trench at maximum ebbing in a tidal cycle. The numerical calculation method shows a strong performance in simulation of the hydrodynamic characteristics of tidal currents in the foundation trench, providing a basis for submarine engineering construction in coastal areas.

Formalized description of assessment procedures of tender offers (of the construction organizer and contracting companies in case of engineering control scheme

Directory of Open Access Journals (Sweden)

Sborshchikov Sergey Borisovich

2016-10-01

Full Text Available The procedure of evaluating and selecting tender offers is not only an important element of the control system of investment and construction activity but is also an effective tool to increase its efficiency due to optimization of construction works price, reduction of their duration, stimulating innovations in the production, increasing the quality and engineering safety of construction production. At the recent time when new organizational forms and control schemes of investment and construction activity are appearing the system of competitive bidding gains more importance and new functions, because the choice of construction organizer and contracting companies directly influences the results of the construction. The authors consider the task of selecting the bidders’ offers which is a multicriterion task. The offers are evaluated according to the set of parameters reflecting the effectiveness of investment and construction projects. The criteria selection is based on the fact that the proposals of the organizer of construction and the contractors are related to the cost of works and to the deadlines which directly affects the implementation parameters of investment and construction projects.

Engineering and erection of a 300kW high-flux solar simulator

Science.gov (United States)

Wieghardt, Kai; Laaber, Dmitrij; Hilger, Patrick; Dohmen, Volkmar; Funken, Karl-Heinz; Hoffschmidt, Bernhard

2017-06-01

German Aerospace Center (DLR) is currently constructing a new high-flux solar simulator synlight which shall be commissioned in late 2016. The new facility will provide three separately operated experimental spaces with expected radiant powers of about 300kW / 240kW / 240kW respectively. synlight was presented to the public for the first time at SolarPACES 2015 [1]. Its engineering and erection is running according to plan. The current presentation reports about the engineering and the ongoing erection of the novel facility, and gives an outlook on its new level of possibilities for solar testing and qualification.

The Crosstalk between Tissue Engineering and Pharmaceutical Biotechnology: Recent Advances and Future Directions.

Science.gov (United States)

Pacheco, Daniela P; Reis, Rui L; Correlo, Vítor M; Marques, Alexandra P

2015-01-01

Tissue-engineered constructs made of biotechnology-derived materials have been preferred due to their chemical and physical composition, which offers both high versatility and a support to enclose/ incorporate relevant signaling molecules and/or genes known to therapeutically induce tissue repair. Herein, a critical overview of the impact of different biotechnology-derived materials, scaffolds, and recombinant signaling molecules over the behavior of cells, another element of tissue engineered constructs, as well its regulatory role in tissue regeneration and disease progression is given. Additionally, these tissue-engineered constructs evolved to three-dimensional (3D) tissue-like models that, as an advancement of two-dimensional standard culture methods, are expected to be a valuable tool in the field of drug discovery and pharmaceutical research. Despite the improved design and conception of current proposed 3D tissue-like models, advanced control systems to enable and accelerate streamlining and automation of the numerous labor-intensive steps intrinsic to the development of tissue-engineered constructs are still to be achieved. In this sense, this review intends to present the biotechnology- derived materials that are being explored in the field of tissue engineering to generate 3D tissue-analogues and briefly highlight their foremost breakthroughs in tissue regeneration and drug discovery. It also aims to reinforce that the crosstalk between tissue engineering and pharmaceutical biotechnology has been fostering the outcomes of tissue engineering approaches through the use of biotechnology-derived signaling molecules. Gene delivery/therapy is also discussed as a forefront area that represents another cross point between tissue engineering and pharmaceutical biotechnology, in which nucleic acids can be considered a "super pharmaceutical" to drive biological responses, including tissue regeneration.

Aerospace Concurrent Engineering Design Teams: Current State, Next Steps and a Vision for the Future

Science.gov (United States)

Hihn, Jairus; Chattopadhyay, Debarati; Karpati, Gabriel; McGuire, Melissa; Borden, Chester; Panek, John; Warfield, Keith

2011-01-01

Over the past sixteen years, government aerospace agencies and aerospace industry have developed and evolved operational concurrent design teams to create novel spaceflight mission concepts and designs. These capabilities and teams, however, have evolved largely independently. In today's environment of increasingly complex missions with limited budgets it is becoming readily apparent that both implementing organizations and today's concurrent engineering teams will need to interact more often than they have in the past. This will require significant changes in the current state of practice. This paper documents the findings from a concurrent engineering workshop held in August 2010 to identify the key near term improvement areas for concurrent engineering capabilities and challenges to the long-term advancement of concurrent engineering practice. The paper concludes with a discussion of a proposed vision for the evolution of these teams over the next decade.

The design and construction of the windscale vitrification plant and vitrified product store

International Nuclear Information System (INIS)

Heafield, W.; Woodall, A.; Elsden, A.D.

1987-01-01

The paper describes the background of High Level Waste storage and vitrification development in the UK and its application to Reprocessing Operations at Sellafield. The main stages in the vitrification process and associated maintenance facilities are described together with the layout of the Windscale Vitrification Plant (WVP) and associated Vitrified Product Store (VPS). The design and construction techniques employed for example, the use of Computer Aided Design and the effect of automatic pipe bending/orbital welding and the use of precast units for cell construction, are discussed and current construction progress is highlighted. The vitrification process uses complex mechanical plant operating in high temperature and radiation fields. An extensive engineering and process development programme has been carried out. A full scale inactive facility (FSIF) has been constructed and the objectives and results from the operation of FSIF are presented. In addition to engineering and process development, a comprehensive programme of glass technology development has been carried out to establish maximum waste incorporation levels, reaction kinetic and product properties of the candidate glass formulations

The Use of Online Current Awareness Services by Natural Sciences and Engineering Faculty at Western Michigan University

Science.gov (United States)

Leatherman, Carrie C.; Eckel, Edward J.

2012-01-01

Nearly every commercial database that covers natural sciences and engineering offers some type of current awareness (CA) service that provides regular updates to users on current literature in a selected field of interest. Current awareness services include e-mail alerts, tables of contents, and RSS feeds. This study was designed to find out what…

Construction of a bibliographic information database and a web directory for the nuclear science and engineering

Energy Technology Data Exchange (ETDEWEB)

Oh, Jeong Hoon; Kim, Tae Whan; Lee, Ji Ho; Chun, Young Chun; Yu, An Na

2005-11-15

The objective of this project is to construct the bibliographic information database and the web directory in the nuclear field. Its construction is very timely and important. Because nuclear science and technology has an considerable effect all over the other sciences and technologies due to its property of giant and complex engineering. We aimed to firmly build up a basis of efficient management of the bibliographic information database and the web directory in the nuclear field. The results of this project that we achieved in this year are as follows : first, construction of the bibliographic information database in the nuclear field(the target title: 1,500 titles ; research report: 1,000 titles, full-text report: 250 titles, full-text article: 250 titles). Second, completion of construction of the web directory in the nuclear field by using SWING (the total figure achieved : 2,613 titles). We plan that we will positively give more information to the general public interested in the nuclear field and to the experts of the field through this bibliographic information database on KAERI's home page, KAERI's electronic library and other related sites as well as participation at various seminars and meetings related to the nuclear field.

Current Advancements and Strategies in Tissue Engineering for Wound Healing: A Comprehensive Review.

Science.gov (United States)

Ho, Jasmine; Walsh, Claire; Yue, Dominic; Dardik, Alan; Cheema, Umber

2017-06-01

Significance: With an aging population leading to an increase in diabetes and associated cutaneous wounds, there is a pressing clinical need to improve wound-healing therapies. Recent Advances: Tissue engineering approaches for wound healing and skin regeneration have been developed over the past few decades. A review of current literature has identified common themes and strategies that are proving successful within the field: The delivery of cells, mainly mesenchymal stem cells, within scaffolds of the native matrix is one such strategy. We overview these approaches and give insights into mechanisms that aid wound healing in different clinical scenarios. Critical Issues: We discuss the importance of the biomimetic niche, and how recapitulating elements of the native microenvironment of cells can help direct cell behavior and fate. Future Directions: It is crucial that during the continued development of tissue engineering in wound repair, there is close collaboration between tissue engineers and clinicians to maintain the translational efficacy of this approach.

Engineering microbes to produce biofuels.

Science.gov (United States)

Wackett, Lawrence P

2011-06-01

The current biofuels landscape is chaotic. It is controlled by the rules imposed by economic forces and driven by the necessity of finding new sources of energy, particularly motor fuels. The need is bringing forth great creativity in uncovering new candidate fuel molecules that can be made via metabolic engineering. These next generation fuels include long-chain alcohols, terpenoid hydrocarbons, and diesel-length alkanes. Renewable fuels contain carbon derived from carbon dioxide. The carbon dioxide is derived directly by a photosynthetic fuel-producing organism(s) or via intermediary biomass polymers that were previously derived from carbon dioxide. To use the latter economically, biomass depolymerization processes must improve and this is a very active area of research. There are competitive approaches with some groups using enzyme based methods and others using chemical catalysts. With the former, feedstock and end-product toxicity loom as major problems. Advances chiefly rest on the ability to manipulate biological systems. Computational and modular construction approaches are key. For example, novel metabolic networks have been constructed to make long-chain alcohols and hydrocarbons that have superior fuel properties over ethanol. A particularly exciting approach is to implement a direct utilization of solar energy to make a usable fuel. A number of approaches use the components of current biological systems, but re-engineer them for more direct, efficient production of fuels. Copyright © 2010 Elsevier Ltd. All rights reserved.

Construction of a Direct Water-Injected Two-Stroke Engine for Phased Direct Fuel Injection-High Pressure Charging Investigations

Science.gov (United States)

Somsel, James P.

1998-01-01

The development of a water injected Orbital Combustion Process (OCP) engine was conducted to assess the viability of using the powerplant for high altitude NASA aircraft and General Aviation (GA) applications. An OCP direct fuel injected, 1.2 liter, three cylinder, two-stroke engine has been enhanced to independently inject water directly into the combustion chamber. The engine currently demonstrates low brake specific fuel consumption capability and an excellent power to weight ratio. With direct water injection, significant improvements can be made to engine power, to knock limits/ignition advance timing, and to engine NO(x) emissions. The principal aim of the testing was to validate a cyclic model developed by the Systems Analysis Branch at NASA Ames Research Center. The work is a continuation of Ames' investigations into a Phased Direct Fuel Injection Engine with High Pressure Charging (PDFI-ITPC).

Working in the Dry: Cofferdams, In-River Construction, and the United States Army Corps of Engineers

Science.gov (United States)

2009-01-01

and dams to manage before 1897, but within 10 years, they would have twenty. Many of the MNC engineers had gained practical experience in small lock...America’s water- ways untapped or under-exploited raw mate- rials requiring development, control, and management for human benefit.6 During the colonial...Section , ^ N 6 to sink into position ^ 5ection 5 Gr<eo.test dapth of waiter in which skeleton wa.s a.ctua.1 ly constru_cted wSig_Lfl fee

Industrial Education. "Small Engines".

Science.gov (United States)

Parma City School District, OH.

Part of a series of curriculum guides dealing with industrial education in junior high schools, this guide provides the student with information and manipulative experiences on small gasoline engines. Included are sections on shop adjustment, safety, small engines, internal combustion, engine construction, four stroke engines, two stroke engines,…

Design and construction of engineering test device of a multi-purpose radwaste incineration system

International Nuclear Information System (INIS)

Wang Peiyi; Zhou Lianquan; Ma Mingxie; Qiu Mingcai; Yang Liguo; Li Xiaohai; Zhang Xiaobin; Lu Xiaowu; Dong Jingling; Wang Xujin; Li Chuanlian; Yang Baomin

2002-01-01

The author describes designs of main un-standard devices, monitoring system and safety system, as well as construction of the engineering system devices for a multi-purpose radwaste incineration system. Un-standard devices include waste crusher, pyrolysis furnace, incinerator furnace, cool stream dilution device and bag filter, etc. The monitoring system mainly includes industrial controlled computer, supported by conventional electrical equipment and instruments. Designs of system safety takes account of containment of radioactive materials fire-prevention, explosion prevention, anti-corrosion, redundance and reservation, emergency system, controlling and electric safety system, etc. Results show that main technological system remains good airtight with leakage ratio at 0.67%

Conditions de contrat applicables aux travaux de construction

CERN Document Server

1999-01-01

Conditions of Contract for Construction, which are recommended for building or engineering works designed by the Employer or by his representative, the Engineer. Under the usual arrangements for this type of contract, the Contractor constructs the works in accordance with a design provided by the Employer. However, the works may include some elements of Contractor-designed civil, mechanical, electrical and/or construction works.

An analysis of USMC heavy construction equipment (HCE) requirements

OpenAIRE

Blaxton, Allen C.; Fay, Michael J.; Hansen, Cheryl M.; Zuchristian, Christopher M.

2003-01-01

MBA Professional Report Approved for public release; distribution is unlimited. According to I and L, HQMC, the Marine Corps needs to re-evaluate current operational requirements for engineer construction equipment. Acquisition and force allocation levels for equipment have remained essentially at constant 1970's, Cold War levels. Because acquisition and allocation levels haven't changed at the same rate as personnel, there is a perception that much of the existing equipment is unnecess...

Genetic engineering for skeletal regenerative medicine.

Science.gov (United States)

Gersbach, Charles A; Phillips, Jennifer E; García, Andrés J

2007-01-01

The clinical challenges of skeletal regenerative medicine have motivated significant advances in cellular and tissue engineering in recent years. In particular, advances in molecular biology have provided the tools necessary for the design of gene-based strategies for skeletal tissue repair. Consequently, genetic engineering has emerged as a promising method to address the need for sustained and robust cellular differentiation and extracellular matrix production. As a result, gene therapy has been established as a conventional approach to enhance cellular activities for skeletal tissue repair. Recent literature clearly demonstrates that genetic engineering is a principal factor in constructing effective methods for tissue engineering approaches to bone, cartilage, and connective tissue regeneration. This review highlights this literature, including advances in the development of efficacious gene carriers, novel cell sources, successful delivery strategies, and optimal target genes. The current status of the field and the challenges impeding the clinical realization of these approaches are also discussed.

Role of civil engineers in design and construction of nuclear power plants

International Nuclear Information System (INIS)

Sivathanu Pillai, C.

2015-01-01

Nuclear energy remains an important element in India's energy mix for sustaining rapid economic growth. In the Indian energy scenario projections for the future, nuclear power through fast reactors has been considered as an important component. Fast reactors are also planned to be built in the medium term to burn minor actinides as means of reducing the burden of radioactive waste management. Nuclear power in India provides 3% of the electricity generated in the country now; it is estimated to go up to 25% by 2050. India has a special interest in developing fast breeder reactors and use of thorium as a source of energy as it has one of the largest reserves of thorium. Nuclear industry always provides challenging works to civil engineers. From geotechnical investigation, structural analysis, design, construction and to material developments and provides unique opportunity for excellence

North American Engineering, Procurement, Fabrication and Construction Worker Safety Climate Perception Affected by Job Position

Directory of Open Access Journals (Sweden)

Clint Pinion

2018-04-01

Full Text Available Understanding and implementing the results of Safety Climate surveys can assist in decreasing occupational injuries and illnesses. The following article presents findings of a cross-sectional study that assessed the relationship between safety climate perceptions and job position among engineering, procurement, fabrication and construction (EPFC employees using a 15-item survey. Descriptive statistics (means and frequencies and an ANACOVA (analysis of covariance were performed on a saturated model. The study had a 62% response rate. Results indicate a statistically significant in mean safety climate scores between job position among EPFC employees when controlling for years in industry and location type (i.e., construction versus fabrication [F (9, 603 = 5.28, p < 0.0001, adjusted R-square = 0.07]. Employee perception of safety climate differed based on the employee’s job position (i.e., laborer, foreman, etc.. Project management reported the highest safety climate scores (0.91, followed by supervisors (0.86, technical support employees and foremen (0.84 and laborers (0.81.

Conditions of contract for construction for building and engineering works designed by the employer : general conditions : guidance for the preparation of particular conditions forms of letter of tender, contract agreement and dispute adjudication agreement

CERN Document Server

1999-01-01

Conditions of Contract for Construction, which are recommended for building or engineering works designed by the Employer or by his representative, the Engineer. Under the usual arrangements for this type of contract, the Contractor constructs the works in accordance with a design provided by the Employer. However, the works may include some elements of Contractor-designed civil, mechanical, electrical and/or construction works.

Reliable and adequateengineering surveys for construction: the rule of two D

Directory of Open Access Journals (Sweden)

Rakitina Natal'ya Nikolaevna

2014-01-01

Full Text Available In the article the current state of quality supply of engineering surveys for construction is discussed. The main criteria for improving the design quality of buildings and structures for industrial, civil and other purposes is the reliability and adequacy of the results of engineering-geological surveys. The authors show the examples of inadequate study of engineering-geological conditions in the design of structures that led to emergency situations. Consideration of the reasons of accidents in structures showed that they are caused by lack of research conducted, the underestimation of the complexity of geological conditions. In the process of conducting geotechnical investigations the works were focused directly in the enclosure of a designed building, and the features of geological and hydrogeological conditions of the off-site were much more complex. In the process of construction during the sinking of the pit activation suffusion processes occurred, which led to an accident. Underestimation of the use of these geological funds in this example shows that even in the presence of fund materials, which are currently almost not increased, errors may occur due to the notorious savings for research. The requirements to ensuring the reliability and adequacy of engineering-geological surveys, which the authors call "The Rule of two D" (in Russian — Reliability and Adequacy, lie in the existing legal acts. The practice of fulfilling requirements to a large extend shows that the desire to save money at the stage of design and exploration works results in additional costs for additional design, recovery from accidents and works on a new project. The authors critically evaluated the development of engineering and geotechnical engineering instead of geological survey, which is not methodologically and theoretically substantiated and leads to the excluding from engineering surveys the consideration of the off-site geotechnical conditions directly below

The Application of Corals in Bone Tissue Engineering

Directory of Open Access Journals (Sweden)

Iraj Nabipour

2017-05-01

Full Text Available Natural coral exoskeleton and coralline hydroxyapatite have been used as bone replacement graft for repairing of bone defects in animal models and humans since two decades ago. These bone replacement grafts have an osteoconductive, biodegradable and biocompatible features. Currently, three lines of researches in bone tissue engineering are conducting on corals. Corals have been used for construction of bony composites, stem cells attachments, and the growth factors-scaffold-based approaches. This review have paid to the wide range of coral use in clinical experiments as a bone graft substitute and cell-scaffold-based approaches in bone tissue engineering.

Perspectives on knowledge in engineering design

Science.gov (United States)

Rasdorf, W. J.

1985-01-01

Various perspectives are given of the knowledge currently used in engineering design, specifically dealing with knowledge-based expert systems (KBES). Constructing an expert system often reveals inconsistencies in domain knowledge while formalizing it. The types of domain knowledge (facts, procedures, judgments, and control) differ from the classes of that knowledge (creative, innovative, and routine). The feasible tasks for expert systems can be determined based on these types and classes of knowledge. Interpretive tasks require reasoning about a task in light of the knowledge available, where generative tasks create potential solutions to be tested against constraints. Only after classifying the domain by type and level can the engineer select a knowledge-engineering tool for the domain being considered. The critical features to be weighed after classification are knowledge representation techniques, control strategies, interface requirements, compatibility with traditional systems, and economic considerations.

Elementary students' engagement in failure-prone engineering design tasks

Science.gov (United States)

Andrews, Chelsea Joy

Although engineering education has been practiced at the undergraduate level for over a century, only fairly recently has the field broadened to include the elementary level; the pre-college division of the American Society of Engineering Education was established in 2003. As a result, while recent education standards require engineering in elementary schools, current studies are still filling in basic research on how best to design and implement elementary engineering activities. One area in need of investigation is how students engage with physical failure in design tasks. In this dissertation, I explore how upper elementary students engage in failure-prone engineering design tasks in an out-of-school environment. In a series of three empirical case studies, I look closely at how students evaluate failed tests and decide on changes to their design constructions, how their reasoning evolves as they repeatedly encounter physical failure, and how students and facilitators co-construct testing norms where repetitive failure is manageable. I also briefly investigate how students' engagement differs in a task that features near-immediate success. By closely examining student groups' discourse and their interactions with their design constructions, I found that these students: are able to engage in iteration and see failure-as-feedback with minimal externally-imposed structure; seem to be designing in a more sophisticated manner, attending to multiple causal factors, after experiencing repetitive failure; and are able to manage the stress and frustration of repetitive failure, provided the co-constructed testing norms of the workshop environment are supportive of failure management. These results have both pedagogical implications, in terms of how to create and facilitate design tasks, and methodological implications--namely, I highlight the particular insights afforded by a case study approach for analyzing engagement in design tasks.

Bone tissue engineering using silica-based mesoporous nanobiomaterials:Recent progress.

Science.gov (United States)

Shadjou, Nasrin; Hasanzadeh, Mohammad

2015-10-01

Bone disorders are of significant concern due to increase in the median age of our population. It is in this context that tissue engineering has been emerging as a valid approach to the current therapies for bone regeneration/substitution. Tissue-engineered bone constructs have the potential to alleviate the demand arising from the shortage of suitable autograft and allograft materials for augmenting bone healing. Silica based mesostructured nanomaterials possessing pore sizes in the range 2-50 nm and surface reactive functionalities have elicited immense interest due to their exciting prospects in bone tissue engineering. In this review we describe application of silica-based mesoporous nanomaterials for bone tissue engineering. We summarize the preparation methods, the effect of mesopore templates and composition on the mesopore-structure characteristics, and different forms of these materials, including particles, fibers, spheres, scaffolds and composites. Also, the effect of structural and textural properties of mesoporous materials on development of new biomaterials for production of bone implants and bone cements was discussed. Also, application of different mesoporous materials on construction of manufacture 3-dimensional scaffolds for bone tissue engineering was discussed. It begins by giving the reader a brief background on tissue engineering, followed by a comprehensive description of all the relevant components of silica-based mesoporous biomaterials on bone tissue engineering, going from materials to scaffolds and from cells to tissue engineering strategies that will lead to "engineered" bone. Copyright © 2015 Elsevier B.V. All rights reserved.

Geometric procedures for civil engineers

CERN Document Server

Tonias, Elias C

2016-01-01

This book provides a multitude of geometric constructions usually encountered in civil engineering and surveying practice.  A detailed geometric solution is provided to each construction as well as a step-by-step set of programming instructions for incorporation into a computing system. The volume is comprised of 12 chapters and appendices that may be grouped in three major parts: the first is intended for those who love geometry for its own sake and its evolution through the ages, in general, and, more specifically, with the introduction of the computer. The second section addresses geometric features used in the book and provides support procedures used by the constructions presented. The remaining chapters and the appendices contain the various constructions. The volume is ideal for engineering practitioners in civil and construction engineering and allied areas.

Radioactive materials in construction projects

International Nuclear Information System (INIS)

Herrmann, Ralf; Ohlendorf, Frank; Kaltz, Andrea Christine

2014-01-01

Till 1990 residues often of the former uranium mining were partly used as building material for road construction, terrain compensation and house construction in Saxony. These recommendations for action are addressed to applicants, planners and building constructors in the engineering and construction sector. It provides information for planning, preliminary investigations, applications, construction supervision related to radiation protection measures and documentation of construction projects where radioactive materials are expected.

The current state of engineered nanomaterials in consumer goods and waste streams: the need to develop nanoproperty-quantifiable sensors for monitoring engineered nanomaterials

Directory of Open Access Journals (Sweden)

Wise K

2011-07-01

Full Text Available Kelsey Wise, Murphy BrasuelDepartment of Chemistry and Biochemistry, Colorado College, Colorado Springs, CO, USAAbstract: As nanomaterials are harnessed for medicine and other technological advances, an understanding of the toxicology of these new materials is required to inform our use. This toxicological knowledge will be required to establish the medical and environmental regulations required to protect consumers and those involved in nanomaterial manufacturing. Nanoparticles of titanium oxide, carbon nanotubes, semiconductor quantum dots, gold, and silver represent a high percentage of the nanotechnology currently available or currently poised to reach consumers. For these nanoparticles, this review aims to identify current applications, the current methods used for characterization and quantification, current environmental concentrations (if known, and an introduction to the toxicology research. Continued development of analytical tools for the characterization and quantification of nanomaterials in complex environmental and biological samples will be required for our understanding of the toxicology and environmental impact of nanomaterials. Nearly all materials exhibit toxicity at a high enough concentration. Robust, rapid, and cost effective analytical techniques will be required to determine current background levels of anthropogenic, accidental, and engineered nanoparticles in air, water, and soil. The impact of the growing number of engineered nanoparticles used in consumer goods and medical applications can then be estimated. This will allow toxicological profiles relevant to the demonstrated or predicted environmental concentrations to be determined.Keywords: titanium dioxide nanoparticles, carbon nanotubes, semiconductor quantum dots, gold nanoparticles, silver nanoparticles, nanoparticles environmental concentrations

Construction of Fluid - solid Coupling Model with Improved Richards - BP & Its Engineering Application

Science.gov (United States)

Xie, Chengyu; Jia, Nan; Shi, Dongping; Lu, Hao

2017-10-01

In order to study the slurry diffusion law during grouting, Richards unsaturated-saturated model was introduced, the definition of the grouting model is clear, the Richards model control equation was established, And the BP neural network was introduced, the improved fluid-solid coupling model was constructed, Through the use of saturated - unsaturated seepage flow model, As well as the overflow boundary iterative solution of the mixed boundary conditions, the free surface is calculated. Engineering practice for an example, with the aid of multi - field coupling analysis software, the diffusion law of slurry was simulated numerically. The results show that the slurry diffusion rule is affected by grouting material, initial pressure and other factors. When the slurry starts, it flows in the cracks along the upper side of the grouting hole, when the pressure gradient is reduced to the critical pressure, that is, to the lower side of the flow, when the slurry diffusion stability, and ultimately its shape like an 8. The slurry is spread evenly from the overall point of view, from the grouting mouth toward the surrounding evenly spread, it gradually reaches saturation by non-saturation, and it is not a purely saturated flow, when the slurry spread and reach a saturated state, the diffusion time is the engineering grouting time.

Systems Engineering Model for ART Energy Conversion

Energy Technology Data Exchange (ETDEWEB)

Mendez Cruz, Carmen Margarita [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rochau, Gary E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wilson, Mollye C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-02-01

The near-term objective of the EC team is to establish an operating, commercially scalable Recompression Closed Brayton Cycle (RCBC) to be constructed for the NE - STEP demonstration system (demo) with the lowest risk possible. A systems engineering approach is recommended to ensure adequate requirements gathering, documentation, and mode ling that supports technology development relevant to advanced reactors while supporting crosscut interests in potential applications. A holistic systems engineering model was designed for the ART Energy Conversion program by leveraging Concurrent Engineering, Balance Model, Simplified V Model, and Project Management principles. The resulting model supports the identification and validation of lifecycle Brayton systems requirements, and allows designers to detail system-specific components relevant to the current stage in the lifecycle, while maintaining a holistic view of all system elements.

Development of an eddy current inspection technique for sleeved engine disk bolt holes

International Nuclear Information System (INIS)

Palanisamy, R.; Lakin, K.M.

1983-01-01

Recent research programs have concentrated mainly on developing techniques to characterize surface breaking cracks and very little has been done towards characterizing subsurface flaws in conducting materials. Presented in this paper are the results of some initial theoretical work aimed at the development of a reliable eddy current technique to detect and characterize defects in engine disk bolt holes under a 0.05'' stainless steel sleeve. The change in impedance of an absolute eddy current coil with and without ferrite core, and the distribution of eddy currents around a second layer crack with and without a thin insulating film between the two conducting layers have been predicted numerically. The overall system development goals and methods to accomplish them are outlined briefly

Improvement of Construction Project Management Processes

Directory of Open Access Journals (Sweden)

Nazarko, J.

2017-07-01

Full Text Available The common denominator of the five papers published in the current edition of the Journal of Engineering, Project, and Production Management is the improvement of construction project management processes for effective use of resources. Execution of proper project management processes is widely recognized as a key success factor influencing likelihood of project success (Alleman, 2014. It is noticeable that four out of five papers in this issue of the Journal are authored or co-authored by Iranian researchers from the same Institute but their conclusions bear importance that cannot be limited to the authors’ region.

Current practices of construction waste reduction through 3R practice among contractors in malaysia: Case study in penang

Science.gov (United States)

Ng, L. S.; Tan, L. W.; Seow, T. W.

2017-11-01

The effectiveness of the implementation of construction waste reduction through 3R reflects the sustainability in construction waste management. Weak implementation of construction waste reduction through 3R among contractors will lead to unsustainable construction waste management. Increase in construction waste on landfills is critical especially on islands where land is very limited for solid waste disposal. This aim of this paper is to investigate current practice of construction waste reduction through 3R practice among contractors in Penang, Malaysia. The findings reported herein is based on feedbacks from 143 construction contractors of grade CIDB G7, G6 and G5 in Penang and experts from Penang Local Authority, CIDB in Penang and its Headquarters, National Solid Waste Management Department, and Headquarters of Solid Waste and Public Cleansing Management Corporation. Interviews and questionnaire surveys have been found that 3R practice is not mandatory in construction waste management in Penang. Only 39.8% construction contractors practiced 3R in managing their waste. Therefore, 3R practices should be emphasized in construction industry. Reducing wastes through 3R practices in construction industry is a way forward towards sustainable construction waste management especially in expanding the lifetime of landfill.

On improving the NPP construction long-term planning

International Nuclear Information System (INIS)

Solov'ev, M.M.

1980-01-01

General approaches to solving the problems of long-term planning of the construction-mounting work volume and introduction of power capacities at different paces of power unit commission and norms of construction time are considered. Problems associated with location and development of subsidiary industries providing NPP construction are discussed. It is shown that decrease of WWER-1000 reactor type NPP construction time from 24 to 12 months results in reduction of required high-skilled engineers, managerial staff, unique construction mechanisms and engines as well as in improvement of conditions for conducting measures on work arrangement during preparation of construction industry and mounting of the first assemblies

Customizable engineered blood vessels using 3D printed inserts.

Science.gov (United States)

Pinnock, Cameron B; Meier, Elizabeth M; Joshi, Neeraj N; Wu, Bin; Lam, Mai T

2016-04-15

Current techniques for tissue engineering blood vessels are not customizable for vascular size variation and vessel wall thickness. These critical parameters vary widely between the different arteries in the human body, and the ability to engineer vessels of varying sizes could increase capabilities for disease modeling and treatment options. We present an innovative method for producing customizable, tissue engineered, self-organizing vascular constructs by replicating a major structural component of blood vessels - the smooth muscle layer, or tunica media. We utilize a unique system combining 3D printed plate inserts to control construct size and shape, and cell sheets supported by a temporary fibrin hydrogel to encourage cellular self-organization into a tubular form resembling a natural artery. To form the vascular construct, 3D printed inserts are adhered to tissue culture plates, fibrin hydrogel is deposited around the inserts, and human aortic smooth muscle cells are then seeded atop the fibrin hydrogel. The gel, aided by the innate contractile properties of the smooth muscle cells, aggregates towards the center post insert, creating a tissue ring of smooth muscle cells. These rings are then stacked into the final tubular construct. Our methodology is robust, easily repeatable and allows for customization of cellular composition, vessel wall thickness, and length of the vessel construct merely by varying the size of the 3D printed inserts. This platform has potential for facilitating more accurate modeling of vascular pathology, serving as a drug discovery tool, or for vessel repair in disease treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

Technician Career Opportunities in Engineering Technology.

Science.gov (United States)

Engineers' Council for Professional Development, New York, NY.

Career opportunities for engineering technicians are available in the technologies relating to air conditioning, heating, and refrigeration, aviation and aerospace, building construction, chemical engineering, civil engineering, electrical engineering, electronics, industrial engineering, instrumentation, internal combustion engines, mechanical…

Repair of articular cartilage defects by tissue-engineered cartilage constructed with adipose-derived stem cells and acellular cartilaginous matrix in rabbits.

Science.gov (United States)

Wang, Z J; An, R Z; Zhao, J Y; Zhang, Q; Yang, J; Wang, J B; Wen, G Y; Yuan, X H; Qi, X W; Li, S J; Ye, X C

2014-06-18

After injury, inflammation, or degeneration, articular cartilage has limited self-repair ability. We aimed to explore the feasibility of repair of articular cartilage defects with tissue-engineered cartilage constructed by acellular cartilage matrices (ACMs) seeded with adipose-derived stem cells (ADSCs). The ADSCs were isolated from 3-month-old New Zealand albino rabbit by using collagenase and cultured and amplified in vitro. Fresh cartilage isolated from adult New Zealand albino rabbit were freeze-dried for 12 h and treated with Triton X-100, DNase, and RNase to obtain ACMs. ADSCs were seeded in the acellular cartilaginous matrix at 2x10(7)/mL, and cultured in chondrogenic differentiation medium for 2 weeks to construct tissue-engineered cartilage. Twenty-four New Zealand white rabbits were randomly divided into A, B, and C groups. Engineered cartilage was transplanted into cartilage defect position of rabbits in group A, group B obtained ACMs, and group C did not receive any transplants. The rabbits were sacrificed in week 12. The restored tissue was evaluated using macroscopy, histology, immunohistochemistry, and transmission electron microscopy (TEM). In the tissue-engineered cartilage group (group A), articular cartilage defects of the rabbits were filled with chondrocyte-like tissue with smooth surface. Immunohistochemistry showed type II-collagen expression and Alcian blue staining was positive. TEM showed chondrocytes in the recesses, with plenty of secretary matrix particles. In the scaffold group (group B), the defect was filled with fibrous tissue. No repaired tissue was found in the blank group (group C). Tissue-engineered cartilage using ACM seeded with ADSCs can help repair articular cartilage defects in rabbits.

Construction project of Flamanville 3 NPP. The participation of Iberdrola engineering and Construction; El proyecto de construccion de la central nuclear de Flamanville 3. La participacion de Iberdrola Ingenieria y Construccion

Energy Technology Data Exchange (ETDEWEB)

Diaz Prada, J. I.; Cubian, B.

2014-10-01

Iberdrola Engineering and Construction (IIC) leads several projects mini EPC for the EPR Flamanville 3 NPP for providing important for safety components and auxiliary systems in the pump house and in the turbine island. The realization of this new nuclear project has been a challenge from the technical and organizational perspective because the plant is the first of the new nuclear station (FDAKE) type EPR 1700 MWe series in a highly restrictive environment due to to the large number of particular requirements from the final customer and the meager degree of progress of the design to the date of commencement of construction. (Author)

Research on construction quality and improvement of assembly construction

Science.gov (United States)

Cheng, Fei

2017-11-01

Based on the acceleration of the urbanization process and the improvement of the quality of life of our residents, the demand for building construction has been increasing. In this context, the construction industry in order to promote the construction efficiency, quality improvement, to meet the needs of the development of the times to strengthen the new technology, the use of new technologies. At present, China’s engineering construction units in the process of carrying out the project to strengthen the use of assembly-type construction technology, which thus achieved for the traditional construction work low-level, high time-consuming issues, and promote the steady improvement of production efficiency. Based on this, this paper focuses on the analysis of the connotation of the assembly structure and analyzes the quality problems in the construction process of the construction projects and puts forward the improvement measures to promote the improvement of the building quality and the construction of the building Construction speed. Based on this, this paper analyzes the structural system and design of prefabricated building.

Method Engineering: Engineering of Information Systems Development Methods and Tools

OpenAIRE

Brinkkemper, J.N.; Brinkkemper, Sjaak

1996-01-01

This paper proposes the term method engineering for the research field of the construction of information systems development methods and tools. Some research issues in method engineering are identified. One major research topic in method engineering is discussed in depth: situational methods, i.e. the configuration of a project approach that is tuned to the project at hand. A language and support tool for the engineering of situational methods are discussed.

Mesh optimization for microbial fuel cell cathodes constructed around stainless steel mesh current collectors

KAUST Repository

Zhang, Fang

2011-02-01

Mesh current collectors made of stainless steel (SS) can be integrated into microbial fuel cell (MFC) cathodes constructed of a reactive carbon black and Pt catalyst mixture and a poly(dimethylsiloxane) (PDMS) diffusion layer. It is shown here that the mesh properties of these cathodes can significantly affect performance. Cathodes made from the coarsest mesh (30-mesh) achieved the highest maximum power of 1616 ± 25 mW m-2 (normalized to cathode projected surface area; 47.1 ± 0.7 W m-3 based on liquid volume), while the finest mesh (120-mesh) had the lowest power density (599 ± 57 mW m-2). Electrochemical impedance spectroscopy showed that charge transfer and diffusion resistances decreased with increasing mesh opening size. In MFC tests, the cathode performance was primarily limited by reaction kinetics, and not mass transfer. Oxygen permeability increased with mesh opening size, accounting for the decreased diffusion resistance. At higher current densities, diffusion became a limiting factor, especially for fine mesh with low oxygen transfer coefficients. These results demonstrate the critical nature of the mesh size used for constructing MFC cathodes. © 2010 Elsevier B.V. All rights reserved.

Popularizing Geological Education among Civil Engineering Students

Science.gov (United States)

Chen, Xiang-jun; Zhou, Ying

2012-01-01

The sustainable development of an economy and a society cannot be realized without the help of modern geoscience. Engineering geology knowledge is necessary on a civil engineering construction site to ensure the construction work goes smoothly. This paper first discusses the importance of geoscience, especially the study of engineering geology.…

The current status of rehabilitation engineering

Science.gov (United States)

Reswick, J. B.

1974-01-01

Mechanical and electrical engineering devices for paralytic patient care are discussed as they are applied to medical problems. These include means of preventing bedsores, mobility aids, upper extremity orthoses, and electrical stimulation.

Two-stage commercial evaluation of engineering systems production projects for high-rise buildings

Science.gov (United States)

Bril, Aleksander; Kalinina, Olga; Levina, Anastasia

2018-03-01

The paper is devoted to the current and debatable problem of methodology of choosing the effective innovative enterprises for venture financing. A two-stage system of commercial innovation evaluation based on the UNIDO methodology is proposed. Engineering systems account for 25 to 40% of the cost of high-rise residential buildings. This proportion increases with the use of new construction technologies. Analysis of the construction market in Russia showed that the production of internal engineering systems elements based on innovative technologies has a growth trend. The production of simple elements is organized in small enterprises on the basis of new technologies. The most attractive for development is the use of venture financing of small innovative business. To improve the efficiency of these operations, the paper proposes a methodology for a two-stage evaluation of small business development projects. A two-stage system of commercial evaluation of innovative projects allows creating an information base for informed and coordinated decision-making on venture financing of enterprises that produce engineering systems elements for the construction business.

Two-stage commercial evaluation of engineering systems production projects for high-rise buildings

Directory of Open Access Journals (Sweden)

Bril Aleksander

2018-01-01

Full Text Available The paper is devoted to the current and debatable problem of methodology of choosing the effective innovative enterprises for venture financing. A two-stage system of commercial innovation evaluation based on the UNIDO methodology is proposed. Engineering systems account for 25 to 40% of the cost of high-rise residential buildings. This proportion increases with the use of new construction technologies. Analysis of the construction market in Russia showed that the production of internal engineering systems elements based on innovative technologies has a growth trend. The production of simple elements is organized in small enterprises on the basis of new technologies. The most attractive for development is the use of venture financing of small innovative business. To improve the efficiency of these operations, the paper proposes a methodology for a two-stage evaluation of small business development projects. A two-stage system of commercial evaluation of innovative projects allows creating an information base for informed and coordinated decision-making on venture financing of enterprises that produce engineering systems elements for the construction business.

Hydrogel microfabrication technology toward three dimensional tissue engineering

Directory of Open Access Journals (Sweden)

Fumiki Yanagawa

2016-03-01

Full Text Available The development of biologically relevant three-dimensional (3D tissue constructs is essential for the alternative methods of organ transplantation in regenerative medicine, as well as the development of improved drug discovery assays. Recent technological advances in hydrogel microfabrication, such as micromolding, 3D bioprinting, photolithography, and stereolithography, have led to the production of 3D tissue constructs that exhibit biological functions with precise 3D microstructures. Furthermore, microfluidics technology has enabled the development of the perfusion culture of 3D tissue constructs with vascular networks. In this review, we present these hydrogel microfabrication technologies for the in vitro reconstruction and cultivation of 3D tissues. Additionally, we discuss current challenges and future perspectives of 3D tissue engineering.

IT-investigation in the building construction industry

DEFF Research Database (Denmark)

Sørensen, Lars Schiøtt

1995-01-01

An investigation of the level of computing in the Danish construction industry. A quantitative and qualitative level was stated among architects, engineers, building owners, contractors a.o. use of computing......An investigation of the level of computing in the Danish construction industry. A quantitative and qualitative level was stated among architects, engineers, building owners, contractors a.o. use of computing...

The constructal law of design and evolution in nature

Science.gov (United States)

Bejan, Adrian; Lorente, Sylvie

2010-01-01

Constructal theory is the view that (i) the generation of images of design (pattern, rhythm) in nature is a phenomenon of physics and (ii) this phenomenon is covered by a principle (the constructal law): ‘for a finite-size flow system to persist in time (to live) it must evolve such that it provides greater and greater access to the currents that flow through it’. This law is about the necessity of design to occur, and about the time direction of the phenomenon: the tape of the design evolution ‘movie’ runs such that existing configurations are replaced by globally easier flowing configurations. The constructal law has two useful sides: the prediction of natural phenomena and the strategic engineering of novel architectures, based on the constructal law, i.e. not by mimicking nature. We show that the emergence of scaling laws in inanimate (geophysical) flow systems is the same phenomenon as the emergence of allometric laws in animate (biological) flow systems. Examples are lung design, animal locomotion, vegetation, river basins, turbulent flow structure, self-lubrication and natural multi-scale porous media. This article outlines the place of the constructal law as a self-standing law in physics, which covers all the ad hoc (and contradictory) statements of optimality such as minimum entropy generation, maximum entropy generation, minimum flow resistance, maximum flow resistance, minimum time, minimum weight, uniform maximum stresses and characteristic organ sizes. Nature is configured to flow and move as a conglomerate of ‘engine and brake’ designs. PMID:20368252

Is the Current Way of Constructing Corporate Authority Records Still Useful?

Directory of Open Access Journals (Sweden)

Qiang Jin

2005-06-01

Full Text Available Catalogers have been establishing corporate body name headings (and other entities in their original language in the official form, as they appear most frequently on the title pages of publications for print publications, for many years. A random sample of corporate headings from the Library of Congress Name Authority File created during 1998–2002 was searched on the Web via Google to find corporate Web pages. The purpose of this research is to begin to answer the question: Does the current way of constructing corporate authority records still help users find resources by and about corporate bodies in the online public access catalog in this Web-oriented environment?

Constructing Aligned Assessments Using Automated Test Construction

Science.gov (United States)

Porter, Andrew; Polikoff, Morgan S.; Barghaus, Katherine M.; Yang, Rui

2013-01-01

We describe an innovative automated test construction algorithm for building aligned achievement tests. By incorporating the algorithm into the test construction process, along with other test construction procedures for building reliable and unbiased assessments, the result is much more valid tests than result from current test construction…

Construction of expression vectors for metabolic engineering of the vanillin-producing actinomycete Amycolatopsis sp. ATCC 39116.

Science.gov (United States)

Fleige, Christian; Steinbüchel, Alexander

2014-01-01

Amycolatopsis sp. ATCC 39116 is able to synthesize the important flavoring agent vanillin from cheap natural substrates. The bacterium is therefore of great interest for the industry and used for the fermentative production of vanillin. In order to improve the production of natural vanillin with Amycolatopsis sp. ATCC 39116, the strain has been genetically engineered to optimize the metabolic flux towards the desired product. Extensive metabolic engineering was hitherto hampered, due to the lack of genetic tools like functional promoters and expression vectors. In this study, we report the establishment of a plasmid-based gene expression system for Amycolatopsis sp. ATCC 39116 that allows a further manipulation of the genotype. Four new Escherichia coli-Amycolatopsis shuttle vectors harboring different promoter elements were constructed, and the functionality of these regulatory elements was proven by the expression of the reporter gene gusA, encoding a β-glucuronidase. Glucuronidase activity was detected in all plasmid-harboring strains, and remarkable differences in the expression strength of the reporter gene depending on the used promoter were observed. The new expression vectors will promote the further genetic engineering of Amycolatopsis sp. ATCC 39116 to get insight into the metabolic network and to improve the strain for a more efficient industrial use.

Hydrogels for lung tissue engineering: Biomechanical properties of thin collagen-elastin constructs.

Science.gov (United States)

Dunphy, Siobhán E; Bratt, Jessica A J; Akram, Khondoker M; Forsyth, Nicholas R; El Haj, Alicia J

2014-10-01

In this study, collagen-elastin constructs were prepared with the aim of producing a material capable of mimicking the mechanical properties of a single alveolar wall. Collagen has been used in a wide range of tissue engineering applications; however, due to its low mechanical properties its use is limited to non load-bearing applications without further manipulation using methods such as cross-linking or mechanical compression. Here, it was hypothesised that the addition of soluble elastin to a collagen hydrogel could improve its mechanical properties. Hydrogels made from collagen only and collagen plus varying amounts elastin were prepared. Young׳s modulus of each membrane was measured using the combination of a non-destructive indentation and a theoretical model previously described. An increase in Young׳s modulus was observed with increasing concentration of elastin. The use of non-destructive indentation allowed for online monitoring of the elastic moduli of cell-seeded constructs over 8 days. The addition of lung fibroblasts into the membrane increased the stiffness of the hydrogels further and cell-seeded collagen hydrogels were found to have a stiffness equal to the theoretical value for a single alveolar wall (≈5kPa). Through provision of some of the native extracellular matrix components of the lung parenchyma these scaffolds may be able to provide an initial building block toward the regeneration of new functional lung tissue. Copyright © 2014 Elsevier Ltd. All rights reserved.

Construction Management for Conventional Facilities of Proton Accelerator

International Nuclear Information System (INIS)

Kim, Jun Yeon; Cho, Jang Hyung; Cho, Sung Won

2013-01-01

Proton Engineering Frontier Project, puts its aim to building 100MeV 20mA linear proton accelerator which is national facility for NT, BT, IT, and future technologies, expected to boost up the national industry competitiveness. This R and D, Construction Management is in charge of the supportive works such as site selection, architecture and engineering of conventional facilities, and overall construction management. The major goals of this work are as follows: At first, architecture and engineering of conventional facilities. Second, construction management, supervision and inspection on construction of conventional facilities. Lastly, cooperation with the project host organization, Gyeongju city, for adjusting technically interrelated work during construction. In this research, We completed the basic, detail, and field changed design of conventional facilities. Acquisition of necessary construction and atomic license, radiation safety analysis, site improvement, access road construction were successfully done as well. Also, we participated in the project host related work as follows: Project host organization and site selection, construction technical work for project host organization and procedure management, etc. Consequently, we so fulfilled all of the own goals which were set up in the beginning of this construction project that we could made contribution for installing and running PEFP's developed 100MeV 20mA linear accelerator

Current trends in rehabilitation engineering in Japan.

Science.gov (United States)

Ohnabe, Hisaichi

2006-01-01

In 2005, the elderly generation comprised 20% of the Japanese population. This percentage will grow to approximately 30% in 2030, meaning that nearly one in three people in Japan will be 65 years of age or older. Japan is the first nation in the world to face this situation. This article uses the context of Japanese society to give an overview of the elderly and people with disabilities; the International Classification of Functioning, Disability, and Health model; rehabilitation engineering-related policy; and education. In addition, we examine how governmental programs and Japanese law regarding technical aids may evolve by 2030. Partner robots, intelligent powered wheelchairs, nursing robots, and other technologies are introduced as examples of rehabilitation engineering and assistive technology. We also discuss the volunteer activities of the Rehabilitation Engineering Society of Japan (RESJA) in response to the Asian tsunami disaster and the achievements of a group of students from a Japanese senior high school of industry.

Knowledge, attitude and practices for design for safety: A study on civil & structural engineers.

Science.gov (United States)

Goh, Yang Miang; Chua, Sijie

2016-08-01

Design for safety (DfS) (also known as prevention through design, safe design and Construction (Design and Management)) promotes early consideration of safety and health hazards during the design phase of a construction project. With early intervention, hazards can be more effectively eliminated or controlled leading to safer worksites and construction processes. DfS is practiced in many countries, including Australia, the UK, and Singapore. In Singapore, the Manpower Ministry enacted the DfS Regulations in July 2015, which will be enforced from August 2016 onwards. Due to the critical role of civil and structural (C&S) engineers during design and construction, the DfS knowledge, attitude and practices (KAP) of C&S engineers have significant impact on the successful implementation of DfS. Thus, this study aims to explore the DfS KAP of C&S engineers so as to guide further research in measuring and improving DfS KAP of designers. During the study, it was found that there is a lack of KAP studies in construction management. Therefore, this study also aims to provide useful lessons for future applications of the KAP framework in construction management research. A questionnaire was developed to assess the DfS KAP of C&S engineers. The responses provided by 43 C&S engineers were analyzed. In addition, interviews with experienced construction professionals were carried out to further understand perceptions of DfS and related issues. The results suggest that C&S engineers are supportive of DfS, but the level of DfS knowledge and practices need to be improved. More DfS guidelines and training should be made available to the engineers. To ensure that DfS can be implemented successfully, there is a need to study the contractual arrangements between clients and designers and the effectiveness of different implementation approaches for the DfS process. The questionnaire and findings in this study provided the foundation for a baseline survey with larger sample size, which is

Gold nanorod-incorporated gelatin-based conductive hydrogels for engineering cardiac tissue constructs.

Science.gov (United States)

Navaei, Ali; Saini, Harpinder; Christenson, Wayne; Sullivan, Ryan Tanner; Ros, Robert; Nikkhah, Mehdi

2016-09-01

The development of advanced biomaterials is a crucial step to enhance the efficacy of tissue engineering strategies for treatment of myocardial infarction. Specific characteristics of biomaterials including electrical conductivity, mechanical robustness and structural integrity need to be further enhanced to promote the functionalities of cardiac cells. In this work, we fabricated UV-crosslinkable gold nanorod (GNR)-incorporated gelatin methacrylate (GelMA) hybrid hydrogels with enhanced material and biological properties for cardiac tissue engineering. Embedded GNRs promoted electrical conductivity and mechanical stiffness of the hydrogel matrix. Cardiomyocytes seeded on GelMA-GNR hybrid hydrogels exhibited excellent cell retention, viability, and metabolic activity. The increased cell adhesion resulted in abundance of locally organized F-actin fibers, leading to the formation of an integrated tissue layer on the GNR-embedded hydrogels. Immunostained images of integrin β-1 confirmed improved cell-matrix interaction on the hybrid hydrogels. Notably, homogeneous distribution of cardiac specific markers (sarcomeric α-actinin and connexin 43), were observed on GelMA-GNR hydrogels as a function of GNRs concentration. Furthermore, the GelMA-GNR hybrids supported synchronous tissue-level beating of cardiomyocytes. Similar observations were also noted by, calcium transient assay that demonstrated the rhythmic contraction of the cardiomyocytes on GelMA-GNR hydrogels as compared to pure GelMA. Thus, the findings of this study clearly demonstrated that functional cardiac patches with superior electrical and mechanical properties can be developed using nanoengineered GelMA-GNR hybrid hydrogels. In this work, we developed gold nanorod (GNR) incorporated gelatin-based hydrogels with suitable electrical conductivity and mechanical stiffness for engineering functional cardiac tissue constructs (e.g. cardiac patches). The synthesized conductive hybrid hydrogels properly