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Sample records for based additive homomorphic

  1. Design of a polynomial ring based symmetric homomorphic encryption scheme

    Directory of Open Access Journals (Sweden)

    Smaranika Dasgupta

    2016-09-01

    Full Text Available Security of data, especially in clouds, has become immensely essential for present-day applications. Fully homomorphic encryption (FHE is a great way to secure data which is used and manipulated by untrusted applications or systems. In this paper, we propose a symmetric FHE scheme based on polynomial over ring of integers. This scheme is somewhat homomorphic due to accumulation of noise after few operations, which is made fully homomorphic using a refresh procedure. After certain amount of homomorphic computations, large ciphertexts are refreshed for proper decryption. The hardness of the scheme is based on the difficulty of factorizing large integers. Also, it requires polynomial addition which is computationally cost effective. Experimental results are shown to support our claim.

  2. Additively homomorphic encryption with a double decryption mechanism, revisited

    NARCIS (Netherlands)

    Peter, Andreas; Kronberg, M.; Trei, W.; Katzenbeisser, S.

    We revisit the notion of additively homomorphic encryption with a double decryption mechanism (DD-PKE), which allows for additions in the encrypted domain while having a master decryption procedure that can decrypt all properly formed ciphertexts by using a special master secret. This type of

  3. An Efficient Homomorphic Aggregate Signature Scheme Based on Lattice

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    Zhengjun Jing

    2014-01-01

    Full Text Available Homomorphic aggregate signature (HAS is a linearly homomorphic signature (LHS for multiple users, which can be applied for a variety of purposes, such as multi-source network coding and sensor data aggregation. In order to design an efficient postquantum secure HAS scheme, we borrow the idea of the lattice-based LHS scheme over binary field in the single-user case, and develop it into a new lattice-based HAS scheme in this paper. The security of the proposed scheme is proved by showing a reduction to the single-user case and the signature length remains invariant. Compared with the existing lattice-based homomorphic aggregate signature scheme, our new scheme enjoys shorter signature length and high efficiency.

  4. Homomorphic encryption-based secure SIFT for privacy-preserving feature extraction

    Science.gov (United States)

    Hsu, Chao-Yung; Lu, Chun-Shien; Pei, Soo-Chang

    2011-02-01

    Privacy has received much attention but is still largely ignored in the multimedia community. Consider a cloud computing scenario, where the server is resource-abundant and is capable of finishing the designated tasks, it is envisioned that secure media retrieval and search with privacy-preserving will be seriously treated. In view of the fact that scale-invariant feature transform (SIFT) has been widely adopted in various fields, this paper is the first to address the problem of secure SIFT feature extraction and representation in the encrypted domain. Since all the operations in SIFT must be moved to the encrypted domain, we propose a homomorphic encryption-based secure SIFT method for privacy-preserving feature extraction and representation based on Paillier cryptosystem. In particular, homomorphic comparison is a must for SIFT feature detection but is still a challenging issue for homomorphic encryption methods. To conquer this problem, we investigate a quantization-like secure comparison strategy in this paper. Experimental results demonstrate that the proposed homomorphic encryption-based SIFT performs comparably to original SIFT on image benchmarks, while preserving privacy additionally. We believe that this work is an important step toward privacy-preserving multimedia retrieval in an environment, where privacy is a major concern.

  5. On the Complexity of Additively Homomorphic UC Commitments

    DEFF Research Database (Denmark)

    Trifiletti, Roberto; Nielsen, Jesper Buus; Frederiksen, Tore Kasper

    2016-01-01

    as the commitment protocol by Garay \\emph{et al.} from Eurocrypt 2014. A main technical improvement over the scheme mentioned above, and other schemes based on using error correcting codes for UC commitment, we develop a new technique which allows to based the extraction property on erasure decoding as opposed...... to error correction. This allows to use a code with significantly smaller minimal distance and allows to use codes without efficient decoding. Our scheme only relies on standard assumptions. Specifically we require a pseudorandom number generator, a linear error correcting code and an ideal oblivious......, we manage to add the additive homo- morphic property, while at the same time reducing the constants. In fact, when opening a large enough batch of commitments we achieve an amor- tized communication complexity converging to the length of the message committed to, i.e., we achieve close to rate 1...

  6. Additively Homomorphic UC commitments with Optimal Amortized Overhead

    DEFF Research Database (Denmark)

    Cascudo Pueyo, Ignacio; Damgård, Ivan Bjerre; David, Bernardo Machado

    2015-01-01

    We propose the first UC secure commitment scheme with (amortized) computational complexity linear in the size of the string committed to. After a preprocessing phase based on oblivious transfer, that only needs to be done once and for all, our scheme only requires a pseudorandom generator and a l......, our basic scheme has amortised concrete efficiency comparable with previous protocols in the Random Oracle Model even though it is constructed in the plain model....

  7. THRIVE: threshold homomorphic encryption based secure and privacy preserving biometric verification system

    Science.gov (United States)

    Karabat, Cagatay; Kiraz, Mehmet Sabir; Erdogan, Hakan; Savas, Erkay

    2015-12-01

    In this paper, we introduce a new biometric verification and template protection system which we call THRIVE. The system includes novel enrollment and authentication protocols based on threshold homomorphic encryption where a private key is shared between a user and a verifier. In the THRIVE system, only encrypted binary biometric templates are stored in a database and verification is performed via homomorphically randomized templates, thus, original templates are never revealed during authentication. Due to the underlying threshold homomorphic encryption scheme, a malicious database owner cannot perform full decryption on encrypted templates of the users in the database. In addition, security of the THRIVE system is enhanced using a two-factor authentication scheme involving user's private key and biometric data. Using simulation-based techniques, the proposed system is proven secure in the malicious model. The proposed system is suitable for applications where the user does not want to reveal her biometrics to the verifier in plain form, but needs to prove her identity by using biometrics. The system can be used with any biometric modality where a feature extraction method yields a fixed size binary template and a query template is verified when its Hamming distance to the database template is less than a threshold. The overall connection time for the proposed THRIVE system is estimated to be 336 ms on average for 256-bit biometric templates on a desktop PC running with quad core 3.2 GHz CPUs at 10 Mbit/s up/down link connection speed. Consequently, the proposed system can be efficiently used in real-life applications.

  8. Stability of a Generalized Euler-Lagrange Type Additive Mapping and Homomorphisms in C∗-Algebras

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    Abbas Najati

    2009-01-01

    Full Text Available Let X,Y be Banach modules over a C∗-algebra and let r1,…,rn∈ℝ be given. We prove the generalized Hyers-Ulam stability of the following functional equation in Banach modules over a unital C∗-algebra: ∑j=1nf(−rjxj+∑1≤i≤n,i≠jrixi+2∑i=1nrif(xi=nf(∑i=1nrixi. We show that if ∑i=1nri≠0, ri,rj≠0 for some 1≤iadditive. As an application, we investigate homomorphisms in unital C∗-algebras.

  9. A Luggage Control System Based on NFC and Homomorphic Cryptography

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    Néstor Álvarez-Díaz

    2017-01-01

    Full Text Available We propose an innovative luggage tracking and management system that can be used to secure airport terminal services and reduce the waiting time of passengers during check-in. This addresses an urgent need to streamline and optimize passenger flows at airport terminals and lowers the risk of terrorist threats. The system employs Near Field Communication (NFC technology and homomorphic cryptography (the Paillier cryptosystem to protect wireless communication and stored data. A security analysis and a performance test show the usability and applicability of the proposed system.

  10. Homomorphic encryption and secure comparison

    NARCIS (Netherlands)

    Damgard, Ivan; Geisler, M.; Kroigaard, M.

    2008-01-01

    We propose a protocol for secure comparison of integers based on homomorphic encryption.We also propose a homomorphic encryption scheme that can be used in our protocol, makes it more efficient than previous solutions, and can also be used as the basis of efficient and general secure Multiparty

  11. About Cryptanalysis of One Fully Homomorphic Cryptosystem Based on Factorization Problem

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    Alina Viktorovna Trepacheva

    2015-12-01

    Full Text Available We present a known plaintext attack (KPA on a recently proposed fully homomorphic cryptosystem (FHC, based on the problem of big integers factoring. We show that the considered FHC is insecure against KPA even if only one pair (plaintext, ciphertext was intercepted by an adversary. The complexity of the proposed KPA depends polynomially on the parameters of FHC and logarithmically on the size of plaintexts space. Also we discuss how ciphertexts only attack (COA on this FHC may be reduced to KPA.

  12. Graphs and Homomorphisms

    CERN Document Server

    Hell, Pavol

    2004-01-01

    This is a book about graph homomorphisms. Graph theory is now an established discipline but the study of graph homomorphisms has only recently begun to gain wide acceptance and interest. The subject gives a useful perspective in areas such as graph reconstruction, products, fractional and circular colourings, and has applications in complexity theory, artificial intelligence, telecommunication, and, most recently, statistical physics.Based on the authors' lecture notes for graduate courses, this book can be used as a textbook for a second course in graph theory at 4th year or master's level an

  13. FORESEE: Fully Outsourced secuRe gEnome Study basEd on homomorphic Encryption.

    Science.gov (United States)

    Zhang, Yuchen; Dai, Wenrui; Jiang, Xiaoqian; Xiong, Hongkai; Wang, Shuang

    2015-01-01

    The increasing availability of genome data motivates massive research studies in personalized treatment and precision medicine. Public cloud services provide a flexible way to mitigate the storage and computation burden in conducting genome-wide association studies (GWAS). However, data privacy has been widely concerned when sharing the sensitive information in a cloud environment. We presented a novel framework (FORESEE: Fully Outsourced secuRe gEnome Study basEd on homomorphic Encryption) to fully outsource GWAS (i.e., chi-square statistic computation) using homomorphic encryption. The proposed framework enables secure divisions over encrypted data. We introduced two division protocols (i.e., secure errorless division and secure approximation division) with a trade-off between complexity and accuracy in computing chi-square statistics. The proposed framework was evaluated for the task of chi-square statistic computation with two case-control datasets from the 2015 iDASH genome privacy protection challenge. Experimental results show that the performance of FORESEE can be significantly improved through algorithmic optimization and parallel computation. Remarkably, the secure approximation division provides significant performance gain, but without missing any significance SNPs in the chi-square association test using the aforementioned datasets. Unlike many existing HME based studies, in which final results need to be computed by the data owner due to the lack of the secure division operation, the proposed FORESEE framework support complete outsourcing to the cloud and output the final encrypted chi-square statistics.

  14. Privacy-Preserving Content-Based Recommendations through Homomorphic Encryption

    NARCIS (Netherlands)

    Erkin, Z.; Erkin, Zekeriya; Beye, M.; Veugen, T.; Lagendijk, R.L.

    2012-01-01

    By offering personalized content to users, recommender systems have become a vital tool in ecommerce and online media applications. Content-based algorithms recommend items or products to users, that are most similar to those previously purchased or consumed. Unfortunately, collecting and storing

  15. Secure Cloud Computing Using Homomorphic Encryption

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    Alexander Olegovich Zhirov

    2013-02-01

    Full Text Available The question of cloud security has become more significant with growing popularity of cloud computing. This article is dedicated to fully homomorphic encryption which is one of the most promising methods to reach the necessary level of privacy. In this article we consider the basic ideas on homomorphic encryption proposed by C. Gentry, make generalization of them and propose three new fully homomorphic encryption schemes based on polynomial rings.

  16. A note on the homomorphism theorem for hemirings

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    D. M. Olson

    1978-01-01

    Full Text Available The fundamental homomorphism theorem for rings is not generally applicable in hemiring theory. In this paper, we show that for the class of N-homomorphism of hemirings the fundamental theorem is valid. In addition, the concept of N-homomorphism is used to prove that every hereditarily semisubtractive hemiring is of type (K.

  17. Efficient Multi-keyword Ranked Search over Outsourced Cloud Data based on Homomorphic Encryption

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    Nie Mengxi

    2016-01-01

    Full Text Available With the development of cloud computing, more and more data owners are motivated to outsource their data to the cloud server for great flexibility and less saving expenditure. Because the security of outsourced data must be guaranteed, some encryption methods should be used which obsoletes traditional data utilization based on plaintext, e.g. keyword search. To solve the search of encrypted data, some schemes were proposed to solve the search of encrypted data, e.g. top-k single or multiple keywords retrieval. However, the efficiency of these proposed schemes is not high enough to be impractical in the cloud computing. In this paper, we propose a new scheme based on homomorphic encryption to solve this challenging problem of privacy-preserving efficient multi-keyword ranked search over outsourced cloud data. In our scheme, the inner product is adopted to measure the relevance scores and the technique of relevance feedback is used to reflect the search preference of the data users. Security analysis shows that the proposed scheme can meet strict privacy requirements for such a secure cloud data utilization system. Performance evaluation demonstrates that the proposed scheme can achieve low overhead on both computation and communication.

  18. Minutiae Matching with Privacy Protection Based on the Combination of Garbled Circuit and Homomorphic Encryption

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    Mengxing Li

    2014-01-01

    Full Text Available Biometrics plays an important role in authentication applications since they are strongly linked to holders. With an increasing growth of e-commerce and e-government, one can expect that biometric-based authentication systems are possibly deployed over the open networks in the near future. However, due to its openness, the Internet poses a great challenge to the security and privacy of biometric authentication. Biometric data cannot be revoked, so it is of paramount importance that biometric data should be handled in a secure way. In this paper we present a scheme achieving privacy-preserving fingerprint authentication between two parties, in which fingerprint minutiae matching algorithm is completed in the encrypted domain. To improve the efficiency, we exploit homomorphic encryption as well as garbled circuits to design the protocol. Our goal is to provide protection for the security of template in storage and data privacy of two parties in transaction. The experimental results show that the proposed authentication protocol runs efficiently. Therefore, the protocol can run over open networks and help to alleviate the concerns on security and privacy of biometric applications over the open networks.

  19. Minutiae matching with privacy protection based on the combination of garbled circuit and homomorphic encryption.

    Science.gov (United States)

    Li, Mengxing; Feng, Quan; Zhao, Jian; Yang, Mei; Kang, Lijun; Wu, Lili

    2014-01-01

    Biometrics plays an important role in authentication applications since they are strongly linked to holders. With an increasing growth of e-commerce and e-government, one can expect that biometric-based authentication systems are possibly deployed over the open networks in the near future. However, due to its openness, the Internet poses a great challenge to the security and privacy of biometric authentication. Biometric data cannot be revoked, so it is of paramount importance that biometric data should be handled in a secure way. In this paper we present a scheme achieving privacy-preserving fingerprint authentication between two parties, in which fingerprint minutiae matching algorithm is completed in the encrypted domain. To improve the efficiency, we exploit homomorphic encryption as well as garbled circuits to design the protocol. Our goal is to provide protection for the security of template in storage and data privacy of two parties in transaction. The experimental results show that the proposed authentication protocol runs efficiently. Therefore, the protocol can run over open networks and help to alleviate the concerns on security and privacy of biometric applications over the open networks.

  20. Continuous-variable quantum homomorphic signature

    Science.gov (United States)

    Li, Ke; Shang, Tao; Liu, Jian-wei

    2017-10-01

    Quantum cryptography is believed to be unconditionally secure because its security is ensured by physical laws rather than computational complexity. According to spectrum characteristic, quantum information can be classified into two categories, namely discrete variables and continuous variables. Continuous-variable quantum protocols have gained much attention for their ability to transmit more information with lower cost. To verify the identities of different data sources in a quantum network, we propose a continuous-variable quantum homomorphic signature scheme. It is based on continuous-variable entanglement swapping and provides additive and subtractive homomorphism. Security analysis shows the proposed scheme is secure against replay, forgery and repudiation. Even under nonideal conditions, it supports effective verification within a certain verification threshold.

  1. A privacy-preserving parallel and homomorphic encryption scheme

    Directory of Open Access Journals (Sweden)

    Min Zhaoe

    2017-04-01

    Full Text Available In order to protect data privacy whilst allowing efficient access to data in multi-nodes cloud environments, a parallel homomorphic encryption (PHE scheme is proposed based on the additive homomorphism of the Paillier encryption algorithm. In this paper we propose a PHE algorithm, in which plaintext is divided into several blocks and blocks are encrypted with a parallel mode. Experiment results demonstrate that the encryption algorithm can reach a speed-up ratio at about 7.1 in the MapReduce environment with 16 cores and 4 nodes.

  2. Homomorphic encryption and secure comparison

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Geisler, Martin; Krøigaard, Mikkel

    2008-01-01

    Computation (MPC). We show how our comparison protocol can be used to improve security of online auctions, and demonstrate that it is efficient enough to be used in practice. For comparison of 16 bits numbers with security based on 1024 bits RSA (executed by two parties), our implementation takes 0.28 sec......We propose a protocol for secure comparison of integers based on homomorphic encryption.We also propose a homomorphic encryption scheme that can be used in our protocol, makes it more efficient than previous solutions, and can also be used as the basis of efficient and general secure Multiparty...

  3. Homomorphic encryption and applications

    CERN Document Server

    Yi, Xun; Bertino, Elisa

    2014-01-01

    This book introduces the fundamental concepts of homomorphic encryption. From these foundations, applications are developed in the fields of private information retrieval, private searching on streaming data, privacy-preserving data mining, electronic voting and cloud computing. The content is presented in an instructional and practical style, with concrete examples to enhance the reader's understanding. This volume achieves a balance between the theoretical and the practical components of modern information security. Readers will learn key principles of homomorphic encryption as well as their

  4. Multiparty Computation from Threshold Homomorphic Encryption

    DEFF Research Database (Denmark)

    Cramer, Ronald; Damgård, Ivan Bjerre; Nielsen, Jesper Buus

    2001-01-01

    We introduce a new approach to multiparty computation (MPC) basing it on homomorphic threshold crypto-systems. We show that given keys for any sufficiently efficient system of this type, general MPC protocols for n parties can be devised which are secure against an active adversary that corrupts...

  5. Application of homomorphism to secure image sharing

    Science.gov (United States)

    Islam, Naveed; Puech, William; Hayat, Khizar; Brouzet, Robert

    2011-09-01

    In this paper, we present a new approach for sharing images between l players by exploiting the additive and multiplicative homomorphic properties of two well-known public key cryptosystems, i.e. RSA and Paillier. Contrary to the traditional schemes, the proposed approach employs secret sharing in a way that limits the influence of the dealer over the protocol and allows each player to participate with the help of his key-image. With the proposed approach, during the encryption step, each player encrypts his own key-image using the dealer's public key. The dealer encrypts the secret-to-be-shared image with the same public key and then, the l encrypted key-images plus the encrypted to-be shared image are multiplied homomorphically to get another encrypted image. After this step, the dealer can safely get a scrambled image which corresponds to the addition or multiplication of the l + 1 original images ( l key-images plus the secret image) because of the additive homomorphic property of the Paillier algorithm or multiplicative homomorphic property of the RSA algorithm. When the l players want to extract the secret image, they do not need to use keys and the dealer has no role. Indeed, with our approach, to extract the secret image, the l players need only to subtract their own key-image with no specific order from the scrambled image. Thus, the proposed approach provides an opportunity to use operators like multiplication on encrypted images for the development of a secure privacy preserving protocol in the image domain. We show that it is still possible to extract a visible version of the secret image with only l-1 key-images (when one key-image is missing) or when the l key-images used for the extraction are different from the l original key-images due to a lossy compression for example. Experimental results and security analysis verify and prove that the proposed approach is secure from cryptographic viewpoint.

  6. A Verifiable Secret Shuffle of Homomorphic Encryptions

    DEFF Research Database (Denmark)

    Groth, Jens

    2003-01-01

    We show how to prove in honest verifier zero-knowledge the correctness of a shuffle of homomorphic encryptions (or homomorphic commitments.) A shuffle consists in a rearrangement of the input ciphertexts and a reencryption of them so that the permutation is not revealed....

  7. An Efficient Quantum Somewhat Homomorphic Symmetric Searchable Encryption

    Science.gov (United States)

    Sun, Xiaoqiang; Wang, Ting; Sun, Zhiwei; Wang, Ping; Yu, Jianping; Xie, Weixin

    2017-04-01

    In 2009, Gentry first introduced an ideal lattices fully homomorphic encryption (FHE) scheme. Later, based on the approximate greatest common divisor problem, learning with errors problem or learning with errors over rings problem, FHE has developed rapidly, along with the low efficiency and computational security. Combined with quantum mechanics, Liang proposed a symmetric quantum somewhat homomorphic encryption (QSHE) scheme based on quantum one-time pad, which is unconditional security. And it was converted to a quantum fully homomorphic encryption scheme, whose evaluation algorithm is based on the secret key. Compared with Liang's QSHE scheme, we propose a more efficient QSHE scheme for classical input states with perfect security, which is used to encrypt the classical message, and the secret key is not required in the evaluation algorithm. Furthermore, an efficient symmetric searchable encryption (SSE) scheme is constructed based on our QSHE scheme. SSE is important in the cloud storage, which allows users to offload search queries to the untrusted cloud. Then the cloud is responsible for returning encrypted files that match search queries (also encrypted), which protects users' privacy.

  8. a fuzzy homomorphic algori omomorphic algorithm for image

    African Journals Online (AJOL)

    eobe

    Homomorphic method in Section III. Section .... Homomorphic filter, which controls the level of enhancement of the ... The vertical axis represents the degree of membership while the .... Image Processing Using MATLAB: Prentice Hall,. 2004.

  9. SYSTEMATIZATION AND ANALYSIS OF PARTIALLY AND FULLY HOMOMORPHIC CRYPTOSYSTEM

    Directory of Open Access Journals (Sweden)

    A. V. Epishkina

    2016-12-01

    Full Text Available In this article provides an overview of the known partially and fully homomorphic cryptosystem, such as: RSA, ElGamal, Paillier, Gentry and Halevi. Justified the homomorphic properties of the considered cryptosystems. The comparative analysis of the homomorphic encryption algorithms has been committed

  10. Assessment of Homomorphic Analysis for Human Activity Recognition from Acceleration Signals.

    Science.gov (United States)

    Vanrell, Sebastian Rodrigo; Milone, Diego Humberto; Rufiner, Hugo Leonardo

    2017-07-03

    Unobtrusive activity monitoring can provide valuable information for medical and sports applications. In recent years, human activity recognition has moved to wearable sensors to deal with unconstrained scenarios. Accelerometers are the preferred sensors due to their simplicity and availability. Previous studies have examined several \\azul{classic} techniques for extracting features from acceleration signals, including time-domain, time-frequency, frequency-domain, and other heuristic features. Spectral and temporal features are the preferred ones and they are generally computed from acceleration components, leaving the acceleration magnitude potential unexplored. In this study, based on homomorphic analysis, a new type of feature extraction stage is proposed in order to exploit discriminative activity information present in acceleration signals. Homomorphic analysis can isolate the information about whole body dynamics and translate it into a compact representation, called cepstral coefficients. Experiments have explored several configurations of the proposed features, including size of representation, signals to be used, and fusion with other features. Cepstral features computed from acceleration magnitude obtained one of the highest recognition rates. In addition, a beneficial contribution was found when time-domain and moving pace information was included in the feature vector. Overall, the proposed system achieved a recognition rate of 91.21% on the publicly available SCUT-NAA dataset. To the best of our knowledge, this is the highest recognition rate on this dataset.

  11. Symmetric weak ternary quantum homomorphic encryption schemes

    Science.gov (United States)

    Wang, Yuqi; She, Kun; Luo, Qingbin; Yang, Fan; Zhao, Chao

    2016-03-01

    Based on a ternary quantum logic circuit, four symmetric weak ternary quantum homomorphic encryption (QHE) schemes were proposed. First, for a one-qutrit rotation gate, a QHE scheme was constructed. Second, in view of the synthesis of a general 3 × 3 unitary transformation, another one-qutrit QHE scheme was proposed. Third, according to the one-qutrit scheme, the two-qutrit QHE scheme about generalized controlled X (GCX(m,n)) gate was constructed and further generalized to the n-qutrit unitary matrix case. Finally, the security of these schemes was analyzed in two respects. It can be concluded that the attacker can correctly guess the encryption key with a maximum probability pk = 1/33n, thus it can better protect the privacy of users’ data. Moreover, these schemes can be well integrated into the future quantum remote server architecture, and thus the computational security of the users’ private quantum information can be well protected in a distributed computing environment.

  12. HOMOMORPHIC ENCRYPTION: CLOUD COMPUTING SECURITY AND OTHER APPLICATIONS (A SURVEY

    Directory of Open Access Journals (Sweden)

    A. I. Trubei

    2015-01-01

    Full Text Available Homomorphic encryption is a form of encryption which allows specific types of computations to be carried out on cipher text and to obtain an encrypted result which matches the result of operations performed on the plain text. The article presents a basic concept of the homomorphic encryption and various encryption algorithms in accordance with the fundamental properties of the homomorphic encryption. The examples of various principles and properties of homomorphic encryption, some homomorphic algorithms using asymmetric key systems such as RSA, ElGamal, Paillier algorithms as well as various homomorphic encryption schemes are given. Prospects of homomorphic encryption application in the field of secure cloud computing, electronic voting, cipher text searching, encrypted mail filtering, mobile cipher and secure feedback systems are considered.

  13. Quantum Fully Homomorphic Encryption with Verification

    DEFF Research Database (Denmark)

    Alagic, Gorjan; Dulek, Yfke; Schaffner, Christian

    2017-01-01

    Fully-homomorphic encryption (FHE) enables computation on encrypted data while maintaining secrecy. Recent research has shown that such schemes exist even for quantum computation. Given the numerous applications of classical FHE (zero-knowledge proofs, secure two-party computation, obfuscation, e...

  14. Automatic continuity for homomorphisms into free products

    DEFF Research Database (Denmark)

    Slutsky, Konstantin

    2013-01-01

    A homomorphism from a completely metrizable topological group into a free product of groups whose image is not contained in a factor of the free product is shown to be continuous with respect to the discrete topology on the range. In particular, any completely metrizable group topology on a free ...

  15. The Techniques for Arbitrary Secure Quering to Encrypted Cloud Database Using Fully Homomorphic Encryption

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    Filipp B. Burtyka

    2017-06-01

    Full Text Available The processing of queries to an encrypted database without its decryption has been actively investigated recently by both cryptographers and database researchers. Such a work is allowed by various types of so-called Processable encryption (PE, as well as special architectures of database management systems (DBMS which use these types of encryption. The most known types of PEs are order-preserving encryption, homomorphic encryption, functional encryption, searchable encryption, and property-preserving encryption. Based on these types of encryption, various DBMSs are built, the most famous of which are CryptDB, Mo- nomi, Arx and DBMS by researchers from Novosibirsk. These DBMSs are built on the basis of various types of PEs, for example order-preserving encryption, homomorphic encryption and traditional block encryption. However, this approach can cause privacy problems. The best approach from the security viewpoint is to build a cryptographic database using only homomorphic encryption. An obstacle to this is insufficient efficiency of the existing homomorphic encryption schemes and incomplete solution of a set of issues related to ensuring the confidentiality of decisions making in an untrusted environment. In this paper, we propose the techniques for solving these problems, in particular for organization of execution arbitrary secure query to the encrypted relational database using fully homomorphic encryption. Also we propose a model of query condition that splits query into atomic predicates and linking condition. One of roposed technique is aimed at ensuring the security of linking condition of queries, others keep security of atomic predicates. The parameters of the proposed techniques make it possible to implement them using the already existing homomorphic encryption schemes. The proposed techniques can be a basis for building secure cryptographic cloud databases.

  16. Homomorphic embeddings in n-groups

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    Mona Cristescu

    2013-06-01

    Full Text Available We prove that an cancellative n-groupoid A can be homotopic embedded in an n-group if and only if in A are satisfied all n-ary Malcev conditions. Now we shall prove that in the presence of associative law we obtain homomorphic embeddings. Furthermore, if A has a lateral identity a such embeddings is assured by a subset of n-ary Malcev conditions - unary Malcev conditions.

  17. (Non-) homomorphic approaches to denoise intensity SAR images with non-local means and stochastic distances

    Science.gov (United States)

    Penna, Pedro A. A.; Mascarenhas, Nelson D. A.

    2018-02-01

    The development of new methods to denoise images still attract researchers, who seek to combat the noise with the minimal loss of resolution and details, like edges and fine structures. Many algorithms have the goal to remove additive white Gaussian noise (AWGN). However, it is not the only type of noise which interferes in the analysis and interpretation of images. Therefore, it is extremely important to expand the filters capacity to different noise models present in li-terature, for example the multiplicative noise called speckle that is present in synthetic aperture radar (SAR) images. The state-of-the-art algorithms in remote sensing area work with similarity between patches. This paper aims to develop two approaches using the non local means (NLM), developed for AWGN. In our research, we expanded its capacity for intensity SAR ima-ges speckle. The first approach is grounded on the use of stochastic distances based on the G0 distribution without transforming the data to the logarithm domain, like homomorphic transformation. It takes into account the speckle and backscatter to estimate the parameters necessary to compute the stochastic distances on NLM. The second method uses a priori NLM denoising with a homomorphic transformation and applies the inverse Gamma distribution to estimate the parameters that were used into NLM with stochastic distances. The latter method also presents a new alternative to compute the parameters for the G0 distribution. Finally, this work compares and analyzes the synthetic and real results of the proposed methods with some recent filters of the literature.

  18. Volume sums of polar Blaschke–Minkowski homomorphisms

    Indian Academy of Sciences (India)

    In this article, we establish Minkowski and Aleksandrov–Fenchel type inequalities for the volume sum of polars of Blaschke–Minkowski homomorphisms. Keywords. Blaschke–Minkowski homomorphism; volume differences; volume sum; projection body operator. 2010 Mathematics Subject Classification. 52A40, 52A30. 1.

  19. Puiseux monoids and transfer homomorphisms

    OpenAIRE

    Gotti, Felix

    2017-01-01

    There are several families of atomic monoids whose arithmetical invariants have received a great deal of attention during the last two decades. The factorization theory of finitely generated monoids, strongly primary monoids, Krull monoids, and C-monoids are among the most systematically studied. Puiseux monoids, which are additive submonoids of $\\mathbb{Q}_{\\ge 0}$ consisting of nonnegative rational numbers, have only been studied recently. In this paper, we provide evidence that this family...

  20. Secure Data Aggregation with Fully Homomorphic Encryption in Large-Scale Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Xing Li

    2015-07-01

    Full Text Available With the rapid development of wireless communication technology, sensor technology, information acquisition and processing technology, sensor networks will finally have a deep influence on all aspects of people’s lives. The battery resources of sensor nodes should be managed efficiently in order to prolong network lifetime in large-scale wireless sensor networks (LWSNs. Data aggregation represents an important method to remove redundancy as well as unnecessary data transmission and hence cut down the energy used in communication. As sensor nodes are deployed in hostile environments, the security of the sensitive information such as confidentiality and integrity should be considered. This paper proposes Fully homomorphic Encryption based Secure data Aggregation (FESA in LWSNs which can protect end-to-end data confidentiality and support arbitrary aggregation operations over encrypted data. In addition, by utilizing message authentication codes (MACs, this scheme can also verify data integrity during data aggregation and forwarding processes so that false data can be detected as early as possible. Although the FHE increase the computation overhead due to its large public key size, simulation results show that it is implementable in LWSNs and performs well. Compared with other protocols, the transmitted data and network overhead are reduced in our scheme.

  1. Secure Data Aggregation with Fully Homomorphic Encryption in Large-Scale Wireless Sensor Networks.

    Science.gov (United States)

    Li, Xing; Chen, Dexin; Li, Chunyan; Wang, Liangmin

    2015-07-03

    With the rapid development of wireless communication technology, sensor technology, information acquisition and processing technology, sensor networks will finally have a deep influence on all aspects of people's lives. The battery resources of sensor nodes should be managed efficiently in order to prolong network lifetime in large-scale wireless sensor networks (LWSNs). Data aggregation represents an important method to remove redundancy as well as unnecessary data transmission and hence cut down the energy used in communication. As sensor nodes are deployed in hostile environments, the security of the sensitive information such as confidentiality and integrity should be considered. This paper proposes Fully homomorphic Encryption based Secure data Aggregation (FESA) in LWSNs which can protect end-to-end data confidentiality and support arbitrary aggregation operations over encrypted data. In addition, by utilizing message authentication codes (MACs), this scheme can also verify data integrity during data aggregation and forwarding processes so that false data can be detected as early as possible. Although the FHE increase the computation overhead due to its large public key size, simulation results show that it is implementable in LWSNs and performs well. Compared with other protocols, the transmitted data and network overhead are reduced in our scheme.

  2. Optimal Rate Private Information Retrieval from Homomorphic Encryption

    Directory of Open Access Journals (Sweden)

    Kiayias Aggelos

    2015-06-01

    Full Text Available We consider the problem of minimizing the communication in single-database private information retrieval protocols in the case where the length of the data to be transmitted is large. We present first rate-optimal protocols for 1-out-of-n computationallyprivate information retrieval (CPIR, oblivious transfer (OT, and strong conditional oblivious transfer (SCOT. These protocols are based on a new optimalrate leveled homomorphic encryption scheme for large-output polynomial-size branching programs, that might be of independent interest. The analysis of the new scheme is intricate: the optimal rate is achieved if a certain parameter s is set equal to the only positive root of a degree-(m + 1 polynomial, where m is the length of the branching program. We show, by using Galois theory, that even when m = 4, this polynomial cannot be solved in radicals. We employ the Newton-Puiseux algorithm to find a Puiseux series for s, and based on this, propose a Θ (logm-time algorithm to find an integer approximation to s.

  3. Canonical extensions of the Johnson homomorphisms to the Torelli groupoid

    DEFF Research Database (Denmark)

    Bene, Alex; Kawazumi, Nariya; Penner, Robert

    2009-01-01

    We prove that every trivalent marked bordered fatgraph comes equipped with a canonical generalized Magnus expansion in the sense of Kawazumi. This Magnus expansion is used to give canonical extensions of the higher Johnson homomorphisms τm , for m 1 , to the Torelli groupoid, and we provide...... a recursive combinatorial formula for tensor representatives of these extensions. In particular, we give an explicit 1-cocycle in the dual fatgraph complex which extends τ2 and thus answer affirmatively a question of Morita and Penner. To illustrate our techniques for calculating higher Johnson homomorphisms...

  4. A Fuzzy Homomorphic Algorithm for Image Enhancement | Nnolim ...

    African Journals Online (AJOL)

    The implementation and analysis of a novel Fuzzy Homomorphic image enhancement technique is presented. The technique combines the logarithmic transform with fuzzy membership functions to deliver an intuitive method of image enhancement. This algorithm reduces the computational complexity by eliminating the ...

  5. Homomorphism and quotient of fuzzy k-hyperideals

    Directory of Open Access Journals (Sweden)

    R. Ameri

    2010-12-01

    Full Text Available In [15], we introduced the notion of weak (resp. strong fuzzy k- hyperideal. In this note we investigate the behavior of them under homomorphisms of semihyperrings. Also we define the quotient of fuzzy weak (resp. strong k-hyperideals by a regular relation of semihyperring and obtain some results.

  6. Stability of the equation of homomorphism and completeness of the underlying space

    Directory of Open Access Journals (Sweden)

    Zenon Moszner

    2008-01-01

    Full Text Available We prove that all assumptions of a Theorem of Forti and Schwaiger (cf. [G. L. Forti, J. Schwaiger, Stability of homomorphisms and completeness, C. R. Math. Rep. Acad. Sci. Canada 11 (1989, 215–220] on the coherence of stability of the equation of homomorphism with the completeness of the space of values of all these homomorphisms, are essential. We give some generalizations of this theorem and certain examples of applications.

  7. Co-designed accelerator for homomorphic encryption applications

    Directory of Open Access Journals (Sweden)

    Asma Mkhinini

    2018-02-01

    Full Text Available Fully Homomorphic Encryption (FHE is considered as a key cryptographic tool in building a secure cloud computing environment since it allows computing arbitrary functions directly on encrypted data. However, existing FHE implementations remain impractical due to very high time and resource costs. These costs are essentially due to the computationally intensive modular polynomial multiplication. In this paper, we present a software/hardware co-designed modular polynomial multiplier in order to accelerate homomorphic schemes. The hardware part is implemented through a High-Level Synthesis (HLS flow. Experimental results show competitive latencies when compared with hand-made designs, while maintaining large advantages on resources. Moreover, we show that our high-level description can be easily configured with different parameters and very large sizes in negligible time, generating new designs for numerous applications.

  8. A Framework For Efficient Homomorphic Universally Composable Commitments

    DEFF Research Database (Denmark)

    David, Bernardo Machado

    primitives and protocols while retaining security guarantees. Moreover, commitments with homomorphic properties enable significantly more efficient constructions of protocols for applications such as zero knowledge proofs, two-party computation through garbled circuits and multiparty computation. However......, achieving universal composability for commitment schemes often sacrifices both concrete and asymptotic efficiency, specially if homomorphic properties are required. In this thesis we bridge the gap between stand alone and universally composable commitment schemes, for which we achieve optimal efficiency...... related to a statistical security parameter as a setup. The rest of our constructions leverage secret sharing and coding theory techniques, including a novel method for verifying that a large number of strings are codewords of a given linear code with linear complexity....

  9. Homomorphic encryption experiments on IBM's cloud quantum computing platform

    Science.gov (United States)

    Huang, He-Liang; Zhao, You-Wei; Li, Tan; Li, Feng-Guang; Du, Yu-Tao; Fu, Xiang-Qun; Zhang, Shuo; Wang, Xiang; Bao, Wan-Su

    2017-02-01

    Quantum computing has undergone rapid development in recent years. Owing to limitations on scalability, personal quantum computers still seem slightly unrealistic in the near future. The first practical quantum computer for ordinary users is likely to be on the cloud. However, the adoption of cloud computing is possible only if security is ensured. Homomorphic encryption is a cryptographic protocol that allows computation to be performed on encrypted data without decrypting them, so it is well suited to cloud computing. Here, we first applied homomorphic encryption on IBM's cloud quantum computer platform. In our experiments, we successfully implemented a quantum algorithm for linear equations while protecting our privacy. This demonstration opens a feasible path to the next stage of development of cloud quantum information technology.

  10. Semi-Homomorphic Encryption and Multiparty Computation

    DEFF Research Database (Denmark)

    Bendlin, Rikke; Damgård, Ivan Bjerre; Orlandi, Claudio

    2011-01-01

    allow us to construct an efficient multiparty computation protocol for arithmetic circuits, UC-secure against a dishonest majority. The protocol consists of a preprocessing phase and an online phase. Neither the inputs nor the function to be computed have to be known during preprocessing. Moreover......, the online phase is extremely efficient as it requires no cryptographic operations: the parties only need to exchange additive shares and verify information theoretic MACs. Our contribution is therefore twofold: from a theoretical point of view, we can base multiparty computation on a variety of different...

  11. Privacy-preserving genome-wide association studies on cloud environment using fully homomorphic encryption.

    Science.gov (United States)

    Lu, Wen-Jie; Yamada, Yoshiji; Sakuma, Jun

    2015-01-01

    Developed sequencing techniques are yielding large-scale genomic data at low cost. A genome-wide association study (GWAS) targeting genetic variations that are significantly associated with a particular disease offers great potential for medical improvement. However, subjects who volunteer their genomic data expose themselves to the risk of privacy invasion; these privacy concerns prevent efficient genomic data sharing. Our goal is to presents a cryptographic solution to this problem. To maintain the privacy of subjects, we propose encryption of all genotype and phenotype data. To allow the cloud to perform meaningful computation in relation to the encrypted data, we use a fully homomorphic encryption scheme. Noting that we can evaluate typical statistics for GWAS from a frequency table, our solution evaluates frequency tables with encrypted genomic and clinical data as input. We propose to use a packing technique for efficient evaluation of these frequency tables. Our solution supports evaluation of the D' measure of linkage disequilibrium, the Hardy-Weinberg Equilibrium, the χ2 test, etc. In this paper, we take χ2 test and linkage disequilibrium as examples and demonstrate how we can conduct these algorithms securely and efficiently in an outsourcing setting. We demonstrate with experimentation that secure outsourcing computation of one χ2 test with 10, 000 subjects requires about 35 ms and evaluation of one linkage disequilibrium with 10, 000 subjects requires about 80 ms. With appropriate encoding and packing technique, cryptographic solutions based on fully homomorphic encryption for secure computations of GWAS can be practical.

  12. Nonterminals, homomorphisms and codings in different variations of OL-systems. II. Nondeterministic systems

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Rozenberg, Grzegorz; Salomaa, Arto

    1974-01-01

    Continuing the work begun in Part I of this paper, we consider now variations of nondeterministic OL-systems. The present Part II of the paper contains a systematic classification of the effect of nonterminals, codings, weak codings, nonerasing homomorphisms and homomorphisms for all basic variat...

  13. Homomorphisms and functional calculus on algebras on entire functions on Banach spaces

    Directory of Open Access Journals (Sweden)

    H. M. Pryimak

    2015-07-01

    Full Text Available The paper is devoted to study homomorphisms of algebras of entire functionson Banach spaces to a commutative Banach algebra. In particular, it is proposed amethod to construct homomorphisms vanishing on homogeneouspolynomials of degree less or equal that a fixed number $n.$

  14. Torelli groups, extended Johnson homomorphisms, and new cycles on the moduli space of curves

    DEFF Research Database (Denmark)

    Morita, Shigeyuki; Penner, Robert

    modulo N are derived for all N. Furthermore, the first Johnson homomorphism, which is defined from the classical Torelli group to the third exterior power of the homology of the surface, is shown to lift to an explicit canonical 1-cocycle of the Teichmueller space. The main tool for these results...... cocycle lifts of the higher Johnson homomorphisms....

  15. Lattice and algebra homomorphisms on C (X) in Zermelo-Fraenkel ...

    African Journals Online (AJOL)

    Let C (X) denote the lattice-ordered algebra of all real-valued continuous functions on a topological space X. This paper discusses in Zermelo-Fraenkel Set Theory the equivalence on C (X) between algebra homomorphisms, lattice homo- morphisms, and point evaluations. Keywords: Algebra homomorphism, lattice ...

  16. Decomposing highly edge-connected graphs into homomorphic copies of a fixed tree

    DEFF Research Database (Denmark)

    Merker, Martin

    2016-01-01

    far this conjecture has only been verified for paths, stars, and a family of bistars. We prove a weaker version of the Tree Decomposition Conjecture, where we require the subgraphs in the decomposition to be isomorphic to graphs that can be obtained from T by vertex-identifications. We call......The Tree Decomposition Conjecture by Barát and Thomassen states that for every tree T there exists a natural number k(T) such that the following holds: If G is a k(T)-edge-connected simple graph with size divisible by the size of T, then G can be edge-decomposed into subgraphs isomorphic to T. So...... such a subgraph a homomorphic copy of T. This implies the Tree Decomposition Conjecture under the additional constraint that the girth of G is greater than the diameter of T. As an application, we verify the Tree Decomposition Conjecture for all trees of diameter at most 4....

  17. Laser-based additive manufacturing of metals

    CSIR Research Space (South Africa)

    Kumar, S

    2010-11-01

    Full Text Available For making metallic products through Additive Manufacturing (AM) processes, laser-based systems play very significant roles. Laser-based processes such as Selective Laser Melting (SLM) and Laser Engineered Net Shaping (LENS) are dominating processes...

  18. Mammographic image enhancement using wavelet transform and homomorphic filter

    Directory of Open Access Journals (Sweden)

    F Majidi

    2015-12-01

    Full Text Available Mammography is the most effective method for the early diagnosis of breast cancer diseases. As mammographic images contain low signal to noise ratio and low contrast, it becomes too difficult for radiologists to analyze mammogram. To deal with the above stated problems, it is very important to enhance the mammographic images using image processing methods. This paper introduces a new image enhancement approach for mammographic images which uses the modified mathematical morphology, wavelet transform and homomorphic filter to suppress the noise of images. For performance evaluation of the proposed method, contrast improvement index (CII and edge preservation index (EPI are adopted. Experimental results on mammographic images from Pejvak Digital Imaging Center (PDIC show that the proposed algorithm improves the two indexes, thereby achieving the goal of enhancing mammographic images.

  19. Laser-Based Additive Manufacturing of Zirconium

    Directory of Open Access Journals (Sweden)

    Himanshu Sahasrabudhe

    2018-03-01

    Full Text Available Additive manufacturing of zirconium is attempted using commercial Laser Engineered Net Shaping (LENSTM technique. A LENSTM-based approach towards processing coatings and bulk parts of zirconium, a reactive metal, aims to minimize the inconvenience of traditional metallurgical practices of handling and processing zirconium-based parts that are particularly suited to small volumes and one-of-a-kind parts. This is a single-step manufacturing approach for obtaining near net shape fabrication of components. In the current research, Zr metal powder was processed in the form of coating on Ti6Al4V alloy substrate. Scanning electron microscopy (SEM and energy dispersive spectroscopy (EDS as well as phase analysis via X-ray diffraction (XRD were studied on these coatings. In addition to coatings, bulk parts were also fabricated using LENS™ from Zr metal powders, and measured part accuracy.

  20. Cryptographically Secure Multiparty Computation and Distributed Auctions Using Homomorphic Encryption

    Directory of Open Access Journals (Sweden)

    Anunay Kulshrestha

    2017-12-01

    Full Text Available We introduce a robust framework that allows for cryptographically secure multiparty computations, such as distributed private value auctions. The security is guaranteed by two-sided authentication of all network connections, homomorphically encrypted bids, and the publication of zero-knowledge proofs of every computation. This also allows a non-participant verifier to verify the result of any such computation using only the information broadcasted on the network by each individual bidder. Building on previous work on such systems, we design and implement an extensible framework that puts the described ideas to practice. Apart from the actual implementation of the framework, our biggest contribution is the level of protection we are able to guarantee from attacks described in previous work. In order to provide guidance to users of the library, we analyze the use of zero knowledge proofs in ensuring the correct behavior of each node in a computation. We also describe the usage of the library to perform a private-value distributed auction, as well as the other challenges in implementing the protocol, such as auction registration and certificate distribution. Finally, we provide performance statistics on our implementation of the auction.

  1. Secure searching of biomarkers through hybrid homomorphic encryption scheme.

    Science.gov (United States)

    Kim, Miran; Song, Yongsoo; Cheon, Jung Hee

    2017-07-26

    As genome sequencing technology develops rapidly, there has lately been an increasing need to keep genomic data secure even when stored in the cloud and still used for research. We are interested in designing a protocol for the secure outsourcing matching problem on encrypted data. We propose an efficient method to securely search a matching position with the query data and extract some information at the position. After decryption, only a small amount of comparisons with the query information should be performed in plaintext state. We apply this method to find a set of biomarkers in encrypted genomes. The important feature of our method is to encode a genomic database as a single element of polynomial ring. Since our method requires a single homomorphic multiplication of hybrid scheme for query computation, it has the advantage over the previous methods in parameter size, computation complexity, and communication cost. In particular, the extraction procedure not only prevents leakage of database information that has not been queried by user but also reduces the communication cost by half. We evaluate the performance of our method and verify that the computation on large-scale personal data can be securely and practically outsourced to a cloud environment during data analysis. It takes about 3.9 s to search-and-extract the reference and alternate sequences at the queried position in a database of size 4M. Our solution for finding a set of biomarkers in DNA sequences shows the progress of cryptographic techniques in terms of their capability can support real-world genome data analysis in a cloud environment.

  2. On the Relations between the Attacks on Symmetric Homomorphic Encryption over the Residue Ring

    Directory of Open Access Journals (Sweden)

    Alina V. Trepacheva

    2017-06-01

    Full Text Available The paper considers the security of symmetric homomorphic cryptosystems (HC over the residue ring. The main task is to establish an equivalence between ciphertexts only attack (COA and known plaintexts attack (KPA for HC. The notion of reducibility between attacks and sufficient condition of reducibility from COA to KPA are given for this purpose. The main idea is: to prove reducibility from COA to KPA we need to find a function over residue ring being efficiently computable and having a small image size comparing with the size of residue ring. The study of reducibility existence is important since it allows to understand better the security level of symmetric HC proposed in literature. A vulnerability against KPA has been already found for the majority of these HC. Thus the reducibility presence can demonstrate that cryptosystems under the study are not secure even against COA, and therefore they are totally insecure and shouldn’t be used in practice. We give an example of reducibility from COA to KPA for residue ring being a simple field. Based on this example we show an efficient COA on one symmetric HC for small field. Also we separately consider the case of residue ring composed using number n being hard-to-factor. For such n an efficient algorithm to construct an efficiently computable function with small image is unknown so far. So further work related to cryptanalysis of existing symmetric HC will be directed into study of functions properties over residue rings modulo numbers hard for factorization.

  3. Competency Based Hospital Radiopharmacy Training. Additional Information

    International Nuclear Information System (INIS)

    2010-01-01

    Quality management systems in nuclear medicine are vital to a high level of nuclear medicine (NM) practice. Trained and competent staffs are essential for achieving high standards and growth in NM. One of the key bottlenecks for NM is the shortfall in human resources, especially of radiopharmacists. There is an acute shortage in most Member States and in some countries an absence of nationally registered pharmacists with radiopharmacy experience. Most nuclear medicine facilities operate their radiopharmacies (commonly referred to as the hot laboratories) with the support of technologists and radiographers. Recent surveys have found the level of training amongst technologists to be extremely variable. Most had little or no training in hot laboratory practices. The survey also indicated the poor state of hot laboratories in many countries. Basic quality systems in the hot laboratory could be improved significantly with better training. This competency-based education manual is designed with those radiopharmacy practitioners in mind. This competency-based trainer's manual provides trainers in each of the IAEA regions with the essentials of a training programme for all radiopharmacy practitioners. The competency-based training is a two week programme followed up with three months of practice achievements. The syllabus provides a standardized approach to lectures, practical sessions, and interactive workshops focusing on critical aspects of hot laboratory practices. The trainers, with the assistance of this manual, can deliver essential skills, competencies, and underpinning knowledge to operate safely and effectively in their hot laboratory. The course focuses on simple but practical steps that could be undertaken to improve staff performance. In addition, a basic framework of quality management principles related to radiopharmacy practices is also covered. Further, the syllabus can be adapted to the particular needs and characteristics of any training centre, country

  4. Nonterminals, homomorphisms and codings in different variations of OL-systems. I. Deterministic systems

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Rozenberg, Grzegorz; Salomaa, Arto

    1974-01-01

    The use of nonterminals versus the use of homomorphisms of different kinds in the basic types of deterministic OL-systems is studied. A rather surprising result is that in some cases the use of nonterminals produces a comparatively low generative capacity, whereas in some other cases the use of n...

  5. Large and small sets with respect to homomorphisms and products of groups

    Directory of Open Access Journals (Sweden)

    Riccardo Gusso

    2002-10-01

    Full Text Available We study the behaviour of large, small and medium subsets with respect to homomorphisms and products of groups. Then we introduce the definition af a P-small set in abelian groups and we investigate the relations between this kind of smallness and the previous one, giving some examples that distinguish them.

  6. An Efficient Secret Key Homomorphic Encryption Used in Image Processing Service

    Directory of Open Access Journals (Sweden)

    Pan Yang

    2017-01-01

    Full Text Available Homomorphic encryption can protect user’s privacy when operating on user’s data in cloud computing. But it is not practical for wide using as the data and services types in cloud computing are diverse. Among these data types, digital image is an important personal data for users. There are also many image processing services in cloud computing. To protect user’s privacy in these services, this paper proposed a scheme using homomorphic encryption in image processing. Firstly, a secret key homomorphic encryption (IGHE was constructed for encrypting image. IGHE can operate on encrypted floating numbers efficiently to adapt to the image processing service. Then, by translating the traditional image processing methods into the operations on encrypted pixels, the encrypted image can be processed homomorphically. That is, service can process the encrypted image directly, and the result after decryption is the same as processing the plain image. To illustrate our scheme, three common image processing instances were given in this paper. The experiments show that our scheme is secure, correct, and efficient enough to be used in practical image processing applications.

  7. Limitations on Transversal Computation through Quantum Homomorphic Encryption

    OpenAIRE

    Newman, Michael; Shi, Yaoyun

    2017-01-01

    Transversality is a simple and effective method for implementing quantum computation fault-tolerantly. However, no quantum error-correcting code (QECC) can transversally implement a quantum universal gate set (Eastin and Knill, Phys. Rev. Lett., 102, 110502). Since reversible classical computation is often a dominating part of useful quantum computation, whether or not it can be implemented transversally is an important open problem. We show that, other than a small set of non-additive codes ...

  8. Minimizing Overhead for Secure Computation and Fully Homomorphic Encryption: Overhead

    Science.gov (United States)

    2015-11-01

    application for this technology is mobile devices: the preparation work can be performed while the phone is plugged into a power source, then it can later...handle large realistic security parameters. Therefore, we looked into the possibility of augmenting the SAGE system with a backend that could handle...limited mobile devices and yet have ready access to cloud-based computing resources. The techniques we propose form part of a growing line of work aimed

  9. A Regev-Type Fully Homomorphic Encryption Scheme Using Modulus Switching

    Science.gov (United States)

    Chen, Zhigang; Wang, Jian; Song, Xinxia

    2014-01-01

    A critical challenge in a fully homomorphic encryption (FHE) scheme is to manage noise. Modulus switching technique is currently the most efficient noise management technique. When using the modulus switching technique to design and implement a FHE scheme, how to choose concrete parameters is an important step, but to our best knowledge, this step has drawn very little attention to the existing FHE researches in the literature. The contributions of this paper are twofold. On one hand, we propose a function of the lower bound of dimension value in the switching techniques depending on the LWE specific security levels. On the other hand, as a case study, we modify the Brakerski FHE scheme (in Crypto 2012) by using the modulus switching technique. We recommend concrete parameter values of our proposed scheme and provide security analysis. Our result shows that the modified FHE scheme is more efficient than the original Brakerski scheme in the same security level. PMID:25093212

  10. An improvement of the base bleed unit on base drag reduction and heat energy addition as well as mass addition

    International Nuclear Information System (INIS)

    Xue, Xiaochun; Yu, Yonggang

    2016-01-01

    Highlights: • A 2D axisymmetric Navier-Stokes equation for a multi-component reactive system is solved. • The coupling of the internal and wake flow field with secondary combustion is calculated. • Detailed data with combined effects of boattailing and post-combustion are obtained. • The mechanism of heat energy addition and thermodynamics performances is investigated. - Abstract: Numerical simulations are carried out to investigate the base drag and energy characteristics of a base-bleed projectile with and without containing the effect of a post-combustion process for a boattailed afterbody in a supersonic flow, and then to analyze the key factor of drag reduction and pressure decreasing of base bleed projectile. Detailed chemistry models for H_2−CO combustion have been incorporated into a Navier-Stokes computer code and applied to flow field simulation in the base region of a base-bleed projectile. Detailed numerical results for the flow patterns and heat energy addition as well as mass addition for different conditions are presented and compared with existing experimental data. The results shows that, the post-combustion contributes to energy addition and base drag reduction up to 78% on account of that the heat energy released from the post-combustion using fuel-rich reaction products as the fuel in the wake region is much higher than for the corresponding cold bleed and hot bleed cases. In addition, the temperature distribution regularities are changed under post-combustion effect, presenting that the peak appears in a couple of recirculation regions. The fuel-rich bleed gas flows into the shear layer along the crack between these two recirculation regions and then those can readily burn when mixing with the freestream, thus causing component changes of H_2 and CO in the base flowfield.

  11. Additives for cement compositions based on modified peat

    Energy Technology Data Exchange (ETDEWEB)

    Kopanitsa, Natalya, E-mail: kopanitsa@mail.ru; Sarkisov, Yurij, E-mail: sarkisov@tsuab.ru; Gorshkova, Aleksandra, E-mail: kasatkina.alexandra@gmail.com; Demyanenko, Olga, E-mail: angel-n@sibmail.com [Tomsk State University of Architecture and Building, 2, Solyanaya sq., Tomsk, 634003 (Russian Federation)

    2016-01-15

    High quality competitive dry building mixes require modifying additives for various purposes to be included in their composition. There is insufficient amount of quality additives having stable properties for controlling the properties of cement compositions produced in Russia. Using of foreign modifying additives leads to significant increasing of the final cost of the product. The cost of imported modifiers in the composition of the dry building mixes can be up to 90% of the material cost, depending on the composition complexity. Thus, the problem of import substitution becomes relevant, especially in recent years, due to difficult economic situation. The article discusses the possibility of using local raw materials as a basis for obtaining dry building mixtures components. The properties of organo-mineral additives for cement compositions based on thermally modified peat raw materials are studied. Studies of the structure and composition of the additives are carried out by physicochemical research methods: electron microscopy and X-ray analysis. Results of experimental research showed that the peat additives contribute to improving of cement-sand mortar strength and hydrophysical properties.

  12. Additively manufactured metallic porous biomaterials based on minimal surfaces

    DEFF Research Database (Denmark)

    Bobbert, F. S. L.; Lietaert, K.; Eftekhari, Ali Akbar

    2017-01-01

    Porous biomaterials that simultaneously mimic the topological, mechanical, and mass transport properties of bone are in great demand but are rarely found in the literature. In this study, we rationally designed and additively manufactured (AM) porous metallic biomaterials based on four different...... of bone properties is feasible, biomaterials that could simultaneously mimic all or most of the relevant bone properties are rare. We used rational design and additive manufacturing to develop porous metallic biomaterials that exhibit an interesting combination of topological, mechanical, and mass...

  13. Modeling uranium transport in acidic contaminated groundwater with base addition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Fan [Institute of Tibetan Plateau Research, Chinese Academy of Sciences; Luo, Wensui [ORNL; Parker, Jack C. [University of Tennessee, Knoxville (UTK); Brooks, Scott C [ORNL; Watson, David B [ORNL; Jardine, Philip [University of Tennessee, Knoxville (UTK); Gu, Baohua [ORNL

    2011-01-01

    This study investigates reactive transport modeling in a column of uranium(VI)-contaminated sediments with base additions in the circulating influent. The groundwater and sediment exhibit oxic conditions with low pH, high concentrations of NO{sub 3}{sup -}, SO{sub 4}{sup 2-}, U and various metal cations. Preliminary batch experiments indicate that additions of strong base induce rapid immobilization of U for this material. In the column experiment that is the focus of the present study, effluent groundwater was titrated with NaOH solution in an inflow reservoir before reinjection to gradually increase the solution pH in the column. An equilibrium hydrolysis, precipitation and ion exchange reaction model developed through simulation of the preliminary batch titration experiments predicted faster reduction of aqueous Al than observed in the column experiment. The model was therefore modified to consider reaction kinetics for the precipitation and dissolution processes which are the major mechanism for Al immobilization. The combined kinetic and equilibrium reaction model adequately described variations in pH, aqueous concentrations of metal cations (Al, Ca, Mg, Sr, Mn, Ni, Co), sulfate and U(VI). The experimental and modeling results indicate that U(VI) can be effectively sequestered with controlled base addition due to sorption by slowly precipitated Al with pH-dependent surface charge. The model may prove useful to predict field-scale U(VI) sequestration and remediation effectiveness.

  14. Modeling uranium transport in acidic contaminated groundwater with base addition

    International Nuclear Information System (INIS)

    Zhang Fan; Luo Wensui; Parker, Jack C.; Brooks, Scott C.; Watson, David B.; Jardine, Philip M.; Gu Baohua

    2011-01-01

    This study investigates reactive transport modeling in a column of uranium(VI)-contaminated sediments with base additions in the circulating influent. The groundwater and sediment exhibit oxic conditions with low pH, high concentrations of NO 3 - , SO 4 2- , U and various metal cations. Preliminary batch experiments indicate that additions of strong base induce rapid immobilization of U for this material. In the column experiment that is the focus of the present study, effluent groundwater was titrated with NaOH solution in an inflow reservoir before reinjection to gradually increase the solution pH in the column. An equilibrium hydrolysis, precipitation and ion exchange reaction model developed through simulation of the preliminary batch titration experiments predicted faster reduction of aqueous Al than observed in the column experiment. The model was therefore modified to consider reaction kinetics for the precipitation and dissolution processes which are the major mechanism for Al immobilization. The combined kinetic and equilibrium reaction model adequately described variations in pH, aqueous concentrations of metal cations (Al, Ca, Mg, Sr, Mn, Ni, Co), sulfate and U(VI). The experimental and modeling results indicate that U(VI) can be effectively sequestered with controlled base addition due to sorption by slowly precipitated Al with pH-dependent surface charge. The model may prove useful to predict field-scale U(VI) sequestration and remediation effectiveness.

  15. Modeling uranium transport in acidic contaminated groundwater with base addition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Fan, E-mail: zhangfan@itpcas.ac.cn [Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085 (China); Luo Wensui [Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021 (China); Parker, Jack C. [Institute for a Secure and Sustainable Environment, Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Brooks, Scott C.; Watson, David B. [Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Jardine, Philip M. [Biosystems Engineering and Soil Science Department, University of Tennessee, Knoxville, TN 37996 (United States); Gu Baohua [Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

    2011-06-15

    This study investigates reactive transport modeling in a column of uranium(VI)-contaminated sediments with base additions in the circulating influent. The groundwater and sediment exhibit oxic conditions with low pH, high concentrations of NO{sub 3}{sup -}, SO{sub 4}{sup 2-}, U and various metal cations. Preliminary batch experiments indicate that additions of strong base induce rapid immobilization of U for this material. In the column experiment that is the focus of the present study, effluent groundwater was titrated with NaOH solution in an inflow reservoir before reinjection to gradually increase the solution pH in the column. An equilibrium hydrolysis, precipitation and ion exchange reaction model developed through simulation of the preliminary batch titration experiments predicted faster reduction of aqueous Al than observed in the column experiment. The model was therefore modified to consider reaction kinetics for the precipitation and dissolution processes which are the major mechanism for Al immobilization. The combined kinetic and equilibrium reaction model adequately described variations in pH, aqueous concentrations of metal cations (Al, Ca, Mg, Sr, Mn, Ni, Co), sulfate and U(VI). The experimental and modeling results indicate that U(VI) can be effectively sequestered with controlled base addition due to sorption by slowly precipitated Al with pH-dependent surface charge. The model may prove useful to predict field-scale U(VI) sequestration and remediation effectiveness.

  16. Enhanced performance of ultracapacitors using redox additive-based electrolytes

    Science.gov (United States)

    Jain, Dharmendra; Kanungo, Jitendra; Tripathi, S. K.

    2018-05-01

    Different concentrations of potassium iodide (KI) as redox additive had been added to 1 M sulfuric acid (H2SO4) electrolyte with an aim of enhancing the capacitance and energy density of ultracapacitors via redox reactions at the interfaces of electrode-electrolyte. Ultracapacitors were fabricated using chemically treated activated carbon as electrode with H2SO4 and H2SO4-KI as an electrolyte. The electrochemical performances of fabricated supercapacitors were investigated by impedance spectroscopy, cyclic voltammetry and charge-discharge techniques. The maximum capacitance ` C' was observed with redox additives-based electrolyte system comprising 1 M H2SO4-0.3 M KI (1072 F g- 1), which is very much higher than conventional 1 M H2SO4 (61.3 F g- 1) aqueous electrolyte-based ultracapacitors. It corresponds to an energy density of 20.49 Wh kg- 1 at 2.1 A g- 1 for redox additive-based electrolyte, which is six times higher as compared to that of pristine electrolyte (1 M H2SO4) having energy density of only 3.36 Wh kg- 1. The temperature dependence behavior of fabricated cell was also analyzed, which shows increasing pattern in its capacitance values in a temperature range of 5-70 °C. Under cyclic stability test, redox electrolyte-based system shows almost 100% capacitance retention up to 5000 cycles and even more. For comparison, ultracapacitors based on polymer gel electrolyte polyvinyl alcohol (PVA) (10 wt%)—{H2SO4 (1 M)-KI (0.3 M)} (90 wt%) have been fabricated and characterized with the same electrode materials.

  17. Colloidal-based additive manufacturing of bio-inspired composites

    Science.gov (United States)

    Studart, Andre R.

    Composite materials in nature exhibit heterogeneous architectures that are tuned to fulfill the functional demands of the surrounding environment. Examples range from the cellulose-based organic structure of plants to highly mineralized collagen-based skeletal parts like bone and teeth. Because they are often utilized to combine opposing properties such as strength and low-density or stiffness and wear resistance, the heterogeneous architecture of natural materials can potentially address several of the technical limitations of artificial homogeneous composites. However, current man-made manufacturing technologies do not allow for the level of composition and fiber orientation control found in natural heterogeneous systems. In this talk, I will present two additive manufacturing technologies recently developed in our group to build composites with exquisite architectures only rivaled by structures made by living organisms in nature. Since the proposed techniques utilize colloidal suspensions as feedstock, understanding the physics underlying the stability, assembly and rheology of the printing inks is key to predict and control the architecture of manufactured parts. Our results will show that additive manufacturing routes offer a new exciting pathway for the fabrication of biologically-inspired composite materials with unprecedented architectures and functionalities.

  18. Effect of B addition to hypereutectic Ti-based alloys

    International Nuclear Information System (INIS)

    Louzguina-Luzgina, Larissa V.; Louzguine-Luzgin, Dmitri V.; Inoue, Akihisa

    2009-01-01

    The structure and mechanical properties of Ti-Fe-B and Ti-Fe-Co-B alloys produced in the shape of the arc-melted ingots of about 25 mm diameter and 10 mm height are studied. The hypereutectic alloys showed excellent compressive mechanical properties. The structures of the high-strength and ductile hypereutectic alloys studied by X-ray diffractometry and scanning electron microscopy were found to consist of the primary cubic cP2 intermetallic compound (TiFe-phase or a solid solution on its base) and a dispersed eutectic consisting of this cP2 intermetallic compound + BCC cI2 β-Ti supersaturated solid solution phase. The addition of B increased mechanical strength. Si causes embrittlement owing to the formation of alternative intermetallic compounds. The structure and deformation behaviour were studied

  19. Innovative Additive for Bitumen Based on Processed Fats

    Science.gov (United States)

    Babiak, Michał; Kosno, Jacek; Ratajczak, Maria; Zieliński, Krzysztof

    2017-10-01

    Various additives, admixtures and modifiers are used to improve technical properties and strength characteristics of building materials. Manufacturers of waterproofing materials, concrete, ceramics and bitumen have to use innovative, increasingly complex and costly additives, admixtures or modifiers. As a result, simple and inexpensive substances have been replaced by complex, long chain polymers, multi component resins or plastics. For economic and ecological reasons waste materials are more frequently used as additives, admixtures and modifiers. Nowadays the most commonly used physical modifiers of bitumen belong to the group of polymers - large molecular organic compounds of natural origin or being the result of planned chemical synthesis. Polymers are substances that do not chemically react with bitumen, they act as fillers or create a spatial network within bitumen (the so called physical cross-linking). The development of organic chemistry has allowed the synthesis of a number of substances chemically modifying bitumen. The most promising are heterocyclic organic compounds belonging to the group of imidazolines. The aim of the study presented in this paper was to demonstrate the suitability of processed natural and post-refining fat waste (diamidoamine dehydrate) as bitumen modifier. This paper discusses the impact of adding technical imidazoline on selected bitumen characteristics. Samples of bitumen 160/220, which is most commonly used for the production of waterproofing products, were analysed. For base bitumen and bitumen modified with technical imidazoline the following measurements were taken: measurement of the softening point by Ball and Ring method, determination of the breaking point by Fraass method and needle penetration measurement at 25°C. Later the samples were aged using TFOT laboratory method and the basic characteristics were determined again. The results showed that a small amount of imidazoline improved bitumen thermoplastic parameters at

  20. Practical somewhat-secure quantum somewhat-homomorphic encryption with coherent states

    Science.gov (United States)

    Tan, Si-Hui; Ouyang, Yingkai; Rohde, Peter P.

    2018-04-01

    We present a scheme for implementing homomorphic encryption on coherent states encoded using phase-shift keys. The encryption operations require only rotations in phase space, which commute with computations in the code space performed via passive linear optics, and with generalized nonlinear phase operations that are polynomials of the photon-number operator in the code space. This encoding scheme can thus be applied to any computation with coherent-state inputs, and the computation proceeds via a combination of passive linear optics and generalized nonlinear phase operations. An example of such a computation is matrix multiplication, whereby a vector representing coherent-state amplitudes is multiplied by a matrix representing a linear optics network, yielding a new vector of coherent-state amplitudes. By finding an orthogonal partitioning of the support of our encoded states, we quantify the security of our scheme via the indistinguishability of the encrypted code words. While we focus on coherent-state encodings, we expect that this phase-key encoding technique could apply to any continuous-variable computation scheme where the phase-shift operator commutes with the computation.

  1. Adsorption of molecular additive onto lead halide perovskite surfaces: A computational study on Lewis base thiophene additive passivation

    Science.gov (United States)

    Zhang, Lei; Yu, Fengxi; Chen, Lihong; Li, Jingfa

    2018-06-01

    Organic additives, such as the Lewis base thiophene, have been successfully applied to passivate halide perovskite surfaces, improving the stability and properties of perovskite devices based on CH3NH3PbI3. Yet, the detailed nanostructure of the perovskite surface passivated by additives and the mechanisms of such passivation are not well understood. This study presents a nanoscopic view on the interfacial structure of an additive/perovskite interface, consisting of a Lewis base thiophene molecular additive and a lead halide perovskite surface substrate, providing insights on the mechanisms that molecular additives can passivate the halide perovskite surfaces and enhance the perovskite-based device performance. Molecular dynamics study on the interactions between water molecules and the perovskite surfaces passivated by the investigated additive reveal the effectiveness of employing the molecular additives to improve the stability of the halide perovskite materials. The additive/perovskite surface system is further probed via molecular engineering the perovskite surfaces. This study reveals the nanoscopic structure-property relationships of the halide perovskite surface passivated by molecular additives, which helps the fundamental understanding of the surface/interface engineering strategies for the development of halide perovskite based devices.

  2. Additive free thermoplastic vulcanizates based on natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, Manas, E-mail: mondal@ipfdd.de [Leibniz-Institut für Polymerforschung Dresden e.V., Institut für Polymerwerkstoffe, Hohe Straße 6, 01069 Dresden (Germany); Technische Universität Dresden, Institut für Werkstoffwissenschaft, 01069 Dresden (Germany); Gohs, Uwe, E-mail: gohs@ipfdd.de [Leibniz-Institut für Polymerforschung Dresden e.V., Institut für Polymerwerkstoffe, Hohe Straße 6, 01069 Dresden (Germany); Wagenknecht, Udo [Leibniz-Institut für Polymerforschung Dresden e.V., Institut für Polymerwerkstoffe, Hohe Straße 6, 01069 Dresden (Germany); Heinrich, Gert [Leibniz-Institut für Polymerforschung Dresden e.V., Institut für Polymerwerkstoffe, Hohe Straße 6, 01069 Dresden (Germany); Technische Universität Dresden, Institut für Werkstoffwissenschaft, 01069 Dresden (Germany)

    2013-12-16

    Electron induced reactive processing (EIReP) is an eco-friendly and sustainable reactive processing method based on the use of high energy electrons. It was used to cross-link the elastomeric domain phase during melt mixing in order to prepare natural rubber (NR) and polypropylene (PP) based thermoplastic vulcanizates (TPVs). The electron treatment with various values of absorbed dose showed a prominent effect on mechanical, rheological, and morphological characteristics of the PP/NR TPVs. SEM and TEM studies confirmed that these TPVs can exists across the co-continuous or discrete phase morphology. The maximum set of mechanical properties (tensile strength of 15 MPa and elongation at break of more than 500%) were obtained at an absorbed dose of 100 kGy for a 50/50 blend ratio of NR and PP without addition of any compatibilizer or chemicals. At higher values of absorbed dose the degradation of polypropylene showed a negative impact on the properties of the TPVs. Depending on the morphology and the evaluation of mechanical properties a structure–property co-relationship is drawn on the basis of common phenomenological understanding of the TPVs. - Highlights: • Dynamic vulcanization of 50:50 PP/NR blend by high energy electron beam. • PP/NR TPVs show rubber like behavior with melt processability. • High tensile strength of 15 MPa and large extensibility beyond 500%. • Complete phase inversed morphology from NR to PP matrix. • Vulcanized natural rubber particle size of 1–3 μm.

  3. Characterization of the Tribological Behavior of Graphene-Based Additives

    Energy Technology Data Exchange (ETDEWEB)

    Erck, Robert

    2014-09-01

    XG-supplied nanocrystalline additives were extensively tested for friction and wear behavior. A technique for investigating the stability of additives was developed, and a report covered filtration and centrifugation methods for settling and filterable content. Friction and wear trends in partially and fully formulated oils were reported. Particle size analysis was performed and reported.

  4. Monitoring additive manufacturing based products in clinical trials

    NARCIS (Netherlands)

    Marinakis, Yorgos; Harms, Rainer; Walsh, Steven Thomas

    2017-01-01

    Under U.S. federal regulation 31 CFR §312, medical interventions must report on a series of clinical trials phases before being submitted for approval for release to the U.S. market. Clinical trials are now being performed on medical interventions that were constructed through additive

  5. Base Oil-Extreme Pressure Additive Synergy in Lubricants

    Science.gov (United States)

    Extreme pressure (EP) additives are those containing reactive elements such as sulfur, phosphorus, and chlorine. In lubrication processes that occur under extremely severe conditions (e.g., high pressure and/or slow speed), these elements undergo chemical reactions generating new materials (tribofi...

  6. Microcontroller based automatic liquid poison addition control system

    International Nuclear Information System (INIS)

    Kapatral, R.S.; Ananthakrishnan, T.S.; Pansare, M.G.

    1989-01-01

    Microcontrollers are finding increasing applications in instrumentation where complex digital circuits can be substituted by a compact and simple circuit, thus enhancing the reliability. In addition to this, intelligence and flexibility can be incorporated. For applications not requiring large amount of read/write memory (RAM), microcontrollers are ideally suited since they contain programmable memory (Eprom), parallel input/output lines, data memory, programmable timers and serial interface ports in one chip. This paper describes the design of automatic liquid poison addition control system (ALPAS) using intel's 8 bit microcontroller 8751, which is used to generate complex timing control sequence signals for liquid poison addition to the moderator in a nuclear reactor. ALPAS monitors digital inputs coming from protection system and regulating system of a nuclear reactor and provides control signals for liquid poison addition for long term safe shutdown of the reactor after reactor trip and helps the regulating system to reduce the power of the reactor during operation. Special hardware and software features have been incorporated to improve performance and fault detection. (author)

  7. Prediction of Shanghai Index based on Additive Legendre Neural Network

    Directory of Open Access Journals (Sweden)

    Yang Bin

    2017-01-01

    Full Text Available In this paper, a novel Legendre neural network model is proposed, namely additive Legendre neural network (ALNN. A new hybrid evolutionary method besed on binary particle swarm optimization (BPSO algorithm and firefly algorithm is proposed to optimize the structure and parameters of ALNN model. Shanghai stock exchange composite index is used to evaluate the performance of ALNN. Results reveal that ALNN performs better than LNN model.

  8. System and method for high power diode based additive manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    El-Dasher, Bassem S.; Bayramian, Andrew; Demuth, James A.; Farmer, Joseph C.; Torres, Sharon G.

    2018-01-02

    A system is disclosed for performing an Additive Manufacturing (AM) fabrication process on a powdered material forming a substrate. The system may make use of a diode array for generating an optical signal sufficient to melt a powdered material of the substrate. A mask may be used for preventing a first predetermined portion of the optical signal from reaching the substrate, while allowing a second predetermined portion to reach the substrate. At least one processor may be used for controlling an output of the diode array.

  9. System and method for high power diode based additive manufacturing

    Science.gov (United States)

    El-Dasher, Bassem S.; Bayramian, Andrew; Demuth, James A.; Farmer, Joseph C.; Torres, Sharon G.

    2016-04-12

    A system is disclosed for performing an Additive Manufacturing (AM) fabrication process on a powdered material forming a substrate. The system may make use of a diode array for generating an optical signal sufficient to melt a powdered material of the substrate. A mask may be used for preventing a first predetermined portion of the optical signal from reaching the substrate, while allowing a second predetermined portion to reach the substrate. At least one processor may be used for controlling an output of the diode array.

  10. Additivity of Feature-based and Symmetry-based Grouping Effects in Multiple Object Tracking

    Directory of Open Access Journals (Sweden)

    Chundi eWang

    2016-05-01

    Full Text Available Multiple object tracking (MOT is an attentional process wherein people track several moving targets among several distractors. Symmetry, an important indicator of regularity, is a general spatial pattern observed in natural and artificial scenes. According to the laws of perceptual organization proposed by Gestalt psychologists, regularity is a principle of perceptual grouping, such as similarity and closure. A great deal of research reported that feature-based similarity grouping (e.g., grouping based on color, size, or shape among targets in MOT tasks can improve tracking performance. However, no additive feature-based grouping effects have been reported where the tracking objects had two or more features. Additive effect refers to a greater grouping effect produced by grouping based on multiple cues instead of one cue. Can spatial symmetry produce a similar grouping effect similar to that of feature similarity in MOT tasks? Are the grouping effects based on symmetry and feature similarity additive? This study includes four experiments to address these questions. The results of Experiments 1 and 2 demonstrated the automatic symmetry-based grouping effects. More importantly, an additive grouping effect of symmetry and feature similarity was observed in Experiments 3 and 4. Our findings indicate that symmetry can produce an enhanced grouping effect in MOT and facilitate the grouping effect based on color or shape similarity. The where and what pathways might have played an important role in the additive grouping effect.

  11. Moment based model predictive control for systems with additive uncertainty

    NARCIS (Netherlands)

    Saltik, M.B.; Ozkan, L.; Weiland, S.; Ludlage, J.H.A.

    2017-01-01

    In this paper, we present a model predictive control (MPC) strategy based on the moments of the state variables and the cost functional. The statistical properties of the state predictions are calculated through the open loop iteration of dynamics and used in the formulation of MPC cost function. We

  12. Thermal modelling of extrusion based additive manufacturing of composite materials

    DEFF Research Database (Denmark)

    Jensen, Mathias Laustsen; Sonne, Mads Rostgaard; Hattel, Jesper Henri

    One of the hottest topics regarding manufacturing these years is additive manufacturing (AM). AM is a young branch of manufacturing techniques, which by nature is disruptive due to its completely different manufacturing approach, wherein material is added instead of removed. By adding material...... layer by layer, mould and customised tooling requirements from the conventional manufacturing are reduced or removed, which leads to increased customisation options and enables new part complexities without increasing the manufacturing cost. AM hence enables customised small volume productions...... of composite parts not feasible by conventional manufacturing techniques. This sets up new requirements to the part verification and validation, while conventional destructive tests become too expensive. This initial study aims to investigate alternative options to this destructive testing by increasing...

  13. Alternative current source based Schottky contact with additional electric field

    Science.gov (United States)

    Mamedov, R. K.; Aslanova, A. R.

    2017-07-01

    Additional electric field (AEF) in the Schottky contacts (SC) that covered the peripheral contact region wide and the complete contact region narrow (as TMBS diode) SC. Under the influence of AEF is a redistribution of free electrons produced at certain temperatures of the semiconductor, and is formed the space charge region (SCR). As a result of the superposition of the electric fields SCR and AEF occurs the resulting electric field (REF). The REF is distributed along a straight line perpendicular to the contact surface, so that its intensity (and potential) has a minimum value on the metal surface and the maximum value at a great distance from the metal surface deep into the SCR. Under the influence of AEF as a sided force the metal becomes negative pole and semiconductor - positive pole, therefore, SC with AEF becomes an alternative current source (ACS). The Ni-nSi SC with different diameters (20-1000 μm) under the influence of the AEF as sided force have become ACS with electromotive force in the order of 0.1-1.0 mV, which are generated the electric current in the range of 10-9-10-7 A, flowing through the external resistance 1000 Ohm.

  14. TU-H-206-04: An Effective Homomorphic Unsharp Mask Filtering Method to Correct Intensity Inhomogeneity in Daily Treatment MR Images

    International Nuclear Information System (INIS)

    Yang, D; Gach, H; Li, H; Mutic, S

    2016-01-01

    Purpose: The daily treatment MRIs acquired on MR-IGRT systems, like diagnostic MRIs, suffer from intensity inhomogeneity issue, associated with B1 and B0 inhomogeneities. An improved homomorphic unsharp mask (HUM) filtering method, automatic and robust body segmentation, and imaging field-of-view (FOV) detection methods were developed to compute the multiplicative slow-varying correction field and correct the intensity inhomogeneity. The goal is to improve and normalize the voxel intensity so that the images could be processed more accurately by quantitative methods (e.g., segmentation and registration) that require consistent image voxel intensity values. Methods: HUM methods have been widely used for years. A body mask is required, otherwise the body surface in the corrected image would be incorrectly bright due to the sudden intensity transition at the body surface. In this study, we developed an improved HUM-based correction method that includes three main components: 1) Robust body segmentation on the normalized image gradient map, 2) Robust FOV detection (needed for body segmentation) using region growing and morphologic filters, and 3) An effective implementation of HUM using repeated Gaussian convolution. Results: The proposed method was successfully tested on patient images of common anatomical sites (H/N, lung, abdomen and pelvis). Initial qualitative comparisons showed that this improved HUM method outperformed three recently published algorithms (FCM, LEMS, MICO) in both computation speed (by 50+ times) and robustness (in intermediate to severe inhomogeneity situations). Currently implemented in MATLAB, it takes 20 to 25 seconds to process a 3D MRI volume. Conclusion: Compared to more sophisticated MRI inhomogeneity correction algorithms, the improved HUM method is simple and effective. The inhomogeneity correction, body mask, and FOV detection methods developed in this study would be useful as preprocessing tools for many MRI-related research and

  15. POLYMER RESIDUE BASED HYDROPHOBIC-FUNGICIDAL ADDITIVE AND PLASTER DRY MIX BASED ON IT

    Directory of Open Access Journals (Sweden)

    Chikichev Artur Andreevich

    2017-07-01

    Full Text Available Subject of study is the effect of additives on the structure formation of cement. Improvement of the re-sistance to aggressive media of materials for wet rooms. Objective is to develop a scientifically grounded composition of a plaster dry construction mix with increased water resistance and funginertness, with the use of locally available materials and man-made waste.The study was carried out by standard methods of research using XRF and DTA. The hydrophobic fungicidal additive based on the polymer residue of turpentine production and fly ash with the ratio by weight ZU: PO = 1.15: 1 was developed. It has been established that while adding the de-veloped additive in an amount of 2.5 % of the mass of cement, the rate of hydration of cement minerals and resistibility of the sand-cement mortar decrease in early strength with medium workability concrete mix. This creates conditions for the formation of a dense structure with increased resistance to aggressive envi-ronments.Using new hydrophobic fungicidal additive, a dry plaster mortar for wet rooms has been developed. It has increased water resistance values corresponding to the W8 grade and funginertness especially with respect to A. Niger, the pathogen and widespread decomposer.The additive is effective; it is developed on the basis of industrial wastes and recycled materials. Its use in the composition of materials with increased requirements for watertightness and biostability makes it pos-sible to reduce their cost and environmental stress, to increase the efficiency of the use of natural re-sources. The use of the developed plaster mixture will increase the resistance of walls of wet rooms to aggressive environments.

  16. Characterization of Ti and Co based biomaterials processed via laser based additive manufacturing

    Science.gov (United States)

    Sahasrabudhe, Himanshu

    Titanium and Cobalt based metallic materials are currently the most ideal materials for load-bearing metallic bio medical applications. However, the long term tribological degradation of these materials still remains a problem that needs a solution. To improve the tribological performance of these two metallic systems, three different research approaches were adapted, stemming out four different research projects. First, the simplicity of laser gas nitriding was utilized with a modern LENS(TM) technology to form an in situ nitride rich later in titanium substrate material. This nitride rich composite coating improved the hardness by as much as fifteen times and reduced the wear rate by more than a magnitude. The leaching of metallic ions during wear was also reduced by four times. In the second research project, a mixture of titanium and silicon were processed on a titanium substrate in a nitrogen rich environment. The results of this reactive, in situ additive manufacturing process were Ti-Si-Nitride coatings that were harder than the titanium substrate by more than twenty times. These coatings also reduced the wear rate by more than two magnitudes. In the third research approach, composites of CoCrMo alloy and Calcium phosphate (CaP) bio ceramic were processed using LENS(TM) based additive manufacturing. These composites were effective in reducing the wear in the CoCrMo alloy by more than three times as well as reduce the leaching of cobalt and chromium ions during wear. The novel composite materials were found to develop a tribofilm during wear. In the final project, a combination of hard nitride coating and addition of CaP bioceramic was investigated by processing a mixture of Ti6Al4V alloy and CaP in a nitrogen rich environment using the LENS(TM) technology. The resultant Ti64-CaP-Nitride coatings significantly reduced the wear damage on the substrate. There was also a drastic reduction in the metal ions leached during wear. The results indicate that the three

  17. Base Stabilization Guidance and Additive Selection for Pavement Design and Rehabilitation

    Science.gov (United States)

    2017-12-01

    Significant improvements have been made in base stabilization practice that include design specifications and methodology, experience with the selection of stabilizing additives, and equipment for distribution and uniform blending of additives. For t...

  18. Lattice Based Mix Network for Location Privacy in Mobile System

    Directory of Open Access Journals (Sweden)

    Kunwar Singh

    2015-01-01

    Full Text Available In 1981, David Chaum proposed a cryptographic primitive for privacy called mix network (Mixnet. A mixnet is cryptographic construction that establishes anonymous communication channel through a set of servers. In 2004, Golle et al. proposed a new cryptographic primitive called universal reencryption which takes the input as encrypted messages under the public key of the recipients not the public key of the universal mixnet. In Eurocrypt 2010, Gentry, Halevi, and Vaikunthanathan presented a cryptosystem which is an additive homomorphic and a multiplicative homomorphic for only one multiplication. In MIST 2013, Singh et al. presented a lattice based universal reencryption scheme under learning with error (LWE assumption. In this paper, we have improved Singh et al.’s scheme using Fairbrother’s idea. LWE is a lattice hard problem for which till now there is no polynomial time quantum algorithm. Wiangsripanawan et al. proposed a protocol for location privacy in mobile system using universal reencryption whose security is reducible to Decision Diffie-Hellman assumption. Once quantum computer becomes a reality, universal reencryption can be broken in polynomial time by Shor’s algorithm. In postquantum cryptography, our scheme can replace universal reencryption scheme used in Wiangsripanawan et al. scheme for location privacy in mobile system.

  19. Prevalence of Phosphorus-Based Additives in the Australian Food Supply: A Challenge for Dietary Education?

    Science.gov (United States)

    McCutcheon, Jemma; Campbell, Katrina; Ferguson, Maree; Day, Sarah; Rossi, Megan

    2015-09-01

    Phosphorus-based food additives may pose a significant risk in chronic kidney disease given the link between hyperphosphatemia and cardiovascular disease. The objective of the study was to determine the prevalence of phosphorus-based food additives in best-selling processed grocery products and to establish how they were reported on food labels. A data set of 3000 best-selling grocery items in Australia across 15 food and beverage categories was obtained for the 12 months ending December 2013 produced by the Nielsen Company's Homescan database. The nutrition labels of the products were reviewed in store for phosphorus additives. The type of additive, total number of additives, and method of reporting (written out in words or as an E number) were recorded. Presence of phosphorus-based food additives, number of phosphorus-based food additives per product, and the reporting method of additives on product ingredient lists. Phosphorus-based additives were identified in 44% of food and beverages reviewed. Additives were particularly common in the categories of small goods (96%), bakery goods (93%), frozen meals (75%), prepared foods (70%), and biscuits (65%). A total of 19 different phosphorus additives were identified across the reviewed products. From the items containing phosphorus additives, there was a median (minimum-maximum) of 2 (1-7) additives per product. Additives by E number (81%) was the most common method of reporting. Phosphorus-based food additives are common in the Australian food supply. This suggests that prioritizing phosphorus additive education may be an important strategy in the dietary management of hyperphosphatemia. Further research to establish a database of food items containing phosphorus-based additives is warranted. Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  20. Oil base fluids without tensoactive additives; Fluidos a base de oleo sem tensoativos

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Jose Carlos V; Aragao, Atila Fernando L [PETROBRAS, XX (Brazil). Centro de Desenvolvimento de Recursos Humanos Norte e Nordeste

    1990-12-31

    The goal of this paper is to define an ideal oil base fluid composition without tensoactive additives, since these may cause damage to producing formation during drilling or well completion. We investigated the rheological, filtrating and phase separation properties of the systems composed of diesel oil, organophilic clay and a polar agent (water or ethyl alcohol). In order to to that, we used the 286 Baroid digital rotating viscometer, filtrating cells standardized according to the American Petroleum Institute (AP) for temperatures of 25 deg C to 149 deg C and pressures of 6,89 x 10{sup 5} Pa (100 psig) to 3,44 x 10{sup 6} (500 psig), and the setting method, according to the determinations of respectively rheological, filtrating and phase separation parameters. Results proved that the composition: diesel oil-94% v/v, Na Cl saturated solution - 6% v/v and bentone - 17,1 to 22,8 kg/m{sup 3} (6 to 8 lb/bbl), is ideal to meet the properties required for drilling and well completion operations for low densities, that is 0,84% to 1,02 (6,9 to 8,5 ib/gal). In order to obtain densities in the interval of 1,02 to 1,14 (8,5 to 9,5 ib/gal) the system should be condensed with calcite (Ca CO{sub 3}) and the base fluid composition should be : diesel oil-94 to 98% v/v, Na Cl saturated solution - 2 to 6% v/v and bentone 17,1 to 22,8 kg/m{sup 3} (6 to 8 ib/bbl). The average cost per barrel for the systems studied here is of the same order of conventional oil base fluids (with tensoactive additives). (author) 13 refs., 7 figs., 3 tabs.

  1. Oil base fluids without tensoactive additives; Fluidos a base de oleo sem tensoativos

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Jose Carlos V.; Aragao, Atila Fernando L. [PETROBRAS, XX (Brazil). Centro de Desenvolvimento de Recursos Humanos Norte e Nordeste

    1989-12-31

    The goal of this paper is to define an ideal oil base fluid composition without tensoactive additives, since these may cause damage to producing formation during drilling or well completion. We investigated the rheological, filtrating and phase separation properties of the systems composed of diesel oil, organophilic clay and a polar agent (water or ethyl alcohol). In order to to that, we used the 286 Baroid digital rotating viscometer, filtrating cells standardized according to the American Petroleum Institute (AP) for temperatures of 25 deg C to 149 deg C and pressures of 6,89 x 10{sup 5} Pa (100 psig) to 3,44 x 10{sup 6} (500 psig), and the setting method, according to the determinations of respectively rheological, filtrating and phase separation parameters. Results proved that the composition: diesel oil-94% v/v, Na Cl saturated solution - 6% v/v and bentone - 17,1 to 22,8 kg/m{sup 3} (6 to 8 lb/bbl), is ideal to meet the properties required for drilling and well completion operations for low densities, that is 0,84% to 1,02 (6,9 to 8,5 ib/gal). In order to obtain densities in the interval of 1,02 to 1,14 (8,5 to 9,5 ib/gal) the system should be condensed with calcite (Ca CO{sub 3}) and the base fluid composition should be : diesel oil-94 to 98% v/v, Na Cl saturated solution - 2 to 6% v/v and bentone 17,1 to 22,8 kg/m{sup 3} (6 to 8 ib/bbl). The average cost per barrel for the systems studied here is of the same order of conventional oil base fluids (with tensoactive additives). (author) 13 refs., 7 figs., 3 tabs.

  2. 7 CFR 985.153 - Issuance of additional allotment base to new and existing producers.

    Science.gov (United States)

    2010-01-01

    ... made available. (c) Issuance—(1) New producers—(i) Regions: For the purpose of issuing additional... quantities of that class of spearmint oil, shall be eligible to receive a share of the additional allotment... immediately notify each producer who is to receive additional allotment base by issuing that producer an...

  3. On Supra-Additive and Supra-Multiplicative Maps

    OpenAIRE

    Jin Xi Chen; Zi Li Chen

    2013-01-01

    Let A and B be ordered algebras over ℝ, where A has a generating positive cone and B satisfies the property that b2>0 if 0≠b∈B. We give some conditions for a map T:A→B which is supra-additive and supra-multiplicative for all positive and negative elements to be linear and multiplicative; that is, T is a homomorphism of algebras. Our results generalize some known results on supra-additive and supra-multiplicative maps between spaces of real functions.

  4. Influence of metallic based fuel additives on performance and exhaust emissions of diesel engine

    Energy Technology Data Exchange (ETDEWEB)

    Keskin, Ali [Tarsus Technical Education Faculty, Mersin University, 33500 Mersin (Turkey); Guerue, Metin, E-mail: mguru@gazi.edu.t [Engineering and Architectural Faculty, Gazi University, 06570 Maltepe, Ankara (Turkey); Altiparmak, Duran [Technical Education Faculty, Gazi University, 06500 Ankara (Turkey)

    2011-01-15

    In this experimental study, influence of the metallic-based additives on fuel consumption and exhaust emissions of diesel engine were investigated. The metallic-based additives were produced by synthesizing of resin acid (abietic acid) with MnO{sub 2} or MgO. These additives were doped into diesel fuel at the rate of 8 {mu}mol/l and 16 {mu}mol/l for preparing test fuels. Both additives improved the properties of diesel fuel such as viscosity, flash point, cloud point and pour point. The fuels with and without additives were tested in a direct injection diesel engine at full load condition. Maximum reduction of specific fuel consumption was recorded as 4.16%. CO emission and smoke opacity decreased by 16.35% and by 29.82%, respectively. NO{sub x} emission was measured higher and CO{sub 2} emission was not changed considerably with the metallic-based additives.

  5. Boundary lubrication of bearing steel in water-based lubricants with functional additives

    NARCIS (Netherlands)

    Wu, Y.

    2017-01-01

    This thesis focuses on the effect of additives on boundary lubrication of bearing steel for water-based lubrication systems. The oil-in-water (O/W) emulsion and the water-glycol based liquid were selected as the base fluids for research. Sulfur compounds, nitrogen heterocycles and graphene

  6. Impact of Phosphorus-Based Food Additives on Bone and Mineral Metabolism.

    Science.gov (United States)

    Gutiérrez, Orlando M; Luzuriaga-McPherson, Alexandra; Lin, Yiming; Gilbert, Linda C; Ha, Shin-Woo; Beck, George R

    2015-11-01

    Phosphorus-based food additives can substantially increase total phosphorus intake per day, but the effect of these additives on endocrine factors regulating bone and mineral metabolism is unclear. This study aimed to examine the effect of phosphorus additives on markers of bone and mineral metabolism. Design and Setting, and Participants: This was a feeding study of 10 healthy individuals fed a diet providing ∼1000 mg of phosphorus/d using foods known to be free of phosphorus additives for 1 week (low-additive diet), immediately followed by a diet containing identical food items; however, the foods contained phosphorus additives (additive-enhanced diet). Parallel studies were conducted in animals fed low- (0.2%) and high- (1.8%) phosphorus diets for 5 or 15 weeks. The changes in markers of mineral metabolism after each diet period were measured. Participants were 32 ± 8 years old, 30% male, and 70% black. The measured phosphorus content of the additive-enhanced diet was 606 ± 125 mg higher than the low-additive diet (P additive diet, consuming the additive-enhanced diet for 1 week significantly increased circulating fibroblast growth factor 23 (FGF23), osteopontin, and osteocalcin concentrations by 23, 10, and 11%, respectively, and decreased mean sclerostin concentrations (P foods can disturb bone and mineral metabolism in humans. The results of the animal studies suggest that this may compromise bone health.

  7. Efficiency enhancement of CIGS compound solar cell fabricated using homomorphic thin Cr{sub 2}O{sub 3} diffusion barrier formed on stainless steel substrate

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Jae-Kwan; Lee, Seung-Kyu; Kim, Jin-Soo; Jeong, Kwang-Un; Ahn, Haeng-Keun; Lee, Cheul-Ro, E-mail: crlee7@jbnu.ac.kr

    2016-12-15

    Highlights: • A chromium oxide layer is formed as diffusion barrier by thermal oxidation process on STS substrate. • A Cr{sub 2}O{sub 3} layer effectively reduces impurities diffusion into the CIGS absorber layer. • The Cr{sub 2}O{sub 3} layer plays an important role in increasing the efficiency by reduction of impurity diffusion. - Abstract: It is known that the efficiency of flexible Cu(In,Ga)Se{sub 2} (CIGS) solar cells fabricated on stainless-steel (STS) substrates deteriorates due to iron (Fe) and Cr impurities diffusing into the CIGS absorber layer. To overcome this problem, a nanoscale homomorphic chromium oxide layer was formed as a diffusion barrier by thermal oxidation on the surface of STS substrates for 1 min at 600 °C in oxygen atmosphere. By TEM and grazing-incidence X-ray diffraction (GIXRD), it was confirmed that the formed oxide layer on surface of STS substrates was a Cr{sub 2}O{sub 3} layer. It was found that the formed homomorphic Cr{sub 2}O{sub 3} thin layer of about 15 nm thickness was an effective diffusion barrier to reduce impurity diffusion into the CIGS layer by secondary ion mass spectroscopy (SIMS). In contrast to the efficiency of CIGS solar cell without homomorphic Cr{sub 2}O{sub 3} diffusion layer is 8.6%, whereas with diffusion barrier it increases to 10.6% because of impurities such as Fe and Cr from the STS substrate into the CIGS layer. It reveals that the layer formed on the surface of STS substrate by thermal oxidation process plays an important role in increasing the performance of CIGS solar cells.

  8. 20 CFR 10.116 - What additional evidence is needed in cases based on occupational disease?

    Science.gov (United States)

    2010-04-01

    ... based on occupational disease? 10.116 Section 10.116 Employees' Benefits OFFICE OF WORKERS' COMPENSATION... of Proof § 10.116 What additional evidence is needed in cases based on occupational disease? (a) The... occupational diseases. The medical report should also include the information specified on the checklist for...

  9. 78 FR 35115 - Listing of Color Additives Exempt From Certification; Mica-Based Pearlescent Pigments

    Science.gov (United States)

    2013-06-12

    ... (EDI) of the additive from all sources for both the mean and high- intake consumer to an acceptable daily intake (ADI) level established by toxicological data. The EDI is determined by projections based... the issuance of Sec. 73.350 we calculated a cumulative EDI (CEDI) for the use of mica-based...

  10. 26 CFR 54.9802-3T - Additional requirements prohibiting discrimination based on genetic information (temporary).

    Science.gov (United States)

    2010-04-01

    ... assembles the data requested by M and, although N reviews it to delete genetic information, the data from a... discrimination based on genetic information (temporary). 54.9802-3T Section 54.9802-3T Internal Revenue INTERNAL... EXCISE TAXES § 54.9802-3T Additional requirements prohibiting discrimination based on genetic information...

  11. Improvement of acid and base resistance of nickel phosphate pigment by the addition of lanthanum cation

    International Nuclear Information System (INIS)

    Onoda, Hiroaki; Matsui, Hironori; Tanaka, Isao

    2007-01-01

    Transition metal phosphates are used as inorganic pigments, however these materials had a weak point for acid and base resistance. Because lanthanum phosphate is insoluble in acidic and basic solution, the addition of lanthanum cation was tried for the improvement of the acid and base resistance of nickel phosphate pigment. The lanthanum-doped nickel phosphates were prepared from phosphoric acid, nickel nitrate, and lanthanum nitrate solution. The additional effects of lanthanum cation were studied on the chemical composition, particle shape and size distribution, specific surface area, color, acid and base resistance of the precipitations and their thermal products

  12. Mechanical Properties Analysis Of Composite Magnetic Base On hexa ferrite And Polyester Or Epoxy Matrix With Silane Additive Addition

    International Nuclear Information System (INIS)

    Sudirman; Ridwan; Mujamilah; K K, Aloma; Rembulan, Marisa; Fitriyanti

    2003-01-01

    Application of composite magnetic especially hexa ferrite magnet for industry and home industry in Indonesia has been used. Research purposes were making composite magnetic by mixing hexa ferrite powder with polyester or epoxy and studying the effect of coupling agent 3-aminopropyltriethoxysilane (3-APE) addition on mechanical properties of composite magnetic. The coupling agent may increase bonding properties between magnetic powder and matrix polymer, so that tensile strength of magnetic composite will increase without decreasing the magnetic properties. Magnetic powder (SrM or BaM) wich be coated by coupling agent were added to matrix polyester and mekpo or epoxy and versamid, mixed until homogen then pressing into to the dumbbell form molding. For epoxy matrix, pressing was done in hot press at 70 deg. C and 150 kg/cm 2 following by cooling in cold press, while for polyester matrix pressing was done in hydraulic press and following by curing at 70 deg. C in an oven for 1 hour. The composition of magnetic powder were varied to 30, 40 and 50% volume fraction and coupling agent were varied to 5, 10 and 15 ml for every volume fraction. The result showed that 10 ml added of coupling agent was give best mechanical properties both polyester and epoxy matrix. However generally, increasing of magnetic powder content decreased the tensile strength of magnetic composite. The properties of magnetic composite SrM was better than BaM either in polyester or epoxy matrix

  13. Additive effect of BPA and Gd-DTPA for application in accelerator-based neutron source

    International Nuclear Information System (INIS)

    Yoshida, F.; Yamamoto, T.; Nakai, K.; Zaboronok, A.; Matsumura, A.

    2015-01-01

    Because of its fast metabolism gadolinium as a commercial drug was not considered to be suitable for neutron capture therapy. We studied additive effect of gadolinium and boron co-administration using colony forming assay. As a result, the survival of tumor cells with additional 5 ppm of Gd-DTPA decreased to 1/10 compared to the cells with boron only. Using gadolinium to increase the effect of BNCT instead of additional X-ray irradiation might be beneficial, as such combination complies with the short-time irradiation regimen at the accelerator-based neutron source. - Highlights: • Gd-DTPA is widely clinically used as a contrast medium for MRI. • Shift to an accelerator-based neutron source is advantageous for gadolinium NCT. • Boron–gadolinium NCT effects on tumor cell lines were significant. • Additional administration of Gd-DTPA might enhance the effect of BPA–BNCT.

  14. Wood lens design philosophy based on a binary additive manufacturing technique

    Science.gov (United States)

    Marasco, Peter L.; Bailey, Christopher

    2016-04-01

    Using additive manufacturing techniques in optical engineering to construct a gradient index (GRIN) optic may overcome a number of limitations of GRIN technology. Such techniques are maturing quickly, yielding additional design degrees of freedom for the engineer. How best to employ these degrees of freedom is not completely clear at this time. This paper describes a preliminary design philosophy, including assumptions, pertaining to a particular printing technique for GRIN optics. It includes an analysis based on simulation and initial component measurement.

  15. An Overview of Ni Base Additive Fabrication Technologies for Aerospace Applications (Preprint)

    Science.gov (United States)

    2011-03-01

    fusion welding processes that have the ability to add filler material can be used as additive manufacturing processes . The majority of the work in the...Laser Additive Manufacturing (LAM) The LAM process uses a conventional laser welding heat source (CO2 or solid state laser) combined with a...wrought properties. The LAM process typically has a lower deposition rate (0.5 – 10 lbs/hr) compared to EB, PTA or TIG based processes , although as

  16. [Analysis of constituents of ester-type gum bases used as natural food additives].

    Science.gov (United States)

    Tada, Atsuko; Masuda, Aino; Sugimoto, Naoki; Yamagata, Kazuo; Yamazaki, Takeshi; Tanamoto, Kenichi

    2007-12-01

    The differences in the constituents of ten ester-type gum bases used as natural food additives in Japan (urushi wax, carnauba wax, candelilla wax, rice bran wax, shellac wax, jojoba wax, bees wax, Japan wax, montan wax, and lanolin) were investigated. Several kinds of gum bases showed characteristic TLC patterns of lipids. In addition, compositions of fatty acid and alcohol moieties of esters in the gum bases were analyzed by GC/MS after methanolysis and hydrolysis, respectively. The results indicated that the varieties of fatty acids and alcohols and their compositions were characteristic for each gum base. These results will be useful for identification and discrimination of the ester-type gum bases.

  17. Boundary lubrication of stainless steel and CoCrMo alloy materials based on three ester-based additives

    NARCIS (Netherlands)

    Yan, J.; Zeng, Xiangqiong; Ren, T.; van der Heide, Emile

    2014-01-01

    Material selection and lubricant additive development are two important aspects for engineering applications. This work explores the possibilities of three different ester-based additives (DBOP, ODOC and DOB) to generate boundary films on two corrosion and wear resistant materials, stainless steel

  18. Evaluation of some vanillin-modified polyoxyethylene surfactants as additives for water based mud

    Directory of Open Access Journals (Sweden)

    M.M.A. El-Sukkary

    2014-03-01

    Full Text Available Water-based drilling fluids are increasingly being used for oil and gas exploration and are generally considered to be more environmentally acceptable than oil-based or synthetic-based fluids. In this study, new types of vanillin-modified polyoxyethylene surfactants were evaluated as additives in water-based mud. Their rheological properties in water-based mud were investigated which included the apparent viscosity, the plastic viscosity, the yield point, the gel strength, the thixotropy as well as the filtration properties. Also, the effect of high temperature on the rheology of the formulated water based mud was studied. The tested ethoxylated non-ionic surfactants showed good results when utilized in the formulation of water-based mud.

  19. Biocompatibility of hydroxyapatite scaffolds processed by lithography-based additive manufacturing.

    Science.gov (United States)

    Tesavibul, Passakorn; Chantaweroad, Surapol; Laohaprapanon, Apinya; Channasanon, Somruethai; Uppanan, Paweena; Tanodekaew, Siriporn; Chalermkarnnon, Prasert; Sitthiseripratip, Kriskrai

    2015-01-01

    The fabrication of hydroxyapatite scaffolds for bone tissue engineering applications by using lithography-based additive manufacturing techniques has been introduced due to the abilities to control porous structures with suitable resolutions. In this research, the use of hydroxyapatite cellular structures, which are processed by lithography-based additive manufacturing machine, as a bone tissue engineering scaffold was investigated. The utilization of digital light processing system for additive manufacturing machine in laboratory scale was performed in order to fabricate the hydroxyapatite scaffold, of which biocompatibilities were eventually evaluated by direct contact and cell-culturing tests. In addition, the density and compressive strength of the scaffolds were also characterized. The results show that the hydroxyapatite scaffold at 77% of porosity with 91% of theoretical density and 0.36 MPa of the compressive strength are able to be processed. In comparison with a conventionally sintered hydroxyapatite, the scaffold did not present any cytotoxic signs while the viability of cells at 95.1% was reported. After 14 days of cell-culturing tests, the scaffold was able to be attached by pre-osteoblasts (MC3T3-E1) leading to cell proliferation and differentiation. The hydroxyapatite scaffold for bone tissue engineering was able to be processed by the lithography-based additive manufacturing machine while the biocompatibilities were also confirmed.

  20. Numerical modeling of the strand deposition flow in extrusion-based additive manufacturing

    DEFF Research Database (Denmark)

    Comminal, Raphaël; Serdeczny, Marcin P.; Pedersen, David B.

    2018-01-01

    -based additive manufacturing, as well as the surface roughness of the fabricated part. Under the assumptions of an isothermal Newtonian fluid and a creeping laminar flow, the deposition flow is controlled by two parameters: the gap distance between the extrusion nozzle and the substrate, and the velocity ratio...

  1. DNA-based catalytic enantioselective intermolecular oxa-Michael addition reactions

    NARCIS (Netherlands)

    Megens, Rik P.; Roelfes, Gerard

    2012-01-01

    Using the DNA-based catalysis concept, a novel Cu(II) catalyzed enantioselective oxa-Michael addition of alcohols to enones is reported. Enantioselectivities of up to 86% were obtained. The presence of water is important for the reactivity, possibly by reverting unwanted side reactions such as

  2. Vocational High School Students’ Creativity in Food Additives with Problem Based Learning Approach

    Science.gov (United States)

    Ratnasari, D.; Supriyanti, T.; Rosbiono, M.

    2017-09-01

    The aim of this study is to verify the creativity of vocational students through Problem Based Learning approach in the food additives. The method which used quasi-experiment with one group posttest design. The research subjects were 32 students in grade XII of a vocational high school students courses chemical analysis in Bandung city. Instrument of creativity were essay, Student Worksheet, and observation sheets. Creativity measured include creative thinking skills and creative act skills. The results showed creative thinking skills and creative act skills are good. Research showed that the problem based learning approach can be applied to develop creativity of vocational students in the food additives well, because the students are given the opportunity to determine their own experiment procedure that will be used. It is recommended to often implement Problem Based Learning approach in other chemical concepts so that students’ creativity is sustainable.

  3. The prediction of food additives in the fruit juice based on electronic nose with chemometrics.

    Science.gov (United States)

    Qiu, Shanshan; Wang, Jun

    2017-09-01

    Food additives are added to products to enhance their taste, and preserve flavor or appearance. While their use should be restricted to achieve a technological benefit, the contents of food additives should be also strictly controlled. In this study, E-nose was applied as an alternative to traditional monitoring technologies for determining two food additives, namely benzoic acid and chitosan. For quantitative monitoring, support vector machine (SVM), random forest (RF), extreme learning machine (ELM) and partial least squares regression (PLSR) were applied to establish regression models between E-nose signals and the amount of food additives in fruit juices. The monitoring models based on ELM and RF reached higher correlation coefficients (R 2 s) and lower root mean square errors (RMSEs) than models based on PLSR and SVM. This work indicates that E-nose combined with RF or ELM can be a cost-effective, easy-to-build and rapid detection system for food additive monitoring. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Improvement of stress-rupture property by Cr addition in Ni-based single crystal superalloys

    International Nuclear Information System (INIS)

    Chen, J.Y.; Feng, Q.; Cao, L.M.; Sun, Z.Q.

    2011-01-01

    Research highlights: → Cr improved the stress-rupture life of single crystal superalloys significantly. → Cr increased the Re partitioning ratio and resulted in more negative misfit. → Mechanism for improving the stress-rupture life by Cr addition is addressed here. - Abstract: The effects of Cr addition on the microstructure and stress-rupture property have been investigated in three experimental Ni-based single crystal superalloys containing various levels of Cr addition (0-5.7 wt.%). The Re partitioning ratio increased and the lattice misfit became more negative with increasing the Cr addition in both dendrite core and interdendritic region. The changes of elemental partitioning behaviors and the lattice misfit show good agreement with the change of γ' morphology. Cr addition increased the stress-rupture life at 1100 deg. C/140 MPa significantly due to higher γ' volume fraction, more negative lattice misfit and a well rafting structure as well as less width of γ channels. High Cr addition (5.7 wt.%) increased the degree of Re and Cr supersaturation in the γ phase and promoted the formation of topologically close-packed (TCP) phases significantly under thermal exposure and creep deformation at 1100 deg. C.

  5. Choline chloride-based deep eutectic solvents as additives for optimizing chromatographic behavior of caffeic acid

    International Nuclear Information System (INIS)

    Li, Guizhen; Zhu, Tao; Lei, Yingjie

    2015-01-01

    A series of deep eutectic solvents (DESs) were prepared using glycerol and choline chloride (ChCl), and Fourier transform infrared spectrometer (FT-IR) was used to analyze the spectra of glycerol, choline chloride and DESs based on glycerol and choline chloride. Then DESs were used as the additives of mobile phase to optimize chromatographic behavior of caffeic acid in high performance liquid chromatography (HPLC). A 17-run Box-Behnken design (BBD) was employed to evaluate effect of DESs as additives by analyzing the maximum theoretical plate number. Three factors, reaction temperature (60 .deg. C, 80 .deg. C, 100 .deg. C), molar ratio of glycerol and choline chloride (2 : 1, 3 : 1, 4 : 1, n/n), and volume percent of additives (0.05%, 0.10%, 0.15%, v/v), were investigated in BBD. The optimum experiment condition was that of reaction temperature (80 .deg. C), molar ratio of glycerol and ChCl (3 : 1, n/n), and volume percent of additive (0.10%, v/v). The mean chromatographic theoretical plate number of the caffeic acid this condition was 1567.5, and DESs as additives shorten the retention time and modify the chromatogram shape, proving DESs as additives for effective theoretical plate number and column efficiency in HPLC.

  6. Choline chloride-based deep eutectic solvents as additives for optimizing chromatographic behavior of caffeic acid

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guizhen; Zhu, Tao; Lei, Yingjie [Tianjin University of Technology, Tianjin (China)

    2015-10-15

    A series of deep eutectic solvents (DESs) were prepared using glycerol and choline chloride (ChCl), and Fourier transform infrared spectrometer (FT-IR) was used to analyze the spectra of glycerol, choline chloride and DESs based on glycerol and choline chloride. Then DESs were used as the additives of mobile phase to optimize chromatographic behavior of caffeic acid in high performance liquid chromatography (HPLC). A 17-run Box-Behnken design (BBD) was employed to evaluate effect of DESs as additives by analyzing the maximum theoretical plate number. Three factors, reaction temperature (60 .deg. C, 80 .deg. C, 100 .deg. C), molar ratio of glycerol and choline chloride (2 : 1, 3 : 1, 4 : 1, n/n), and volume percent of additives (0.05%, 0.10%, 0.15%, v/v), were investigated in BBD. The optimum experiment condition was that of reaction temperature (80 .deg. C), molar ratio of glycerol and ChCl (3 : 1, n/n), and volume percent of additive (0.10%, v/v). The mean chromatographic theoretical plate number of the caffeic acid this condition was 1567.5, and DESs as additives shorten the retention time and modify the chromatogram shape, proving DESs as additives for effective theoretical plate number and column efficiency in HPLC.

  7. K-capture by Al-Si based Additives in an Entrained Flow Reactor

    DEFF Research Database (Denmark)

    Wang, Guoliang; Jensen, Peter Arendt; Wu, Hao

    2016-01-01

    A water slurry, consisting of KCl and Al-Si based additives (kaolin and coal fly ash) was fed into an entrained flow reactor (EFR) to study the K-capturing reaction of the additives at suspension-fired conditions. Solid products collected from the reactor were analysed with respect to total...... of KCl to K-aluminosilicate decreased. When reaction temperature increased from 1100 °C to 1450 °C, the conversion of KCl does not change significantly, which differs from the trend observed in fixed-bed reactor....

  8. Imidazolium-based ionic liquids used as additives in the nanolubrication of silicon surfaces

    Directory of Open Access Journals (Sweden)

    Patrícia M. Amorim

    2017-09-01

    Full Text Available In recent years, with the development of micro/nanoelectromechanical systems (MEMS/NEMS, the demand for efficient lubricants of silicon surfaces intensified. Although the use of ionic liquids (ILs as additives to base oils in the lubrication of steel/steel or other types of metal/ metal tribological pairs has been investigated, the number of studies involving Si is very low. In this work, we tested imidazolium-based ILs as additives to the base oil polyethylene glycol (PEG to lubricate Si surfaces. The friction coefficients were measured in a nanotribometer. The viscosity of the PEG + IL mixtures as well as their contact angles on the Si surface were measured. The topography and chemical composition of the substrates surfaces were determined with atomic force microscopy (AFM and X-ray photoelectron spectroscopy (XPS, respectively. Due to the hygroscopic properties of PEG, the first step was to assess the effect of the presence of water. Then, a series of ILs based on the cations 1-ethyl-3-methylimidazolium [EMIM], 1-butyl-3-methylimidazolium [BMIM], 1-ethyl-3-vinylimidazolium [EVIM], 1-(2-hydroxyethyl-3-methylimidazolium [C2OHMIM] and 1-allyl-3-methylimidazolium [AMIM] combined with the anions dicyanamide [DCA], trifluoromethanesulfonate [TfO], and ethylsulfate [EtSO4] were added to dry PEG. All additives (2 wt % led to a decrease in friction coefficient as well as an increase in viscosity (with the exception of [AMIM][TfO] and improved the Si wettability. The additives based on the anion [EtSO4] exhibited the most promising tribological behavior, which was attributed to the strong interaction with the Si surface ensuring the formation of a stable surface layer, which hinders the contact between the sliding surfaces.

  9. Dendritic microstructure and hot cracking of laser additive manufactured Inconel 718 under improved base cooling

    International Nuclear Information System (INIS)

    Chen, Yuan; Lu, Fenggui; Zhang, Ke; Nie, Pulin; Elmi Hosseini, Seyed Reza; Feng, Kai; Li, Zhuguo

    2016-01-01

    The base cooling effect was improved by imposing the continuous water flow on the back of the substrate during the laser additive manufacturing of Inconel 718 (IN718). The dendritic microstructure, crystal orientation and hot cracking behavior were studied by using optical microscopy (OM), scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) techniques. The results showed that the crystal orientation was increased by increasing the base cooling effect during the deposition. Also, highly ordered columnar dendrites were established, and mono-crystalline texture was constructed in the final clad. It was fund that the effect of solidification cracking on the properties of final clad was negligible since it was only generated at the top region of the deposit, while liquation cracking was produced and remained in the heat affected zone (HAZ) and needed to be carefully controlled. The susceptibility to the liquation cracking showed a high dependence on the grain boundary misorientation, which was considered to be attributed to the stability of interdendritic liquation films, as well as the magnitude of local stress concentration in the last stage of solidification. - Highlights: • The base cooling effect was increased during laser additive manufacturing. • Highly ordered dendrites were established under improved base cooling. • The crystal orientation was increased by improving the base cooling effect. • Liquation cracking tendency was reduced due to the increase of base cooling. • Liquation cracking increased with the increase of grain boundary misorientation.

  10. Dendritic microstructure and hot cracking of laser additive manufactured Inconel 718 under improved base cooling

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yuan; Lu, Fenggui; Zhang, Ke; Nie, Pulin; Elmi Hosseini, Seyed Reza; Feng, Kai, E-mail: fengkai@sjtu.edu.cn; Li, Zhuguo, E-mail: lizg@sjtu.edu.cn

    2016-06-15

    The base cooling effect was improved by imposing the continuous water flow on the back of the substrate during the laser additive manufacturing of Inconel 718 (IN718). The dendritic microstructure, crystal orientation and hot cracking behavior were studied by using optical microscopy (OM), scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) techniques. The results showed that the crystal orientation was increased by increasing the base cooling effect during the deposition. Also, highly ordered columnar dendrites were established, and mono-crystalline texture was constructed in the final clad. It was fund that the effect of solidification cracking on the properties of final clad was negligible since it was only generated at the top region of the deposit, while liquation cracking was produced and remained in the heat affected zone (HAZ) and needed to be carefully controlled. The susceptibility to the liquation cracking showed a high dependence on the grain boundary misorientation, which was considered to be attributed to the stability of interdendritic liquation films, as well as the magnitude of local stress concentration in the last stage of solidification. - Highlights: • The base cooling effect was increased during laser additive manufacturing. • Highly ordered dendrites were established under improved base cooling. • The crystal orientation was increased by improving the base cooling effect. • Liquation cracking tendency was reduced due to the increase of base cooling. • Liquation cracking increased with the increase of grain boundary misorientation.

  11. Effects of waste glass additions on quality of textile sludge-based bricks.

    Science.gov (United States)

    Rahman, Ari; Urabe, Takeo; Kishimoto, Naoyuki; Mizuhara, Shinji

    2015-01-01

    This research investigated the utilization of textile sludge as a substitute for clay in brick production. The addition of textile sludge to a brick specimen enhanced its pores, thus reducing the quality of the product. However, the addition of waste glass to brick production materials improved the quality of the brick in terms of both compressive strength and water absorption. Maximum compressive strength was observed with the following composition of waste materials: 30% textile sludge, 60% clay and 10% waste glass. The melting of waste glass clogged up pores on the brick, which improved water absorption performance and compressive strength. Moreover, a leaching test on a sludge-based brick to which 10% waste glass did not detect significant heavy metal compounds in leachates, with the product being in conformance with standard regulations. The recycling of textile sludge for brick production, when combined with waste glass additions, may thus be promising in terms of both product quality and environmental aspects.

  12. Mechanical properties of Fe3Al-based alloys with addition of carbon, niobium and titanium

    International Nuclear Information System (INIS)

    Zhang Zhengrong; Liu Wenxi

    2006-01-01

    Several Fe 3 Al-based iron aluminides with the addition of alloying elements carbon, niobium and titanium were produced by vacuum induction melting (VIM) and hot spinning forging. Analytic techniques including transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used in studying the microstructure and fracture manner of these alloys. The results show that due to the addition of alloying elements, the superlattice dislocations tend towards multiple slipping, leaving behind on their slip plane ribbons of square-shaped slip-induced antiphase boundaries. The elongation of Fe 3 Al in tension at room temperature increased to about 10% by the addition of suitable alloying elements, the usage of thermo-mechanical processing that has the function of refining grains and substructures, and subsequent annealing

  13. Role of samarium additions on the shape memory behavior of iron based alloys

    International Nuclear Information System (INIS)

    Shakoor, R.A.; Khalid, F. Ahmad; Kang, Kisuk

    2011-01-01

    Research highlights: → The effect of samarium contents on shape memory behavior has been studied. → Addition of samarium increases the strength, c/a ratio and ε (hcp martensite). → Addition of samarium retards the nucleation of α (bcc martensite). → Improvement in shape memory effect with the increase in samarium contents. - Abstract: The effect of samarium contents on shape memory behavior of iron based shape memory alloys has been studied. It is found that the strength of the alloys increases with the increase in samarium contents. This effect can be attributed to the solid solution strengthening of austenite by samarium addition. It is also noticed that the shape memory effect increases with the increase in samarium contents. This improvement in shape memory effect presumably can be regarded as the effect of improvement in strength, increase in c/a ratio and obstruction of nucleation of α in the microstructure.

  14. Enhancing Surface Finish of Additively Manufactured Titanium and Cobalt Chrome Elements Using Laser Based Finishing

    Science.gov (United States)

    Gora, Wojciech S.; Tian, Yingtao; Cabo, Aldara Pan; Ardron, Marcus; Maier, Robert R. J.; Prangnell, Philip; Weston, Nicholas J.; Hand, Duncan P.

    Additive manufacturing (AM) offers the possibility of creating a complex free form object as a single element, which is not possible using traditional mechanical machining. Unfortunately the typically rough surface finish of additively manufactured parts is unsuitable for many applications. As a result AM parts must be post-processed; typically mechanically machined and/or and polished using either chemical or mechanical techniques (both of which have their limitations). Laser based polishing is based on remelting of a very thin surface layer and it offers potential as a highly repeatable, higher speed process capable of selective area polishing, and without any waste problems (no abrasives or liquids). In this paper an in-depth investigation of CW laser polishing of titanium and cobalt chrome AM elements is presented. The impact of different scanning strategies, laser parameters and initial surface condition on the achieved surface finish is evaluated.

  15. TSKT-ORAM: A Two-Server k-ary Tree Oblivious RAM without Homomorphic Encryption

    Directory of Open Access Journals (Sweden)

    Jinsheng Zhang

    2017-09-01

    Full Text Available This paper proposes TSKT-oblivious RAM (ORAM, an efficient multi-server ORAM construction, to protect a client’s access pattern to outsourced data. TSKT-ORAM organizes each of the server storages as a k-ary tree and adopts XOR-based private information retrieval (PIR and a novel delayed eviction technique to optimize both the data query and data eviction process. TSKT-ORAM is proven to protect the data access pattern privacy with a failure probability of 2 - 80 when system parameter k ≥ 128 . Meanwhile, given a constant-size local storage, when N (i.e., the total number of outsourced data blocks ranges from 2 16 – 2 34 , the communication cost of TSKT-ORAM is only 22–46 data blocks. Asymptotic analysis and practical comparisons are conducted to show that TSKT-ORAM incurs lower communication cost, storage cost and access delay in practical scenarios than the compared state-of-the-art ORAM schemes.

  16. The development of additive manufacturing technique for nickel-base alloys: A review

    Science.gov (United States)

    Zadi-Maad, Ahmad; Basuki, Arif

    2018-04-01

    Nickel-base alloys are an attractive alloy due to its excellent mechanical properties, a high resistance to creep deformation, corrosion, and oxidation. However, it is a hard task to control performance when casting or forging for this material. In recent years, additive manufacturing (AM) process has been implemented to replace the conventional directional solidification process for the production of nickel-base alloys. Due to its potentially lower cost and flexibility manufacturing process, AM is considered as a substitute technique for the existing. This paper provides a comprehensive review of the previous work related to the AM techniques for Ni-base alloys while highlighting current challenges and methods to solving them. The properties of conventionally manufactured Ni-base alloys are also compared with the AM fabricated alloys. The mechanical properties obtained from tension, hardness and fatigue test are included, along with discussions of the effect of post-treatment process. Recommendations for further work are also provided.

  17. Divergent Evolutionary Trajectories of Two Young, Homomorphic, and Closely Related Sex Chromosome Systems

    Science.gov (United States)

    Furman, Benjamin L S; Evans, Ben J

    2018-01-01

    Abstract There exists extraordinary variation among species in the degree and nature of sex chromosome divergence. However, much of our knowledge about sex chromosomes is based on comparisons between deeply diverged species with different ancestral sex chromosomes, making it difficult to establish how fast and why sex chromosomes acquire variable levels of divergence. To address this problem, we studied sex chromosome evolution in two species of African clawed frog (Xenopus), both of whom acquired novel systems for sex determination from a recent common ancestor, and both of whom have female (ZW/ZZ) heterogamy. Derived sex chromosomes of one species, X. laevis, have a small region of suppressed recombination that surrounds the sex determining locus, and have remained this way for millions of years. In the other species, X. borealis, a younger sex chromosome system exists on a different pair of chromosomes, but the region of suppressed recombination surrounding an unidentified sex determining gene is vast, spanning almost half of the sex chromosomes. Differences between these sex chromosome systems are also apparent in the extent of nucleotide divergence between the sex chromosomes carried by females. Our analyses also indicate that in autosomes of both of these species, recombination during oogenesis occurs more frequently and in different genomic locations than during spermatogenesis. These results demonstrate that new sex chromosomes can assume radically different evolutionary trajectories, with far-reaching genomic consequences. They also suggest that in some instances the origin of new triggers for sex determination may be coupled with rapid evolution sex chromosomes, including recombination suppression of large genomic regions. PMID:29608717

  18. Formulation and Testing of Paraffin-Based Solid Fuels Containing Energetic Additives for Hybrid Rockets

    Science.gov (United States)

    Larson, Daniel B.; Boyer, Eric; Wachs,Trevor; Kuo, Kenneth K.; Story, George

    2012-01-01

    Many approaches have been considered in an effort to improve the regression rate of solid fuels for hybrid rocket applications. One promising method is to use a fuel with a fast burning rate such as paraffin wax; however, additional performance increases to the fuel regression rate are necessary to make the fuel a viable candidate to replace current launch propulsion systems. The addition of energetic and/or nano-sized particles is one way to increase mass-burning rates of the solid fuels and increase the overall performance of the hybrid rocket motor.1,2 Several paraffin-based fuel grains with various energetic additives (e.g., lithium aluminum hydride (LiAlH4) have been cast in an attempt to improve regression rates. There are two major advantages to introducing LiAlH4 additive into the solid fuel matrix: 1) the increased characteristic velocity, 2) decreased dependency of Isp on oxidizer-to-fuel ratio. The testing and characterization of these solid-fuel grains have shown that continued work is necessary to eliminate unburned/unreacted fuel in downstream sections of the test apparatus.3 Changes to the fuel matrix include higher melting point wax and smaller energetic additive particles. The reduction in particle size through various methods can result in more homogeneous grain structure. The higher melting point wax can serve to reduce the melt-layer thickness, allowing the LiAlH4 particles to react closer to the burning surface, thus increasing the heat feedback rate and fuel regression rate. In addition to the formulation of LiAlH4 and paraffin wax solid-fuel grains, liquid additives of triethylaluminum and diisobutylaluminum hydride will be included in this study. Another promising fuel formulation consideration is to incorporate a small percentage of RDX as an additive to paraffin. A novel casting technique will be used by dissolving RDX in a solvent to crystallize the energetic additive. After dissolving the RDX in a solvent chosen for its compatibility

  19. Effect of conductive additives to gel electrolytes on activated carbon-based supercapacitors

    Science.gov (United States)

    Barzegar, Farshad; Dangbegnon, Julien K.; Bello, Abdulhakeem; Momodu, Damilola Y.; Johnson, A. T. Charlie; Manyala, Ncholu

    2015-09-01

    This article is focused on polymer based gel electrolyte due to the fact that polymers are cheap and can be used to achieve extended potential window for improved energy density of the supercapacitor devices when compared to aqueous electrolytes. Electrochemical characterization of a symmetric supercapacitor devices based on activated carbon in different polyvinyl alcohol (PVA) based gel electrolytes was carried out. The device exhibited a maximum energy density of 24 Wh kg-1 when carbon black was added to the gel electrolyte as conductive additive. The good energy density was correlated with the improved conductivity of the electrolyte medium which is favorable for fast ion transport in this relatively viscous environment. Most importantly, the device remained stable with no capacitance lost after 10,000 cycles.

  20. Effect of conductive additives to gel electrolytes on activated carbon-based supercapacitors

    Directory of Open Access Journals (Sweden)

    Farshad Barzegar

    2015-09-01

    Full Text Available This article is focused on polymer based gel electrolyte due to the fact that polymers are cheap and can be used to achieve extended potential window for improved energy density of the supercapacitor devices when compared to aqueous electrolytes. Electrochemical characterization of a symmetric supercapacitor devices based on activated carbon in different polyvinyl alcohol (PVA based gel electrolytes was carried out. The device exhibited a maximum energy density of 24 Wh kg−1 when carbon black was added to the gel electrolyte as conductive additive. The good energy density was correlated with the improved conductivity of the electrolyte medium which is favorable for fast ion transport in this relatively viscous environment. Most importantly, the device remained stable with no capacitance lost after 10,000 cycles.

  1. Robot-based additive manufacturing for flexible die-modelling in incremental sheet forming

    Science.gov (United States)

    Rieger, Michael; Störkle, Denis Daniel; Thyssen, Lars; Kuhlenkötter, Bernd

    2017-10-01

    The paper describes the application concept of additive manufactured dies to support the robot-based incremental sheet metal forming process (`Roboforming') for the production of sheet metal components in small batch sizes. Compared to the dieless kinematic-based generation of a shape by means of two cooperating industrial robots, the supporting robot models a die on the back of the metal sheet by using the robot-based fused layer manufacturing process (FLM). This tool chain is software-defined and preserves the high geometrical form flexibility of Roboforming while flexibly generating support structures adapted to the final part's geometry. Test series serve to confirm the feasibility of the concept by investigating the process challenges of the adhesion to the sheet surface and the general stability as well as the influence on the geometric accuracy compared to the well-known forming strategies.

  2. The influence of Pb addition on the properties of fly ash-based geopolymers.

    Science.gov (United States)

    Nikolić, Violeta; Komljenović, Miroslav; Džunuzović, Nataša; Miladinović, Zoran

    2018-05-15

    Preventing or reducing negative effects on the environment from the waste landfilling is the main goal defined by the European Landfill Directive. Generally geopolymers can be considered as sustainable binders for immobilization of hazardous wastes containing different toxic elements. In this paper the influence of addition of high amount of lead on structure, strength, and leaching behavior (the effectiveness of Pb immobilization) of fly ash-based geopolymers depending on the geopolymer curing conditions was investigated. Lead was added during the synthesis of geopolymers in the form of highly soluble salt - lead-nitrate. Structural changes of geopolymers as a result of lead addition/immobilization were assessed by means of XRD, SEM/EDS, and 29 Si MAS NMR analysis. Investigated curing conditions significantly influenced structure, strength and leaching behavior of geopolymers. High addition of lead caused a sizeable decrease in compressive strength of geopolymers and promoted formation of aluminum-deficient aluminosilicate gel (depolymerization of aluminosilicate gel), regardless of the curing conditions investigated. According to the EUWAC limitations, 4% of lead was successfully immobilized by fly ash-based geopolymers cured for 28 days in a humid chamber at room temperature. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Effects of La and Ce Addition on the Modification of Al-Si Based Alloys

    Directory of Open Access Journals (Sweden)

    Emad M. Elgallad

    2016-01-01

    Full Text Available This study focuses on the effects of the addition of rare earth metals (mainly lanthanum and cerium on the eutectic Si characteristics in Al-Si based alloys. Based on the solidification curves and microstructural examination of the corresponding alloys, it was found that addition of La or Ce increases the alloy melting temperature and the Al-Si eutectic temperature, with an Al-Si recalescence of 2-3°C, and the appearance of post-α-Al peaks attributed to precipitation of rare earth intermetallics. Addition of La or Ce to Al-(7–13% Si causes only partial modification of the eutectic Si particles. Lanthanum has a high affinity to react with Sr, which weakens the modification efficiency of the latter. Cerium, however, has a high affinity for Ti, forming a large amount of sludge. Due to the large difference in the length of the eutectic Si particles in the same sample, the normal use of standard deviation in this case is meaningless.

  4. Numerical simulation of residual stress in laser based additive manufacturing process

    Science.gov (United States)

    Kalyan Panda, Bibhu; Sahoo, Seshadev

    2018-03-01

    Minimizing the residual stress build-up in metal-based additive manufacturing plays a pivotal role in selecting a particular material and technique for making an industrial part. In beam-based additive manufacturing, although a great deal of effort has been made to minimize the residual stresses, it is still elusive how to do so by simply optimizing the processing parameters, such as beam size, beam power, and scan speed. Amid different types of additive manufacturing processes, Direct Metal Laser Sintering (DMLS) process uses a high-power laser to melt and sinter layers of metal powder. The rapid solidification and heat transfer on powder bed endows a high cooling rate which leads to the build-up of residual stresses, that will affect the mechanical properties of the build parts. In the present work, the authors develop a numerical thermo-mechanical model for the measurement of residual stress in the AlSi10Mg build samples by using finite element method. Transient temperature distribution in the powder bed was assessed using the coupled thermal to structural model. Subsequently, the residual stresses were estimated with varying laser power. From the simulation result, it found that the melt pool dimensions increase with increasing the laser power and the magnitude of residual stresses in the built part increases.

  5. Online measurement of bead geometry in GMAW-based additive manufacturing using passive vision

    International Nuclear Information System (INIS)

    Xiong, Jun; Zhang, Guangjun

    2013-01-01

    Additive manufacturing based on gas metal arc welding is an advanced technique for depositing fully dense components with low cost. Despite this fact, techniques to achieve accurate control and automation of the process have not yet been perfectly developed. The online measurement of the deposited bead geometry is a key problem for reliable control. In this work a passive vision-sensing system, comprising two cameras and composite filtering techniques, was proposed for real-time detection of the bead height and width through deposition of thin walls. The nozzle to the top surface distance was monitored for eliminating accumulated height errors during the multi-layer deposition process. Various image processing algorithms were applied and discussed for extracting feature parameters. A calibration procedure was presented for the monitoring system. Validation experiments confirmed the effectiveness of the online measurement system for bead geometry in layered additive manufacturing. (paper)

  6. Calibration-free absolute frequency response measurement of directly modulated lasers based on additional modulation.

    Science.gov (United States)

    Zhang, Shangjian; Zou, Xinhai; Wang, Heng; Zhang, Yali; Lu, Rongguo; Liu, Yong

    2015-10-15

    A calibration-free electrical method is proposed for measuring the absolute frequency response of directly modulated semiconductor lasers based on additional modulation. The method achieves the electrical domain measurement of the modulation index of directly modulated lasers without the need for correcting the responsivity fluctuation in the photodetection. Moreover, it doubles measuring frequency range by setting a specific frequency relationship between the direct and additional modulation. Both the absolute and relative frequency response of semiconductor lasers are experimentally measured from the electrical spectrum of the twice-modulated optical signal, and the measured results are compared to those obtained with conventional methods to check the consistency. The proposed method provides calibration-free and accurate measurement for high-speed semiconductor lasers with high-resolution electrical spectrum analysis.

  7. Inverting the diastereoselectivity of the mukaiyama-michael addition with graphite-based catalysts

    KAUST Repository

    Acocella, Maria Rosaria

    2014-02-07

    Here, we show that graphite-based catalysts, mainly graphite oxide (GO) and exfoliated GO, are effective recyclable catalysts for a relevant stereoselective Mukaiyama-Michael addition, outperforming currently available catalysts. Moreover, the graphite-based catalysts described here invert the diastereoselectivity relative to that observed with known catalysts, with the unprecedented large prevalence of the anti diastereoisomer. This inverted diastereoselectivity is increased when the catalyst concentration is reduced and after catalyst recycling. Density functional theory calculations suggest that the selectivity is determined by two types of supramolecular interactions operating between the catalyst and the substrates at the diastereoselectivity- determining transition state, specifically, the π-stacking of b-nitrostyrene with graphite and the van der Waals interaction between the SiMe3 group of the silyl ether and the graphite. © 2013 American Chemical Society.

  8. Metal hydride and pyrophoric fuel additives for dicyclopentadiene based hybrid propellants

    Science.gov (United States)

    Shark, Steven C.

    The purpose of this study is to investigate the use of reactive energetic fuel additives that have the potential to increase the combustion performance of hybrid rocket propellants in terms of solid fuel regression rate and combustion efficiency. Additives that can augment the combustion flame zone in a hybrid rocket motor by means of increased energy feedback to the fuel grain surface are of great interest. Metal hydrides have large volumetric hydrogen densities, which gives these materials high performance potential as fuel additives in terms of specifc impulse. The excess hydrogen and corresponding base metal may also cause an increase in the hybrid rocket solid fuel regression rate. Pyrophoric additives also have potential to increase the solid fuel regression rate by reacting more readily near the burning fuel surface providing rapid energy feedback. An experimental performance evaluation of metal hydride fuel additives for hybrid rocket motor propulsion systems is examined in this study. Hypergolic ignition droplet tests and an accelerated aging study revealed the protection capabilities of Dicyclopentadiene (DCPD) as a fuel binder, and the ability for unaided ignition. Static hybrid rocket motor experiments were conducted using DCPD as the fuel. Sodium borohydride (NabH4) and aluminum hydride (AlH3) were examined as fuel additives. Ninety percent rocket grade hydrogen peroxide (RGHP) was used as the oxidizer. In this study, the sensitivity of solid fuel regression rate and characteristic velocity (C*) efficiency to total fuel grain port mass flux and particle loading is examined. These results were compared to HTPB combustion performance as a baseline. Chamber pressure histories revealed steady motor operation in most tests, with reduced ignition delays when using NabH4 as a fuel additive. The addition of NabH4 and AlH3 produced up to a 47% and 85% increase in regression rate over neat DCPD, respectively. For all test conditions examined C* efficiency ranges

  9. The influence of additives on crystallization of blends based on polylactid acid

    Science.gov (United States)

    Perd'ochová, D.; Tomanová, K.; Alexy, P.; Bočkaj, J.; Feranc, J.; Plavec, R.; Omaníková, L.; Jurkovič, P.; Prikřyl, R.

    2017-11-01

    The sustainable development consists of the effort of replacing commonly used polymer materials for the biodegradable ones. They do not have sufficient physical and mechanical properties, therefore they have to be modified by producing various ratio mixtures or with the additives. Improving their processability and properties is an important challenge to be afforded before using these materials on the market. One way to improve the properties of these materials is to prepare their blends [1]. The most common way of the preparation of packaging materials is the injection moulding, where the crystallization of material is very important. That is the reason the crystallization has become one of the most studied characteristics of biodegradable blends based on PLA / PHB. The work is a contribution to works that deal with the description of the structure of PLA / PHB blends, which have been modified by the addition of various types of additives, mainly nucleating agents and plasticizers [2]. The films of these blends keep approximately unchanged mechanical properties after two weeks of storage. The presence of plasticizer (ATBC) and nucleating agent (BN) has no significant impact on the processing stability of PLA/PHB blends. The results show that the combination of the plasticizer and nucleating agent greatly affects the process of crystallization of PLA/PHB blends as well as the ratio of polymers and the heat treatment process.

  10. Coffee Flower Honey (Coffea sp. Addition to Kefir Quality Based on Microbiology Characteristic

    Directory of Open Access Journals (Sweden)

    Astri Wulandari

    2017-11-01

    Full Text Available The Objective of this research was to determine the best concentration of addition coffee flower honey to kefir based on total plate count, lactic acid bacteria, acidity, and pH value. The materials used in this research were honey kefir made from cow’s milk, kefir grains, and coffee flowers honey. The method used in this research was experimental with Completely Randomized Design by 4 treatments and 4 replications and continued by using Duncan’s Multiple Range Test. The result showed that the effect of addition coffee flowers honey was not significantly different (P>0.05 on total plate count, lactic acid bacteria, acidity, give highly significant different (P<0.01 on pH value. Addition 20% of  coffee flower honey was the best treatment with quality of total plate count 6.21 ± 0.60 log CFU/mL, total lactic acid bacteria 6.16 ± 0.14 log CFU/mL, acidity 0.76 ± 0.11 % and pH value 3.596 ± 0.021. Further study is needed to figure the storability of honey kefir.

  11. Additive Manufacturing of Silicon Carbide-Based Ceramic Matrix Composites: Technical Challenges and Opportunities

    Science.gov (United States)

    Singh, Mrityunjay; Halbig, Michael C.; Grady, Joseph E.

    2016-01-01

    Advanced SiC-based ceramic matrix composites offer significant contributions toward reducing fuel burn and emissions by enabling high overall pressure ratio (OPR) of gas turbine engines and reducing or eliminating cooling air in the hot-section components, such as shrouds, combustor liners, vanes, and blades. Additive manufacturing (AM), which allows high value, custom designed parts layer by layer, has been demonstrated for metals and polymer matrix composites. However, there has been limited activity on additive manufacturing of ceramic matrix composites (CMCs). In this presentation, laminated object manufacturing (LOM), binder jet process, and 3-D printing approaches for developing ceramic composite materials are presented. For the laminated object manufacturing (LOM), fiber prepreg laminates were cut into shape with a laser and stacked to form the desired part followed by high temperature heat treatments. For the binder jet, processing optimization was pursued through silicon carbide powder blending, infiltration with and without SiC nano powder loading, and integration of fibers into the powder bed. Scanning electron microscopy was conducted along with XRD, TGA, and mechanical testing. Various technical challenges and opportunities for additive manufacturing of ceramics and CMCs will be presented.

  12. The extension of a DNA double helix by an additional Watson-Crick base pair on the same backbone

    DEFF Research Database (Denmark)

    Kumar, P.; Sharma, P. K.; Madsen, Charlotte S.

    2013-01-01

    Additional base pair: The DNA duplex can be extended with an additional Watson-Crick base pair on the same backbone by the use of double-headed nucleotides. These also work as compressed dinucleotides and form two base pairs with cognate nucleobases on the opposite strand.......Additional base pair: The DNA duplex can be extended with an additional Watson-Crick base pair on the same backbone by the use of double-headed nucleotides. These also work as compressed dinucleotides and form two base pairs with cognate nucleobases on the opposite strand....

  13. Effect of Silicon Addition on Microstructure and Mechanical Properties of Chromium and Titanium Based Coatings

    Directory of Open Access Journals (Sweden)

    Luis Carlos Ardila-Téllez

    2014-07-01

    Full Text Available The changes in the microstructure, mechanical properties and residual stresses of AlTiN, AlTiSiN, AlCrN and AlCrSiN coatings, has been studied before and after annealing at 900 ºC and 1100 ºC, using scanning and transmission electron microscopy, along with nano-indentation and X-ray diffraction techniques. The As-deposited coatings show a columnar structure, with a crystallite size between 18 nm and 28 nm. Despite the silicon addition, no effect on the crystallite size refinement was observed.However, the addition of silicon increases hardness, elastic modulus and compressive residual stresses. After annealing at 900 ºC, the crystallite size growth and the residual stress relaxes; therefore, the coating hardness decreases. At 1100 ºC, the oxide layers formed in AlTiN and AlTiSiN, which act as protective layers enhancing oxidation resistance; meanwhile, a complete oxidation of AlCrN and AlCrSiN coatings take place. The Titanium based coatings present some superior mechanical properties and oxidation resistance than the chromium based coatings at 900 ºC and 1100 ºC.

  14. Adding functionality with additive manufacturing: Fabrication of titanium-based antibiotic eluting implants.

    Science.gov (United States)

    Cox, Sophie C; Jamshidi, Parastoo; Eisenstein, Neil M; Webber, Mark A; Hassanin, Hany; Attallah, Moataz M; Shepherd, Duncan E T; Addison, Owen; Grover, Liam M

    2016-07-01

    Additive manufacturing technologies have been utilised in healthcare to create patient-specific implants. This study demonstrates the potential to add new implant functionality by further exploiting the design flexibility of these technologies. Selective laser melting was used to manufacture titanium-based (Ti-6Al-4V) implants containing a reservoir. Pore channels, connecting the implant surface to the reservoir, were incorporated to facilitate antibiotic delivery. An injectable brushite, calcium phosphate cement, was formulated as a carrier vehicle for gentamicin. Incorporation of the antibiotic significantly (p=0.01) improved the compressive strength (5.8±0.7MPa) of the cement compared to non-antibiotic samples. The controlled release of gentamicin sulphate from the calcium phosphate cement injected into the implant reservoir was demonstrated in short term elution studies using ultraviolet-visible spectroscopy. Orientation of the implant pore channels were shown, using micro-computed tomography, to impact design reproducibility and the back-pressure generated during cement injection which ultimately altered porosity. The amount of antibiotic released from all implant designs over a 6hour period (additively manufacture a titanium-based antibiotic eluting implant, which is an attractive alternative to current treatment strategies of periprosthetic infections. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Cloud-Based Automated Design and Additive Manufacturing: A Usage Data-Enabled Paradigm Shift.

    Science.gov (United States)

    Lehmhus, Dirk; Wuest, Thorsten; Wellsandt, Stefan; Bosse, Stefan; Kaihara, Toshiya; Thoben, Klaus-Dieter; Busse, Matthias

    2015-12-19

    Integration of sensors into various kinds of products and machines provides access to in-depth usage information as basis for product optimization. Presently, this large potential for more user-friendly and efficient products is not being realized because (a) sensor integration and thus usage information is not available on a large scale and (b) product optimization requires considerable efforts in terms of manpower and adaptation of production equipment. However, with the advent of cloud-based services and highly flexible additive manufacturing techniques, these obstacles are currently crumbling away at rapid pace. The present study explores the state of the art in gathering and evaluating product usage and life cycle data, additive manufacturing and sensor integration, automated design and cloud-based services in manufacturing. By joining and extrapolating development trends in these areas, it delimits the foundations of a manufacturing concept that will allow continuous and economically viable product optimization on a general, user group or individual user level. This projection is checked against three different application scenarios, each of which stresses different aspects of the underlying holistic concept. The following discussion identifies critical issues and research needs by adopting the relevant stakeholder perspectives.

  16. Cloud-Based Automated Design and Additive Manufacturing: A Usage Data-Enabled Paradigm Shift

    Science.gov (United States)

    Lehmhus, Dirk; Wuest, Thorsten; Wellsandt, Stefan; Bosse, Stefan; Kaihara, Toshiya; Thoben, Klaus-Dieter; Busse, Matthias

    2015-01-01

    Integration of sensors into various kinds of products and machines provides access to in-depth usage information as basis for product optimization. Presently, this large potential for more user-friendly and efficient products is not being realized because (a) sensor integration and thus usage information is not available on a large scale and (b) product optimization requires considerable efforts in terms of manpower and adaptation of production equipment. However, with the advent of cloud-based services and highly flexible additive manufacturing techniques, these obstacles are currently crumbling away at rapid pace. The present study explores the state of the art in gathering and evaluating product usage and life cycle data, additive manufacturing and sensor integration, automated design and cloud-based services in manufacturing. By joining and extrapolating development trends in these areas, it delimits the foundations of a manufacturing concept that will allow continuous and economically viable product optimization on a general, user group or individual user level. This projection is checked against three different application scenarios, each of which stresses different aspects of the underlying holistic concept. The following discussion identifies critical issues and research needs by adopting the relevant stakeholder perspectives. PMID:26703606

  17. Adding functionality with additive manufacturing: Fabrication of titanium-based antibiotic eluting implants

    International Nuclear Information System (INIS)

    Cox, Sophie C.; Jamshidi, Parastoo; Eisenstein, Neil M.; Webber, Mark A.; Hassanin, Hany; Attallah, Moataz M.; Shepherd, Duncan E.T.; Addison, Owen; Grover, Liam M.

    2016-01-01

    Additive manufacturing technologies have been utilised in healthcare to create patient-specific implants. This study demonstrates the potential to add new implant functionality by further exploiting the design flexibility of these technologies. Selective laser melting was used to manufacture titanium-based (Ti-6Al-4V) implants containing a reservoir. Pore channels, connecting the implant surface to the reservoir, were incorporated to facilitate antibiotic delivery. An injectable brushite, calcium phosphate cement, was formulated as a carrier vehicle for gentamicin. Incorporation of the antibiotic significantly (p = 0.01) improved the compressive strength (5.8 ± 0.7 MPa) of the cement compared to non-antibiotic samples. The controlled release of gentamicin sulphate from the calcium phosphate cement injected into the implant reservoir was demonstrated in short term elution studies using ultraviolet-visible spectroscopy. Orientation of the implant pore channels were shown, using micro-computed tomography, to impact design reproducibility and the back-pressure generated during cement injection which ultimately altered porosity. The amount of antibiotic released from all implant designs over a 6 hour period (< 28% of the total amount) were found to exceed the minimum inhibitory concentrations of Staphylococcus aureus (16 μg/mL) and Staphylococcus epidermidis (1 μg/mL); two bacterial species commonly associated with periprosthetic infections. Antibacterial efficacy was confirmed against both bacterial cultures using an agar diffusion assay. Interestingly, pore channel orientation was shown to influence the directionality of inhibition zones. Promisingly, this work demonstrates the potential to additively manufacture a titanium-based antibiotic eluting implant, which is an attractive alternative to current treatment strategies of periprosthetic infections. - Highlights: • Titanium implants were additively manufactured with surface connected reservoirs. • Implants

  18. Processing of pure titanium containing titanium-based reinforcing ceramics additives using spark plasma sintering

    Directory of Open Access Journals (Sweden)

    Mondiu Olayinka DUROWOJU

    2017-06-01

    Full Text Available The densification behaviour, microstructural changes and hardness characteristics during spark plasma sintering of CP-Ti reinforced with TiC, TiN, TiCN and TiB2 were investigated. Commercially pure Ti powders were dry mixed with varied amounts (2.5 and 5 wt. % of the ceramic additives using a T2F Turbula mixer for 5 h and at a speed of 49 rpm. The blended composite powders were then sintered using spark plasma sintering system (model HHPD-25 from FCT Germany at a heating rate of 100oC min-1, dwell time of 5 min and sintering temperature of 950ºC. The sintering of CP-Ti was used as a base study to select the proper spark plasma sintering temperature for full density. Densification was monitored through analysis of the recorded punch displacement and the measured density of the sintered samples using Archimedes method. High densities ranging from 97.8% for 5% TiB2 addition to 99.6% for 5% TiCN addition were achieved at a relatively low temperature of 950°C. Microstructural analyses show a uniform distribution of the additives and finer structure showing their inhibitive effect on grain growth. An improved hardness was observed in all the cases with highest values obtained with TiCN as a result of the combined effect of TiC and TiN. A change in the fracture mode from trans granular to intergranular was also observed.

  19. Improved microstructure of cement-based composites through the addition of rock wool particles

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Wei-Ting [Dept. of Civil Engineering, National Ilan University, Ilan 26047, Taiwan (China); Institute of Nuclear Energy Research, Atomic Energy Council, Taoyuan 32546, Taiwan (China); Cheng, An, E-mail: ancheng@niu.edu.tw [Dept. of Civil Engineering, National Ilan University, Ilan 26047, Taiwan (China); Huang, Ran; Zou, Si-Yu [Dept. of Harbor and River Engineering, National Taiwan Ocean University, Keelung 20224, Taiwan (China)

    2013-10-15

    Rock wool is an inorganic fibrous substance produced by steam blasting and cooling molten glass. As with other industrial by-products, rock wool particles can be used as cementitious materials or ultra fine fillers in cement-based composites. This study investigated the microstructure of mortar specimens produced with cement-based composites that include various forms of rock wool particles. It conducted compressive strength testing, rapid chloride penetration tests, X-ray diffraction analysis, thermo-gravimetric analysis, and scanning electronic microscopy to evaluate the macro- and micro-properties of the cement-based composites. Test results indicate that inclusion of rock wool particles in composites improved compressive strength and reduced chloride ion penetration at the age of 91 days due to the reduction of calcium hydroxide content. Microscopic analysis confirms that the use of rock wool particles contributed to the formation of a denser, more compact microstructure within the hardened paste. In addition, X-ray diffraction analysis shows few changes in formation of pozzolanic reaction products and no new hydrations are formed with incorporating rock wool particles. - Highlights: • We report the microstructural characterization of cement-based composites. • Different mixes produced with various rock wool particles have been tested. • The influence of different mixes on macro and micro properties has been discussed. • The macro properties are included compressive strength and permeability. • XRD and SEM observations confirm the pozzolanic reaction in the resulting pastes.

  20. Spatial downscaling of soil prediction models based on weighted generalized additive models in smallholder farm settings.

    Science.gov (United States)

    Xu, Yiming; Smith, Scot E; Grunwald, Sabine; Abd-Elrahman, Amr; Wani, Suhas P; Nair, Vimala D

    2017-09-11

    Digital soil mapping (DSM) is gaining momentum as a technique to help smallholder farmers secure soil security and food security in developing regions. However, communications of the digital soil mapping information between diverse audiences become problematic due to the inconsistent scale of DSM information. Spatial downscaling can make use of accessible soil information at relatively coarse spatial resolution to provide valuable soil information at relatively fine spatial resolution. The objective of this research was to disaggregate the coarse spatial resolution soil exchangeable potassium (K ex ) and soil total nitrogen (TN) base map into fine spatial resolution soil downscaled map using weighted generalized additive models (GAMs) in two smallholder villages in South India. By incorporating fine spatial resolution spectral indices in the downscaling process, the soil downscaled maps not only conserve the spatial information of coarse spatial resolution soil maps but also depict the spatial details of soil properties at fine spatial resolution. The results of this study demonstrated difference between the fine spatial resolution downscaled maps and fine spatial resolution base maps is smaller than the difference between coarse spatial resolution base maps and fine spatial resolution base maps. The appropriate and economical strategy to promote the DSM technique in smallholder farms is to develop the relatively coarse spatial resolution soil prediction maps or utilize available coarse spatial resolution soil maps at the regional scale and to disaggregate these maps to the fine spatial resolution downscaled soil maps at farm scale.

  1. Method for mapping population-based case-control studies: an application using generalized additive models

    Directory of Open Access Journals (Sweden)

    Aschengrau Ann

    2006-06-01

    Full Text Available Abstract Background Mapping spatial distributions of disease occurrence and risk can serve as a useful tool for identifying exposures of public health concern. Disease registry data are often mapped by town or county of diagnosis and contain limited data on covariates. These maps often possess poor spatial resolution, the potential for spatial confounding, and the inability to consider latency. Population-based case-control studies can provide detailed information on residential history and covariates. Results Generalized additive models (GAMs provide a useful framework for mapping point-based epidemiologic data. Smoothing on location while controlling for covariates produces adjusted maps. We generate maps of odds ratios using the entire study area as a reference. We smooth using a locally weighted regression smoother (loess, a method that combines the advantages of nearest neighbor and kernel methods. We choose an optimal degree of smoothing by minimizing Akaike's Information Criterion. We use a deviance-based test to assess the overall importance of location in the model and pointwise permutation tests to locate regions of significantly increased or decreased risk. The method is illustrated with synthetic data and data from a population-based case-control study, using S-Plus and ArcView software. Conclusion Our goal is to develop practical methods for mapping population-based case-control and cohort studies. The method described here performs well for our synthetic data, reproducing important features of the data and adequately controlling the covariate. When applied to the population-based case-control data set, the method suggests spatial confounding and identifies statistically significant areas of increased and decreased odds ratios.

  2. The use of plasticizing additives based on recycled raw materials in the petrochemical rubber mixtures

    Directory of Open Access Journals (Sweden)

    Z. S. Shashok

    2016-01-01

    Full Text Available At present, the development of alternative products for elastomers based on recycling petrochemical raw materials is a new trend of the rubber industry progress. Petrochemical raw materials include spent lubricants and motor oils are among such recycling products. In this context, the influence of the products of recycling waste engine oil (DVCH and RA in comparison with industrial oil (I-20 on the technological properties of filled elastomeric compositions was investigated. The elastomeric compositions were based on poly isoprene and divinyl rubbers. The plasticizing components were manufactured by IOOO “DVCH-Menedzhment”. They are mixture of hydro-carbons, C16–C20 and differ from each other in the content of linear and branched paraffin. Plastic-elastic properties of rubber compounds on the shear disk viscometer MV2000 in accordance with GOST 10722–76 was carried out. Kinetics of vulcanization on the rheometer ODR2000 according to GOST 12535–84 was defined. It is shown that the introduction of RA test plasticizing component provides a significant effect on Mooney viscosity, as compared to elastomeric compositions containing a plasticizer and I-20 and plasticizing additive DVCH. It revealed that the administration of all components in the studied plasticizing elastomer compositions based on a combination poly isoprene and divinyl rubbers has no significant effect on the rate of relaxation of stress of rubber compounds. It is found that elastomeric compositions containing as additives investigated processing waste oil products (DVCH and RA are characterized by a slightly smaller value of time to reach an optimal degree of vulcanization.

  3. Feature based Weld-Deposition for Additive Manufacturing of Complex Shapes

    Science.gov (United States)

    Panchagnula, Jayaprakash Sharma; Simhambhatla, Suryakumar

    2018-06-01

    Fabricating functional metal parts using Additive Manufacturing (AM) is a leading trend. However, realizing overhanging features has been a challenge due to the lack of support mechanism for metals. Powder-bed fusion techniques like, Selective Laser Sintering (SLS) employ easily-breakable-scaffolds made of the same material to realize the overhangs. However, the same approach is not extendible to deposition processes like laser or arc based direct energy deposition processes. Although it is possible to realize small overhangs by exploiting the inherent overhanging capability of the process or by blinding some small features like holes, the same cannot be extended for more complex geometries. The current work presents a novel approach for realizing complex overhanging features without the need of support structures. This is possible by using higher order kinematics and suitably aligning the overhang with the deposition direction. Feature based non-uniform slicing and non-uniform area-filling are some vital concepts required in realizing the same and are briefly discussed here. This method can be used to fabricate and/or repair fully dense and functional components for various engineering applications. Although this approach has been implemented for weld-deposition based system, the same can be extended to any other direct energy deposition processes also.

  4. Forecast for Artificial Muscle Tremor Behavior Based on Dynamic Additional Grey Catastrophe Prediction

    Directory of Open Access Journals (Sweden)

    Yu Fu

    2018-02-01

    Full Text Available Recently, bio-inspired artificial muscles based on ionic polymers have shown a bright perspective in engineering and medical research, but the inherent tremor behavior can cause instability of output response. In this paper, dynamic additional grey catastrophe prediction (DAGCP is proposed to forecast the occurrence time of tremor behavior, providing adequate preparation time for the suppression of the chitosan-based artificial muscles. DAGCP constructs various dimensions of time subsequence models under different starting points based on the threshold of tremor occurrence times and peak-to-peak values in unit time. Next, the appropriate subsequence is selected according to grey correlation degree and prediction accuracy, then it is updated with the newly generated values to achieve a real-time forecast of forthcoming tremor time. Compared with conventional grey catastrophe prediction (GCP, the proposed method has the following advantages: (1 the degradation of prediction accuracy caused by the immobilization of original parameters is prevented; (2 the dynamic input, real-time update and gradual forecast of time sequence are incorporated into the model. The experiment results show that the novel DAGCP can predict forthcoming tremor time earlier and more accurately than the conventional GCP. The generation mechanism of tremor behavior is illustrated as well.

  5. Incidence of sulfur based additives to the microstructure of nuclear fuels. Elaboration and characterizations

    International Nuclear Information System (INIS)

    Caranoni, L.

    2002-05-01

    Even though the global reactor working of MOX fuel is good, the fission gas emission now represents the limitative factor of its use at high burn-up. The increase of the average grain size promotes the diffusional length of fission gas inside the grain, slowing down their emission. In this respect, we have studied the influence of sulphur based additives on the crystal grain growth of nuclear oxide ceramics. The first part of this work concerns the preparation and characterisation of sulfur additives and especially the uranium oxy-sulphur, UOS. The study of its thermal behaviour has shown that the partial pressure ratio pH 2 O/pH 2 S controls the reaction kinetics between UOS and H 2 O vapour, which leads to SO 2 emission. After sintering at 1700 deg. C under reducing atmosphere, the UOS grains are strongly anisotropic. Their structure is characterised by (0,0,1) planar defects. The second part presents the study of the incorporation of these additives in UO 2 powder. We have shown that the sulphur has a very favourable action on crystal growth. After sintering at 1700 deg C during 4 hours under Ar-5% H 2 - 1000 ppm H 2 O atmosphere, the average grain size is about 25-30 microns. The samples present a local grain size gradient between a thick peripheral layer (usual grain size) and the core (large grains) which is in accordance with a local sulphur concentration gradient. The sulphur action suddenly appears during the thermal cycle between 1600 deg C and 1700 deg C, whereas its mass concentration is lower than 30 ppm. SIMS analysis have highlighted, in the core, the segregation of sulphur at the grain boundary. According to these observations, a mechanism has been proposed to explain the activation induced by sulphur. The experiences carried out on mixed oxide, especially (U, Pu)O 2 , confirm that the grain growth activation is induced by the presence of sulphur. (authors)

  6. Education packed in technology to promote innovations: Teaching Additive Manufacturing based on a rolling Lab

    Directory of Open Access Journals (Sweden)

    Thurn Laura Katharina

    2017-01-01

    Full Text Available 3D Printing is about to revolutionize the way we design and produce future products. This causes not just immense research and development activities worldwide but requires intensive education and training efforts. As 3D Printing is an ideal tool to set up a decentralized production, it is one key to integrate even rural and under-industrialized parts of the country into high tech education and professional training needed. But how to reach the relevant groups - pupils from schools as well as professional staff of preferably companies? Remembered the old proverb: “If the mountain won’t come to the prophet, the prophet must go to the mountain” the plan of a mobile 3D printing lab was born. Based on our experiences, we designed the technical infrastructure and the educational approach to adopt Additive Manufacturing courses to a short term comprehensive teaching. To create a fully equipped workplace for every participant, we redesigned a double-decker bus. The paper addresses the strategy behind the bus, the infrastructure in detail, the developed courses taught and the resonance on this project. Looking forward, the paper gives a sneak preview on the further development in terms of specialized courses to be given in the bus as well as in the frame of accompanying activities such as engineering design of parts, application of new materials for Additive Manufacturing such as metals and follow-up production like plastic injection molding.

  7. Effects of additional team-based learning on students' clinical reasoning skills: a pilot study.

    Science.gov (United States)

    Jost, Meike; Brüstle, Peter; Giesler, Marianne; Rijntjes, Michel; Brich, Jochen

    2017-07-14

    In the field of Neurology good clinical reasoning skills are essential for successful diagnosing and treatment. Team-based learning (TBL), an active learning and small group instructional strategy, is a promising method for fostering these skills. The aim of this pilot study was to examine the effects of a supplementary TBL-class on students' clinical decision-making skills. Fourth- and fifth-year medical students participated in this pilot study (static-group comparison design). The non-treatment group (n = 15) did not receive any additional training beyond regular teaching in the neurology course. The treatment group (n = 11) took part in a supplementary TBL-class optimized for teaching clinical reasoning in addition to the regular teaching in the neurology course. Clinical decision making skills were assessed using a key-feature problem examination. Factual and conceptual knowledge was assessed by a multiple-choice question examination. The TBL-group performed significantly better than the non-TBL-group (p = 0.026) in the key-feature problem examination. No significant differences between the results of the multiple-choice question examination of both groups were found. In this pilot study participants of a supplementary TBL-class significantly improved clinical decision-making skills, indicating that TBL may be an appropriate method for teaching clinical decision making in neurology. Further research is needed for replication in larger groups and other clinical fields.

  8. Effect of addition of organo clay on mechanical properties and dynamic-mechanical based TPV

    International Nuclear Information System (INIS)

    Honorato, Luciana R.; Silva, Adriana A.; Soares, Bluma G.; Soares, Ketly P.

    2011-01-01

    The effect of organophilic clay on the mechanical and dynamical-mechanical properties of thermoplastic elastomers based on polypropylene (PP) and nitrile rubber (NBR) was investigated. The addition of clay was performed from a master batch prepared by a solution intercalation of NBR inside the clay galleries. Since the PP/NBR blend is highly incompatible, PP functionalized with maleic anhydride (PP-g-MA) and carboxylated NBR (XNBR) were employed as compatibilizing system together with triethylene-tetramine (TETA) used as coupling agent. The addition of Clay inside the elastomeric phase of the TPV resulted in a significant decrease of the elongation at break without changes on the tensile strength. The presence of clay also promoted a slight increase of the storage modulus and the glass transition temperature. The small angle X ray scattering confirmed the high dispersion of clay inside the TPV. Analysis of light scattering small angle (SAXS) confirmed the high dispersion of clay in the matrix of the TPV. (author)

  9. Health-risk assessment based on an additive to paints made from isobutyric aldehyde condensation products

    Directory of Open Access Journals (Sweden)

    Jan Tic Wilhelm

    2017-01-01

    The results of selected toxicological tests relating to the human health risk effect of the hydroxyester HE-1 – environmentally-friendly additive to paints and varnishes are presented. The test results indicate that HE-1 causes skin irritation in rabbit only when used at its maximum concentrations. No lesions in the cornea or iris were observed in any of the test rabbits after the application of the hydroxyester HE-1. In the mutagenic effect test of HE-1 on the bacteria Salmonella typhimurium, the result was negative. Based on the test results, it was found that the hydroxyester HE-1 may only have a human health risk effect when used at its maximum concentrations.

  10. Evaporation model for beam based additive manufacturing using free surface lattice Boltzmann methods

    International Nuclear Information System (INIS)

    Klassen, Alexander; Scharowsky, Thorsten; Körner, Carolin

    2014-01-01

    Evaporation plays an important role in many technical applications including beam-based additive manufacturing processes, such as selective electron beam or selective laser melting (SEBM/SLM). In this paper, we describe an evaporation model which we employ within the framework of a two-dimensional free surface lattice Boltzmann method. With this method, we solve the hydrodynamics as well as thermodynamics of the molten material taking into account the mass and energy losses due to evaporation and the recoil pressure acting on the melt pool. Validation of the numerical model is performed by measuring maximum melt depths and evaporative losses in samples of pure titanium and Ti–6Al–4V molten by an electron beam. Finally, the model is applied to create processing maps for an SEBM process. The results predict that the penetration depth of the electron beam, which is a function of the acceleration voltage, has a significant influence on evaporation effects. (paper)

  11. Fuzzy Logic-Based Filter for Removing Additive and Impulsive Noise from Color Images

    Science.gov (United States)

    Zhu, Yuhong; Li, Hongyang; Jiang, Huageng

    2017-12-01

    This paper presents an efficient filter method based on fuzzy logics for adaptively removing additive and impulsive noise from color images. The proposed filter comprises two parts including noise detection and noise removal filtering. In the detection part, the fuzzy peer group concept is applied to determine what type of noise is added to each pixel of the corrupted image. In the filter part, the impulse noise is deducted by the vector median filter in the CIELAB color space and an optimal fuzzy filter is introduced to reduce the Gaussian noise, while they can work together to remove the mixed Gaussian-impulse noise from color images. Experimental results on several color images proves the efficacy of the proposed fuzzy filter.

  12. Microscopic simulation of xenon-based optical TPCs in the presence of molecular additives

    Science.gov (United States)

    Azevedo, C. D. R.; González-Díaz, D.; Biagi, S. F.; Oliveira, C. A. B.; Henriques, C. A. O.; Escada, J.; Monrabal, F.; Gómez-Cadenas, J. J.; Álvarez, V.; Benlloch-Rodríguez, J. M.; Borges, F. I. G. M.; Botas, A.; Cárcel, S.; Carrión, J. V.; Cebrián, S.; Conde, C. A. N.; Díaz, J.; Diesburg, M.; Esteve, R.; Felkai, R.; Fernandes, L. M. P.; Ferrario, P.; Ferreira, A. L.; Freitas, E. D. C.; Goldschmidt, A.; Gutiérrez, R. M.; Hauptman, J.; Hernandez, A. I.; Morata, J. A. Hernando; Herrero, V.; Jones, B. J. P.; Labarga, L.; Laing, A.; Lebrun, P.; Liubarsky, I.; Lopez-March, N.; Losada, M.; Martín-Albo, J.; Martínez-Lema, G.; Martínez, A.; McDonald, A. D.; Monteiro, C. M. B.; Mora, F. J.; Moutinho, L. M.; Vidal, J. Muñoz; Musti, M.; Nebot-Guinot, M.; Novella, P.; Nygren, D.; Palmeiro, B.; Para, A.; Pérez, J.; Querol, M.; Renner, J.; Ripoll, L.; Rodríguez, J.; Rogers, L.; Santos, F. P.; dos Santos, J. M. F.; Serra, L.; Shuman, D.; Simón, A.; Sofka, C.; Sorel, M.; Stiegler, T.; Toledo, J. F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J. F. C. A.; Webb, R.; White, J. T.; Yahlali, N.

    2018-01-01

    We introduce a simulation framework for the transport of high and low energy electrons in xenon-based optical time projection chambers (OTPCs). The simulation relies on elementary cross sections (electron-atom and electron-molecule) and incorporates, in order to compute the gas scintillation, the reaction/quenching rates (atom-atom and atom-molecule) of the first 41 excited states of xenon and the relevant associated excimers, together with their radiative cascade. The results compare positively with observations made in pure xenon and its mixtures with CO2 and CF4 in a range of pressures from 0.1 to 10 bar. This work sheds some light on the elementary processes responsible for the primary and secondary xenon-scintillation mechanisms in the presence of additives, that are of interest to the OTPC technology.

  13. Alkali-activated fly ash-based geopolymers with zeolite or bentonite as additives

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Mingyu; Zhu, Xiaomin; Long, Fumei [Nanchang University, Nanchang (China). College of Civil Engineering

    2009-11-15

    Geopolymers were synthesized by using fly ash as the main starting material, zeolite or bentonite as supplementary materials, and NaOH and CaO together as activator. An orthogonal array testing protocol was used to analyze the influence of the mix proportion on the properties of the geopolymers. The results indicate that the concentration of NaOH solution and the CaO content play an important role on the strength of the materials. Especially, with zeolite as additive, the fly ash-based geopolymer shows the highest strength and the best sulfate resistance. Infrared spectroscopy, X-ray, and SEM-EDX demonstrate that supplementary zeolite may involve the process of geopolymerization to form a stable zeolitic structure and improve the properties of the geopolymer. Bentonite simply acts as a filler to make the geopolymer more compact, but shows no improvement on the compositions and the microstructures of the geopolymer.

  14. The extension of a DNA double helix by an additional Watson-Crick base pair on the same backbone.

    Science.gov (United States)

    Kumar, Pawan; Sharma, Pawan K; Madsen, Charlotte S; Petersen, Michael; Nielsen, Poul

    2013-06-17

    Additional base pair: The DNA duplex can be extended with an additional Watson-Crick base pair on the same backbone by the use of double-headed nucleotides. These also work as compressed dinucleotides and form two base pairs with cognate nucleobases on the opposite strand. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Additive Functional Inequalities in Banach Modules

    Directory of Open Access Journals (Sweden)

    An JongSu

    2008-01-01

    Full Text Available Abstract We investigate the following functional inequality in Banach modules over a -algebra and prove the generalized Hyers-Ulam stability of linear mappings in Banach modules over a -algebra in the spirit of the Th. M. Rassias stability approach. Moreover, these results are applied to investigate homomorphisms in complex Banach algebras and prove the generalized Hyers-Ulam stability of homomorphisms in complex Banach algebras.

  16. Adding functionality with additive manufacturing: Fabrication of titanium-based antibiotic eluting implants

    Energy Technology Data Exchange (ETDEWEB)

    Cox, Sophie C. [School of Chemical Engineering, University of Birmingham, Edgbaston B15 2TT (United Kingdom); Jamshidi, Parastoo [School of Materials and Metallurgy, University of Birmingham, Edgbaston B15 2TT (United Kingdom); Eisenstein, Neil M. [School of Chemical Engineering, University of Birmingham, Edgbaston B15 2TT (United Kingdom); Royal Centre for Defence Medicine, Birmingham Research Park, Vincent Drive, Edgbaston B15 2SQ (United Kingdom); Webber, Mark A. [School of Biosciences, University of Birmingham, Edgbaston B15 2TT (United Kingdom); Hassanin, Hany [School of Materials and Metallurgy, University of Birmingham, Edgbaston B15 2TT (United Kingdom); School of Mechanical and Automotive Engineering, Kingston University, London SW15 3DW (United Kingdom); Attallah, Moataz M. [School of Materials and Metallurgy, University of Birmingham, Edgbaston B15 2TT (United Kingdom); Shepherd, Duncan E.T. [Department of Mechanical Engineering, School of Engineering, University of Birmingham, Edgbaston B15 2TT (United Kingdom); Addison, Owen [School of Dentistry, University of Birmingham, Edgbaston B15 2TT (United Kingdom); Grover, Liam M. [School of Chemical Engineering, University of Birmingham, Edgbaston B15 2TT (United Kingdom)

    2016-07-01

    Additive manufacturing technologies have been utilised in healthcare to create patient-specific implants. This study demonstrates the potential to add new implant functionality by further exploiting the design flexibility of these technologies. Selective laser melting was used to manufacture titanium-based (Ti-6Al-4V) implants containing a reservoir. Pore channels, connecting the implant surface to the reservoir, were incorporated to facilitate antibiotic delivery. An injectable brushite, calcium phosphate cement, was formulated as a carrier vehicle for gentamicin. Incorporation of the antibiotic significantly (p = 0.01) improved the compressive strength (5.8 ± 0.7 MPa) of the cement compared to non-antibiotic samples. The controlled release of gentamicin sulphate from the calcium phosphate cement injected into the implant reservoir was demonstrated in short term elution studies using ultraviolet-visible spectroscopy. Orientation of the implant pore channels were shown, using micro-computed tomography, to impact design reproducibility and the back-pressure generated during cement injection which ultimately altered porosity. The amount of antibiotic released from all implant designs over a 6 hour period (< 28% of the total amount) were found to exceed the minimum inhibitory concentrations of Staphylococcus aureus (16 μg/mL) and Staphylococcus epidermidis (1 μg/mL); two bacterial species commonly associated with periprosthetic infections. Antibacterial efficacy was confirmed against both bacterial cultures using an agar diffusion assay. Interestingly, pore channel orientation was shown to influence the directionality of inhibition zones. Promisingly, this work demonstrates the potential to additively manufacture a titanium-based antibiotic eluting implant, which is an attractive alternative to current treatment strategies of periprosthetic infections. - Highlights: • Titanium implants were additively manufactured with surface connected reservoirs. • Implants

  17. Solid-state supercapacitors with ionic liquid based gel polymer electrolyte: Effect of lithium salt addition

    Science.gov (United States)

    Pandey, G. P.; Hashmi, S. A.

    2013-12-01

    Performance characteristics of the solid-state supercapacitors fabricated with ionic liquid (IL) incorporated gel polymer electrolyte and acid treated multiwalled carbon nanotube (MWCNT) electrodes have been studied. The effect of Li-salt (LiPF6) addition in the IL (1-ethyl-3-methylimidazolium tris(pentafluoroethyl) trifluorophosphate, EMImFAP) based gel electrolyte on the performance of supercapacitors has been specifically investigated. The LiPF6/IL/poly(vinylidine fluoride-co-hexafluoropropylene) (PVdF-HFP) gel electrolyte film possesses excellent electrochemical window of 4 V (from -2.0 to 2.0 V), high ionic conductivity ∼2.6 × 10-3 S cm-1 at 20 °C and high enough thermal stability. The comparative performance of supercapacitors employing electrolytes with and without lithium salt has been evaluated by impedance spectroscopy and cyclic voltammetric studies. The acid-treated MWCNT electrodes show specific capacitance of ∼127 F g-1 with IL/LiPF6 containing gel polymer electrolyte as compared to that with the gel polymer electrolyte without Li-salt, showing the value of ∼76 F g-1. The long cycling stability of the solid state supercapacitor based on the Li-salt containing gel polymer electrolyte confirms the electrochemical stability of the electrolyte.

  18. Additive Manufacturing of Nickel-Base Superalloy IN100 Through Scanning Laser Epitaxy

    Science.gov (United States)

    Basak, Amrita; Das, Suman

    2018-01-01

    Scanning laser epitaxy (SLE) is a laser powder bed fusion (LPBF)-based additive manufacturing process that uses a high-power laser to consolidate metal powders facilitating the fabrication of three-dimensional objects. In the present study, SLE is used to produce samples of IN100, a high-γ' non-weldable nickel-base superalloy on similar chemistry substrates. A thorough analysis is performed using various advanced material characterization techniques such as high-resolution optical microscopy, scanning electron microscopy, energy dispersive x-ray spectroscopy, and Vickers microhardness measurements to characterize and compare the quality of the SLE-fabricated IN100 deposits with the investment cast IN100 substrates. The results show that the IN100 deposits have a finer γ/γ' microstructure, weaker elemental segregation, and higher microhardness compared with the substrate. Through this study, it is demonstrated that the SLE process has tremendous potential in the repair and manufacture of gas turbine hot-section components.

  19. Health-risk assessment based on an additive to paints made from isobutyric aldehyde condensation products

    Science.gov (United States)

    Jan Tic, Wilhelm

    2017-10-01

    Solvents are primarily used for making protective coatings. Considering their chemical nature, there are a great variety of coatings, including those based on liquid hydrocarbons and organic chloroderivatives. These products are a serious load to the environment because of their physicochemical properties, therefore, they have for some time been replaced with more-environmentally friendly, new generation products. One of them is the hydroxyester HE-1: made from isobutyric aldehyde condensation products, it is an alternative to those coalescents for paints and varnishes which are intended to be replaced or their use restricted. The results of selected toxicological tests relating to the human health risk effect of the hydroxyester HE-1 - environmentally-friendly additive to paints and varnishes are presented. The test results indicate that HE-1 causes skin irritation in rabbit only when used at its maximum concentrations. No lesions in the cornea or iris were observed in any of the test rabbits after the application of the hydroxyester HE-1. In the mutagenic effect test of HE-1 on the bacteria Salmonella typhimurium, the result was negative. Based on the test results, it was found that the hydroxyester HE-1 may only have a human health risk effect when used at its maximum concentrations.

  20. Properties enhancement of cassava starch based bioplastics with addition of graphene oxide

    Science.gov (United States)

    Amri, A.; Ekawati, L.; Herman, S.; Yenti, S. R.; Zultiniar; Aziz, Y.; Utami, S. P.; Bahruddin

    2018-04-01

    The properties of cassava starch based bioplastic have been successfully enhanced by additioning of graphene oxide (GO) filler. The composite was synthesized via starch intercalation method using glycerol plasticizer with variation of 5 – 15 % v/v GO filler and mixing time of 30 and 60 minutes. The effects of GO content and the mixing time to the mechanical, water uptake and biodegradation were studied. The synthesis of GO and its integration in the bioplastic composite were also elucidated. The increasing of the GO content and mixing time improved the mechanical properties of composite mainly due to of good homogeneity among the constituents in the composite as indicated by scanning electron microscopy (SEM) and Fourier Transfom Infrared (FTIR) spectroscopy. The bioplastic produced using 15% of GO and 60 minutes mixing time had the highest mechanical properties with tensile strenght of 3,92 Mpa, elongation of 13,22% and modulus young of 29,66 MPa. The water uptake and biodegradation increased as the increase of GO content and decreased as the increase of the mixing time. Graphene oxide is the promissing filler for further development of cassava starch based bioplastics.

  1. Dropwise additive manufacturing of pharmaceutical products for solvent-based dosage forms.

    Science.gov (United States)

    Hirshfield, Laura; Giridhar, Arun; Taylor, Lynne S; Harris, Michael T; Reklaitis, Gintaras V

    2014-02-01

    In recent years, the US Food and Drug Administration has encouraged pharmaceutical companies to develop more innovative and efficient manufacturing methods with improved online monitoring and control. Mini-manufacturing of medicine is one such method enabling the creation of individualized product forms for each patient. This work presents dropwise additive manufacturing of pharmaceutical products (DAMPP), an automated, controlled mini-manufacturing method that deposits active pharmaceutical ingredients (APIs) directly onto edible substrates using drop-on-demand (DoD) inkjet printing technology. The use of DoD technology allows for precise control over the material properties, drug solid state form, drop size, and drop dynamics and can be beneficial in the creation of high-potency drug forms, combination drugs with multiple APIs or individualized medicine products tailored to a specific patient. In this work, DAMPP was used to create dosage forms from solvent-based formulations consisting of API, polymer, and solvent carrier. The forms were then analyzed to determine the reproducibility of creating an on-target dosage form, the morphology of the API of the final form and the dissolution behavior of the drug over time. DAMPP is found to be a viable alternative to traditional mass-manufacturing methods for solvent-based oral dosage forms. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association.

  2. Can Additional Homeopathic Treatment Save Costs? A Retrospective Cost-Analysis Based on 44500 Insured Persons.

    Directory of Open Access Journals (Sweden)

    Julia K Ostermann

    Full Text Available The aim of this study was to compare the health care costs for patients using additional homeopathic treatment (homeopathy group with the costs for those receiving usual care (control group.Cost data provided by a large German statutory health insurance company were retrospectively analysed from the societal perspective (primary outcome and from the statutory health insurance perspective. Patients in both groups were matched using a propensity score matching procedure based on socio-demographic variables as well as costs, number of hospital stays and sick leave days in the previous 12 months. Total cumulative costs over 18 months were compared between the groups with an analysis of covariance (adjusted for baseline costs across diagnoses and for six specific diagnoses (depression, migraine, allergic rhinitis, asthma, atopic dermatitis, and headache.Data from 44,550 patients (67.3% females were available for analysis. From the societal perspective, total costs after 18 months were higher in the homeopathy group (adj. mean: EUR 7,207.72 [95% CI 7,001.14-7,414.29] than in the control group (EUR 5,857.56 [5,650.98-6,064.13]; p<0.0001 with the largest differences between groups for productivity loss (homeopathy EUR 3,698.00 [3,586.48-3,809.53] vs. control EUR 3,092.84 [2,981.31-3,204.37] and outpatient care costs (homeopathy EUR 1,088.25 [1,073.90-1,102.59] vs. control EUR 867.87 [853.52-882.21]. Group differences decreased over time. For all diagnoses, costs were higher in the homeopathy group than in the control group, although this difference was not always statistically significant.Compared with usual care, additional homeopathic treatment was associated with significantly higher costs. These analyses did not confirm previously observed cost savings resulting from the use of homeopathy in the health care system.

  3. Electric poling-assisted additive manufacturing process for PVDF polymer-based piezoelectric device applications

    International Nuclear Information System (INIS)

    Lee, ChaBum; Tarbutton, Joshua A

    2014-01-01

    This paper presents a new additive manufacturing (AM) process to directly and continuously print piezoelectric devices from polyvinylidene fluoride (PVDF) polymeric filament rods under a strong electric field. This process, called ‘electric poling-assisted additive manufacturing or EPAM, combines AM and electric poling processes and is able to fabricate free-form shape piezoelectric devices continuously. In this process, the PVDF polymer dipoles remain well-aligned and uniform over a large area in a single design, production and fabrication step. During EPAM process, molten PVDF polymer is simultaneously mechanically stresses in-situ by the leading nozzle and electrically poled by applying high electric field under high temperature. The EPAM system was constructed to directly print piezoelectric structures from PVDF polymeric filament while applying high electric field between nozzle tip and printing bed in AM machine. Piezoelectric devices were successfully fabricated using the EPAM process. The crystalline phase transitions that occurred from the process were identified by using the Fourier transform infrared spectroscope. The results indicate that devices printed under a strong electric field become piezoelectric during the EPAM process and that stronger electric fields result in greater piezoelectricity as marked by the electrical response and the formation of sharper peaks at the polar β crystalline wavenumber of the PVDF polymer. Performing this process in the absence of an electric field does not result in dipole alignment of PVDF polymer. The EPAM process is expected to lead to the widespread use of AM to fabricate a variety of piezoelectric PVDF polymer-based devices for sensing, actuation and energy harvesting applications with simple, low cost, single processing and fabrication step. (paper)

  4. Can Additional Homeopathic Treatment Save Costs? A Retrospective Cost-Analysis Based on 44500 Insured Persons

    Science.gov (United States)

    Ostermann, Julia K.; Reinhold, Thomas; Witt, Claudia M.

    2015-01-01

    Objectives The aim of this study was to compare the health care costs for patients using additional homeopathic treatment (homeopathy group) with the costs for those receiving usual care (control group). Methods Cost data provided by a large German statutory health insurance company were retrospectively analysed from the societal perspective (primary outcome) and from the statutory health insurance perspective. Patients in both groups were matched using a propensity score matching procedure based on socio-demographic variables as well as costs, number of hospital stays and sick leave days in the previous 12 months. Total cumulative costs over 18 months were compared between the groups with an analysis of covariance (adjusted for baseline costs) across diagnoses and for six specific diagnoses (depression, migraine, allergic rhinitis, asthma, atopic dermatitis, and headache). Results Data from 44,550 patients (67.3% females) were available for analysis. From the societal perspective, total costs after 18 months were higher in the homeopathy group (adj. mean: EUR 7,207.72 [95% CI 7,001.14–7,414.29]) than in the control group (EUR 5,857.56 [5,650.98–6,064.13]; phomeopathy EUR 3,698.00 [3,586.48–3,809.53] vs. control EUR 3,092.84 [2,981.31–3,204.37]) and outpatient care costs (homeopathy EUR 1,088.25 [1,073.90–1,102.59] vs. control EUR 867.87 [853.52–882.21]). Group differences decreased over time. For all diagnoses, costs were higher in the homeopathy group than in the control group, although this difference was not always statistically significant. Conclusion Compared with usual care, additional homeopathic treatment was associated with significantly higher costs. These analyses did not confirm previously observed cost savings resulting from the use of homeopathy in the health care system. PMID:26230412

  5. Characteristic study of chitosan addition in Tilapia (Oreochromis niloticus) bone based gelatin film

    Science.gov (United States)

    Atmaka, W.; Yudhistira, B.; Putro, M. I. S.

    2018-03-01

    Tilapia (Oreochromis niloticus) is one of popular fish species in Indonesia. The high number in tilapia’s production and export of tilapia resulting in the increase of bone fish waste. an attempt to decrease the amount of the aforementioned waste, the fish bones were turned into gelatine. The gelatine produced from this waste can be put to good use by turning it into edible film due to its high water resistance and low tensile strength value. However, in order to make a proper film, both the water resistance and the tensile strength value needs another appropriate additional biopolymer. In this case, the appropriate biopolymer needed both to form the film and to repair its characteristics is chitosan. The purpose of this research is to find out the effect of the chitosan addition on the tilapia bone based gelatine film. The research used several mixtures of gelatine (G) and chitosan (C) with the following ratio: G100:C0 (GC1), G75:C25 (GC2), G50:C50 (GC3), G25:C75 (GC4), G0:C100 (GC5). ANOVA results (Psolubility, tensile strength, elongation at break, Fourier Transform Infrared (FTIR), color a, and color b but no significant effects on the vapor permeability and color L. The best result is shown on GC2 with thickness 0.119 mm; solubility 74.95%; tensile strength 2.635 Mpa; elongation at break 68.26%; water vapor permeability 5.897 g/h m2 and FTIR. The parameters in GC2 shows good compatibility between the two biopolymers.

  6. A Novel Marking Reader for Progressive Addition Lenses Based on Gabor Holography.

    Science.gov (United States)

    Perucho, Beatriz; Picazo-Bueno, José Angel; Micó, Vicente

    2016-05-01

    Progressive addition lenses (PALs) are marked with permanent engraved marks (PEMs) at standardized locations. Permanent engraved marks are very useful through the manufacturing and mounting processes, act as locator marks to re-ink the removable marks, and contain useful information about the PAL. However, PEMs are often faint and weak, obscured by scratches, partially occluded, and difficult to recognize on tinted lenses or with antireflection or scratch-resistant coatings. The aim of this article is to present a new generation of portable marking reader based on an extremely simplified concept for visualization and identification of PEMs in PALs. Permanent engraved marks on different PALs are visualized using classical Gabor holography as underlying principle. Gabor holography allows phase sample visualization with adjustable magnification and can be implemented in either classical or digital versions. Here, visual Gabor holography is used to provide a magnified defocused image of the PEMs onto a translucent visualization screen where the PEM is clearly identified. Different types of PALs (conventional, personalized, old and scratched, sunglasses, etc.) have been tested to visualize PEMs with the proposed marking reader. The PEMs are visible in every case, and variable magnification factor can be achieved simply moving up and down the PAL in the instrument. In addition, a second illumination wavelength is also tested, showing the applicability of this novel marking reader for different illuminations. A new concept of marking reader ophthalmic instrument has been presented and validated in the laboratory. The configuration involves only a commercial-grade laser diode and a visualization screen for PEM identification. The instrument is portable, economic, and easy to use, and it can be used for identifying patient's current PAL model and for marking removable PALs again or finding test points regardless of the age of the PAL, its scratches, tints, or coatings.

  7. Characterization-Based Molecular Design of Bio-Fuel Additives Using Chemometric and Property Clustering Techniques

    International Nuclear Information System (INIS)

    Hada, Subin; Solvason, Charles C.; Eden, Mario R.

    2014-01-01

    In this work, multivariate characterization data such as infrared spectroscopy was used as a source of descriptor data involving information on molecular architecture for designing structured molecules with tailored properties. Application of multivariate statistical techniques such as principal component analysis allowed capturing important features of the molecular architecture from enormous amount of complex data to build appropriate latent variable models. Combining the property clustering techniques and group contribution methods based on characterization (cGCM) data in a reverse problem formulation enabled identifying candidate components by combining or mixing molecular fragments until the resulting properties match the targets. The developed methodology is demonstrated using molecular design of biodiesel additive, which when mixed with off-spec biodiesel produces biodiesel that meets the desired fuel specifications. The contribution of this work is that the complex structures and orientations of the molecule can be included in the design, thereby allowing enumeration of all feasible candidate molecules that matched the identified target but were not part of original training set of molecules.

  8. Repurposing mainstream CNC machine tools for laser-based additive manufacturing

    Science.gov (United States)

    Jones, Jason B.

    2016-04-01

    The advent of laser technology has been a key enabler for industrial 3D printing, known as Additive Manufacturing (AM). Despite its commercial success and unique technical capabilities, laser-based AM systems are not yet able to produce parts with the same accuracy and surface finish as CNC machining. To enable the geometry and material freedoms afforded by AM, yet achieve the precision and productivity of CNC machining, hybrid combinations of these two processes have started to gain traction. To achieve the benefits of combined processing, laser technology has been integrated into mainstream CNC machines - effectively repurposing them as hybrid manufacturing platforms. This paper reviews how this engineering challenge has prompted beam delivery innovations to allow automated changeover between laser processing and machining, using standard CNC tool changers. Handling laser-processing heads using the tool changer also enables automated change over between different types of laser processing heads, further expanding the breadth of laser processing flexibility in a hybrid CNC. This paper highlights the development, challenges and future impact of hybrid CNCs on laser processing.

  9. Wastes as Aggregates, Binders or Additions in Mortars: Selecting Their Role Based on Characterization.

    Science.gov (United States)

    Farinha, Catarina Brazão; de Brito, Jorge; Veiga, Rosário; Fernández, J M; Jiménez, J R; Esquinas, A R

    2018-03-20

    The production of waste has increased over the years and, lacking a recycle or recovery solution, it is forwarded to landfill. The incorporation of wastes in cement-based materials is a solution to reduce waste deposition. In this regard, some researchers have been studying the incorporation of wastes with different functions: aggregate, binder and addition. The incorporation of wastes should take advantage of their characteristics. It requires a judicious analysis of their particles. This research involves the analysis of seven industrial wastes: biomass ashes, glass fibre, reinforced polymer dust, sanitary ware, fluid catalytic cracking, acrylic fibre, textile fibre and glass fibre. The main characteristics and advantages of each waste are enunciated and the best type of introduction in mortars is discussed. The characterization of the wastes as particles is necessary to identify the most suitable incorporation in mortars. In this research, some wastes are studied with a view to their re-use or recycling in mortars. Thus, this research focuses on the chemical, physical and mechanical characterization of industrial wastes and identification of the potentially most advantageous type of incorporation.

  10. Wastes as Aggregates, Binders or Additions in Mortars: Selecting Their Role Based on Characterization

    Directory of Open Access Journals (Sweden)

    Catarina Brazão Farinha

    2018-03-01

    Full Text Available The production of waste has increased over the years and, lacking a recycle or recovery solution, it is forwarded to landfill. The incorporation of wastes in cement-based materials is a solution to reduce waste deposition. In this regard, some researchers have been studying the incorporation of wastes with different functions: aggregate, binder and addition. The incorporation of wastes should take advantage of their characteristics. It requires a judicious analysis of their particles. This research involves the analysis of seven industrial wastes: biomass ashes, glass fibre, reinforced polymer dust, sanitary ware, fluid catalytic cracking, acrylic fibre, textile fibre and glass fibre. The main characteristics and advantages of each waste are enunciated and the best type of introduction in mortars is discussed. The characterization of the wastes as particles is necessary to identify the most suitable incorporation in mortars. In this research, some wastes are studied with a view to their re-use or recycling in mortars. Thus, this research focuses on the chemical, physical and mechanical characterization of industrial wastes and identification of the potentially most advantageous type of incorporation.

  11. Dropwise additive manufacturing of pharmaceutical products for melt-based dosage forms.

    Science.gov (United States)

    Içten, Elçin; Giridhar, Arun; Taylor, Lynne S; Nagy, Zoltan K; Reklaitis, Gintaras V

    2015-05-01

    The US Food and Drug Administration introduced the quality by design approach and process analytical technology guidance to encourage innovation and efficiency in pharmaceutical development, manufacturing, and quality assurance. As part of this renewed emphasis on the improvement of manufacturing, the pharmaceutical industry has begun to develop more efficient production processes with more intensive use of online measurement and sensing, real-time quality control, and process control tools. Here, we present dropwise additive manufacturing of pharmaceutical products (DAMPP) as an alternative to conventional pharmaceutical manufacturing methods. This mini-manufacturing process for the production of pharmaceuticals utilizes drop on demand printing technology for automated and controlled deposition of melt-based formulations onto edible substrates. The advantages of drop-on-demand technology, including reproducible production of small droplets, adjustable drop sizing, high placement accuracy, and flexible use of different formulations, enable production of individualized dosing even for low-dose and high-potency drugs. In this work, DAMPP is used to produce solid oral dosage forms from hot melts of an active pharmaceutical ingredient and a polymer. The dosage forms are analyzed to show the reproducibility of dosing and the dissolution behavior of different formulations. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  12. Wastes as Aggregates, Binders or Additions in Mortars: Selecting Their Role Based on Characterization

    Science.gov (United States)

    de Brito, Jorge; Veiga, Rosário

    2018-01-01

    The production of waste has increased over the years and, lacking a recycle or recovery solution, it is forwarded to landfill. The incorporation of wastes in cement-based materials is a solution to reduce waste deposition. In this regard, some researchers have been studying the incorporation of wastes with different functions: aggregate, binder and addition. The incorporation of wastes should take advantage of their characteristics. It requires a judicious analysis of their particles. This research involves the analysis of seven industrial wastes: biomass ashes, glass fibre, reinforced polymer dust, sanitary ware, fluid catalytic cracking, acrylic fibre, textile fibre and glass fibre. The main characteristics and advantages of each waste are enunciated and the best type of introduction in mortars is discussed. The characterization of the wastes as particles is necessary to identify the most suitable incorporation in mortars. In this research, some wastes are studied with a view to their re-use or recycling in mortars. Thus, this research focuses on the chemical, physical and mechanical characterization of industrial wastes and identification of the potentially most advantageous type of incorporation. PMID:29558418

  13. An additive manufacturing-based PCL-alginate-chondrocyte bioprinted scaffold for cartilage tissue engineering.

    Science.gov (United States)

    Kundu, Joydip; Shim, Jin-Hyung; Jang, Jinah; Kim, Sung-Won; Cho, Dong-Woo

    2015-11-01

    Regenerative medicine is targeted to improve, restore or replace damaged tissues or organs using a combination of cells, materials and growth factors. Both tissue engineering and developmental biology currently deal with the process of tissue self-assembly and extracellular matrix (ECM) deposition. In this investigation, additive manufacturing (AM) with a multihead deposition system (MHDS) was used to fabricate three-dimensional (3D) cell-printed scaffolds using layer-by-layer (LBL) deposition of polycaprolactone (PCL) and chondrocyte cell-encapsulated alginate hydrogel. Appropriate cell dispensing conditions and optimum alginate concentrations for maintaining cell viability were determined. In vitro cell-based biochemical assays were performed to determine glycosaminoglycans (GAGs), DNA and total collagen contents from different PCL-alginate gel constructs. PCL-alginate gels containing transforming growth factor-β (TGFβ) showed higher ECM formation. The 3D cell-printed scaffolds of PCL-alginate gel were implanted in the dorsal subcutaneous spaces of female nude mice. Histochemical [Alcian blue and haematoxylin and eosin (H&E) staining] and immunohistochemical (type II collagen) analyses of the retrieved implants after 4 weeks revealed enhanced cartilage tissue and type II collagen fibril formation in the PCL-alginate gel (+TGFβ) hybrid scaffold. In conclusion, we present an innovative cell-printed scaffold for cartilage regeneration fabricated by an advanced bioprinting technology. Copyright © 2013 John Wiley & Sons, Ltd.

  14. Rapid production of hollow SS316 profiles by extrusion based additive manufacturing

    Science.gov (United States)

    Rane, Kedarnath; Cataldo, Salvatore; Parenti, Paolo; Sbaglia, Luca; Mussi, Valerio; Annoni, Massimiliano; Giberti, Hermes; Strano, Matteo

    2018-05-01

    Complex shaped stainless steel tubes are often required for special purpose biomedical equipment. Nevertheless, traditional manufacturing technologies, such as extrusion, lack the ability to compete in a market of customized complex components because of associated expenses towards tooling and extrusion presses. To rapid manufacture few of such components with low cost and high precision, a new Extrusion based Additive Manufacturing (EAM) process, is proposed in this paper, and as an example, short stainless steel 316L complex shaped and sectioned tubes were prepared by EAM. Several sample parts were produced using this process; the dimensional stability, surface roughness and chemical composition of sintered samples were investigated to prove process competence. The results indicate that feedstock with a 316L particle content of 92.5 wt. % can be prepared with a sigma blade mixing, whose rheological behavior is fit for EAM. The green samples have sufficient strength to handle them for subsequent treatments. The sintered samples considerably shrunk to designed dimensions and have a homogeneous microstructure to impart mechanical strength. Whereas, maintaining comparable dimensional accuracy and chemical composition which are required for biomedical equipment still need iterations, a kinematic correction and modification in debinding cycle was proposed.

  15. Addition and multiplication of beta-expansions in generalized Tribonacci base

    Directory of Open Access Journals (Sweden)

    Petr Ambrož

    2007-05-01

    Full Text Available We study properties of β-numeration systems, where β > 1 is the real root of the polynomial x 3  - mx 2  - x - 1, m ∈ ℕ, m ≥ 1. We consider arithmetic operations on the set of β-integers, i.e., on the set of numbers whose greedy expansion in base β has no fractional part. We show that the number of fractional digits arising under addition of β-integers is at most 5 for m ≥ 3 and 6 for m = 2, whereas under multiplication it is at most 6 for all m ≥ 2. We thus generalize the results known for Tribonacci numeration system, i.e., for m = 1. We summarize the combinatorial properties of infinite words naturally defined by β-integers. We point out the differences between the structure of β-integers in cases m = 1 and m ≥ 2.

  16. Characterization-Based Molecular Design of Bio-Fuel Additives Using Chemometric and Property Clustering Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Hada, Subin; Solvason, Charles C.; Eden, Mario R., E-mail: edenmar@auburn.edu [Department of Chemical Engineering, Auburn University, Auburn, AL (United States)

    2014-06-10

    In this work, multivariate characterization data such as infrared spectroscopy was used as a source of descriptor data involving information on molecular architecture for designing structured molecules with tailored properties. Application of multivariate statistical techniques such as principal component analysis allowed capturing important features of the molecular architecture from enormous amount of complex data to build appropriate latent variable models. Combining the property clustering techniques and group contribution methods based on characterization (cGCM) data in a reverse problem formulation enabled identifying candidate components by combining or mixing molecular fragments until the resulting properties match the targets. The developed methodology is demonstrated using molecular design of biodiesel additive, which when mixed with off-spec biodiesel produces biodiesel that meets the desired fuel specifications. The contribution of this work is that the complex structures and orientations of the molecule can be included in the design, thereby allowing enumeration of all feasible candidate molecules that matched the identified target but were not part of original training set of molecules.

  17. The Importance of Rare-Earth Additions in Zr-Based AB2 Metal Hydride Alloys

    Directory of Open Access Journals (Sweden)

    Kwo-Hsiung Young

    2016-07-01

    Full Text Available Effects of substitutions of rare earth (RE elements (Y, La, Ce, and Nd to the Zr-based AB2 multi-phase metal hydride (MH alloys on the structure, gaseous phase hydrogen storage (H-storage, and electrochemical properties were studied and compared. Solubilities of the RE atoms in the main Laves phases (C14 and C15 are very low, and therefore the main contributions of the RE additives are through the formation of the RENi phase and change in TiNi phase abundance. Both the RENi and TiNi phases are found to facilitate the bulk diffusion of hydrogen but impede the surface reaction. The former is very effective in improving the activation behaviors. −40 °C performances of the Ce-doped alloys are slightly better than the Nd-doped alloys but not as good as those of the La-doped alloys, which gained the improvement through a different mechanism. While the improvement in ultra-low-temperature performance of the Ce-containing alloys can be associated with a larger amount of metallic Ni-clusters embedded in the surface oxide, the improvement in the La-containing alloys originates from the clean alloy/oxide interface as shown in an earlier transmission electron microscopy study. Overall, the substitution of 1 at% Ce to partially replace Zr gives the best electrochemical performances (capacity, rate, and activation and is recommended for all the AB2 MH alloys for electrochemical applications.

  18. Characterization-Based Molecular Design of Biofuel Additives Using Chemometric and Property Clustering Techniques

    Directory of Open Access Journals (Sweden)

    Subin eHada

    2014-06-01

    Full Text Available In this work, multivariate characterization data such as infrared (IR spectroscopy was used as a source of descriptor data involving information on molecular architecture for designing structured molecules with tailored properties. Application of multivariate statistical techniques such as principal component analysis (PCA allowed capturing important features of the molecular architecture from complex data to build appropriate latent variable models. Combining the property clustering techniques and group contribution methods (GCM based on characterization data in a reverse problem formulation enabled identifying candidate components by combining or mixing molecular fragments until the resulting properties match the targets. The developed methodology is demonstrated using molecular design of biodiesel additive which when mixed with off-spec biodiesel produces biodiesel that meets the desired fuel specifications. The contribution of this work is that the complex structures and orientations of the molecule can be included in the design, thereby allowing enumeration of all feasible candidate molecules that matched the identified target but were not part of original training set of molecules.

  19. Aqueous dispersion of red clay-based ceramic powder with the addition of starch

    Directory of Open Access Journals (Sweden)

    Maria Victoria Alcantar Umaran

    2013-04-01

    Full Text Available The optimum dispersion and rheological properties of red clay-based ceramic suspension loaded with unary and binary starch were investigated in aqueous medium. The aqueous ceramic suspension was prepared consisting of red clay, quartz, feldspar, and distilled water. Using a polyelectrolyte dispersant (Darvan 821A, the ternary ceramic powder was initially optimized to give the smallest average particle size at 0.8 wt. (% dispersant dosage as supported by sedimentation test. This resulted into an optimum high solid loading of 55 wt. (%. The addition of either unary or binary starches to the optimized ceramic slurry increased the viscosity but maintained an acceptable fluidity. The mechanism of such viscosity increase was found to be due to an adsorption of starch granules onto ceramic surfaces causing tolerable agglomeration. Correspondingly, the rheological evaluations showed that the flow behaviors of all starch-loaded ceramic slurries can be described using Herschel-Bulkley model. The parameters from this model indicated that all ceramic slurries loaded with starch are shear thinning that is required for direct casting process.

  20. Improving precipitation hardening behavior of Mg−Zn based alloys with Ce−Ca microalloying additions

    Energy Technology Data Exchange (ETDEWEB)

    Langelier, B., E-mail: langelb@mcmaster.ca [Mechanical & Mechatronics Engineering, The University of Waterloo, N2L 3G1 (Canada); Canadian Centre for Electron Microscopy, McMaster University, L8S 4L8 (Canada); Korinek, A. [Canadian Centre for Electron Microscopy, McMaster University, L8S 4L8 (Canada); Donnadieu, P. [Univ. Grenoble Alpes, SIMAP, F-38000 Grenoble (France); CNRS, SIMAP, F-38000 Grenoble (France); Esmaeili, S. [Mechanical & Mechatronics Engineering, The University of Waterloo, N2L 3G1 (Canada)

    2016-10-15

    The precipitation hardening behavior of newly developed Mg−Zn−Ca−Ce alloys, with modified texture and improved ductility, is studied to delineate the microstructural characteristics that lead to effective hardening upon ageing treatments. Advanced electron microscopy and atom probe techniques are used to analyze the structural characteristics in relevance to the hardening potential. It has been found that the formation of a new basal precipitate phase, which evolves from a single atomic layer GP zone, and is finely distributed in both under-aged and peak-aged microstructures, has a significant impact in the improvement of the hardening response compared with the base Mg−Zn alloys. It has also been found that the β′{sub 1} rod precipitates, commonly formed during ageing treatments of Mg−Zn alloys, have their size and distribution significantly refined in the Ca−Ce containing alloys. The role of alloy chemistry in the formation of the fine basal plate GP zones and the refinement in β′{sub 1} precipitation and their relationships to the hardening behavior are discussed. It is proposed that Ca microalloying governs the formation of the GP zones and the enhancement of hardening, particularly in the under-aged conditions, but that this is aided by a beneficial effect from Ce. - Highlights: • Ce−Ca microalloying additions improve hardening in Mg−Zn, over Ce or Ca alone. • Improved hardening is due to refined β′{sub 1} rods, and fine basal plate precipitates. • Atom probe tomography identifies Ca in both β′{sub 1} and the fine basal plates. • The fine basal plates originate as ordered monolayer GP zones with 1:1 Zn:Ca (at.%). • With ageing GP zones become more Zn-rich and transform to the fine basal plates.

  1. Tricalcium phosphate based resorbable ceramics: Influence of NaF and CaO addition

    Energy Technology Data Exchange (ETDEWEB)

    Seeley, Zachary; Bandyopadhyay, Amit [W. M. Keck Biomedical Materials Research Lab, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164 (United States); Bose, Susmita [W. M. Keck Biomedical Materials Research Lab, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164 (United States)], E-mail: sbose@wsu.edu

    2008-01-10

    Resorbable bioceramics have gained much attention due to their time-varying mechanical properties in-vivo. Implanted ceramics degrade allowing bone in-growth and eventual replacement of the artificial material with natural tissue. Calcium phosphate based materials have caught the most significant attention because of their excellent biocompatibility and compositional similarities to natural bone. Doping these ceramics with various metal ions has significantly influenced their properties. In this study, tricalcium phosphate (TCP) compacts were fabricated via uniaxial compression with five compositions: (i) pure TCP, (ii) TCP with 2.0 wt.% NaF, (iii) TCP with 3.0 wt.% CaO, (iv) TCP with a binary of 2.0 wt.% NaF and 0.5 wt.% Ag{sub 2}O, and (v) TCP with a quaternary of 1.0 wt.% TiO{sub 2}, 0.5 wt.% Ag{sub 2}O, 2.0 wt.% NaF, and 3.0 wt.% CaO. These compacts were sintered at 1250 deg. C for 4 h to obtain dense ceramic structures. Phase analyses were carried out using X-ray diffraction. The presence of NaF in TCP improved densification and increased compression strength from 70 ({+-} 25) to 130 ({+-} 40) MPa. Addition of CaO had no influence on density or strength. Human osteoblast cell growth behavior was studied using an osteoprecursor cell line (OPC 1) to assure that the biocompatibility of these ceramics was not altered due to the dopants. For long-term biodegradation studies, density, weight change, surface microstructure, and uniaxial compression strength were measured as a function of time in a simulated body fluid (SBF). Weight gain in SBF correlated strongly with precipitation viewed in the inter-connected pores of the samples. After 3 months in SBF, all samples displayed a reduction in strength. NaF, CaO and the quaternary compositions maintained the most steady strength loss under SBF.

  2. Microstructure of rapidly solidified Nb-based pre-alloyed powders for additive manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Yueling; Jia, Lina, E-mail: jialina@buaa.edu.cn; Kong, Bin; Zhang, Shengnan; Zhang, Fengxiang; Zhang, Hu

    2017-07-01

    Highlights: • Sphere shaped Nb-37Ti-13Cr-2Al-1Si pre-alloyed powders were prepared by PREP. • An oxide layer with a thickness of 9.39 nm was generated on the powder surface. • The main phases of the pre-alloyed powders were Nbss and Cr{sub 2}Nb. • SDAS increased and microhardness decreased with the increase of powder size. • Microstructure of powders evolved into large grains from dendrite structures after HT. - Abstract: For powder-based additive manufacturing, sphere-shaped Nb-37Ti-13Cr-2Al-1Si pre-alloyed powders were prepared by plasma rotating electrode processing (PREP). The microstructure, surface oxidation and microhardness of the pre-alloyed powders were systematically investigated. Results showed that the main phases were Nb solid solution (Nbss) and Cr{sub 2}Nb. The Cr{sub 2}Nb phases were further determined using transmission electron microscopy (TEM). Fine dendrite structures were observed in the as-fabricated pre-alloyed powders, which transformed to large grains after heat treatment (HT) at 1450 °C for 3 h. With the increase of powder size, the secondary dendrite arm spacing (SDAS) increased and the microhardness (HV) decreased. A clean powder surface free of oxide particles was obtained by PREP and an oxide layer with 9.39 nm in thickness was generated on the powder surface. Compared with Cr- and Nb-oxides, more Ti-oxides were formed on outmost powder surface with a higher content of Ti (up to 47.86 at.%). The differences upon the microstructure and microhardness of the pre-alloyed powders with different sizes were discussed.

  3. Topsoil organic carbon content of Europe, a new map based on a generalised additive model

    Science.gov (United States)

    de Brogniez, Delphine; Ballabio, Cristiano; Stevens, Antoine; Jones, Robert J. A.; Montanarella, Luca; van Wesemael, Bas

    2014-05-01

    There is an increasing demand for up-to-date spatially continuous organic carbon (OC) data for global environment and climatic modeling. Whilst the current map of topsoil organic carbon content for Europe (Jones et al., 2005) was produced by applying expert-knowledge based pedo-transfer rules on large soil mapping units, the aim of this study was to replace it by applying digital soil mapping techniques on the first European harmonised geo-referenced topsoil (0-20 cm) database, which arises from the LUCAS (land use/cover area frame statistical survey) survey. A generalized additive model (GAM) was calibrated on 85% of the dataset (ca. 17 000 soil samples) and a backward stepwise approach selected slope, land cover, temperature, net primary productivity, latitude and longitude as environmental covariates (500 m resolution). The validation of the model (applied on 15% of the dataset), gave an R2 of 0.27. We observed that most organic soils were under-predicted by the model and that soils of Scandinavia were also poorly predicted. The model showed an RMSE of 42 g kg-1 for mineral soils and of 287 g kg-1 for organic soils. The map of predicted OC content showed the lowest values in Mediterranean countries and in croplands across Europe, whereas highest OC content were predicted in wetlands, woodlands and in mountainous areas. The map of standard error of the OC model predictions showed high values in northern latitudes, wetlands, moors and heathlands, whereas low uncertainty was mostly found in croplands. A comparison of our results with the map of Jones et al. (2005) showed a general agreement on the prediction of mineral soils' OC content, most probably because the models use some common covariates, namely land cover and temperature. Our model however failed to predict values of OC content greater than 200 g kg-1, which we explain by the imposed unimodal distribution of our model, whose mean is tilted towards the majority of soils, which are mineral. Finally, average

  4. Advanced Process Chains for Prototyping and Pilot Production based on Additive Manufacturing

    DEFF Research Database (Denmark)

    Mischkot, Michael

    2015-01-01

    For many years, Additive Manufacturing (AM) has been a well-established production technology used mainly for rapid prototyping. But the need for increased flexibility and economic low volume production led to the discovery of Additive Manufacturing as a suitable fabrication technique (Mellor 2013...

  5. Polyelectrolyte addition effect on the properties of setting hydraulic cements based on calcium phosphate

    International Nuclear Information System (INIS)

    Santos, Luis A. dos; Oliveira, Luci C. de; Rigo, Eliana C.S.; Boschi, Anselmo Ortega; Carrodeguas, Raul Gracia

    1997-01-01

    In the present work the effects of the addition of some poly electrolytes (sodium alginate and poly acrylic acid) on the solubility, crystalline phases, pH and mechanical strength under compression of three calcium phosphate cements were studied. (author)

  6. Classification of suppressor additives based on synergistic and antagonistic ensemble effects

    Energy Technology Data Exchange (ETDEWEB)

    Broekmann, P., E-mail: peter.broekmann@iac.unibe.ch [BASF SE, Global Business Unit Electronic Materials, 67056 Ludwigshafen (Germany); Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland); Fluegel, A.; Emnet, C.; Arnold, M.; Roeger-Goepfert, C.; Wagner, A. [BASF SE, Global Business Unit Electronic Materials, 67056 Ludwigshafen (Germany); Hai, N.T.M. [Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland); Mayer, D. [BASF SE, Global Business Unit Electronic Materials, 67056 Ludwigshafen (Germany)

    2011-05-01

    Highlights: > Three fundamental types of suppressor additives for copper electroplating could be identified by means of potential transient measurements. > These suppressor additives differ in their synergistic and antagonistic interplay with anions that are chemisorbed on the metallic copper surface during electrodeposition. > In addition these suppressor chemistries reveal different barrier properties with respect to cupric ions and plating additives (Cl, SPS). - Abstract: Three fundamental types of suppressor additives for copper electroplating could be identified by means of potential transient measurements. These suppressor additives differ in their synergistic and antagonistic interplay with anions that are chemisorbed on the metallic copper surface during electrodeposition. In addition these suppressor chemistries reveal different barrier properties with respect to cupric ions and plating additives (Cl, SPS). While the type-I suppressor selectively forms efficient barriers for copper inter-diffusion on chloride-terminated electrode surfaces we identified a type-II suppressor that interacts non-selectively with any kind of anions chemisorbed on copper (chloride, sulfate, sulfonate). Type-I suppressors are vital for the superconformal copper growth mode in Damascene processing and show an antagonistic interaction with SPS (Bis-Sodium-Sulfopropyl-Disulfide) which involves the deactivation of this suppressor chemistry. This suppressor deactivation is rationalized in terms of compositional changes in the layer of the chemisorbed anions due to the competition of chloride and MPS (Mercaptopropane Sulfonic Acid) for adsorption sites on the metallic copper surface. MPS is the product of the dissociative SPS adsorption within the preexisting chloride matrix on the copper surface. The non-selectivity in the adsorption behavior of the type-II suppressor is rationalized in terms of anion/cation pairing effects of the poly-cationic suppressor and the anion-modified copper

  7. Effect of revert addition on microstructure and mechanical properties of M951 Ni-base superalloy

    International Nuclear Information System (INIS)

    Yang, Y.H.; Yu, J.J.; Sun, X.F.; Jin, T.; Guan, H.R.; Hu, Z.Q.

    2012-01-01

    Highlights: ► The microstructure is not influenced by the additions of recycled alloy. ► The stress rupture life significantly decreases with addition of recycled alloy. ► The stress rupture life is remarkably dependent on various revert additions. ► The stress rupture life has been significantly improved after filtration. ► The melt filtered through 20 ppi shows the lowest stress rupture life. - Abstract: The effect of recycled alloy proportion on the composition, microstructure and mechanical properties of M951 alloy has been investigated. With the addition of the recycled alloy proportion, the concentrations of boron and carbon obviously decrease. The microstructure is not influenced by the additions of recycled alloy. The stress rupture life significantly decreases with the addition of recycled alloy proportion. Because of the removal of oxide inclusions by filtration, the stress rupture life has been significantly improved, and it also shows a clear dependence upon passage size of the filter. The melt filtered through passage size of 20 ppi shows the lowest stress rupture life.

  8. Novel detached system to MnCO3 nanowires: A self-sacrificing template for homomorphous Mn3O4 and α-Mn2O3 nanostructures

    International Nuclear Information System (INIS)

    Lei Shuijin; Peng Xiaomin; Li Xiuping; Liang Zhihong; Yang Yi; Cheng Baochang; Xiao Yanhe; Zhou Lang

    2011-01-01

    Research highlights: → A novel detached system along with solvothermal treatment was developed. → Radially aggregated MnCO 3 nanowires were successfully fabricated. → The detached system, solvent, surfactant and reaction time were important. → MnCO 3 nanowires could act as the self-sacrificing template for Mn 3 O 4 and α-Mn 2 O 3 . - Abstract: MnCO 3 , an important raw material, exhibits attractive properties and significant industrial applications. However, few concerns have been raised on the fabrication of its 1D nanostructures. In this paper, a novel detached system was successfully employed for the preparation of MnCO 3 nanowires by a surfactant-assisted solvothermal treatment using N,N-dimethylformamide as the solvent and cetyltrimethylammonium bromide as the surfactant. X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy were employed to study the crystal structure and morphologies of the products. Experiments showed that the detached system, solvent, surfactant and reaction time were critical for the formation of the MnCO 3 nanowires. The thermal characterization was studied by differential scanning calorimetric analysis and thermogravimetric analysis measurements. The experimental results demonstrated that the as-prepared MnCO 3 nanocrystals can act as an efficient precursor for production of homomorphous Mn 3 O 4 and α-Mn 2 O 3 nanostructures by calcination at 400 deg. C under the atmosphere of argon and air, respectively. A possible growth mechanism for the MnCO 3 nanowires was also proposed.

  9. Boosting the Performance of Ionic-Liquid-Based Supercapacitors with Polar Additives

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Kun [Univ. of California, Riverside, CA (United States). Dept. of Chemical and Environmental Engineering; Wu, Jianzhong [Univ. of California, Riverside, CA (United States). Dept. of Chemical and Environmental Engineering

    2016-10-05

    Recent years have witnessed growing interests in both the fundamentals and applications of electric double layer capacitors (EDLCs), also known as supercapacitors. A number of strategies have been explored to optimize the device performance in terms of both the energy and power densities. Because the properties of electric double layers (EDL) are sensitive to ion distributions in the close vicinity of the electrode surfaces, the supercapacitor performance is sensitive to both the electrode pore structure and the electrolyte composition. In this paper, we study the effects of polar additives on EDLC capacitance using the classical density functional theory within the framework of a coarse-grained model for the microscopic structure of the porous electrodes and room-temperature ionic liquids. The theoretical results indicate that a highly polar, low-molecular-weight additive is able to drastically increase the EDLC capacitance at low bulk concentration. Additionally, the additive is able to dampen the oscillatory dependence of the capacitance on the pore size, thereby boosting the performance of amorphous electrode materials. Finally, the theoretical predictions are directly testable with experiments and provide new insights into the additive effects on EDL properties.

  10. Influence of agglomeration of a recycled cement additive on the hydration and microstructure development of cement based materials

    NARCIS (Netherlands)

    Yu, R.; Shui, Z.H.

    2013-01-01

    This paper presents a study, including experimental and mechanism analysis, on investigating the effect of agglomeration of a recycled cement additive on the hydration and microstructure development of cement based materials. The recycled additive is firstly produced form waste hardened cement paste

  11. Network Physics - the only company to provide physics-based network management - secures additional funding and new executives

    CERN Multimedia

    2003-01-01

    "Network Physics, the only provider of physics-based network management products, today announced an additional venture round of $6 million in funding, as well as the addition of David Jones as president and CEO and Tom Dunn as vice president of sales and business development" (1 page).

  12. Application of Finite Element, Phase-field, and CALPHAD-based Methods to Additive Manufacturing of Ni-based Superalloys.

    Science.gov (United States)

    Keller, Trevor; Lindwall, Greta; Ghosh, Supriyo; Ma, Li; Lane, Brandon M; Zhang, Fan; Kattner, Ursula R; Lass, Eric A; Heigel, Jarred C; Idell, Yaakov; Williams, Maureen E; Allen, Andrew J; Guyer, Jonathan E; Levine, Lyle E

    2017-10-15

    Numerical simulations are used in this work to investigate aspects of microstructure and microseg-regation during rapid solidification of a Ni-based superalloy in a laser powder bed fusion additive manufacturing process. Thermal modeling by finite element analysis simulates the laser melt pool, with surface temperatures in agreement with in situ thermographic measurements on Inconel 625. Geometric and thermal features of the simulated melt pools are extracted and used in subsequent mesoscale simulations. Solidification in the melt pool is simulated on two length scales. For the multicomponent alloy Inconel 625, microsegregation between dendrite arms is calculated using the Scheil-Gulliver solidification model and DICTRA software. Phase-field simulations, using Ni-Nb as a binary analogue to Inconel 625, produced microstructures with primary cellular/dendritic arm spacings in agreement with measured spacings in experimentally observed microstructures and a lesser extent of microsegregation than predicted by DICTRA simulations. The composition profiles are used to compare thermodynamic driving forces for nucleation against experimentally observed precipitates identified by electron and X-ray diffraction analyses. Our analysis lists the precipitates that may form from FCC phase of enriched interdendritic compositions and compares these against experimentally observed phases from 1 h heat treatments at two temperatures: stress relief at 1143 K (870 °C) or homogenization at 1423 K (1150 °C).

  13. Producing carbon-based boundary films from catalytically active lubricant additives

    Science.gov (United States)

    Erdemir, Ali; Mane, Anil U.; Elam, Jeffrey W.; Ramirez, Giovanni; Eryilmaz, Osman

    2018-04-24

    A lubricant composition includes an oil including a plurality of long-chain hydrocarbon molecules. A quantity of a catalytically active metal-organic additive is mixed with the oil. The metal-organic additive is formulated to fragment the long-chain hydrocarbon molecules of the oil into at least one of dimers and trimers under the influence of at least one of a mechanical loading and a thermal loading. In some embodiments, the metal-organic additive includes a compound of formula II: ##STR00001## where: X is Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Rf, Db, Sg, Bh, Hs, Mt, Ds, Rg or Cn, and R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are alkyl or alkyl halide.

  14. Enhancing PCR Amplification of DNA from Recalcitrant Plant Specimens Using a Trehalose-Based Additive

    Directory of Open Access Journals (Sweden)

    Tharangamala Samarakoon

    2013-01-01

    Full Text Available Premise of the study: PCR amplification of DNA extracted from plants is sometimes difficult due to the presence of inhibitory compounds. An effective method to overcome the inhibitory effect of compounds that contaminate DNA from difficult plant specimens is needed. Methods and Results: The effectiveness of a PCR additive reagent containing trehalose, bovine serum albumin (BSA, and polysorbate-20 (Tween-20 (TBT-PAR was tested. PCR of DNA extracted from fresh, silica-dried, and herbarium leaf material of species of Achariaceae, Asteraceae, Lacistemataceae, and Samydaceae that failed using standard techniques were successful with the addition of TBT-PAR. Conclusions: The addition of TBT-PAR during routine PCR is an effective method to improve amplification of DNA extracted from herbarium specimens or plants that are known to contain PCR inhibitors.

  15. Low-cost Electromagnetic Heating Technology for Polymer Extrusion-based Additive Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Carter, William G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rios, Orlando [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Akers, Ronald R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Morrison, William A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-01-07

    To improve the flow of materials used in in polymer additive manufacturing, ORNL and Ajax Tocco created an induction system for heating fused deposition modeling (FDM) nozzles used in polymer additive manufacturing. The system is capable of reaching a temperature of 230 C, a typical nozzle temperature for extruding ABS polymers, in 17 seconds. A prototype system was built at ORNL and sent to Ajax Tocco who analyzed the system and created a finalized power supply. The induction system was mounted to a PrintSpace Altair desktop printer and used to create several test parts similar in quality to those created using a resistive heated nozzle.

  16. Lewis base additives improve the zeolite ferrierite-catalyzed synthesis of isostearic acid

    Science.gov (United States)

    Isostearic acid (IA) is of interest for industrial purposes especially in the area of biolubricants, such as cosmetics and slip additives for polyolefin and related copolymer films. This study was designed to develop a zeolitic catalysis process for IA production through isomerization of fatty aci...

  17. Electrical and magnetic properties of Fe-based bulk metallic glass with minor Co and Ni addition

    Energy Technology Data Exchange (ETDEWEB)

    Jung, H.Y. [IFW Dresden, Institute for Complex Materials, D–01069 Dresden (Germany); Stoica, M. [IFW Dresden, Institute for Complex Materials, D–01069 Dresden (Germany); POLITEHNICA University of Timisoara, P-ta Victoriei 2, Timisoara (Romania); Yi, S. [Department of Materials Science and Metallurgical Engineering, Kyungpook National University, 702–701 Daegu (Korea, Republic of); Kim, D.H. [Center for Non-crystalline Materials, Department of Metallurgical Engineering, Yonsei University, 120–749 Seoul (Korea, Republic of); Eckert, J. [IFW Dresden, Institute for Complex Materials, D–01069 Dresden (Germany); University of Technology Dresden, Institute of Materials Science, D–01062 Dresden (Germany)

    2014-09-01

    The effect of minor Co and Ni alloying on soft magnetic properties and electrical resistivity of Fe{sub 75.5}C{sub 7.0}Si{sub 3.3}B{sub 5.5}P{sub 8.7} (at%) bulk metallic glass has been investigated. Within examined compositional range (Co and Ni up to 4 at%, respectively), the saturation magnetization and electrical resistivity of the alloys continuously decrease with increasing Co or Ni content, while the Curie temperature and initial permeability increase. Comparing the effect of Co and Ni additions, the alloys with Co addition have much higher Curie temperature and saturation magnetization than the alloy with Ni addition. Also, the Co-added alloys show smaller coercivity and larger permeability than the Ni-added alloys. The present results suggest that minor addition of Co can provide better effectiveness to enhance the magnetic softness of Fe-based BMGs than minor Ni addition. - Highlights: • Soft magnetic characteristics of CI-based BMGs can be enhanced with minor Co and Ni alloying. • Minor Co addition can provide better effectiveness to enhance the magnetic softness of CI-based BMG than Ni addition. • Optimum Co addition enlarges atomic packing density and randomness of amorphous structure.

  18. Bio-based renewable additives for anti-icing applications (phase one).

    Science.gov (United States)

    2016-09-04

    The performance and impacts of several bio-based anti-icers along with a traditional chloride-based anti-icer (salt brine) were evaluated. : A statistical design of experiments (uniform design) was employed for developing anti-icing liquids consistin...

  19. Laser additive manufacturing of multimaterial tool inserts: a simulation-based optimization study

    DEFF Research Database (Denmark)

    Mohanty, Sankhya; Hattel, Jesper Henri

    2017-01-01

    laser additive manufacturing. The physical handling of multi-material in a SLM setup continues to be a primary challenge along with the selection of process parameters/plan to achieve the desired results – both challenges requiring considerable experimental undertakings. Consequently, numerical process...... which a layer of steel has been deposited using cold-spraying technique, such as to protect the microstructure of Ni during selective laser melting. The process modelled thus entails additively manufacturing a steel tool insert around the multi-material specimen with a goal of achieving a dense product......Selective laser melting is fast evolving into an industrially applicable manufacturing process. While components produced from high-value materials, such as Ti6Al4V and Inconel 718 alloys, are already being produced, the processing of multi-material components still remains to be achieved by using...

  20. Qualification of laser based additive production for manufacturing of forging Tools

    Directory of Open Access Journals (Sweden)

    Junker Daniel

    2015-01-01

    Full Text Available Mass customization leads to very short product life cycles, so the costs of a tool have to be amortized with a low number of workpieces. Especially for highly loaded tools, like those for forging, that leads to expensive products. Therefore more economical production processes for tool manufacturing have to be investigated. As laser additive manufacturing is already used for the production of moulds for injection moulding, this technology maybe could also improve the forging tool production. Within this paper laser metal deposition, which is industrially used for tool repair, will be investigated for the use in tool manufacturing. Therefore a mechanical characterization of parts built with different laser process parameters out of the hot work tool steel 1.2709 is made by upsetting tests and hardness measurements. So the influence of the additive manufacturing process on the hardness distribution is analysed.

  1. Metalorganic solution deposition of lead zirconate titanate films onto an additively manufactured Ni-based superalloy

    International Nuclear Information System (INIS)

    Patel, T.; Khassaf, H.; Vijayan, S.; Bassiri-Gharb, N.; Aindow, M.; Alpay, S.P.; Hebert, R.J.

    2017-01-01

    Recent advances in additive manufacturing of high-temperature alloys for structural aerospace applications has led to interest in integrating additional functionality into such parts. Lead zirconate titanate (PZT) is a prototypical ferroelectric ceramic used as the electro-active material in many piezoelectric sensors and actuators. In this study, 300 nm thick PbZr_0_._2Ti_0_._8O_3 (PZT 20/80) films were grown using metalorganic solution deposition onto additively manufactured substrates of Inconel 718. The microstructures of the films and the nature of the film/substrate interfaces were characterized using a combination of X-ray diffraction and electron microscopy techniques. Electrical measurements were performed to determine the ferroelectric, dielectric, and conductive responses of the PZT films. Our findings show that the PZT films exhibit robust ferroelectricity characterized by well-defined polarization-applied electric field (P-E) hysteresis loops. The samples display internal bias of up to ∼40 kV/cm. The room temperature remnant polarization and the small signal dielectric permittivity are ∼70 μC/cm"2 and 205, respectively. The dielectric loss (tan δ) and the leakage current at 1 kHz are 9% and 1 nA at 1 V, respectively. We attribute the internal bias observed in the hysteresis loops and the overall large dielectric losses to the presence of an intermediate oxide layer at the PZT/Inconel interface, which forms during the high temperature crystallization of the ferroelectric film. These results show that it is possible to grow functional oxides with promising electrical properties onto additively manufactured metallic substrates.

  2. Food additives and children's behaviour: evidence based policy at the margins of certainty

    OpenAIRE

    Stevenson, Jim

    2009-01-01

    The possible effects of food additives (specifically artificial colours) have been debated for over 30 years. The evidence accumulated suggests that for some children with attention deficit hyperactivity disorder (ADHD) food colours exacerbate their condition. Two studies undertaken by a research group at the University of Southampton have extended these findings to the effects on hyperactivity in children from the general population who do not show ADHD. This article reviews the response ...

  3. Mechanical Properties of a Newly Additive Manufactured Implant Material Based on Ti-42Nb.

    Science.gov (United States)

    Schulze, Christian; Weinmann, Markus; Schweigel, Christoph; Keßler, Olaf; Bader, Rainer

    2018-01-13

    The application of Ti-6Al-4V alloy or commercially pure titanium for additive manufacturing enables the fabrication of complex structural implants and patient-specific implant geometries. However, the difference in Young's modulus of α + β-phase Ti alloys compared to the human bone promotes stress-shielding effects in the implant-bone interphase. The aim of the present study is the mechanical characterization of a new pre-alloyed β-phase Ti-42Nb alloy for application in additive manufacturing. The present investigation focuses on the mechanical properties of SLM-printed Ti-42Nb alloy in tensile and compression tests. In addition, the raw Ti-42Nb powder, the microstructure of the specimens prior to and after compression tests, as well as the fracture occurring in tensile tests are characterized by means of the SEM/EDX analysis. The Ti-42Nb raw powder exhibits a dendrite-like Ti-structure, which is melted layer-by-layer into a microstructure with a very homogeneous distribution of Nb and Ti during the SLM process. Tensile tests display Young's modulus of 60.51 ± 3.92 GPa and an ultimate tensile strength of 683.17 ± 16.67 MPa, whereas, under a compressive load, a compressive strength of 1330.74 ± 53.45 MPa is observed. The combination of high mechanical strength and low elastic modulus makes Ti-42Nb an interesting material for orthopedic and dental implants. The spherical shape of the pre-alloyed material additionally allows for application in metal 3D printing, enabling the fabrication of patient-specific structural implants.

  4. Mechanical Properties of a Newly Additive Manufactured Implant Material Based on Ti-42Nb

    Directory of Open Access Journals (Sweden)

    Christian Schulze

    2018-01-01

    Full Text Available The application of Ti-6Al-4V alloy or commercially pure titanium for additive manufacturing enables the fabrication of complex structural implants and patient-specific implant geometries. However, the difference in Young’s modulus of α + β-phase Ti alloys compared to the human bone promotes stress-shielding effects in the implant–bone interphase. The aim of the present study is the mechanical characterization of a new pre-alloyed β-phase Ti-42Nb alloy for application in additive manufacturing. The present investigation focuses on the mechanical properties of SLM-printed Ti-42Nb alloy in tensile and compression tests. In addition, the raw Ti-42Nb powder, the microstructure of the specimens prior to and after compression tests, as well as the fracture occurring in tensile tests are characterized by means of the SEM/EDX analysis. The Ti-42Nb raw powder exhibits a dendrite-like Ti-structure, which is melted layer-by-layer into a microstructure with a very homogeneous distribution of Nb and Ti during the SLM process. Tensile tests display Young’s modulus of 60.51 ± 3.92 GPa and an ultimate tensile strength of 683.17 ± 16.67 MPa, whereas, under a compressive load, a compressive strength of 1330.74 ± 53.45 MPa is observed. The combination of high mechanical strength and low elastic modulus makes Ti-42Nb an interesting material for orthopedic and dental implants. The spherical shape of the pre-alloyed material additionally allows for application in metal 3D printing, enabling the fabrication of patient-specific structural implants.

  5. Development of a QTL-environment-based predictive model for node addition rate in common bean.

    Science.gov (United States)

    Zhang, Li; Gezan, Salvador A; Eduardo Vallejos, C; Jones, James W; Boote, Kenneth J; Clavijo-Michelangeli, Jose A; Bhakta, Mehul; Osorno, Juan M; Rao, Idupulapati; Beebe, Stephen; Roman-Paoli, Elvin; Gonzalez, Abiezer; Beaver, James; Ricaurte, Jaumer; Colbert, Raphael; Correll, Melanie J

    2017-05-01

    This work reports the effects of the genetic makeup, the environment and the genotype by environment interactions for node addition rate in an RIL population of common bean. This information was used to build a predictive model for node addition rate. To select a plant genotype that will thrive in targeted environments it is critical to understand the genotype by environment interaction (GEI). In this study, multi-environment QTL analysis was used to characterize node addition rate (NAR, node day - 1 ) on the main stem of the common bean (Phaseolus vulgaris L). This analysis was carried out with field data of 171 recombinant inbred lines that were grown at five sites (Florida, Puerto Rico, 2 sites in Colombia, and North Dakota). Four QTLs (Nar1, Nar2, Nar3 and Nar4) were identified, one of which had significant QTL by environment interactions (QEI), that is, Nar2 with temperature. Temperature was identified as the main environmental factor affecting NAR while day length and solar radiation played a minor role. Integration of sites as covariates into a QTL mixed site-effect model, and further replacing the site component with explanatory environmental covariates (i.e., temperature, day length and solar radiation) yielded a model that explained 73% of the phenotypic variation for NAR with root mean square error of 16.25% of the mean. The QTL consistency and stability was examined through a tenfold cross validation with different sets of genotypes and these four QTLs were always detected with 50-90% probability. The final model was evaluated using leave-one-site-out method to assess the influence of site on node addition rate. These analyses provided a quantitative measure of the effects on NAR of common beans exerted by the genetic makeup, the environment and their interactions.

  6. Effect of commercial mineral-based additives on composting and compost quality.

    Science.gov (United States)

    Himanen, M; Hänninen, K

    2009-08-01

    The effectiveness of two commercial additives meant to improve the composting process was studied in a laboratory-scale experiment. Improver A (sulphates and oxides of iron, magnesium, manganese, and zinc mixed with clay) and B (mixture of calcium hydroxide, peroxide, and oxide) were added to source-separated biowaste:peat mixture (1:1, v/v) in proportions recommended by the producers. The composting process (T, emissions of CO(2), NH(3), and CH(4)) and the quality of the compost (pH, conductivity, C/N ratio, water-soluble NH(4)-N and NO(3)-N, water- and NaOH-soluble low-weight carboxylic acids, nutrients, heavy metals and phytotoxicity to Lepidium sarivum) were monitored during one year. Compared with the control, the addition of improver B increased pH by two units, led to an earlier elimination of water-soluble ammonia, an increase in nitrates, a 10-fold increase in concentrations of acetic acid, and shortened phytotoxicity period by half; as negative aspect it led to volatilization of ammonia. The addition of improver A led to a longer thermophilic stage by one week and lower concentrations of low-weight carboxylic acids (both water- and NaOH-extractable) with formic and acetic of similar amounts, however, most of the aspects claimed by the improver's producer were not confirmed in this trial.

  7. Analysis of redox additive-based overcharge protection for rechargeable lithium batteries

    Science.gov (United States)

    Narayanan, S. R.; Surampudi, S.; Attia, A. I.; Bankston, C. P.

    1991-01-01

    The overcharge condition in secondary lithium batteries employing redox additives for overcharge protection, has been theoretically analyzed in terms of a finite linear diffusion model. The analysis leads to expressions relating the steady-state overcharge current density and cell voltage to the concentration, diffusion coefficient, standard reduction potential of the redox couple, and interelectrode distance. The model permits the estimation of the maximum permissible overcharge rate for any chosen set of system conditions. Digital simulation of the overcharge experiment leads to numerical representation of the potential transients, and estimate of the influence of diffusion coefficient and interelectrode distance on the transient attainment of the steady state during overcharge. The model has been experimentally verified using 1,1-prime-dimethyl ferrocene as a redox additive. The analysis of the experimental results in terms of the theory allows the calculation of the diffusion coefficient and the formal potential of the redox couple. The model and the theoretical results may be exploited in the design and optimization of overcharge protection by the redox additive approach.

  8. A method for the preparation of a fuel, by the addition of one or more components to a base fuel

    NARCIS (Netherlands)

    2013-01-01

    The present invention relates to a method for the preparation of a fuel, by the addition of one or more components to a base fuel, wherein the method comprises the following steps: i) providing a base fuel; ii) withdrawing aromatic components from a styrene / propylene ox ide production plant; iii)

  9. Inverting the diastereoselectivity of the mukaiyama-michael addition with graphite-based catalysts

    KAUST Repository

    Acocella, Maria Rosaria; Mauro, Marco; Falivene, Laura; Cavallo, Luigi; Guerra, Gaetano

    2014-01-01

    , the graphite-based catalysts described here invert the diastereoselectivity relative to that observed with known catalysts, with the unprecedented large prevalence of the anti diastereoisomer. This inverted diastereoselectivity is increased when the catalyst

  10. Additive Manufacture of Three Dimensional Nanocomposite Based Objects through Multiphoton Fabrication

    Directory of Open Access Journals (Sweden)

    Yaan Liu

    2016-09-01

    Full Text Available Three-dimensional structures prepared from a gold-polymer composite formulation have been fabricated using multiphoton lithography. In this process, gold nanoparticles were simultaneously formed through photoreduction whilst polymerisation of two possible monomers was promoted. The monomers, trimethylopropane triacrylate (TMPTA and pentaerythritol triacrylate (PETA were mixed with a gold salt, but it was found that the addition of a ruthenium(II complex enhanced both the geometrical uniformity and integrity of the polymerised/reduced material, enabling the first production of 3D gold-polymer structures by single step multiphoton lithography.

  11. The additive technology for obtaining thermal storages based on nanomodified materials

    Directory of Open Access Journals (Sweden)

    Shchegolkov Alexander

    2017-01-01

    Full Text Available The approaches for the implementation of an additive technology for obtaining heat accumulators are considered. The implementation of the provided technology can be realized on the standard 3D printers, which are aimed to obtain plastic materials. However, the software of the printers has to include adjusting analytical expressions, which take into account thermophysical properties of the heat-retaining materials. The analytical expressions have been derived by solving a mathematical model. The mathematical model contains the main data on thermophysical and mechanical and physical properties of the nanomodified material. These properties of the nanomodified material are defined during the experimental studies.

  12. Effect of glass microfibre addition on the mechanical performances of fly ash-based geopolymer composites

    Directory of Open Access Journals (Sweden)

    Thamer Alomayri

    2017-09-01

    Full Text Available In the present study, various amounts of glass microfibres were introduced into a geopolymer for reinforcement purposes. The influence of these microfibres on the performance of the geopolymer composites was investigated. Results show that the appropriate addition of glass microfibres can improve the mechanical properties of geopolymer composites. In particular, the flexural strength, flexural modulus and impact strength increase at an optimum fibre content of 2 wt%. Further, adding glass microfibres to a plain geopolymer matrix has a significant effect on the pre-cracking behaviour. It substantially enhances the post-cracking response.

  13. Microstructural discovery of Al addition on Sn–0.5Cu-based Pb-free solder design

    International Nuclear Information System (INIS)

    Koo, Jahyun; Lee, Changsoo; Hong, Sung Jea; Kim, Keun-Soo; Lee, Hyuck Mo

    2015-01-01

    It is important to develop Pb-free solder alloys suitable for automotive use instead of traditional Sn–Pb solder due to environmental regulations (e.g., Restriction of Hazardous Substances (RoHS)). Al addition has been spotlighted to enhance solder properties. In this study, we investigated the microstructural change of Sn–0.5Cu wt.% based Pb-free solder alloys with Al addition (0.01–0.05 wt.%). The small amount of Al addition caused a remarkable microstructural change. The Al was favored to form Cu–Al intermetallic compounds inside the solder matrix. We identified the Cu–Al intermetallic compound as Cu_3_3Al_1_7, which has a rhombohedral structure, using EPMA and TEM analyses. This resulted in refined Cu_6Sn_5 networks in the Sn–0.5Cu based solder alloy. In addition, we conducted thermal analysis to confirm its stability at a high temperature of approximately 230 °C, which is the necessary temperature range for automotive applications. The solidification results were substantiated thermodynamically using the Scheil solidification model. We can provide criteria for the minimum aluminum content to modify the microstructure of Pb-free solder alloys. - Graphical abstract: The minor Al additions refined eutectic Cu_6Sn_5 IMC networks on the Sn–0.5Cu based solder alloys. The microstructure was dramatically changed with the minor Al addition. - Highlights: • We observed dramatic microstructure-change with Al additions. • We defined Cu_3_3Al_1_7 IMC with Al additions using TEM analysis. • We investigated grain refinement with Al additions using EBSD. • We discussed the refinement based on Scheil solidification model.

  14. Microstructural discovery of Al addition on Sn–0.5Cu-based Pb-free solder design

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Jahyun; Lee, Changsoo [Department of Materials Science and Engineering, KAIST, Daejeon 305-701 (Korea, Republic of); Hong, Sung Jea [MK Electron Co., Ltd., Yongin Cheoin-gu 316-2 (Korea, Republic of); Kim, Keun-Soo, E-mail: keunsookim@hoseo.edu [Department of Display Engineering, Hoseo University, Asan 336-795 (Korea, Republic of); Lee, Hyuck Mo, E-mail: hmlee@kaist.ac.kr [Department of Materials Science and Engineering, KAIST, Daejeon 305-701 (Korea, Republic of)

    2015-11-25

    It is important to develop Pb-free solder alloys suitable for automotive use instead of traditional Sn–Pb solder due to environmental regulations (e.g., Restriction of Hazardous Substances (RoHS)). Al addition has been spotlighted to enhance solder properties. In this study, we investigated the microstructural change of Sn–0.5Cu wt.% based Pb-free solder alloys with Al addition (0.01–0.05 wt.%). The small amount of Al addition caused a remarkable microstructural change. The Al was favored to form Cu–Al intermetallic compounds inside the solder matrix. We identified the Cu–Al intermetallic compound as Cu{sub 33}Al{sub 17}, which has a rhombohedral structure, using EPMA and TEM analyses. This resulted in refined Cu{sub 6}Sn{sub 5} networks in the Sn–0.5Cu based solder alloy. In addition, we conducted thermal analysis to confirm its stability at a high temperature of approximately 230 °C, which is the necessary temperature range for automotive applications. The solidification results were substantiated thermodynamically using the Scheil solidification model. We can provide criteria for the minimum aluminum content to modify the microstructure of Pb-free solder alloys. - Graphical abstract: The minor Al additions refined eutectic Cu{sub 6}Sn{sub 5} IMC networks on the Sn–0.5Cu based solder alloys. The microstructure was dramatically changed with the minor Al addition. - Highlights: • We observed dramatic microstructure-change with Al additions. • We defined Cu{sub 33}Al{sub 17} IMC with Al additions using TEM analysis. • We investigated grain refinement with Al additions using EBSD. • We discussed the refinement based on Scheil solidification model.

  15. The Pathogen-Host Interactions database (PHI-base): additions and future developments.

    Science.gov (United States)

    Urban, Martin; Pant, Rashmi; Raghunath, Arathi; Irvine, Alistair G; Pedro, Helder; Hammond-Kosack, Kim E

    2015-01-01

    Rapidly evolving pathogens cause a diverse array of diseases and epidemics that threaten crop yield, food security as well as human, animal and ecosystem health. To combat infection greater comparative knowledge is required on the pathogenic process in multiple species. The Pathogen-Host Interactions database (PHI-base) catalogues experimentally verified pathogenicity, virulence and effector genes from bacterial, fungal and protist pathogens. Mutant phenotypes are associated with gene information. The included pathogens infect a wide range of hosts including humans, animals, plants, insects, fish and other fungi. The current version, PHI-base 3.6, available at http://www.phi-base.org, stores information on 2875 genes, 4102 interactions, 110 host species, 160 pathogenic species (103 plant, 3 fungal and 54 animal infecting species) and 181 diseases drawn from 1243 references. Phenotypic and gene function information has been obtained by manual curation of the peer-reviewed literature. A controlled vocabulary consisting of nine high-level phenotype terms permits comparisons and data analysis across the taxonomic space. PHI-base phenotypes were mapped via their associated gene information to reference genomes available in Ensembl Genomes. Virulence genes and hotspots can be visualized directly in genome browsers. Future plans for PHI-base include development of tools facilitating community-led curation and inclusion of the corresponding host target(s). © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  16. Effect of Rh-based additives on NO and CO formed during regeneration of spent FCC catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Iliopoulou, E.F.; Efthimiadis, E.A.; Vasalos, I.A. [Aristotle University of Thessaloniki and Center for Research and Technology Hellas, Chemical Process Engineering Research Institute, Department of Chemical Engineering, P.O. Box 1517, 54006 University City, Thessaloniki (Greece); Barth, J.-O.; Lercher, J.A. [Institut fur Technische Chemie, Technische Universitat Munchen, Lichtenbergstrasse 4, D-85748 Garching (Germany)

    2004-02-10

    Regeneration studies of spent FCC catalyst were performed in a bench-scale unit under reaction conditions that sufficiently simulate those in the regenerator of the fluid catalytic cracking (FCC) unit. The effect of a conventional Pt-based CO promoter (CP-3) on the composition of flue gases was examined. As expected addition of CP-3 in the catalytic inventory decreased CO emissions by one order of magnitude, but tripled the NO emissions independently of the concentration of CO promoter used. Addition of a series of Rh-based catalysts modified the composition of flue gases emitted during regeneration. The parameters under study were the catalytic support, the Rh loading on the additive, and the amount of additive used during regeneration. Both a stoichiometric spinel MgO{center_dot}Al{sub 2}O{sub 3} of high crystallinity and a commercial alumina were competent supports. Promotion of the alumina support with Ce or performing regeneration introducing CO did not affect the additive performance significantly. A combined performance of CO oxidation and NO reduction was achieved minimizing both the Rh loading in the additive (0.1wt.%) and the concentration of additive used during regeneration (1wt.%). IR studies suggest that NO reduction by CO over Rh/alumina additives proceeds via the dissociative adsorption of NO, the formation of NCO species on Rh and their migration to the alumina support to finally yield N{sub 2} and CO{sub 2}.

  17. Addition of Bacillus Coagulans (Lactba cillus Esporogenes to a Powder Mixture Based Instant Cerea ls

    Directory of Open Access Journals (Sweden)

    Martha Lucia Libreros López

    2012-06-01

    Full Text Available This paper discloses the results of the application of a probiotic infant formula based instant cereals through accelerated life assessment. This process is carried out at laboratory level, based on the assay technique / error.The selected strain of probiotic, Lactobacilluis (Bacillus coagulans, must comply with the following characteristics: be of human origin, survival during gastric transit, bile salts tolerate and adhere to intestinal epithelial tissue. From the technological point of view, the probiotic must: be tolerant to oxygen and acids, have the ability to grow in milk and probiotics to metabolize and not affect the sensory characteristics of the product.The probiotic must meet the technical and production requirements and be resistant to adverse external conditions that may alter its composition or life.The process of incorporating probiotics to infant cereal mixture is performed by a theoretical calculation based. If the recommended dose is used, the presence of bacillus coagulans is ensured during the accelerated life.

  18. Effects of additives on microstructures of titanate based nanotubes prepared by the hydrothermal process

    International Nuclear Information System (INIS)

    Kubo, Takashi; Sugimoto, Keijiro; Onoki, Takamasa; Nakahira, Atsushi; Yamasaki, Yuki

    2009-01-01

    Silica-containing TiO 2 -derived titanate nanotubes were prepared by the addition of a small amount of tetraethyl orthosilicate (TEOS) to TiO 2 -derived titanate nanotubes prepared by the hydrothermal process and a subsequent heat-treatment at 473 K in air. The microstructure and thermal behavior of synthesized silica containing TiO 2 -derived titanate nanotubes were investigated by various methods such as X-ray diffraction (XRD), X-ray absorption fine structure (XAF), and X-ray photoelectron spectroscopy (XPS). As a result, the addition of a small amount of TEOS leaded to the improvement of the thermal stability for TiO 2 -derived titanate nanotubes. XPS results revealed that Si was combined onto the surface of TiO 2 -derived titanate nanotubes, forming partial Si-O-Ti chemical bonds. Therefore, it was inferred that the thermal stability could be modified by forming partial Si-O-Ti chemical bonds at interface of silica and TiO 2 -derived titanate nanotubes. (author)

  19. Lightweight custom composite prosthetic components using an additive manufacturing-based molding technique.

    Science.gov (United States)

    Leddy, Michael T; Belter, Joseph T; Gemmell, Kevin D; Dollar, Aaron M

    2015-01-01

    Additive manufacturing techniques are becoming more prominent and cost-effective as 3D printing becomes higher quality and more inexpensive. The idea of 3D printed prosthetics components promises affordable, customizable devices, but these systems currently have major shortcomings in durability and function. In this paper, we propose a fabrication method for custom composite prostheses utilizing additive manufacturing, allowing for customizability, as well the durability of professional prosthetics. The manufacturing process is completed using 3D printed molds in a multi-stage molding system, which creates a custom finger or palm with a lightweight epoxy foam core, a durable composite outer shell, and soft urethane gripping surfaces. The composite material was compared to 3D printed and aluminum materials using a three-point bending test to compare stiffness, as well as gravimetric measurements to compare weight. The composite finger demonstrates the largest stiffness with the lowest weight compared to other tested fingers, as well as having customizability and lower cost, proving to potentially be a substantial benefit to the development of upper-limb prostheses.

  20. Extension to linear dynamics for hybrid stress finite element formulation based on additional displacements

    Science.gov (United States)

    Sumihara, K.

    Based upon legitimate variational principles, one microscopic-macroscopic finite element formulation for linear dynamics is presented by Hybrid Stress Finite Element Method. The microscopic application of Geometric Perturbation introduced by Pian and the introduction of infinitesimal limit core element (Baby Element) have been consistently combined according to the flexible and inherent interpretation of the legitimate variational principles initially originated by Pian and Tong. The conceptual development based upon Hybrid Finite Element Method is extended to linear dynamics with the introduction of physically meaningful higher modes.

  1. Application of electron beam equipment based on a plasma cathode gun in additive technology

    Science.gov (United States)

    Galchenko, N. K.; Kolesnikova, K. A.; Semenov, G. V.; Rau, A. G.; Raskoshniy, S. Y.; Bezzubko, A. V.; Dampilon, B. V.; Sorokova, S. N.

    2016-11-01

    The paper discusses the application of electron beam equipment based on a plasma cathode gun for three-dimensional surface modification of metals and alloys. The effect of substrate surface preparation on the adhesion strength of gas thermal coatings has been investigated.

  2. Polypyrrole Additional functions to bio-based façades

    NARCIS (Netherlands)

    Sailer, M.F. (Michael); Oostra, M.A.R. (Mieke); Eversdijk, J. (Jacco)

    2015-01-01

    AbstractDue to the crisis of 2008 the construction and real estate market became more demand-driven. Architects, builders and developers are looking for high-quality solutions for the realization of sustainable buildings. Supplying SMEs experience an increasing demand for bio-based materials with

  3. Magnetic properties of FeNi-based thin film materials with different additives

    KAUST Repository

    Liang, C.; Gooneratne, C.P.; Wang, Q.X.; Liu, Y.; Gianchandani, Y.; Kosel, Jü rgen

    2014-01-01

    This paper presents a study of FeNi-based thin film materials deposited with Mo, Al and B using a co-sputtering process. The existence of soft magnetic properties in combination with strong magneto-mechanical coupling makes these materials

  4. A new smart additive of reinforced concrete based on modified hydrotalcites: Preparation, characterization and anticorrosion applications

    NARCIS (Netherlands)

    Yang, Z.; Fischer, H.; Polder, R.

    2012-01-01

    A carbonate form of Mg-Al-hydrotalcite and its p-aminobenzoate (pAB) modified derivative (i.e.,Mg(2)Al-pAB) were synthesized and characterized by means of XRD and FT-IR. The anticorrosion behavior was evaluated based on open circuit potential (OCP) of carbon steel in simulated concrete pore solution

  5. 45 CFR 146.122 - Additional requirements prohibiting discrimination based on genetic information.

    Science.gov (United States)

    2010-10-01

    ... genetic information and should review the records to excise any genetic information. N assembles the data requested by M and, although N reviews it to delete genetic information, the data from a specific region... based on genetic information. 146.122 Section 146.122 Public Welfare DEPARTMENT OF HEALTH AND HUMAN...

  6. The effect of magnesium-based additives on particulate emissions from oil-fired power plants

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, L.S.; Galeano, V.C.; Pena, E.S.; Caballero, P.G.

    1986-02-01

    To improve present knowledge of characteristics of particulate emissions from large-size boilers, in particular the role played by magnesium-oxide slurries, research was carried out with the following main objectives in mind: To identify the elementary chemical composition of emissions from a large boiler burning heavy fuel-oil; To define the differences caused by the use of MgO slurries regarding both quantity and characteristics of emissions; To study the boiler's transient response to sudden changes in additive dosage. The use of different fuel-oil during the experiments has given cause to discuss the following aspects: The joint presence of carbon and sulfur in particulate matter; The influence of certain characteristics of fuel-oil in emissions.

  7. Titanium-Based Hip Stems with Drug Delivery Functionality through Additive Manufacturing.

    Science.gov (United States)

    Bezuidenhout, Martin B; Dimitrov, Dimitar M; van Staden, Anton D; Oosthuizen, Gert A; Dicks, Leon M T

    2015-01-01

    Postoperative infections are a major concern in patients that receive implants. These infections generally occur in areas with poor blood flow and pathogens do not always respond to antibiotic treatment. With the latest developments in nanotechnology, the incorporation of antibiotics into prosthetic implants may soon become a standard procedure. The success will, however, depend on the ability to control the release of antibiotics at concentrations high enough to prevent the development of antibiotic-resistant strains. Through additive manufacturing, antibiotics can be incorporated into cementless femoral stems to produce prosthetic devices with antimicrobial properties. With the emerging increase in resistance to antibiotics, the incorporation of antimicrobial compounds other than antibiotics, preferably drugs with a broader spectrum of antimicrobial activity, will have to be explored. This review highlights the microorganisms associated with total hip arthroplasty (THA), discusses the advantages and disadvantages of the latest materials used in hip implants, compares different antimicrobial agents that could be incorporated, and addresses novel ideas for future research.

  8. Consolidation & Factors Influencing Sintering Process in Polymer Powder Based Additive Manufacturing

    Science.gov (United States)

    Sagar, M. B.; Elangovan, K.

    2017-08-01

    Additive Manufacturing (AM) is two decade old technology; where parts are build layer manufacturing method directly from a CAD template. Over the years, AM techniques changes the future way of part fabrication with enhanced intricacy and custom-made features are aimed. Commercially polymers, metals, ceramic and metal-polymer composites are in practice where polymers enhanced the expectations in AM and are considered as a kind of next industrial revolution. Growing trend in polymer application motivated to study their feasibility and properties. Laser sintering, Heat sintering and Inhibition sintering are the most successful AM techniques for polymers but having least application. The presentation gives up selective sintering of powder polymers and listed commercially available polymer materials. Important significant factors for effective processing and analytical approaches to access them are discussed.

  9. Al2O3 base composites, with addition of NbC and MgO

    International Nuclear Information System (INIS)

    Tonello, Karolina Pereira dos Santos

    2009-01-01

    The worldwide technological advances generate the needs of improved materials with better properties, according to its final purpose. Alumina composites with the addition of carbide particles have become an interesting option for structural applications. This work studies the influence of two commercial aluminas with different particle size and the adding of 1.5 and 6% in volume of niobium carbide and MgO 500 ppm in microstructural and mechanical properties of the composite. Samples were prepared by uniaxial and isostatic pressing and sintering was carried out in a graphite resistance furnace at 1600, 1650, 1700 and 1750 degree C for thirty minutes in Ar atmosphere. The obtained samples were evaluated sintering behavior, density, microstructure and mechanical properties, diffusion tests were realized to verify chemical reactivity between pairs formed by alumina and gray cast iron samples. The differences between aluminas caused some changes on the composites final properties. The composites produced with A16 alumina presented density about 2% higher than those produced with A1000 alumina. Similarly, the hardness also showed higher values. The carbide niobium added to the matrix of alumina delayed the sintering start, with an increase of about 30% in shrinkage initial states, when 6% of NbC was added. Composite with addition of 1,5% of NbC have higher density and hardness, even at lower sintering temperatures. The adding of niobium carbide to the alumina matrix and higher sintering temperatures provided higher density, hardness and fracture toughness to the composite. The best densification and hardness results of were obtained for composites produced with alumina A16 and when 1.5% of NbC was added. (author)

  10. Laser-based additive manufacturing: where it has been, where it needs to go

    Science.gov (United States)

    Cooper, Khershed P.

    2014-03-01

    It is no secret that the laser was the driver for additive manufacturing (AM) of 3D objects since such objects were first demonstrated in the mid-1980s. A myriad of techniques utilizing the directed energy of lasers were invented. Lasers are used to selectively sinter or fuse incremental layers in powder-beds, melt streaming powder following a programmed path, and polymerize photopolymers in a liquid vat layer-by-layer. The laser is an energy source of choice for repair of damaged components, for manufacture of new or replacement parts, and for rapid prototyping of concept designs. Lasers enable microstructure gradients and heterogeneous structures designed to exhibit unique properties and behavior. Laserbased additive manufacturing has been successful in producing relatively simple near net-shape metallic parts saving material and cost, but requiring finish-machining and in repair and refurbishment of worn components. It has been routinely used to produce polymer parts. These capabilities have been widely recognized as evidenced by the explosion in interest in AM technology, nationally. These successes are, however, tempered by challenges facing practitioners such as process and part qualification and verification, which are needed to bring AM as a true manufacturing technology. The ONR manufacturing science program, in collaboration with other agencies, invested in basic R&D in AM since its beginnings. It continues to invest, currently focusing on developing cyber-enabled manufacturing systems for AM. It is believed that such computation, communication and control approaches will help in validating AM and moving it to the factory floor along side CNC machines.

  11. Influence of titanium addition on the microstructure of the novel ferrous-based stainless steel

    International Nuclear Information System (INIS)

    Lin, Chia-Cheng; Lin, Li-Hsiang; Hung, Jing-Ming; Shih, Yung-Hsun; Wu, Ching-Zong; Ou, Keng-Liang; Chao, Chih-Yeh

    2011-01-01

    Highlights: → The microstructure of the as-quenched alloy is a mixture of γ, (α + B2 + DO 3 ), and TiC x phases. → The TiC x carbide had a face-center-cubic structure with a lattice parameter a = 0.432 nm.→ Formation of the TiC x carbide causing a γ → (α + γ) transition in the matrix of the alloy. → Addition of Ti promotes the formation of the α phase at high temperatures. - Abstract: The microstructural characteristics of the Fe-9Al-30Mn-1C-5Ti (wt.%) alloy were determined by scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectrometry. The microstructure of the alloy was essentially a mixture of (γ + TiC x + (α + B2 + DO 3 )) phases during solution treatment between 950 deg. C and 1150 deg. C. The TiC x carbide had a face-center-cubic structure with a lattice parameter a of 0.432 nm. When the as-quenched alloy was subjected to aging treatment at temperatures of 450-850 deg. C, the following microstructural transformation occurred: (γ + TiC x + κ + (α + DO 3 )) → (γ + TiC x + κ + (α + B2 + DO 3 + TiC x )) → (γ + TiC x + κ + κ' + (α + B2 + DO 3 )) → (γ + TiC x + (α + B2 + DO 3 )). Addition of Ti promotes the formation of the α phase at high temperatures.

  12. Usage of Vermiculite as Additive Material in Water-Based Drilling Muds

    Directory of Open Access Journals (Sweden)

    Onur Eser Kök

    2018-05-01

    Full Text Available Drilling mud is used in drilling operations to ensure well stability and to transport the cut-offs to the surface and is generally classified as; Spud, Lignosulfonate and Polymer types. Spud Mud is the simple mud and mostly used at the beginning of drilling operations. It is mainly composed of bentonite and water. With increasing depth, It is hard to keep well stability and to carry cuttings from the bottom of hole to the surface with the basic drilling fluid. Thus, some materials are used to maintain the rheological and filtration properties of the mud. One of them is vermiculite that is a general name of the hydrated ferromagnesian aluminium silicate group. It has expanded properties when heated. Like all clay minerals, the cation exchange capacity is very high and very similar to the montmorillonites in terms of high cation exchange capacity. In this study, the usage of vermiculite as an additive material in drilling muds was investigated. Spud muds containing vermiculite in different amounts were prepared. Then rheological and filtration analysis of the muds were done according to American Petroleum Institute (API RP-13B-1 Standard. When evaluated the results, AV reached 41cP, PV 27cP, YP 28lb/100ft2 , 10 sec. gel strength 17lb/100ft2 , 10 min. gel strength 26 lb/100ft2 and filtration 9cc. The results showed that the vermiculite can might be used as a viscosifier and fluid loss reducing additive material in the drilling mud.

  13. Neutron measurements of stresses in a test artifact produced by laser-based additive manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Gnäupel-Herold, Thomas [Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg MD 20899-6102 (United States); Slotwinski, John; Moylan, Shawn [Intelligent Systems Division, National Institute of Standards and Technology, Gaithersburg MD 20899-8220 (United States)

    2014-02-18

    A stainless steel test artifact produced by Direct Metal Laser Sintering and similar to a proposed standardized test artifact was examined using neutron diffraction. The artifact contained a number of structures with different aspect ratios pertaining to wall thickness, height above base plate, and side length. Through spatial resolutions of the order of one millimeter the volumetric distribution of stresses in several was measured. It was found that the stresses peak in the tensile region around 500 MPa near the top surface, with balancing compressive stresses in the interior. The presence of a support structure (a one millimeter high, thin walled, hence weaker, lattice structure deposited on the base plate, followed by a fully dense AM structure) has only minor effects on the stresses.

  14. Impedance-based structural health monitoring of additive manufactured structures with embedded piezoelectric wafers

    Science.gov (United States)

    Scheyer, Austin G.; Anton, Steven R.

    2017-04-01

    Embedding sensors within additive manufactured (AM) structures gives the ability to develop smart structures that are capable of monitoring the mechanical health of a system. AM provides an opportunity to embed sensors within a structure during the manufacturing process. One major limitation of AM technology is the ability to verify the geometric and material properties of fabricated structures. Over the past several years, the electromechanical impedance (EMI) method for structural health monitoring (SHM) has been proven to be an effective method for sensing damage in structurers. The EMI method utilizes the coupling between the electrical and mechanical properties of a piezoelectric transducer to detect a change in the dynamic response of a structure. A piezoelectric device, usually a lead zirconate titanate (PZT) ceramic wafer, is bonded to a structure and the electrical impedance is measured across as range of frequencies. A change in the electrical impedance is directly correlated to changes made to the mechanical condition of the structure. In this work, the EMI method is employed on piezoelectric transducers embedded inside AM parts to evaluate the feasibility of performing SHM on parts fabricated using additive manufacturing. The fused deposition modeling (FDM) method is used to print specimens for this feasibility study. The specimens are printed from polylactic acid (PLA) in the shape of a beam with an embedded monolithic piezoelectric ceramic disc. The specimen is mounted as a cantilever while impedance measurements are taken using an HP 4194A impedance analyzer. Both destructive and nondestructive damage is simulated in the specimens by adding an end mass and drilling a hole near the free end of the cantilever, respectively. The Root Mean Square Deviation (RMSD) method is utilized as a metric for quantifying damage to the system. In an effort to determine a threshold for RMSD, the values are calculated for the variation associated with taking multiple

  15. Improved hydrogen absorption and desorption kinetics of magnesium-based alloy via addition of yttrium

    Science.gov (United States)

    Yang, Tai; Li, Qiang; Liu, Ning; Liang, Chunyong; Yin, Fuxing; Zhang, Yanghuan

    2018-02-01

    Yttrium (Y) is selected to modify the microstructure of magnesium (Mg) to improve the hydrogen storage performance. Thereby, binary alloys with the nominal compositions of Mg24Yx (x = 1-5) are fabricated by inexpensive casting technique. Their microstructure and phase transformation during hydriding and dehydriding process are characterized by using X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy analysis. The isothermal hydrogen absorption and desorption kinetics are also measured by a Sievert's-type apparatus at various temperatures. Typical multiphase structures of binary alloy can be clearly observed. All of these alloys can reversibly absorb and desorb large amount of hydrogen at proper temperatures. The addition of Y markedly promotes the hydrogen absorption kinetics. However, it results in a reduction of reversible hydrogen storage capacity. A maximum value of dehydrogenation rate is observed with the increase of Y content. The Mg24Y3 alloy has the optimal desorption kinetic performance, and it can desorb about 5.4 wt% of hydrogen at 380 °C within 12 min. Combining Johnson-Mehl-Avrami kinetic model and Arrhenius equation, the dehydrogenation activation energy of the alloys are evaluated. The Mg24Y3 alloy also has the lowest dehydrogenation activation energy (119 kJ mol-1).

  16. Specific Adaptation of Gas Atomization Processing for Al-Based Alloy Powder for Additive Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iver [Ames Lab., Ames, IA (United States); Siemon, John [Alcoa Inc., Pittsburgh, PA (United States)

    2017-06-30

    The charge for each gas atomization experiment was provided by Alcoa and consisted of cast blocks cut into 1 inch by 1 inch square rods of the chosen aluminum alloys. The atmosphere in the melting chamber and connected atomization system was evacuated with a mechanical pump prior to backfilling with ultrahigh purity (UHP grade) Ar. The melt was contained in a bottom tapped alumina crucible with an alumina stopper rod to seal the exit while heating to a pouring temperature of 1000 – 1400°C. When the desired superheat was reached, the stopper rod was lifted and melt flowed through pour tube and was atomized with Ar from a 45-22-052-409 gas atomization nozzle (or atomization die), having a jet apex angle of 45 degrees with 22 cylindrical gas jets (each with diameter of 1.32 mm or 0.052 inches) arrayed around the axis of a 10.4 mm central bore. The Ar atomization gas supply regulator pressure was set to produce nozzle manifold pressures for the series of runs at pressures of 250-650 psi. Secondary gas halos of Ar+O2 and He also were added to the interior of the spray chamber at various downstream locations for additional cooling of the atomized droplets, surface passivation, and to prevent coalescence of the resulting powder.

  17. Specific Adaptation of Gas Atomization Processing for Al-Based Alloy Powder for Additive Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iver [Ames Lab., Ames, IA (United States); Siemon, John [Alcoa, Inc, Pittsburgh, PA (United States)

    2017-06-30

    The initial three atomization attempts resulted in “freeze-outs” within the pour tubes in the pilot-scale system and yielded no powder. Re-evaluation of the alloy liquidus temperatures and melting characteristics, in collaboration with Alcoa, showed further superheat to be necessary to allow the liquid metal to flow through the pour tube to the atomization nozzle. A subsequent smaller run on the experimental atomization system verified these parameters and was successful, as were all successive runs on the larger pilot scale system. One alloy composition froze-out part way through the atomization on both pilot scale runs. SEM images showed needle formation and phase segregations within the microstructure. Analysis of the pour tube freeze-out microstructures showed that large needles formed within the pour tube during the atomization experiment, which eventually blocked the melt stream. Alcoa verified the needle formation in this alloy using theoretical modeling of phase solidification. Sufficient powder of this composition was still generated to allow powder characterization and additive manufacturing trials at Alcoa.

  18. Novel Interecting Blends Based on Amino Terminited Oligoimides by Using Michael Addition Reaction-II

    Directory of Open Access Journals (Sweden)

    Rita R. Patel

    2012-01-01

    Full Text Available New amino terminated oligoimides (AOIs were prepared by the Michael addition reaction of various bismaleimide (1, namely, 1-(4-((4-((2, 5-dioxocyclopent-3 enylamino methyl cyclohexyl methyl cyclohexyl-1, 6-dihydropyridine-2, 5-dione with excess of various diamines (2a-c. These AOIs were characterized by elemental analysis, FT-IR spectral studies and number average molecular weight estimated by non-aqueous conductometric titrations. AOIs were then treated with acrylol chloride and resultant acryl terminated oligoimides (AcOIs samples were also characterized thermogravimetrically. Each of these AcOI was then combined with the N-phenyl maleimide (PM in THF solvent. The resultant suspensions were then heated in the presence of azobisisobutyronitrile (AIBN as an initiator. The AcOI and PM polymerized through double bond simultaneously and form interacting blends, which were analyzed thermogravimetrically. The glass fiber reinforced composites were fabricated by using the suspensions of the AcOI and PM. The composites of Interacting blends were analyzed for their mechanical, chemical and electrical properties.

  19. Titanium-Based Hip Stems with Drug Delivery Functionality through Additive Manufacturing

    Directory of Open Access Journals (Sweden)

    Martin B. Bezuidenhout

    2015-01-01

    Full Text Available Postoperative infections are a major concern in patients that receive implants. These infections generally occur in areas with poor blood flow and pathogens do not always respond to antibiotic treatment. With the latest developments in nanotechnology, the incorporation of antibiotics into prosthetic implants may soon become a standard procedure. The success will, however, depend on the ability to control the release of antibiotics at concentrations high enough to prevent the development of antibiotic-resistant strains. Through additive manufacturing, antibiotics can be incorporated into cementless femoral stems to produce prosthetic devices with antimicrobial properties. With the emerging increase in resistance to antibiotics, the incorporation of antimicrobial compounds other than antibiotics, preferably drugs with a broader spectrum of antimicrobial activity, will have to be explored. This review highlights the microorganisms associated with total hip arthroplasty (THA, discusses the advantages and disadvantages of the latest materials used in hip implants, compares different antimicrobial agents that could be incorporated, and addresses novel ideas for future research.

  20. Simulation of microstructure evolution in fused-coating additive manufacturing based on phase field approach

    Directory of Open Access Journals (Sweden)

    Ru-wei Geng

    2017-11-01

    Full Text Available The mechanical properties of metal components are determined by the solidification behaviour and microstructure. A quantitative phase field model is used to investigate the microstructure evolution of fused-coating additive manufacturing, by which to improve the quality of deposition. During the fused-coating process, the molten metal in a crucible flows out of a nozzle and then reaches the substrate. The solidification happens at the moment when the molten metal comes into contact with substrate moving in three-dimensional space. The macroscopic heat transfer model of fused-coating is established to get the temperature field considered as the initial temperature boundary conditions in the phase field model. The numerical and experimental results show that the morphology of grains varies with different solidification environments. Columnar grains are observed during the early period at the bottom of fused-coating layer and the equiaxed grains appear subsequently ahead of the columnar grains. Columnar dendrites phase field simulations about the grains morphology and solute distribution are conducted considering the solidification environments. The simulation results are in good agreement with experimental results.

  1. Additive Manufacturing of SiC Based Ceramics and Ceramic Matrix Composites

    Science.gov (United States)

    Halbig, Michael Charles; Singh, Mrityunjay

    2015-01-01

    Silicon carbide (SiC) ceramics and SiC fiber reinforcedSiC ceramic matrix composites (SiCSiC CMCs) offer high payoff as replacements for metals in turbine engine applications due to their lighter weight, higher temperature capability, and lower cooling requirements. Additive manufacturing approaches can offer game changing technologies for the quick and low cost fabrication of parts with much greater design freedom and geometric complexity. Four approaches for developing these materials are presented. The first two utilize low cost 3D printers. The first uses pre-ceramic pastes developed as feed materials which are converted to SiC after firing. The second uses wood containing filament to print a carbonaceous preform which is infiltrated with a pre-ceramic polymer and converted to SiC. The other two approaches pursue the AM of CMCs. The first is binder jet SiC powder processing in collaboration with rp+m (Rapid Prototyping+Manufacturing). Processing optimization was pursued through SiC powder blending, infiltration with and without SiC nano powder loading, and integration of nanofibers into the powder bed. The second approach was laminated object manufacturing (LOM) in which fiber prepregs and laminates are cut to shape by a laser and stacked to form the desired part. Scanning electron microscopy was conducted on materials from all approaches with select approaches also characterized with XRD, TGA, and bend testing.

  2. Electron beam irradiation and addition of poly(vinyl alcohol) affect gelatin based-films properties

    International Nuclear Information System (INIS)

    Inamura, Patricia Y.; Mastro, Nelida L. del

    2015-01-01

    Gelatin is a mixture of high molecular weight polypeptides, product of denaturation, and partial structural degradation of collagen, and one of the first materials employed as biomaterials. Aqueous solutions of gelatin (10%), glycerin as plasticizer and poly(vinyl alcohol) (PVA) up to 10% were prepared in a water bath at 70 deg C under constant stirring. Films were irradiated with 10 and 20 kGy using an electron beam accelerator, dose rate of 22.4 kGy s -1 , energy 1.407 MeV, at room temperature, in the presence of air. After irradiation, mechanical properties, color measurements, water absorption, moisture and film solubility were analyzed. The films showed an improvement in maximum force to rupture the film with increase of the irradiation dose. The higher the puncture force to rupture the lower the elongation at break. Colorimetric tests showed significant differences between samples, and also differences depending of the applied radiation dose, and analyzed color parameter. In water absorption tests a decrease of absorption percentage was found with the increase of the dose for PVA free and 5% PVA samples. The addition of PVA increased the water absorption for all applied doses. The modifications in gelatin colloids can be appointed to radiation-induced crosslinking. Also, the PVA concentration in the samples influenced the resultant material properties. (author)

  3. Electron beam irradiation and addition of poly(vinyl alcohol) affect gelatin based-films properties

    Energy Technology Data Exchange (ETDEWEB)

    Inamura, Patricia Y.; Mastro, Nelida L. del, E-mail: pinamura@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Gelatin is a mixture of high molecular weight polypeptides, product of denaturation, and partial structural degradation of collagen, and one of the first materials employed as biomaterials. Aqueous solutions of gelatin (10%), glycerin as plasticizer and poly(vinyl alcohol) (PVA) up to 10% were prepared in a water bath at 70 deg C under constant stirring. Films were irradiated with 10 and 20 kGy using an electron beam accelerator, dose rate of 22.4 kGy s{sup -1}, energy 1.407 MeV, at room temperature, in the presence of air. After irradiation, mechanical properties, color measurements, water absorption, moisture and film solubility were analyzed. The films showed an improvement in maximum force to rupture the film with increase of the irradiation dose. The higher the puncture force to rupture the lower the elongation at break. Colorimetric tests showed significant differences between samples, and also differences depending of the applied radiation dose, and analyzed color parameter. In water absorption tests a decrease of absorption percentage was found with the increase of the dose for PVA free and 5% PVA samples. The addition of PVA increased the water absorption for all applied doses. The modifications in gelatin colloids can be appointed to radiation-induced crosslinking. Also, the PVA concentration in the samples influenced the resultant material properties. (author)

  4. The Effect of Carbon Nanotube Composite Addition on Biomass-Based Supercapacitor

    Directory of Open Access Journals (Sweden)

    Pramujo Widiatmoko

    2016-11-01

    Full Text Available Electric vehicles are set to become a most attractive alternative transportation mode due to their high efficiency and low emission. Electric vehicles require an efficient energy storage system, e.g. a supercapacitor. Coconut shells have high lignocellulosic content and are not being fully utilized in Indonesia. The lignocellulose could be converted into activated carbon for use as the electrode on a hybrid supercapacitor. This research focused on studying the effect of the addition of carbon nanotube (CNT composite to porous graphene-like nanosheets (PGNS as the electrode on a hybrid supercapacitor. The PGNS and CNT composite were synthesized via simultaneous activation and carbonization. Nickel oxide was used as the counter electrode. The CNT composite had a large surface area of 1374.8 m2g-1, pore volume of 1.1 cm3g, and pore size of 3.2 nm. On the other hand, the PGNS had a surface area of 666.1 m2g-1, pore volume of 0.47 cm3g , and pore size of 2.8 nm. The electrode pair between the NiO and the activated carbon achieved 5.69 F/g and 94.1% cycle durability after 10 charging and discharging cycles. The composite had an energy density of 0.38 W h kg-1. The aim of this research was to provide an alternative formula for producing high-performance supercapacitor materials.

  5. Photochemical addition of amino acids and peptides to homopolyribonucleotides of the major DNA bases

    International Nuclear Information System (INIS)

    Shetlar, M.D.; Hom, K.; Carbone, J.; Moy, D.; Steady, E.; Watanabe, M.

    1984-01-01

    The photochemical quantum yields for addition of glycine and the L-amino acids commonly occurring in proteins to polyadenylic acid, polycytidylic acid, polyguanylic acid and polyribothymidylic acid have been determined in deoxygenated phosphate buffer using a fluorescamine assay technique. Polyadenylic acid was reactive with eleven of the twenty amino acids tested, with phenylalanine, tyrosine, glutamine, lysine and asparagine having the highest quantum yields. Polyguanylic acid reacted with sixteen amino acids; phenylalanine, arginine, cysteine, tyrosine, and lysine displayed the largest quantum yields. Polycytidylic acid showed reactivity with fifteen amino acids with lysine, phenylalanine, cysteine, tyrosine and arginine having the greatest quantum yields. Polyribothymidylic acid, reactive with fifteen of nineteen amino acids surveyed, showed the highest quantum yields for cysteine, phenylalanine, tyrosine, lysine and asparagine. None of the polynucleotides were reactive with aspartic acid or glutamic acid. The quantum yields for photoaddition of eighteen dipeptides of the form gycyl X (X being an amino acid), and of L-alanyl-L-tryptophan, L-seryl-L-seryl-L-serine, L-threonyl-L-threonyl-L-threonine, L-cystine-bis-glycine, and Nsup(α)-acetyllysine to polyadenylic acid, polycytidylic acid and polyguanylic acid were measured. All were found to add photochemically to each of these polymers. Polyribothymidylic acid, tested with eleven peptides and with Nsup(α)-acetyllysine, was found to be reactive with all. (author)

  6. GEKF, GUKF and GGPF based prediction of chaotic time-series with additive and multiplicative noises

    International Nuclear Information System (INIS)

    Wu Xuedong; Song Zhihuan

    2008-01-01

    On the assumption that random interruptions in the observation process are modelled by a sequence of independent Bernoulli random variables, this paper generalize the extended Kalman filtering (EKF), the unscented Kalman filtering (UKF) and the Gaussian particle filtering (GPF) to the case in which there is a positive probability that the observation in each time consists of noise alone and does not contain the chaotic signal (These generalized novel algorithms are referred to as GEKF, GUKF and GGPF correspondingly in this paper). Using weights and network output of neural networks to constitute state equation and observation equation for chaotic time-series prediction to obtain the linear system state transition equation with continuous update scheme in an online fashion, and the prediction results of chaotic time series represented by the predicted observation value, these proposed novel algorithms are applied to the prediction of Mackey–Glass time-series with additive and multiplicative noises. Simulation results prove that the GGPF provides a relatively better prediction performance in comparison with GEKF and GUKF. (general)

  7. Low-level radioactive wastes. A bibliography of additions to the Energy Data Base in 1981

    International Nuclear Information System (INIS)

    Grissom, M.C.

    1981-12-01

    Access to information on management of low-level radioactive wastes is provided by this special bibliography and other products of the Technical Information Center. Citations to 215 references on low-level radioactive wastes added to the Energy Data Base in 1981 are presented. The abstracts are grouped in broad subject categories. Within each category the arrangement is by report number for reports, followed by non-reports in reverse chronological order. These citations are to research reports, journal articles, books, patents, theses, and conference papers. Five indexes, each preceded by a brief description, are provided: Corporate Author, Personal Author, Subject, Contract Number, and Report Number

  8. The scaled-charge additive force field for amino acid based ionic liquids

    DEFF Research Database (Denmark)

    Fileti, E. E.; Chaban, V. V.

    2014-01-01

    Ionic liquids (ILs) constitute an emerging research field. New ILs involve more and more organic and inorganic ions. Amino acid based ILs (AAILs) represent a specific interest due to their evolutional connection to proteins. We report a new non-polarizable force field (FF) for the eight AAILs...... comprising 1-ethyl-3-methylimidazolium cation and amino acid anions. The anions were obtained via deprotonation of carboxyl group. Specific cation-anion non-covalent interactions were taken into account by computing electrostatic potential for ion pairs. The van der Waals interactions were adopted from...

  9. Implementation of Non-Destructive Evaluation and Process Monitoring in DLP-based Additive Manufacturing

    Science.gov (United States)

    Kovalenko, Iaroslav; Verron, Sylvain; Garan, Maryna; Šafka, Jiří; Moučka, Michal

    2017-04-01

    This article describes a method of in-situ process monitoring in the digital light processing (DLP) 3D printer. It is based on the continuous measurement of the adhesion force between printing surface and bottom of a liquid resin bath. This method is suitable only for the bottom-up DPL printers. Control system compares the force at the moment of unsticking of printed layer from the bottom of the tank, when it has the largest value in printing cycle, with theoretical value. Implementation of suggested algorithm can make detection of faults during the printing process possible.

  10. Lewis base catalyzed 1,3-dithiane addition to carbonyl and imino compounds using 2-trimethylsilyl-1,3-dithiane.

    Science.gov (United States)

    Michida, Makoto; Mukaiyama, Teruaki

    2008-09-01

    Lewis base-catalyzed 1,3-dithiane addition to electrophiles such as carbonyl compounds and N-substituted aldimines with 2-trimethylsilyl-1,3-dithiane (TMS-dithiane) is described. By the activation of the carbon-silicon bond in the presence of a Lewis base catalyst such as tetrabutylammonium phenoxide (PhONnBu(4)), a 1,3-dithiane addition reaction proceeded smoothly to afford the corresponding adducts in good to high yields under mild conditions. This synthesis is also applied to the reactions of ketones having alpha-protons, and of N-substituted aldimines.

  11. TREHALOSE-BASED ADDITIVE IMPROVED INTER-PRIMER BINDING SITE REACTIONS FOR DNA ISOLATED FROM RECALCITRANT PLANTS

    Directory of Open Access Journals (Sweden)

    Veronika Lancíková

    2014-02-01

    Full Text Available Trehalose-based (TBT-PAR additive was tested in order to optimize PCR amplification for DNA isolated from recalcitrant plants. Retrotransposon-based inter-primer binding site reactions were significantly improved with TBT-PAR solution using genomic DNA isolated from flax (Linum usitatissimum L., genotypes Kyivskyi, Bethune grown in radio-contaminated and non-radioactive remediated Chernobyl experimental fields. Additionally, similar improvements were observed using 19 recalcitrant genotypes of maize (Zea mays L. and three genotypes of yacon (Smallanthus sonchifolius, Poepp. et Endl., genotypes PER05, ECU45, BOL22 grown in standard field conditions.

  12. Biodiesel production from tall oil with synthesized Mn and Ni based additives: effects of the additives on fuel consumption and emissions

    Energy Technology Data Exchange (ETDEWEB)

    Ali Keskin; Metin Guru; Duran Altiparmak [Mersin University, Mersin (Turkey). Technical Education Faculty

    2007-05-15

    In this study, biodiesel fuel and fuel additives were produced from crude tall oil that is a by-product in the pulp manufacturing by craft or sulphate pulping process. Fatty acids and resinic acids were obtained from crude tall oil by distillation method. Tall oil methyl ester (biodiesel) was produced from fatty acids. Resinic acids were reacted with NiO and MnO{sub 2} stoichiometrically for production of metallic fuel additives. Each metallic fuel additive was added at the rate of 8 {mu}mol/l and 12 {mu}mol/l to make mixtures of 60% tall oil methyl ester/40% diesel fuel (TE60) for preparing test fuels. Metallic fuel additives improved properties of biodiesel fuels, such as pour point and viscosity values. Biodiesel fuels were tested in an unmodified direct injection diesel engine at full load condition. Specific fuel consumption of biodiesel fuels increased by 6.00%, however, in comparison with TE60, it showed trend of decreasing with adding of additives. Exhaust emission profile of biodiesel fuels improved. CO emissions and smoke opacity decreased up to 64.28% and 30.91% respectively. Low NOx emission was also observed in general for the biodiesel fuels. 28 refs., 4 figs., 3 tabs.

  13. Mechanical Properties of Additive Manufactured Ti-6Al-4V Using Wire and Powder Based Processes

    International Nuclear Information System (INIS)

    Brandl, Erhard; Palm, Frank; Leyens, Christoph

    2011-01-01

    Since 1986 several techniques of building up geometries layer by layer have been developed and successfully commercialized under numerous trade names. Today, not only prototypes are realized by these techniques, but serial production parts are envisaged. To achieve this progress, the development activities have to focus on the reliability and output material quality. Particularly for aerospace applications, the material quality is an all-dominant factor. In this paper, an electron beam based powder-bed process and a laser based wire-feed process are investigated. Microstructure, chemical composition, static tensile and high cycle fatigue properties of Ti-6Al-4V samples are presented and evaluated from an aerospace application point of view. The static tensile properties resulting from both processes are mostly comparable to properties of cast or wrought material depending on post heat treatment and test direction. Fatigue limits of all samples are similar to those of wrought material. The impurity levels of oxygen, nitrogen, carbon and hydrogen are below the maximum level of plate material (AMS 4911L). The wire-feed process leads to a material with fewer impurities than the powder-bed process.

  14. Design of an additional heat sink based on natural circulation in pressurized water reactors

    International Nuclear Information System (INIS)

    Frischengruber, Kurt; Solanilla, Roberto; Fernandez, Ricardo; Blumenkrantz, Arnaldo; Castano, Jorge

    1989-01-01

    Residual heat removal through the steam generators in Nuclear Power Plant with pressurized water reactors (PWR) or pressurized heavy water reactors (PHWR in pressured vessel or pressured tube types) requires the maintenance of the steam generator inventory and the availability of and appropriate heat sink, which are based on the operability of the steam generators feedwater system. This paper describes the conceptual design of an assured heat removal system which includes only passive elements and is based on natural circulation. The system can supplement the original systems of the plant. The new system includes a condenser/boiler heat exchanger to condense the steam produced in the steam generator, transferring the heat to the water of an open pool at atmospheric pressure. The condensed steam flows back to the steam generators by natural circulation effects. The performance of an Atucha type PHWR nuclear power station with and without the proposed system is calculated in an emergency power case for the first 5000 seconds after the incident. The analysis shows that the proposed system offers the possibility to cool-down the plant to a low energy state during several hours and avoids the repeated actuation of the primary and secondary system safety valves. (Author) [es

  15. Effect of TaC addition on the microstructures and mechanical properties of Ti(C, N)-based cermets

    International Nuclear Information System (INIS)

    Wu, Peng; Zheng, Yong; Zhao, Yongle; Yu, Haizhou

    2010-01-01

    The microstructures of the prepared Ti(C, N)-based cermets with various TaC additions were studied using X-ray diffractometry (XRD) and scanning electron microscopy (SEM). Mechanical properties such as transverse rupture strength (TRS), fracture toughness (K 1C ) and hardness (HRA) were also measured. The results showed that the grain size of the cermets decreased with increasing TaC addition, but too high TaC addition resulted in agglomeration of the grains. An increasing TaC addition increased the dissolution of tungsten, titanium, molybdenum and tantalum in the binder phase. The hardness of the cermets decreased slightly with increasing TaC addition. The transverse rupture strength was the highest for the cermets with 5 wt.% TaC addition, which was characterized by fine grains, homogeneous microstructure and the moderate thickness of rim phase in the binder. The fracture toughness of the cermets with TaC addition from 0 to 5 wt.% decreased obviously, which resulting from decreased grain size. The further decreasing of fracture toughness for the cermets with 7 wt.% TaC addition was due to increased porosity and interfacial tensile stress.

  16. Toward Self-Growing Soft Robots Inspired by Plant Roots and Based on Additive Manufacturing Technologies.

    Science.gov (United States)

    Sadeghi, Ali; Mondini, Alessio; Mazzolai, Barbara

    2017-09-01

    In this article, we present a novel class of robots that are able to move by growing and building their own structure. In particular, taking inspiration by the growing abilities of plant roots, we designed and developed a plant root-like robot that creates its body through an additive manufacturing process. Each robotic root includes a tubular body, a growing head, and a sensorized tip that commands the robot behaviors. The growing head is a customized three-dimensional (3D) printer-like system that builds the tubular body of the root in the format of circular layers by fusing and depositing a thermoplastic material (i.e., polylactic acid [PLA] filament) at the tip level, thus obtaining movement by growing. A differential deposition of the material can create an asymmetry that results in curvature of the built structure, providing the possibility of root bending to follow or escape from a stimulus or to reach a desired point in space. Taking advantage of these characteristics, the robotic roots are able to move inside a medium by growing their body. In this article, we describe the design of the growing robot together with the modeling of the deposition process and the description of the implemented growing movement strategy. Experiments were performed in air and in an artificial medium to verify the functionalities and to evaluate the robot performance. The results showed that the robotic root, with a diameter of 50 mm, grows with a speed of up to 4 mm/min, overcoming medium pressure of up to 37 kPa (i.e., it is able to lift up to 6 kg) and bending with a minimum radius of 100 mm.

  17. Composite materials based on high-modulus compounds for additive technology

    Science.gov (United States)

    Grigoriev, M.; Kotelnikov, N.; Buyakova, S.; Kulkov, S.

    2016-07-01

    The effect of adding nanocrystalline ZrO2 and submicron TiC to ultrafine Al2O3 on mechanical properties and the microstructure of the composites developed by hot pressing was investigated. It was shown that by means of hot pressing in argon atmosphere at the sintering temperature of 1500 °C one can obtain the composites of Al2O3-ZrO2-TiC with a fine structure and minimal porosity. It was shown that in the material a multi-scale hierarchical structure is formed, which possesses high physical and mechanical properties: the hardness and fracture toughness was 22 GPa and 5.2 MPa*m1/2, respectively. It has been shown that mechanical properties of the composite are better than those of commercial composites based on aluminum oxide (Al2O3, ZTA, Al2O3-TiC) and are comparable to those of silicon nitride.

  18. Environmentally friendly paint and varnish additives based on isobutyrate aldehyde condensation products

    Science.gov (United States)

    Guziałowska-Tic, Joanna; Jan Tic, Wilhelm

    2017-10-01

    The demand for exploitation of new plasticizers and coalescents to be used for production of water dispersion adhesives based on poli(vinyl acetate), turned to be recently of particular significance because the use of all kind of toxic phthalates was banned and certain restrictions were made to use glycol derivatives classified as volatile organic compounds. An alternative for toxic plasticizers used for production of adhesives is hydroxyester (HE-1) obtained from isobutanal during the process of aldol condensation under subsequent Cannizaro and Tischenko reactions. The paper presents selected results of ecotoxicological tests on the environmental impact of hydroxyester HE-1. It was found that the substance is biodegradable and has no negative impact on algae growth rate, however it may inhibit algae biomass growth. The results of Daphnia immobilization test shows that the substance is safe for the aquatic environment. Whereas, at higher concentrations, hydroxyester HE-1 may exhibit acute toxicity to rainbow trout.

  19. Development of road soil cement compositions modified with complex additive based on polycarboxylic ether

    Science.gov (United States)

    Bulanov, P. E.; Vdovin, E. A.; Mavliev, L. F.; Kuznetsov, D. A.

    2018-03-01

    The paper is focused on the research results of the main physical and technical properties of the cement-stabilized polymineral clay modified with a complex hydrophobic plasticizer based on polycarboxylate and octyltriethoxysilane ethers. A graphical result interpretation of the mathematic model which shows the influence of the complex hydrophobic plasticizer components on the cement-stabilized polymineral clay, containing more than 85% of relict minerals, has been designed. The research significance for the building sector lies in the fact that applying a complex hydrophobic plasticizer provides increasing the compressive strength of the cement-stabilized polymineral clay up to 102%, the tensile bending strength – up to 88%, the freeze-thaw resistance – up to 114%.

  20. Addition of visual noise boosts evoked potential-based brain-computer interface.

    Science.gov (United States)

    Xie, Jun; Xu, Guanghua; Wang, Jing; Zhang, Sicong; Zhang, Feng; Li, Yeping; Han, Chengcheng; Li, Lili

    2014-05-14

    Although noise has a proven beneficial role in brain functions, there have not been any attempts on the dedication of stochastic resonance effect in neural engineering applications, especially in researches of brain-computer interfaces (BCIs). In our study, a steady-state motion visual evoked potential (SSMVEP)-based BCI with periodic visual stimulation plus moderate spatiotemporal noise can achieve better offline and online performance due to enhancement of periodic components in brain responses, which was accompanied by suppression of high harmonics. Offline results behaved with a bell-shaped resonance-like functionality and 7-36% online performance improvements can be achieved when identical visual noise was adopted for different stimulation frequencies. Using neural encoding modeling, these phenomena can be explained as noise-induced input-output synchronization in human sensory systems which commonly possess a low-pass property. Our work demonstrated that noise could boost BCIs in addressing human needs.

  1. Enhancing the Oxidation Performance of Wrought Ni-Base Superalloy by Minor Additions of Active Elements

    Science.gov (United States)

    Tawancy, H. M.

    2016-12-01

    We show that the oxidation performance of Cr2O3-forming superalloy based upon the Ni-Cr-W system is significantly improved by the presence of minor concentrations of La, Si and Mn, which outweigh the detrimental effect of high W concentration in the alloy. Although Cr2O3 is known to transform into volatile CrO3 at temperatures ≥950 °C, the respective protection is extended to temperatures reaching 1150 °C, which has also been correlated with the beneficial effects of La, Si and Mn. During high-temperature oxidation, an inner protective La- and Si-modified layer of α-Cr2O3 in contact with the superalloy substrate is developed and shielded by an outermost layer of MnCr2O4. The distribution of La and Si in the inner oxide layer has been characterized down to the scale of transmission electron microscopy, and the possible mechanisms underlying their beneficial effects are elucidated.

  2. Accelerometry-based gait analysis, an additional objective approach to screen subjects at risk for falling.

    Science.gov (United States)

    Senden, R; Savelberg, H H C M; Grimm, B; Heyligers, I C; Meijer, K

    2012-06-01

    This study investigated whether the Tinetti scale, as a subjective measure for fall risk, is associated with objectively measured gait characteristics. It is studied whether gait parameters are different for groups that are stratified for fall risk using the Tinetti scale. Moreover, the discriminative power of gait parameters to classify elderly according to the Tinetti scale is investigated. Gait of 50 elderly with a Tinneti>24 and 50 elderly with a Tinetti≤24 was analyzed using acceleration-based gait analysis. Validated algorithms were used to derive spatio-temporal gait parameters, harmonic ratio, inter-stride amplitude variability and root mean square (RMS) from the accelerometer data. Clear differences in gait were found between the groups. All gait parameters correlated with the Tinetti scale (r-range: 0.20-0.73). Only walking speed, step length and RMS showed moderate to strong correlations and high discriminative power to classify elderly according to the Tinetti scale. It is concluded that subtle gait changes that have previously been related to fall risk are not captured by the subjective assessment. It is therefore worthwhile to include objective gait assessment in fall risk screening. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Rice husk (RH) as additive in fly ash based geopolymer mortar

    Science.gov (United States)

    Yahya, Zarina; Razak, Rafiza Abd; Abdullah, Mohd Mustafa Al Bakri; Rahim, Mohd Azrin Adzhar; Nasri, Armia

    2017-09-01

    In recent year, the Ordinary Portland Cement (OPC) concrete is vastly used as main binder in construction industry which lead to depletion of natural resources in order to manufacture large amount of OPC. Nevertheless, with the introduction of geopolymer as an alternative binder which is more environmental friendly due to less emission of carbon dioxide (CO2) and utilized waste materials can overcome the problems. Rice husk (RH) is an agricultural residue which can be found easily in large quantity due to production of paddy in Malaysia and it's usually disposed in landfill. This paper investigated the effect of rice husk (RH) content on the strength development of fly ash based geopolymer mortar. The fly ash is replaced with RH by 0%, 5%, 10%, 15% and 20% where the sodium silicate and sodium hydroxide was used as alkaline activator. A total of 45 cubes were casted and their compressive strength, density and water absorption were evaluated at 1, 3, and 7 days. The result showed compressive strength decreased when the percentage of RH increased. At 5% replacement of RH, the maximum strength of 17.1MPa was recorded at day 7. The geopolymer has lowest rate of water absorption (1.69%) at 20% replacement of RH. The density of the sample can be classified as lightweight geopolymer concrete.

  4. The Addition of Sago Flour in Yoghurt Based on Physical Propeties of Yoghurt Ice Cream

    Directory of Open Access Journals (Sweden)

    Ika Ayu Wijayanti

    2017-02-01

    Full Text Available The purpose of this research was to determine the best concentration of adding sago flour in yoghurt based on viscosity, overrun, melting rate and total solid of yoghurt ice cream. The experiment was designed by Completely Randomized Design (CRD using four treatments were 0 %, 2 %, 4 %, 6 % from volume of fresh milk and four replications. The data were analyzed by using Analysis of Variance (ANOVA and continued by Duncan’s Multiple Range Test (DMRT. Result of this research showed that concentration of adding sago flour in yoghurt gave highly significant difference effect (P<0.01 on viscosity, overrun, melting rate and total solid of yoghurt ice cream. It can be concluded that the adding of sago flour 2% in yoghurt gave the best result with the viscosity was 1750.75 cP, overrun was 25.14%, melting rate was 39.13 minutes/50 g, total solid was 36.20% and gave the best quality of yoghurt ice cream.

  5. Identification by microscopy and MS-based electronic nose of a fraudulent addition to maize gluten

    Directory of Open Access Journals (Sweden)

    Frick G.

    2009-01-01

    Full Text Available Classical and chemometric methods have been used to detect falsified maize gluten products. Microscopic observations (numerous starch grains, seed envelopes and wheat bran fragments clearly showed the presence of atypical maize gluten particles in samples with otherwise normal crude protein levels (≥ 60% and the usual gold-yellow color. Chemical analyses in a few samples confirmed the presence of urea (19 to 174 g.kg-1, melamine (0 to 20 g.kg-1, and cyanuric acid (0 to 10 g.kg-1 coping for the low levels of methionine (0 to 13 g.kg-1 in incriminated products (genuine maize gluten methionine level ≥ 16 g.kg-1. Furthermore, a fast technique (an electronic nose based on mass spectrometry detection also proved to be reliable for the identification of falsified maize gluten products: 100% correct classification of model and unknown samples was achieved with principal component analysis. As a consequence of these results, the Swiss feed-inspection authority blocked the import, or restricted the use, of 2,500 tons of the falsified products.

  6. Corrosion Behavior of PEO Coatings Formed on AZ31 Alloy in Phosphate-Based Electrolytes with Calcium Acetate Additive

    Science.gov (United States)

    Ziyaei, E.; Atapour, M.; Edris, H.; Hakimizad, A.

    2017-07-01

    The PEO coating started on magnesium AZ31 using a unipolar DC power source. The coating was generated in the electrolyte based on Na3PO4·12H2O and KOH with calcium acetate as additive. The x-ray diffraction method showed some phases containing calcium and phosphate, which was created in the presence of additive. Also, the EDS tests of the sample's surfaces proved the existence of calcium on the surface. Based on the electrochemical tests results, the most corrosion resistance belongs to the sample with calcium acetate additive. In fact, the results of the EIS tests showed the coating with calcium acetate has the highest resistance but the lowest capacitance. However, this state belongs to the surface morphology, the lower porosity, and surface chemical composition.

  7. Alcohol based-deep eutectic solvent (DES) as an alternative green additive to increase rotenone yield

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Zetty Shafiqa; Hassan, Nur Hasyareeda; Zubairi, Saiful Irwan [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor (Malaysia)

    2015-09-25

    Deep eutectic solvents (DESs) are basically molten salts that interact by forming hydrogen bonds between two added components at a ratio where eutectic point reaches a melting point lower than that of each individual component. Their remarkable physicochemical properties (similar to ionic liquids) with remarkable green properties, low cost and easy handling make them a growing interest in many fields of research. Therefore, the objective of pursuing this study is to analyze the potential of alcohol-based DES as an extraction medium for rotenone extraction from Derris elliptica roots. DES was prepared by a combination of choline chloride, ChCl and 1, 4-butanediol at a ratio of 1/5. The structure of elucidation of DES was analyzed using FTIR, {sup 1}H-NMR and {sup 13}C-NMR. Normal soaking extraction (NSE) method was carried out for 14 hours using seven different types of solvent systems of (1) acetone; (2) methanol; (3) acetonitrile; (4) DES; (5) DES + methanol; (6) DES + acetonitrile; and (7) [BMIM] OTf + acetone. Next, the yield of rotenone, % (w/w), and its concentration (mg/ml) in dried roots were quantitatively determined by means of RP-HPLC. The results showed that a binary solvent system of [BMIM] OTf + acetone and DES + acetonitrile was the best solvent system combination as compared to other solvent systems. It contributed to the highest rotenone content of 0.84 ± 0.05% (w/w) (1.09 ± 0.06 mg/ml) and 0.84 ± 0.02% (w/w) (1.03 ± 0.01 mg/ml) after 14 hours of exhaustive extraction time. In conclusion, a combination of the DES with a selective organic solvent has been proven to have a similar potential and efficiency as of ILs in extracting bioactive constituents in the phytochemical extraction process.

  8. Magnetic Properties of FeNi-Based Thin Film Materials with Different Additives

    Directory of Open Access Journals (Sweden)

    Cai Liang

    2014-07-01

    Full Text Available This paper presents a study of FeNi-based thin film materials deposited with Mo, Al and B using a co-sputtering process. The existence of soft magnetic properties in combination with strong magneto-mechanical coupling makes these materials attractive for sensor applications. Our findings show that FeNi deposited with Mo or Al yields magnetically soft materials and that depositing with B further increases the softness. The out-of-plane magnetic anisotropy of FeNi thin films is reduced by depositing with Al and completely removed by depositing with B. The effect of depositing with Mo is dependent on the Mo concentration. The coercivity of FeNiMo and FeNiAl is reduced to less than a half of that of FeNi, and a value as low as 40 A/m is obtained for FeNiB. The surfaces of the obtained FeNiMo, FeNiAl and FeNiB thin films reveal very different morphologies. The surface of FeNiMo shows nano-cracks, while the FeNiAl films show large clusters and fewer nano-cracks. When FeNi is deposited with B, a very smooth morphology is obtained. The crystal structure of FeNiMo strongly depends on the depositant concentration and changes into an amorphous structure at a higher Mo level. FeNiAl thin films remain polycrystalline, even at a very high concentration of Al, and FeNiB films are amorphous, even at a very low concentration of B.

  9. Magnetic properties of FeNi-based thin film materials with different additives

    KAUST Repository

    Liang, C.

    2014-07-04

    This paper presents a study of FeNi-based thin film materials deposited with Mo, Al and B using a co-sputtering process. The existence of soft magnetic properties in combination with strong magneto-mechanical coupling makes these materials attractive for sensor applications. Our findings show that FeNi deposited with Mo or Al yields magnetically soft materials and that depositing with B further increases the softness. The out-of-plane magnetic anisotropy of FeNi thin films is reduced by depositing with Al and completely removed by depositing with B. The effect of depositing with Mo is dependent on the Mo concentration. The coercivity of FeNiMo and FeNiAl is reduced to less than a half of that of FeNi, and a value as low as 40 A/m is obtained for FeNiB. The surfaces of the obtained FeNiMo, FeNiAl and FeNiB thin films reveal very different morphologies. The surface of FeNiMo shows nano-cracks, while the FeNiAl films show large clusters and fewer nano-cracks. When FeNi is deposited with B, a very smooth morphology is obtained. The crystal structure of FeNiMo strongly depends on the depositant concentration and changes into an amorphous structure at a higher Mo level. FeNiAl thin films remain polycrystalline, even at a very high concentration of Al, and FeNiB films are amorphous, even at a very low concentration of B. 2014 by the authors.

  10. Additively manufactured metallic porous biomaterials based on minimal surfaces : A unique combination of topological, mechanical, and mass transport properties

    NARCIS (Netherlands)

    Bobbert, F S L; Lietaert, K; Eftekhari, A A; Pouran, B; Ahmadi, S M; Weinans, H; Zadpoor, A A

    2017-01-01

    Porous biomaterials that simultaneously mimic the topological, mechanical, and mass transport properties of bone are in great demand but are rarely found in the literature. In this study, we rationally designed and additively manufactured (AM) porous metallic biomaterials based on four different

  11. Effect of ferrite addition above the base ferrite on the coupling factor of wireless power transfer for vehicle applications

    DEFF Research Database (Denmark)

    Batra, Tushar; Schaltz, Erik; Ahn, Seungyoung

    2015-01-01

    and reduce magnetic emissions to the surroundings. Effect of adding extra ferrite above the base ferrite at different physical locations on the self-inductance, mutual inductance and coupling factor is under investigation in this paper. The addition can increase or decrease the mutual inductance depending...

  12. Sodium- and phosphorus-based food additives: persistent but surmountable hurdles in the management of nutrition in chronic kidney disease.

    Science.gov (United States)

    Gutiérrez, Orlando M

    2013-03-01

    Sodium- and phosphorus-based food additives are among the most commonly consumed nutrients in the world. This is because both have diverse applications in processed food manufacturing, leading to their widespread use by the food industry. Since most foods are naturally low in salt, sodium additives almost completely account for the excessive consumption of sodium throughout the world. Similarly, phosphorus additives represent a major and "hidden" phosphorus load in modern diets. These factors pose a major barrier to successfully lowering sodium or phosphorus intake in patients with CKD. As such, any serious effort to reduce sodium or phosphorus consumption will require reductions in the use of these additives by the food industry. The current regulatory environment governing the use of food additives does not favor this goal, however, in large part because these additives have historically been classified as generally safe for public consumption. To overcome these barriers, coordinated efforts will be needed to demonstrate that high intake of these additives is not safe for public consumption and as such should be subject to greater regulatory scrutiny. Copyright © 2013 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  13. Sodium and phosphorus-based food additives: persistent but surmountable hurdles in the management of nutrition in chronic kidney disease

    Science.gov (United States)

    Gutiérrez, Orlando M.

    2012-01-01

    Sodium and phosphorus-based food additives are among the most commonly consumed nutrients in the world. This is because both have diverse applications in processed food manufacturing, leading to their widespread utilization by the food industry. Since most foods are naturally low in salt, sodium additives almost completely account for the excessive consumption of sodium throughout the world. Similarly, phosphorus additives represent a major and “hidden” phosphorus load in modern diets. These factors pose a major barrier to successfully lowering sodium or phosphorus intake in patients with chronic kidney disease. As such, any serious effort to reduce sodium or phosphorus consumption will require reductions in the use of these additives by the food industry. The current regulatory environment governing the use of food additives does not favor this goal, however, in large part because these additives have historically been classified as generally safe for public consumption. To overcome these barriers, coordinated efforts will be needed to demonstrate that high intakes of these additives are not safe for public consumption and as such, should be subject to greater regulatory scrutiny. PMID:23439374

  14. PHI-base: a new interface and further additions for the multi-species pathogen–host interactions database

    Science.gov (United States)

    Urban, Martin; Cuzick, Alayne; Rutherford, Kim; Irvine, Alistair; Pedro, Helder; Pant, Rashmi; Sadanadan, Vidyendra; Khamari, Lokanath; Billal, Santoshkumar; Mohanty, Sagar; Hammond-Kosack, Kim E.

    2017-01-01

    The pathogen–host interactions database (PHI-base) is available at www.phi-base.org. PHI-base contains expertly curated molecular and biological information on genes proven to affect the outcome of pathogen–host interactions reported in peer reviewed research articles. In addition, literature that indicates specific gene alterations that did not affect the disease interaction phenotype are curated to provide complete datasets for comparative purposes. Viruses are not included. Here we describe a revised PHI-base Version 4 data platform with improved search, filtering and extended data display functions. A PHIB-BLAST search function is provided and a link to PHI-Canto, a tool for authors to directly curate their own published data into PHI-base. The new release of PHI-base Version 4.2 (October 2016) has an increased data content containing information from 2219 manually curated references. The data provide information on 4460 genes from 264 pathogens tested on 176 hosts in 8046 interactions. Prokaryotic and eukaryotic pathogens are represented in almost equal numbers. Host species belong ∼70% to plants and 30% to other species of medical and/or environmental importance. Additional data types included into PHI-base 4 are the direct targets of pathogen effector proteins in experimental and natural host organisms. The curation problems encountered and the future directions of the PHI-base project are briefly discussed. PMID:27915230

  15. PHI-base: a new interface and further additions for the multi-species pathogen-host interactions database.

    Science.gov (United States)

    Urban, Martin; Cuzick, Alayne; Rutherford, Kim; Irvine, Alistair; Pedro, Helder; Pant, Rashmi; Sadanadan, Vidyendra; Khamari, Lokanath; Billal, Santoshkumar; Mohanty, Sagar; Hammond-Kosack, Kim E

    2017-01-04

    The pathogen-host interactions database (PHI-base) is available at www.phi-base.org PHI-base contains expertly curated molecular and biological information on genes proven to affect the outcome of pathogen-host interactions reported in peer reviewed research articles. In addition, literature that indicates specific gene alterations that did not affect the disease interaction phenotype are curated to provide complete datasets for comparative purposes. Viruses are not included. Here we describe a revised PHI-base Version 4 data platform with improved search, filtering and extended data display functions. A PHIB-BLAST search function is provided and a link to PHI-Canto, a tool for authors to directly curate their own published data into PHI-base. The new release of PHI-base Version 4.2 (October 2016) has an increased data content containing information from 2219 manually curated references. The data provide information on 4460 genes from 264 pathogens tested on 176 hosts in 8046 interactions. Prokaryotic and eukaryotic pathogens are represented in almost equal numbers. Host species belong ∼70% to plants and 30% to other species of medical and/or environmental importance. Additional data types included into PHI-base 4 are the direct targets of pathogen effector proteins in experimental and natural host organisms. The curation problems encountered and the future directions of the PHI-base project are briefly discussed. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  16. A review on powder-based additive manufacturing for tissue engineering: selective laser sintering and inkjet 3D printing.

    Science.gov (United States)

    Shirazi, Seyed Farid Seyed; Gharehkhani, Samira; Mehrali, Mehdi; Yarmand, Hooman; Metselaar, Hendrik Simon Cornelis; Adib Kadri, Nahrizul; Osman, Noor Azuan Abu

    2015-06-01

    Since most starting materials for tissue engineering are in powder form, using powder-based additive manufacturing methods is attractive and practical. The principal point of employing additive manufacturing (AM) systems is to fabricate parts with arbitrary geometrical complexity with relatively minimal tooling cost and time. Selective laser sintering (SLS) and inkjet 3D printing (3DP) are two powerful and versatile AM techniques which are applicable to powder-based material systems. Hence, the latest state of knowledge available on the use of AM powder-based techniques in tissue engineering and their effect on mechanical and biological properties of fabricated tissues and scaffolds must be updated. Determining the effective setup of parameters, developing improved biocompatible/bioactive materials, and improving the mechanical/biological properties of laser sintered and 3D printed tissues are the three main concerns which have been investigated in this article.

  17. Active-Reactive Additional Damping Control of a Doubly-Fed Induction Generator Based on Active Disturbance Rejection Control

    Directory of Open Access Journals (Sweden)

    Yanfeng Ma

    2018-05-01

    Full Text Available Large-scale wind power interfacing to the power grid has an impact on the stability of the power system. However, with an additional damping controller of the wind generator, new ways for improving system damping and suppressing the low frequency oscillation (LFO of power systems can be put forward. In this paper, an active-reactive power additional damping controller based on active disturbance rejection control (ADRC is proposed. In order to improve the precision of the controller, the theory of data driven control is adopted, using the numerical algorithms for subspace state space system identification (N4SID to obtain the two order model of the ADRC controlled object. Based on the identification model, the ADRC additional damping controller is designed. Taking a 2-area 4-machine system containing the doubly fed induction generator (DFIG wind farm as an example, it is verified that the active-reactive additional damping controller designed in this paper performs well in suppressing negative-damping LFO and forced power oscillation. When the operation state of the power system changes, it can still restrain the LFO effectively, showing stronger robustness and better effectiveness compared to the traditional proportional–integral–derivative (PID additional damping controller.

  18. Improvement of lithium-ion battery performance at low temperature by adopting polydimethylsiloxane-based electrolyte additives

    International Nuclear Information System (INIS)

    Kim, Kwang Man; Ly, Nguyen Vu; Won, Jung Ha; Lee, Young-Gi; Cho, Won Il; Ko, Jang Myoun; Kaner, Richard B.

    2014-01-01

    Three kinds of polydimethylsiloxane (PDMS)-based grafted and ungrafted copolymers such as poly[dimethylsiloxane-co-(siloxane-g-acrylate)] (PDMS-A), poly(dimethylsiloxane-co-phenylsiloxane) (PDMS-P), and poly[dimethylsiloxane-co-(siloxane-g-ethylene oxide)] (PDMS-EO) are used as additives to standard liquid electrolyte solutions to enhance the lithium-ion battery performance at low temperatures. Liquid electrolyte solutions with PDMS-based additives are electrochemically stable under 5.0 V and have adequate ionic conductivities of 10 −4 S cm −1 at -20 °C. Particularly, liquid electrolytes with PDMS-P and PDMS-EO exhibit higher ionic conductivities of around 5 × 10 −4 S cm −1 at -20 °C, indicating a specific resisting property against the freezing of the liquid electrolyte components. As a result, the addition of PDMS-based additives to liquid electrolytes improves the capacity retention ratio and rate-capability of lithium-ion batteries at low temperatures

  19. Large-scale Manufacturing of Nanoparticulate-based Lubrication Additives for Improved Energy Efficiency and Reduced Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Erdemir, Ali [Argonne National Laboratory

    2013-09-26

    This project was funded under the Department of Energy (DOE) Lab Call on Nanomanufacturing for Energy Efficiency and was directed toward the development of novel boron-based nanocolloidal lubrication additives for improving the friction and wear performance of machine components in a wide range of industrial and transportation applications. Argonne's research team concentrated on the scientific and technical aspects of the project, using a range of state-of-the art analytical and tribological test facilities. Argonne has extensive past experience and expertise in working with boron-based solid and liquid lubrication additives, and has intellectual property ownership of several. There were two industrial collaborators in this project: Ashland Oil (represented by its Valvoline subsidiary) and Primet Precision Materials, Inc. (a leading nanomaterials company). There was also a sub-contract with the University of Arkansas. The major objectives of the project were to develop novel boron-based nanocolloidal lubrication additives and to optimize and verify their performance under boundary-lubricated sliding conditions. The project also tackled problems related to colloidal dispersion, larger-scale manufacturing and blending of nano-additives with base carrier oils. Other important issues dealt with in the project were determination of the optimum size and concentration of the particles and compatibility with various base fluids and/or additives. Boron-based particulate additives considered in this project included boric acid (H{sub 3}BO{sub 3}), hexagonal boron nitride (h-BN), boron oxide, and borax. As part of this project, we also explored a hybrid MoS{sub 2} + boric acid formulation approach for more effective lubrication and reported the results. The major motivation behind this work was to reduce energy losses related to friction and wear in a wide spectrum of mechanical systems and thereby reduce our dependence on imported oil. Growing concern over greenhouse

  20. Nontargeted Screening Method for Illegal Additives Based on Ultrahigh-Performance Liquid Chromatography-High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Fu, Yanqing; Zhou, Zhihui; Kong, Hongwei; Lu, Xin; Zhao, Xinjie; Chen, Yihui; Chen, Jia; Wu, Zeming; Xu, Zhiliang; Zhao, Chunxia; Xu, Guowang

    2016-09-06

    Identification of illegal additives in complex matrixes is important in the food safety field. In this study a nontargeted screening strategy was developed to find illegal additives based on ultrahigh-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS). First, an analytical method for possible illegal additives in complex matrixes was established including fast sample pretreatment, accurate UHPLC separation, and HRMS detection. Second, efficient data processing and differential analysis workflow were suggested and applied to find potential risk compounds. Third, structure elucidation of risk compounds was performed by (1) searching online databases [Metlin and the Human Metabolome Database (HMDB)] and an in-house database which was established at the above-defined conditions of UHPLC-HRMS analysis and contains information on retention time, mass spectra (MS), and tandem mass spectra (MS/MS) of 475 illegal additives, (2) analyzing fragment ions, and (3) referring to fragmentation rules. Fish was taken as an example to show the usefulness of the nontargeted screening strategy, and six additives were found in suspected fish samples. Quantitative analysis was further carried out to determine the contents of these compounds. The satisfactory application of this strategy in fish samples means that it can also be used in the screening of illegal additives in other kinds of food samples.

  1. Role of additives in combustion waves and effect on stable combustion limit of double-base propellants

    Energy Technology Data Exchange (ETDEWEB)

    Kubota, N [Japan Defence Agency, Tachikawa. 3. Research Center

    1978-12-01

    The effect of additives on the flame structures and the burning rates of double-base propellants have been examined by means of photographic observations and temperature profile measurements. The additives used for this study are lead salicylate (PbSa, 2%), nickel (Ni, 1%), ammonium perchlorate (AP, 30%), and cyclotetramethylene tetranitramine (HMX, 30%). The addition of PbSa increases the burning rate, but does not improve the flame temperature characteristics. The addition of Ni increases the flame temperature significantly at pressures below 30 atm. The Ni acts as a catalyst to promote the flame reaction while it does not act as a burning rate modifier. The additions of AP and HMX increase the thermal performance of the propellant system, however, the HMX does not improve the stable combustion limit of the rocket motor at low pressures. The addition of Ni or AP is found to increase the flame temperature at pressures below 30 atm, and the stable combustion limits is lowered to below 3 atm.

  2. Effects of Au nanoparticle addition to hole transfer layer in organic solar cells based on copper naphthalocyanine and fullerene

    Institute of Scientific and Technical Information of China (English)

    Akihiko Nagata; Takeo Okun; Tsuyoshi Akiyaman; Atsushi Suzuki

    2014-01-01

    Organic solar cells based on copper naphthalocyanine (CuNc) and fullerene (C60) were fabricated, and their photovoltaic properties were investigated. C60 and CuNc were used as n-type and p-type semiconductors, respectively. In addition, the effect of Au nanoparticle addition on a hole transfer layer was investigated, and the power conversion efficiency of the devices was improved after blending the Au nanoparticles into the hole transport layer. Nanostructures of Au nanoparticles were investigated by transmission electron microscopy and X-ray diffraction. Energy levels of molecules were calculated by molecular orbital calculations, and the nanostructure and electronic properties were discussed.

  3. Effects of chromium addition on microstructure and properties of TiC–VC reinforced Fe-based laser cladding coatings

    International Nuclear Information System (INIS)

    Zhang, Hui; Zou, Yong; Zou, Zengda; Shi, Chuanwei

    2014-01-01

    Highlights: • In situ TiC–VC reinforced Fe-based coatings with different Cr addition were obtained. • Some long strip Cr 3 C 2 synthesized while the Cr addition was 12.0% or more. • A moderate amount of Cr improved hardness and corrosion resistance significantly. • The cladding layer microhardness could reach as high as 1090HV 0.2 with 3.0% Cr. • The corrosion resistance could improve 4.5 times with 12.0% Cr. - Abstract: Effects of different addition of Cr on microstructure and properties (especially the corrosion resistance) of cladding layers were investigated by means of X-ray diffractometry (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), potentio-dynamic polarization and electrochemical impedance spectroscopy (EIS). Results showed that Fe–Ti–V–C alloy powders with different addition of Cr formed good cladding layers without defects such as cracking and porosity. Phases of the cladding layers were α-Fe, γ-Fe, TiC, VC and TiVC 2 . A certain amount of long strip Cr 3 C 2 synthesized while the addition of Cr was 12.0% or more. Microhardness and corrosion resistance of cladding layer both improved greatly with a moderate amount of Cr. The cladding layer with 3.0% Cr showed a highest microhardness 1090HV 0.2 , and the variation tendency of the hardness is not a linearly relationship with increasing the chromium addition. The cladding layer with 12.0% Cr addition showed the best corrosion resistance, which was about 4.5 times than that of the cladding layer without Cr. EIS spectrum of the cladding layer without Cr was composed of an inductive arc at low frequency and a capacitive arc at high frequency. However, the inductive arc at low frequency transformed into a capacitive arc gradually with the addition of Cr increasing

  4. Effects of chromium addition on microstructure and properties of TiC–VC reinforced Fe-based laser cladding coatings

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hui; Zou, Yong, E-mail: yzou@sdu.edu.cn; Zou, Zengda; Shi, Chuanwei

    2014-11-25

    Highlights: • In situ TiC–VC reinforced Fe-based coatings with different Cr addition were obtained. • Some long strip Cr{sub 3}C{sub 2} synthesized while the Cr addition was 12.0% or more. • A moderate amount of Cr improved hardness and corrosion resistance significantly. • The cladding layer microhardness could reach as high as 1090HV{sub 0.2} with 3.0% Cr. • The corrosion resistance could improve 4.5 times with 12.0% Cr. - Abstract: Effects of different addition of Cr on microstructure and properties (especially the corrosion resistance) of cladding layers were investigated by means of X-ray diffractometry (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), potentio-dynamic polarization and electrochemical impedance spectroscopy (EIS). Results showed that Fe–Ti–V–C alloy powders with different addition of Cr formed good cladding layers without defects such as cracking and porosity. Phases of the cladding layers were α-Fe, γ-Fe, TiC, VC and TiVC{sub 2}. A certain amount of long strip Cr{sub 3}C{sub 2} synthesized while the addition of Cr was 12.0% or more. Microhardness and corrosion resistance of cladding layer both improved greatly with a moderate amount of Cr. The cladding layer with 3.0% Cr showed a highest microhardness 1090HV{sub 0.2}, and the variation tendency of the hardness is not a linearly relationship with increasing the chromium addition. The cladding layer with 12.0% Cr addition showed the best corrosion resistance, which was about 4.5 times than that of the cladding layer without Cr. EIS spectrum of the cladding layer without Cr was composed of an inductive arc at low frequency and a capacitive arc at high frequency. However, the inductive arc at low frequency transformed into a capacitive arc gradually with the addition of Cr increasing.

  5. Differently-catalyzed silica-based precursors as functional additives for the epoxy-based hybrid materials

    Czech Academy of Sciences Publication Activity Database

    Perchacz, Magdalena; Beneš, Hynek; Zhigunov, Alexander; Serkis, Magdalena; Pavlova, Ewa

    2016-01-01

    Roč. 99, 2 September (2016), s. 434-446 ISSN 0032-3861 R&D Projects: GA ČR(CZ) GA14-05146S; GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : epoxy-silica hybrid material * solvent-free sol-gel process * silica-based precursor Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.684, year: 2016

  6. Preparation and Tribological Properties of Dual-Coated TiO2 Nanoparticles as Water-Based Lubricant Additives

    Directory of Open Access Journals (Sweden)

    Yue Gu

    2014-01-01

    Full Text Available Titanium dioxide nanoparticles (TiO2 were synthesized and then dual-coated with silane coupling agent (KH-570 and OP-10 in sequence in order to be dispersed stably in water as lubricant additives. The tribological properties and the application performance in Q235 steel machining of the nanoparticles as water-based lubricant additives were investigated on an MSR-10D four-ball tribotester and on a bench drilling machine, respectively. Scanning electron microscope (SEM and atomic force microscope (AFM were used to analyze the worn surface. The results show that the surface-modified TiO2 nanoparticles can remarkably improve the load-carrying capacity, the friction reducing, and anti wear abilities of pure water. The wear scar diameter and the coefficient of friction of the water-based lubricating fluids with TiO2 nanoparticles decreased, and the thick deep furrows on the surface of wear scar also decreased obviously with the increase of TiO2 concentration. The power consumption in drilling process was lower and the cutting surface was smoother using the water-based lubricating fluids added TiO2 nanoparticles compared to the fluid without addition. The reason for nanoparticles improving tribological properties of water based lubricating fluid might be the formation of a dynamic deposition film during rubbing process according to analysis of the worn surface.

  7. Effect of molybdenum and chromium additions on the mechanical properties of Fe3Al-based alloys

    International Nuclear Information System (INIS)

    Sun Yangshan; Xue Feng; Mei Jianping; Yu Xingquan; Zhang Lining

    1995-01-01

    Iron aluminides based on Fe 3 Al offer excellent oxidation and sulfidation resistance, with lower material cost and density than stainless steels. However, their potential use as structural material has been hindered by limited ductility and a sharp drop in strength above 600 C. Recent development efforts have indicated that adequate engineering ductility of 10--20% and tensile yield strength of as high as 500 MPa can be achieved through control of composition and microstructure. These improved tensile properties make Fe 3 Al-based alloys more competitive against conventional austenic and ferritic steels. The improvement of high temperature mechanical properties has been achieved mainly by alloying processes. Molybdenum has been found to be one of the most important alloying elements for strengthening Fe 3 Al-based alloys at high temperatures. However, the RT(room temperature) ductility decreases with the increase of a molybdenum addition. On the other hand, a chromium addition to Fe 3 Al-based alloys is very efficient for improving RT ductility but not beneficial to yield strength at temperatures to 800 C. The purpose of the present paper is to report the effects of combined additions of molybdenum and chromium on mechanical properties at ambient temperature and high temperature of 600 C

  8. Enhancing Specific Energy and Power in Asymmetric Supercapacitors - A Synergetic Strategy based on the Use of Redox Additive Electrolytes

    Science.gov (United States)

    Singh, Arvinder; Chandra, Amreesh

    2016-01-01

    The strategy of using redox additive electrolyte in combination with multiwall carbon nanotubes/metal oxide composites leads to a substantial improvements in the specific energy and power of asymmetric supercapacitors (ASCs). When the pure electrolyte is optimally modified with a redox additive viz., KI, ~105% increase in the specific energy is obtained with good cyclic stability over 3,000 charge-discharge cycles and ~14.7% capacitance fade. This increase is a direct consequence of the iodine/iodide redox pairs that strongly modifies the faradaic and non-faradaic type reactions occurring on the surface of the electrodes. Contrary to what is shown in few earlier reports, it is established that indiscriminate increase in the concentration of redox additives will leads to performance loss. Suitable explanations are given based on theoretical laws. The specific energy or power values being reported in the fabricated ASCs are comparable or higher than those reported in ASCs based on toxic acetonitrile or expensive ionic liquids. The paper shows that the use of redox additive is economically favorable strategy for obtaining cost effective and environmentally friendly ASCs. PMID:27184260

  9. Annealing-free P3HT:PCBM-based organic solar cells via two halohydrocarbons additives with similar boiling points

    International Nuclear Information System (INIS)

    Bao, Xichang; Wang, Ting; Yang, Ailing; Yang, Chunpeng; Dou, Xiaowei; Chen, Weichao; Wang, Ning; Yang, Renqiang

    2014-01-01

    Highlights: • Two halohydrocarbons were selected as additives for polymer solar cells. • The additives can improve the photocurrent of photovoltaic devices. • Extensive characterization of the blends was done to explore the mechanism. -- Abstract: Efficient annealing-free inverted bulk heterojunction (BHJ) organic solar cells based on poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C 61 -butyric acid methyl ester (PCBM) (1:1, w/w) have been obtained using two easily accessible halohydrocarbons (1,6-dibromohexane (DBH) and 1-bromodecane (BD)) with the same boiling points as solvent additives. The devices treated with 2.5 wt% additives removed the grain boundary of the large PCBM-rich phase, resulting in more-uniform film morphology on the nanoscale. The more-uniform film morphology greatly improved the short circuit current density of the devices. Finally, PCEs of the devices processed with DBH and BD reached 3.81% and 3.68%, respectively. Both additives with almost the same boiling points had a similar impact on device performance, despite of different chemical structures with different polarities and other physical properties

  10. Experimental Investigation of the Use of Waste Mineral Oils as a Fuel with Organic-Based Mn Additive

    Directory of Open Access Journals (Sweden)

    Bülent Özdalyan

    2018-06-01

    Full Text Available The heat values of waste mineral oils are equal to the heat value of the fuel oil. However, heat value alone is not sufficient for the use of waste minerals oils as fuel. However, the critical physical properties of fuels such as density and viscosity need to be adapted to the system in order to be used. In this study, the engine oils used in the first 10,000 km of the vehicles were used as waste mineral oil. An organic-based Mn additive was synthesized to improve the properties of the waste mineral oil. It was observed that mixing the Mn additive with the waste mineral oil at different doses (4, 8, 12, and 16 ppm improves the viscosity of the waste oil and the flash point. The resulting fuel was evaluated for emission using different loads in a 5 kW capacity generator to compare the fuel with standard diesel fuel and to determine the effect of Mn addition. In the experimental study, it was observed that the emission characteristics of the fuel obtained from waste mineral oil were worse than diesel fuel, but some improvement was observed with Mn addition. As a result, we found that the use of waste mineral oils in engines in fuel standards was not appropriate, but may be improved with additives.

  11. Deposition Time and Thermal Cycles of Fabricating Thin-wall Steel Parts by Double Electrode GMAW Based Additive Manufacturing

    Directory of Open Access Journals (Sweden)

    Yang Dongqing

    2017-01-01

    Full Text Available The deposition time for fabricating the thin-wall part as well as the peak temperature of the substrate during the process was analyzed in the double electrode gas metal arc welding (DE-GMAW based additive manufacturing (AM. The total deposition time and the interlayer idle time of the manufacturing process decreased with the increasing of the bypass current under the same interlayer temperature and the same deposition rate. The thermal cycling curves illustrated that the peak temperature of the substrate was lower in the DE-GMAW base AM under the same conditions. When depositing the thin-wall parts, the DE-GMAW based AM can reduce the heat input to the substrate and improve the fabrication efficiency, compared with the GMAW based AM.

  12. Emissions from a Diesel Engine using Fe-based Fuel Additives and a Sintered Metal Filtration System.

    Science.gov (United States)

    Bugarski, Aleksandar D; Hummer, Jon A; Stachulak, Jozef S; Miller, Arthur; Patts, Larry D; Cauda, Emanuele G

    2016-03-01

    A series of laboratory tests were conducted to assess the effects of Fe-containing fuel additives on aerosols emitted by a diesel engine retrofitted with a sintered metal filter (SMF) system. Emission measurements performed upstream and downstream of the SMF system were compared, for cases when the engine was fueled with neat ultralow sulfur diesel (ULSD) and with ULSD treated with two formulations of additives containing Fe-based catalysts. The effects were assessed for four steady-state engine operating conditions and one transient cycle. The results showed that the SMF system reduced the average total number and surface area concentrations of aerosols by more than 100-fold. The total mass and elemental carbon results confirmed that the SMF system was indeed very effective in the removal of diesel aerosols. When added at the recommended concentrations (30 p.p.m. of iron), the tested additives had minor adverse impacts on the number, surface area, and mass concentrations of filter-out (FOut) aerosols. For one of the test cases, the additives may have contributed to measurable concentrations of engine-out (EOut) nucleation mode aerosols. The additives had only a minor impact on the concentration and size distribution of volatile and semi-volatile FOut aerosols. Metal analysis showed that the introduction of Fe with the additives substantially increased Fe concentration in the EOut, but the SMF system was effective in removal of Fe-containing aerosols. The FOut Fe concentrations for all three tested fuels were found to be much lower than the corresponding EOut Fe concentrations for the case of untreated ULSD fuel. The results support recommendations that these additives should not be used in diesel engines unless they are equipped with exhaust filtration systems. Since the tested SMF system was found to be very efficient in removing Fe introduced by the additives, the use of these additives should not result in a measurable increase in emissions of de novo generated

  13. Evaluation of DVH-based treatment plan verification in addition to gamma passing rates for head and neck IMRT

    International Nuclear Information System (INIS)

    Visser, Ruurd; Wauben, David J.L.; Groot, Martijn de; Steenbakkers, Roel J.H.M.; Bijl, Henk P.; Godart, Jeremy; Veld, Aart A. van’t; Langendijk, Johannes A.; Korevaar, Erik W.

    2014-01-01

    Background and purpose: Treatment plan verification of intensity modulated radiotherapy (IMRT) is generally performed with the gamma index (GI) evaluation method, which is difficult to extrapolate to clinical implications. Incorporating Dose Volume Histogram (DVH) information can compensate for this. The aim of this study was to evaluate DVH-based treatment plan verification in addition to the GI evaluation method for head and neck IMRT. Materials and methods: Dose verifications of 700 subsequent head and neck cancer IMRT treatment plans were categorised according to gamma and DVH-based action levels. Fractionation dependent absolute dose limits were chosen. The results of the gamma- and DVH-based evaluations were compared to the decision of the medical physicist and/or radiation oncologist for plan acceptance. Results: Nearly all treatment plans (99.7%) were accepted for treatment according to the GI evaluation combined with DVH-based verification. Two treatment plans were re-planned according to DVH-based verification, which would have been accepted using the evaluation alone. DVH-based verification increased insight into dose delivery to patient specific structures increasing confidence that the treatment plans were clinically acceptable. Moreover, DVH-based action levels clearly distinguished the role of the medical physicist and radiation oncologist within the Quality Assurance (QA) procedure. Conclusions: DVH-based treatment plan verification complements the GI evaluation method improving head and neck IMRT-QA

  14. The use of amorphous silica-alumina-based additive in the adhesive dry mixes of building materials

    Directory of Open Access Journals (Sweden)

    Loganina VI

    2018-01-01

    Full Text Available Proved the possibility of using amorphous aluminosilicate as a modifying agent for the adhesive dry mixes. Are given the data on the microstructure and chemical composition of the amorphous aluminosilicates. Installed , that the microstructure of the synthetic additives is characterized by particles of round shape, dimensions 5,208-5,704 μm, Also there are particles of elongated shape in size 7.13-8.56 μm. Predominate chemical elements O, Si, Na, S, and Al in quantity 60.69%, 31.26%, 24.23%, 18.69% and 8.29% respectively. Described the character changes in the rheological properties of cement-sand mortar, depending on the percentage of additives. Determined, that the introduction in the cement-sand mortar the additive based on amorphous aluminosilicate leads to higher values of plastic strength. Are given the model of cement stone strength using synthetic additives in the formulation. The results of the evaluation of the frost resistance of cement-based tile adhesives with the use of amorphous aluminosilicates as a modifying additive are presented. In the article is determined the mark on frost resistance of tile glue and frost resistance of the contact zone of tile glue. The evaluation of the performance properties of the layer of tile adhesive on the basis of cement, dry mixes. The calculation of the value of displacement of the adhesive layer made on the basis of the developed recipes cement dry mixes applied to a vertical surface. Experimental data obtained values of displacement tiles relative to the substrate. Described the results of physical and mechanical properties of tile adhesive made on the basis of the developed adhesive dry mix formulations.

  15. Additive manufacturing of three-dimensional (3D) microfluidic-based microelectromechanical systems (MEMS) for acoustofluidic applications.

    Science.gov (United States)

    Cesewski, Ellen; Haring, Alexander P; Tong, Yuxin; Singh, Manjot; Thakur, Rajan; Laheri, Sahil; Read, Kaitlin A; Powell, Michael D; Oestreich, Kenneth J; Johnson, Blake N

    2018-06-13

    Three-dimensional (3D) printing now enables the fabrication of 3D structural electronics and microfluidics. Further, conventional subtractive manufacturing processes for microelectromechanical systems (MEMS) relatively limit device structure to two dimensions and require post-processing steps for interface with microfluidics. Thus, the objective of this work is to create an additive manufacturing approach for fabrication of 3D microfluidic-based MEMS devices that enables 3D configurations of electromechanical systems and simultaneous integration of microfluidics. Here, we demonstrate the ability to fabricate microfluidic-based acoustofluidic devices that contain orthogonal out-of-plane piezoelectric sensors and actuators using additive manufacturing. The devices were fabricated using a microextrusion 3D printing system that contained integrated pick-and-place functionality. Additively assembled materials and components included 3D printed epoxy, polydimethylsiloxane (PDMS), silver nanoparticles, and eutectic gallium-indium as well as robotically embedded piezoelectric chips (lead zirconate titanate (PZT)). Electrical impedance spectroscopy and finite element modeling studies showed the embedded PZT chips exhibited multiple resonant modes of varying mode shape over the 0-20 MHz frequency range. Flow visualization studies using neutrally buoyant particles (diameter = 0.8-70 μm) confirmed the 3D printed devices generated bulk acoustic waves (BAWs) capable of size-selective manipulation, trapping, and separation of suspended particles in droplets and microchannels. Flow visualization studies in a continuous flow format showed suspended particles could be moved toward or away from the walls of microfluidic channels based on selective actuation of in-plane or out-of-plane PZT chips. This work suggests additive manufacturing potentially provides new opportunities for the design and fabrication of acoustofluidic and microfluidic devices.

  16. Destabilization emulsion of oil by means of additives based on silicones polyethers; Desestabilizacao de emulsoes de petroleo por meio de aditivos a base de silicones polieteres

    Energy Technology Data Exchange (ETDEWEB)

    Jarque, Erika A.; Mansur, Claudia R.E. [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Professora Eloisa Mano], e-mails: alegrio@ima.ufrj.br, celias@ima.ufrj.br

    2011-07-01

    The process of demulsification has great importance in the petroleum industry, since the formation of emulsions is a natural phenomenon in this sector. Several polymers have been used commercially as additives emulsion destabilizing, among them are the block copolymers of poly (ethylene oxide)-poly (propylene oxide) (PEO-PPO). This work aims to study the efficiency of five additives based on silicones polyethers, which have structures in their chains of poly (ethylene oxide) (PEO) or PEO-PPO copolymers. The results show that the addition of these additives in the water / oil reduced the values of interfacial tension of systems. From the testing of gravitational separation water / oil was observed that all the additives promoted the breakdown of water / oil, but those who hold in their structures the chains of block copolymers of PEO-PPO were the most efficient, and that the caused a smaller reduction in the interfacial tensions of these systems. (author)

  17. Benefits of carbon addition on the hydrogen absorption properties of Mg-based thin films grown by Pulsed Laser Deposition

    International Nuclear Information System (INIS)

    Darok, X.; Rougier, A.; Bhat, V.; Aymard, L.; Dupont, L.; Laffont, L.; Tarascon, J.-M.

    2006-01-01

    Mg-Ni thin films were grown using Pulsed Laser Deposition. In situ optical changes from shiny metallic to transparent states were observed for films deposited in vacuum and under an Ar/H 2 gas mixture (93/7%), respectively. Optical changes were also achieved by ex situ hydrogenation under hydrogen gas pressure of 15 bars at 200 deg. C. However, after ex situ hydrogenation, the optical transmittance of the Mg-based hydrogenated thin films did not exceed 25%. Such limitation was attributed to oxygen contamination, as deduced by High Resolution Transmission Electron Microscopy observations, showing the co-existence of both Mg-based and MgO phases for as-deposited films. A significant decrease in oxygen contamination was successfully achieved with the addition of carbon, leading to the preparation of (Mg-based)-C x (x < 20%) thin films showing a faster and easier hydrogenation

  18. Microstructure, characterizations, functionality and compressive strength of cement-based materials using zinc oxide nanoparticles as an additive

    Energy Technology Data Exchange (ETDEWEB)

    Nochaiya, Thanongsak [Department of Physics, Faculty of Science, Naresuan University, Phitsanulok 65000 (Thailand); Sekine, Yoshika [Department of Chemistry, School of Science, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Choopun, Supab [Applied Physics Research Laboratory, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Chaipanich, Arnon, E-mail: arnon.chaipanich@cmu.ac.th [Advanced Cement-Based Materials Research Unit, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2015-05-05

    Highlights: • Nano zinc oxide was used as an additive material. • Microstructure and phase characterization of pastes were characterized using SEM and XRD. • TGA and FTIR were also used to determine the hydration reaction. • Compressive strength of ZnO mixes was found to increase at 28 days. - Abstract: Zinc oxide nanoparticles as a nanophotocatalyst has great potential for self-cleaning applications in concrete structures, its effects on the cement hydration, setting time and compressive strength are also important when using it in practice. This paper reports the effects of zinc oxide nanoparticles, as an additive material, on properties of cement-based materials. Setting time, compressive strength and porosity of mortars were investigated. Microstructure and morphology of pastes were characterized using scanning electron microscope and X-ray diffraction (XRD), respectively. Moreover, thermal gravimetric analysis (TGA) and Fourier-transform infrared spectrometer (FTIR) were also used to determine the hydration reaction. The results show that Portland cement paste with additional ZnO was found to slightly increase the water requirement while the setting time presented prolongation period than the control mix. However, compressive strength of ZnO mixes was found to be higher than that of PC mix up to 15% (at 28 days) via filler effect. Microstructure, XRD and TGA results of ZnO pastes show less hydration products before 28 days but similar at 28 days. In addition, FTIR results confirmed the retardation when ZnO was partially added in Portland cement pastes.

  19. Microstructure, characterizations, functionality and compressive strength of cement-based materials using zinc oxide nanoparticles as an additive

    International Nuclear Information System (INIS)

    Nochaiya, Thanongsak; Sekine, Yoshika; Choopun, Supab; Chaipanich, Arnon

    2015-01-01

    Highlights: • Nano zinc oxide was used as an additive material. • Microstructure and phase characterization of pastes were characterized using SEM and XRD. • TGA and FTIR were also used to determine the hydration reaction. • Compressive strength of ZnO mixes was found to increase at 28 days. - Abstract: Zinc oxide nanoparticles as a nanophotocatalyst has great potential for self-cleaning applications in concrete structures, its effects on the cement hydration, setting time and compressive strength are also important when using it in practice. This paper reports the effects of zinc oxide nanoparticles, as an additive material, on properties of cement-based materials. Setting time, compressive strength and porosity of mortars were investigated. Microstructure and morphology of pastes were characterized using scanning electron microscope and X-ray diffraction (XRD), respectively. Moreover, thermal gravimetric analysis (TGA) and Fourier-transform infrared spectrometer (FTIR) were also used to determine the hydration reaction. The results show that Portland cement paste with additional ZnO was found to slightly increase the water requirement while the setting time presented prolongation period than the control mix. However, compressive strength of ZnO mixes was found to be higher than that of PC mix up to 15% (at 28 days) via filler effect. Microstructure, XRD and TGA results of ZnO pastes show less hydration products before 28 days but similar at 28 days. In addition, FTIR results confirmed the retardation when ZnO was partially added in Portland cement pastes

  20. Microstructure and corrosion resistance of Ni-based alloy laser coatings with nanosize CeO2 addition

    Science.gov (United States)

    Zhang, Shi Hong; Li, Ming Xi; Yoon, Jae Hong; Cho, Tong Yul; Zhu He, Yi; Lee, Chan Gyu

    2008-07-01

    Micron-size Ni-base alloy (NBA) powders were mixed with both 1.5 wt.% (hereinafter %) micron-size CeO2 (m-CeO2) and also 1.5% and 3.0% nano-size CeO2 (n- CeO2) powders. These mixtures were coated on low-carbon steel (Q235) by 2.0 kW CO2 laser cladding. The effects on the microstructures, phases and electrochemical corrosion of the coatings upon the addition of m- and n- CeO2 powders to NBA (m- and n- CeO2 /NBA) have been investigated. The results showed that a smooth coating was prepared under suitable processing parameters (P= 2.0 kW, V= 180 mm min- 1) by adding 1.5% n- CeO2. In addition to the primary phases of γ-Ni, Cr23 C6 and Ni3 B in the Ni-base alloy coating, CeNi3 was formed in Ni-base alloy coatings with both n- CeO2 and m-CeO2 particles, and CeNi5 appeared in the coating upon decreasing the size of CeO2 particles. Well-developed dendrites were observed in the Ni-base alloy coating; directional dendrites grew at the interface in the coating upon the addition of m-CeO2, whereas fine and multioriented dendrites grew upon decreasing the size of CeO2 particles to the nanoscale. Actinomorphic dendrites and compact equiaxed dendrites grew from the interface to near the surface upon increasing the content of n- CeO2 from 1.5 to 3.0%. In strongly acidic HNO3 solution, the severe corrosion of dendrites occurred and there were many corrosion pits in the Ni-base alloy coating; intercrystalline corrosion also has a dominant role upon the addition of m-CeO2, whereas uniform corrosion occurs in the coating as the size of CeO2 particles is decreased to nanoscale.

  1. Microstructure and corrosion resistance of Ni-based alloy laser coatings with nanosize CeO2 addition

    Directory of Open Access Journals (Sweden)

    Shi Hong Zhang et al

    2008-01-01

    Full Text Available Micron-size Ni-base alloy (NBA powders were mixed with both 1.5 wt.% (hereinafter % micron-size CeO2 (m-CeO2 and also 1.5% and 3.0% nano-size CeO2 (n- CeO2 powders. These mixtures were coated on low-carbon steel (Q235 by 2.0 kW CO2 laser cladding. The effects on the microstructures, phases and electrochemical corrosion of the coatings upon the addition of m- and n- CeO2 powders to NBA (m- and n- CeO2 /NBA have been investigated. The results showed that a smooth coating was prepared under suitable processing parameters (P= 2.0 kW, V= 180 mm min- 1 by adding 1.5% n- CeO2. In addition to the primary phases of γ-Ni, Cr23 C6 and Ni3 B in the Ni-base alloy coating, CeNi3 was formed in Ni-base alloy coatings with both n- CeO2 and m-CeO2 particles, and CeNi5 appeared in the coating upon decreasing the size of CeO2 particles. Well-developed dendrites were observed in the Ni-base alloy coating; directional dendrites grew at the interface in the coating upon the addition of m-CeO2, whereas fine and multioriented dendrites grew upon decreasing the size of CeO2 particles to the nanoscale. Actinomorphic dendrites and compact equiaxed dendrites grew from the interface to near the surface upon increasing the content of n- CeO2 from 1.5 to 3.0%. In strongly acidic HNO3 solution, the severe corrosion of dendrites occurred and there were many corrosion pits in the Ni-base alloy coating; intercrystalline corrosion also has a dominant role upon the addition of m-CeO2, whereas uniform corrosion occurs in the coating as the size of CeO2 particles is decreased to nanoscale.

  2. Development ceramic composites based on Al2O3, SiO2 and IG-017 additive

    Science.gov (United States)

    Kurovics, E.; Shmakova, A.; Kanev, B.; Gömze, L. A.

    2017-02-01

    Based on high purity alumina and quartz powders and IG-017 bio-original additives the authors have developed new ceramic composite materials for different industrial purposes. The main goal was to fine a material and morphological structures of high performance ceramic composites as frames for development complex materials for extreme consumptions in the future. For this the mixed powders of Al2O3 , SiO2 and IG-017 bio-original additive were uniaxially pressed at different compaction pressures into disc shapes and were sintered in electric kiln under air (1) and nitrogrn (2) atmosphere. The grain size distributions of the raw materials were determined by laser granulometry. There thermo-physical properties were also determined by derivatography. The prepared and sintered specimens were tested on geometrical sizes, microstructure and morphology by scanning electron microscopy, porosity and water absorption. In this work the authors present the results of their research and investigation.

  3. Improving the Cold Temperature Properties of Tallow-Based Methyl Ester Mixtures Using Fractionation, Blending, and Additives

    Science.gov (United States)

    Elwell, Caleb

    biodiesel, only two of the additives had any significant effect on TME CP. The additive formulated by Meat & Livestock Australia (MLA) outperformed Evonik's Viscoplex 10-530. The MLA additive was investigated further and its effect on CP was characterized in pure TME and in CME/TME blends. When mixed in CME/TME blends, the MLA additive had a synergistic effect and produced lower CPs than the addition of mixing MLA in TME and blending CME with TME. To evalulate the cold temperature properties of TME blended with petroleum diesel, CPs of TME/diesel blends from 0 to 100% were measured. The TME/diesel blends were treated with the MLA additives to determine the effects of the additives under these blend conditions. The MLA additive also had a synergistic effect when mixed in TME/diesel blends. Finally, all three of the TME CP reduction methods were evaluated in an economic model to determine the conditions under which each method would be economically viable. Each of the CP reduction methods were compared using a common metric based on the cost of reducing the CP of 1 gallon of finished biodiesel by 1°C (i.e. $/gal/°C). Since the cost of each method is dependent on varying commodity prices, further development of the economic model (which was developed and tested with 2012 prices) to account for stochastic variation in commodity prices is recommended.

  4. ORGANIZATIONAL AND METHODICAL BASES OF MULTICULTURAL SELF-ORGANIZATION OF STUDENTS IN THE ADDITIONAL FOREIGN LANGUAGE EDUCATION

    Directory of Open Access Journals (Sweden)

    V N Kartashova

    2016-12-01

    Full Text Available The article deals with the organizational and methodical bases of multicultural self-organization of the linguistic personality of the student in terms of additional foreign language education. According to the authors’ opinion, the methodological basis is a dialogue of cultures as a philosophy of mutual understanding, mutual relations in today’s global environment. Changing the socio-cultural context of foreign language education paradigm allows you to select multicultural (teaching a foreign language on the principle of “native culture - the culture of the foreign language speaking country - the culture of the world” and active (the development and functioning of a person in the normal course of his activities, where the starting point is the introduction of man to the world of culture and his self-development approach as a priority. The contents of additional education is oriented towards the disclosure and a possible solution of specific problems in the educational practice, and based on the principles of humanism and diversification.The article analyzes the individual programs of additional education and professional training in the field of foreign languages, developed by universities in recent decades. The authors present the experience of the scientific and methodological development and implementation at the department of foreign languages and teaching methods of Bunin Yelets State University of the additional foreign language education system that provides the multicultural self-organization of the student’s linguistic personality. The description of the program of professional retraining “The multicultural self-organization expert in the field of business, management and tourism (English”, designed for the students of non-language training areas, is presented, too. The positive dynamics of mastering foreign languages, the development of global attitude of the linguistic personality to the culture and his/her cultural

  5. Bacterial-based additives for the production of artificial snow: what are the risks to human health?

    Science.gov (United States)

    Lagriffoul, A; Boudenne, J L; Absi, R; Ballet, J J; Berjeaud, J M; Chevalier, S; Creppy, E E; Gilli, E; Gadonna, J P; Gadonna-Widehem, P; Morris, C E; Zini, S

    2010-03-01

    For around two decades, artificial snow has been used by numerous winter sports resorts to ensure good snow cover at low altitude areas or more generally, to lengthen the skiing season. Biological additives derived from certain bacteria are regularly used to make artificial snow. However, the use of these additives has raised doubts concerning the potential impact on human health and the environment. In this context, the French health authorities have requested the French Agency for Environmental and Occupational Health Safety (Afsset) to assess the health risks resulting from the use of such additives. The health risk assessment was based on a review of the scientific literature, supplemented by professional consultations and expertise. Biological or chemical hazards from additives derived from the ice nucleation active bacterium Pseudomonas syringae were characterised. Potential health hazards to humans were considered in terms of infectious, toxic and allergenic capacities with respect to human populations liable to be exposed and the means of possible exposure. Taking into account these data, a qualitative risk assessment was carried out, according to four exposure scenarios, involving the different populations exposed, and the conditions and routes of exposure. It was concluded that certain health risks can exist for specific categories of professional workers (mainly snowmakers during additive mixing and dilution tank cleaning steps, with risks estimated to be negligible to low if workers comply with safety precautions). P. syringae does not present any pathogenic capacity to humans and that the level of its endotoxins found in artificial snow do not represent a danger beyond that of exposure to P. syringae endotoxins naturally present in snow. However, the risk of possible allergy in some particularly sensitive individuals cannot be excluded. Another important conclusion of this study concerns use of poor microbiological water quality to make artificial snow.

  6. Bacterial-based additives for the production of artificial snow: What are the risks to human health?

    International Nuclear Information System (INIS)

    Lagriffoul, A.; Boudenne, J.L.; Absi, R.; Ballet, J.J.; Berjeaud, J.M.; Chevalier, S.; Creppy, E.E.; Gilli, E.; Gadonna, J.P.; Gadonna-Widehem, P.; Morris, C.E.; Zini, S.

    2010-01-01

    For around two decades, artificial snow has been used by numerous winter sports resorts to ensure good snow cover at low altitude areas or more generally, to lengthen the skiing season. Biological additives derived from certain bacteria are regularly used to make artificial snow. However, the use of these additives has raised doubts concerning the potential impact on human health and the environment. In this context, the French health authorities have requested the French Agency for Environmental and Occupational Health Safety (Afsset) to assess the health risks resulting from the use of such additives. The health risk assessment was based on a review of the scientific literature, supplemented by professional consultations and expertise. Biological or chemical hazards from additives derived from the ice nucleation active bacterium Pseudomonas syringae were characterised. Potential health hazards to humans were considered in terms of infectious, toxic and allergenic capacities with respect to human populations liable to be exposed and the means of possible exposure. Taking into account these data, a qualitative risk assessment was carried out, according to four exposure scenarios, involving the different populations exposed, and the conditions and routes of exposure. It was concluded that certain health risks can exist for specific categories of professional workers (mainly snowmakers during additive mixing and dilution tank cleaning steps, with risks estimated to be negligible to low if workers comply with safety precautions). P. syringae does not present any pathogenic capacity to humans and that the level of its endotoxins found in artificial snow do not represent a danger beyond that of exposure to P. syringae endotoxins naturally present in snow. However, the risk of possible allergy in some particularly sensitive individuals cannot be excluded. Another important conclusion of this study concerns use of poor microbiological water quality to make artificial snow.

  7. Bacterial-based additives for the production of artificial snow: What are the risks to human health?

    Energy Technology Data Exchange (ETDEWEB)

    Lagriffoul, A. [Agence Francaise de Securite Sanitaire de l' Environnement et du Travail, 253, avenue du General Leclerc, 94701 Maisons-Alfort (France); Boudenne, J.L. [Universite de Provence, Laboratoire Chimie Provence, UMR6264, 3 Place Victor Hugo case 29 13331 Marseille CEDEX 3 (France); Absi, R. [Institut Polytechnique Saint-Louis, Ecole de Biologie Industrielle, Laboratoire EBInnov, 32 Boulevard du Port, 95094 Cergy-Pontoise (France); Ballet, J.J. [Laboratoire d' immunologie et immunopathologie, Centre hospitalo-universitaire de Caen, avenue de la cote de nacre 14000 Caen (France); Berjeaud, J.M. [Universite de Poitiers, Laboratoire de Chimie et Microbiologie de l' Eau, UMR6008, 40 avenue du recteur Pineau, 86022 Poitiers CEDEX (France); Chevalier, S. [Universite de Rouen, Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Securite Sanitaire, 55 rue St Germain, 27000 Evreux (France); Creppy, E.E. [Universite Bordeaux 2, UFR des Sciences Pharmaceutiques, Laboratoire de Toxicologie, 146, rue Leo-Saignat, 33076 Bordeaux CEDEX (France); Gilli, E. [Universite Paris 8, Departement de geographie, 2, rue de la Liberte, 93526 Saint Denis CEDEX (France); UMR Espace 6012, 98 bd Edouard Herriot, 06204, Nice, CEDEX 3 (France); Gadonna, J.P. [Institut Polytechnique Saint-Louis, Ecole de Biologie Industrielle, Laboratoire EBInnov, 32 Boulevard du Port, 95094 Cergy-Pontoise (France); Gadonna-Widehem, P. [Institut Polytechnique LaSalle Beauvais, departement STAI, rue P. Waguet BP 30313, 60026 Beauvais CEDEX (France); Morris, C.E. [INRA, Unite de Pathologie Vegetale UR407, F-84140 Montfavet (France); Zini, S., E-mail: sylvie.zini@afsset.fr [Agence Francaise de Securite Sanitaire de l' Environnement et du Travail, 253, avenue du General Leclerc, 94701 Maisons-Alfort (France)

    2010-03-01

    For around two decades, artificial snow has been used by numerous winter sports resorts to ensure good snow cover at low altitude areas or more generally, to lengthen the skiing season. Biological additives derived from certain bacteria are regularly used to make artificial snow. However, the use of these additives has raised doubts concerning the potential impact on human health and the environment. In this context, the French health authorities have requested the French Agency for Environmental and Occupational Health Safety (Afsset) to assess the health risks resulting from the use of such additives. The health risk assessment was based on a review of the scientific literature, supplemented by professional consultations and expertise. Biological or chemical hazards from additives derived from the ice nucleation active bacterium Pseudomonas syringae were characterised. Potential health hazards to humans were considered in terms of infectious, toxic and allergenic capacities with respect to human populations liable to be exposed and the means of possible exposure. Taking into account these data, a qualitative risk assessment was carried out, according to four exposure scenarios, involving the different populations exposed, and the conditions and routes of exposure. It was concluded that certain health risks can exist for specific categories of professional workers (mainly snowmakers during additive mixing and dilution tank cleaning steps, with risks estimated to be negligible to low if workers comply with safety precautions). P. syringae does not present any pathogenic capacity to humans and that the level of its endotoxins found in artificial snow do not represent a danger beyond that of exposure to P. syringae endotoxins naturally present in snow. However, the risk of possible allergy in some particularly sensitive individuals cannot be excluded. Another important conclusion of this study concerns use of poor microbiological water quality to make artificial snow.

  8. Influence of polyoxyethylene phytosterol addition in ionic liquid-based electrolyte on photovoltaic performance of dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Takahashi, Masashi; Sato, Kei; Sakurai, Sho; Kobayashi, Koichi

    2016-01-01

    Highlights: • The ionic liquid solution of less solvophilic BPS exhibits a better surface active property and a weaker dye-desorption effect. • Photovoltaic performances of the N719- and NKX2677-sensitized DSSCs can be improved by the BPS addition to the IL-based electrolyte. • BPS added to the electrolyte plays a key role in reducing charge-transfer resistance and increasing electron lifetime in the TiO 2 electrode. - Abstract: In this work, we studied influence of polyoxyethylene phytosterol (BPS) addition in ionic liquid (IL)-based electrolyte on photovoltaic performance of dye-sensitized solar cells (DSSCs) using 1-methyl-3-propylimidazolium iodide as an IL. Surface tension, photocurrent density-voltage characteristics and electrochemical impedance spectra were measured to clarify the role of BPS in the DSSCs using three different dyes. The results showed that the IL solution of less solvophilic BPS-EO5 exhibited a better surface active property and a weaker dye-desorption effect than BPS-EO30 and BPS-PO7/EO30. Short-circuit current densities of the N719- and NKX2677-sensitized cells were found to be noticeably increased by the addition of either BPS-EO5 or BPS-EO30 to the IL-based electrolyte in the concentration range of 0.001–0.01 mol dm −3 . Enhanced photovoltaic conversion efficiencies were obtained for these DSSCs, which most likely resulted from the effects of BPS on reducing charge-transfer resistance at the TiO 2 /dye/electrolyte interface and on increasing electron lifetime within the TiO 2 photoanode.

  9. Density prediction and dimensionality reduction of mid-term electricity demand in China: A new semiparametric-based additive model

    International Nuclear Information System (INIS)

    Shao, Zhen; Yang, Shan-Lin; Gao, Fei

    2014-01-01

    Highlights: • A new stationary time series smoothing-based semiparametric model is established. • A novel semiparametric additive model based on piecewise smooth is proposed. • We model the uncertainty of data distribution for mid-term electricity forecasting. • We provide efficient long horizon simulation and extraction for external variables. • We provide stable and accurate density predictions for mid-term electricity demand. - Abstract: Accurate mid-term electricity demand forecasting is critical for efficient electric planning, budgeting and operating decisions. Mid-term electricity demand forecasting is notoriously complicated, since the demand is subject to a range of external drivers, such as climate change, economic development, which will exhibit monthly, seasonal, and annual complex variations. Conventional models are based on the assumption that original data is stable and normally distributed, which is generally insignificant in explaining actual demand pattern. This paper proposes a new semiparametric additive model that, in addition to considering the uncertainty of the data distribution, includes practical discussions covering the applications of the external variables. To effectively detach the multi-dimensional volatility of mid-term demand, a novel piecewise smooth method which allows reduction of the data dimensionality is developed. Besides, a semi-parametric procedure that makes use of bootstrap algorithm for density forecast and model estimation is presented. Two typical cases in China are presented to verify the effectiveness of the proposed methodology. The results suggest that both meteorological and economic variables play a critical role in mid-term electricity consumption prediction in China, while the extracted economic factor is adequate to reveal the potentially complex relationship between electricity consumption and economic fluctuation. Overall, the proposed model can be easily applied to mid-term demand forecasting, and

  10. Modified Chitosan Nanoparticle by Radiation Synthesis: An Approach to Drug Delivery and Bio-Based Additive for Biomedical Applications

    International Nuclear Information System (INIS)

    Pasanphan, W.; Rimdusit, P.; Rattanawongwiboon, T.; Choofong, S.

    2010-01-01

    Self-assembly chitosan nanoparticle (CsNP) has been synthesized via radiolytic methodology using gamma irradiation. The systematic condition in preparation was studied. Chitosan nanoparticle was modified using hydrophobic core of deoxycholic acid (DC) and stearyl methacrylate (SMA) and the hydrophilic shell of polyethylene glycol monomethacrylate (PEG). The hydrophobic/hydrophilic CsNP was prepared for drug carrier molecule. The SMA-CsNP was also conjugated with pyperidine, hindered amine light stabilizer function, to achieve a bio-based additive for biomedical plastic. (author)

  11. Modified Chitosan Nanoparticle by Radiation Synthesis: An Approach to Drug Delivery and Bio-Based Additive for Biomedical Applications

    Energy Technology Data Exchange (ETDEWEB)

    Pasanphan, W.; Rimdusit, P.; Rattanawongwiboon, T.; Choofong, S., E-mail: sciwvm@ku.ac.th, E-mail: pwanvimol@yahoo.com [Kasetsart University, Faculty of Science, Department of Applied Radiation and Isotopes, 50 Phahonyothin Road, Chatuchak, Bangkok 1090 (Thailand)

    2010-07-01

    Self-assembly chitosan nanoparticle (CsNP) has been synthesized via radiolytic methodology using gamma irradiation. The systematic condition in preparation was studied. Chitosan nanoparticle was modified using hydrophobic core of deoxycholic acid (DC) and stearyl methacrylate (SMA) and the hydrophilic shell of polyethylene glycol monomethacrylate (PEG). The hydrophobic/hydrophilic CsNP was prepared for drug carrier molecule. The SMA-CsNP was also conjugated with pyperidine, hindered amine light stabilizer function, to achieve a bio-based additive for biomedical plastic. (author)

  12. MICROSTRUCTURE AND TENSILE PROPERTIES OF Fe3Al-BASED ALLOYS WITH VC AND TiC ADDITIONS

    Institute of Scientific and Technical Information of China (English)

    W.L.Xu; Y.S.Sun; S.S.Ding

    2001-01-01

    Microstructure and tensile properties of Fe3Al-based alloys with additions of TiC andVC particles have been investigated.Results show that the formation of TiC particlesresults in the refinement of the macrostructure of as-cast ingots.Although the additionof VC particles does not cause significant change of the as-cast microstructure,themicrostructure of the alloy after hot-working and recrystallization has been found tobe refined.The formation of both VC and TiC particles results in the increase of yieldstrength,especially at high temperature of 600℃.

  13. Mining Data of Noisy Signal Patterns in Recognition of Gasoline Bio-Based Additives using Electronic Nose

    Directory of Open Access Journals (Sweden)

    Osowski Stanisław

    2017-03-01

    Full Text Available The paper analyses the distorted data of an electronic nose in recognizing the gasoline bio-based additives. Different tools of data mining, such as the methods of data clustering, principal component analysis, wavelet transformation, support vector machine and random forest of decision trees are applied. A special stress is put on the robustness of signal processing systems to the noise distorting the registered sensor signals. A special denoising procedure based on application of discrete wavelet transformation has been proposed. This procedure enables to reduce the error rate of recognition in a significant way. The numerical results of experiments devoted to the recognition of different blends of gasoline have shown the superiority of support vector machine in a noisy environment of measurement.

  14. Effect of zinc additions on oxide rupture strain and repassivation kinetics of iron-based alloys in 288 C water

    International Nuclear Information System (INIS)

    Angeliu, T.M.; Andresen, P.L.

    1996-01-01

    The effect of Zn water chemistry additions on the mechanism of intergranular stress corrosion cracking (IGSCC) of Fe-based alloys in water at 288 C was evaluated in terms of the slip-dissolution model. In this model, an increase in the oxide film rupture strain or surface film repassivation kinetics improved resistance to IGSCC. The oxide rupture strain of type 304L (UNS S30403) stainless steel (SS) increased up to a factor of two in deaerated and 200 ppb oxygenated, high-purity water ( 300 h of exposure. Repassivation kinetics experiments showed Zn additions of ∼ 100 ppb increased the repassivation rate of an Fe-12% Cr alloys up to a factor of two in various deaerated water environments at 288 C. Life prediction modeling revealed that the combination of a more ductile oxide film and faster repassivation kinetics resulted in a reduction in the overall crack growth rate (CGR) by at least a factor of four. This factor of improvement was consistent with data from compact tension experiments in similar environments where CGR decreased as the Zn addition increased, with a greater decrease in CGR realized at lower pre-Zn CGR

  15. Effect of zirconium oxide nanoparticles addition on the optical and tensile properties of polymethyl methacrylate denture base material.

    Science.gov (United States)

    Gad, Mohammed M; Abualsaud, Reem; Rahoma, Ahmed; Al-Thobity, Ahmad M; Al-Abidi, Khalid S; Akhtar, Sultan

    2018-01-01

    Polymethyl methacrylate (PMMA) is widely used for the fabrication of removable prostheses. Recently, zirconium oxide nanoparticles (nano-ZrO 2 ) have been added to improve some properties of PMMA, but their effect on the optical properties and tensile strength are neglected. The aim of this study was to investigate the effect of nano-ZrO 2 addition on the translucency and tensile strength of the PMMA denture base material. Eighty specimens (40 dumbbell-shaped and 40 discs) were prepared out of heat-polymerized acrylic resin and divided into four groups per test (n=10). The control group for each test included unreinforced acrylic, while the test groups were reinforced with 2.5, 5, and 7.5 wt% nano-ZrO 2 . Acrylic resin was mixed according to manufacturer's instructions, packed, and processed by conventional method. After polymerization, all specimens were finished, polished, and stored in distilled water at 37°C for 48±2 hours. Tensile strength (MPa) was evaluated using the universal testing machine while the specimens' translucency was examined using a spectrophotometer. Statistical analysis was carried out by SPSS using the paired sample t -test ( p ≤0.05). A scanning electron microscope was used to analyze the morphological changes and topography of the fractured surfaces. This study showed that the mean tensile strength of the PMMA in the test groups of 2.5%NZ, 5%NZ, and 7.5%NZ was significantly higher than the control group. The tensile strength increased significantly after nano-ZrO 2 addition, and the maximum increase seen was in the 7.5%NZ group. The translucency values of the experimental groups were significantly lower than those of the control group. Within the reinforced groups, the 2.5%NZ group had significantly higher translucency values when compared to the 5%NZ and 7.5%NZ groups. The addition of nano-ZrO 2 increased the tensile strength of the denture base acrylic. The increase was directly proportional to the nano-ZrO 2 concentration. The

  16. Thermoelectric Cooling-Aided Bead Geometry Regulation in Wire and Arc-Based Additive Manufacturing of Thin-Walled Structures

    Directory of Open Access Journals (Sweden)

    Fang Li

    2018-01-01

    Full Text Available Wire and arc-based additive manufacturing (WAAM is a rapidly developing technology which employs a welding arc to melt metal wire for additive manufacturing purposes. During WAAM of thin-walled structures, as the wall height increases, the heat dissipation to the substrate is slowed down gradually and so is the solidification of the molten pool, leading to variation of the bead geometry. Though gradually reducing the heat input via adjusting the process parameters can alleviate this issue, as suggested by previous studies, it relies on experience to a large extent and inevitably sacrifices the deposition rate because the wire feed rate is directly coupled with the heat input. This study introduces for the first time an in-process active cooling system based on thermoelectric cooling technology into WAAM, which aims to eliminate the difference in heat dissipation between upper and lower layers. The case study shows that, with the aid of thermoelectric cooling, the bead width error is reduced by 56.8%, the total fabrication time is reduced by 60.9%, and the average grain size is refined by 25%. The proposed technique provides new insight into bead geometry regulation during WAAM with various benefits in terms of geometric accuracy, productivity, and microstructure.

  17. Influence of additional coupling agent on the mechanical properties of polyester–agave cantala roxb based composites

    Energy Technology Data Exchange (ETDEWEB)

    Ubaidillah, E-mail: ubaidillah@uns.ac.id [Mechanical Engineering Department, Faculty of Engineering, Sebelas Maret University, Jl. Ir. Sutami 36A, Kentingan, Surakarta, 57126 (Indonesia); Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, Kuala Lumpur (Malaysia); Raharjo, Wijang W.; Wibowo, A. [Mechanical Engineering Department, Faculty of Engineering, Sebelas Maret University, Jl. Ir. Sutami 36A, Kentingan, Surakarta, 57126 (Indonesia); Harjana [Iwany Acoustic Research Group, Sebelas Maret University, Jl. Ir. Sutami 36A, Kentingan, Surakarta, 57126 (Indonesia); Mazlan, S. A., E-mail: amri.kl@utm.my [Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, Kuala Lumpur (Malaysia)

    2016-03-29

    The mechanical and morphological properties of the unsaturated polyester resins (UPRs)-agave cantala roxb based composite are investigated in this paper. The cantala fiber woven in 3D angle interlock was utilized as the composite reinforcement. Surface grafting of the cantala fiber through chemical treatment was performed by introducing silane coupling agent to improving the compatibility with the polymer matrix. The fabrication of the composite specimens was conducted using vacuum bagging technique. The effect of additional coupling agent to the morphological appearance of surface fracture was observed using scanning electron microscopy. Meanwhile, the influence of additional silane to the mechanical properties was examined using tensile, bending and impact test. The photograph of surface fracture on the treated specimens showed the residual matrix left on the fibers in which the phenomenon was not found in the untreated specimens. Based on mechanical tests, the treated specimens were successfully increased their mechanical properties by 55%, 9.67%, and 92.4% for tensile strength, flexural strength, and impact strength, respectively, at 1.5% silane coupling agent.

  18. Influence of activating solution and the addition of NaF on metakaolin-based geopolymer physico-chemical properties

    International Nuclear Information System (INIS)

    Agullo, J.; Muzeau, B.; Trepy, N.; L'Hostis, V.; Lambertin, D.

    2015-01-01

    The technology of geo-polymerisation is attracting a lot of interest due to the wide variety of potential applications. Recently emerging and alternative cementitious systems based on geo-polymers have been reported in literature. Geo-polymer materials have been proposed as new binders for safe radioactive waste containment. Moreover, their good fluidity and fire resistance make them compatible with industrial processes for embedding wastes. The purpose of this work was to investigate the physico-chemical properties of meta-kaolin-based geo-polymer which could be used as mineral binder for encapsulation of metallic nuclear wastes. To improve the knowledge of this binder, its microstructure and its interstitial solution have been characterized during hydration (up to 28 days). Interstitial solutions were extracted at different hydration time and subsequent analyses allow us to determine their chemical composition. pH measurements confirm the high alkalinity of the interstitial pore solution. The influence of the activating solution (NaOH or KOH) and the addition of NaF as corrosion inhibitor in the geo-polymer composition were also studied. The nature of different crystalline phases was identified by X-ray diffraction. Water accessible porosity for these materials was estimated around 59%. The pore size distribution was determined by mercury intrusion porosity. Alkaline cations have proved to induce changes in the pore size distribution, these ones coming from whether the activating solution or the NaF addition. (authors)

  19. Synthesis of l-threitol-based crown ethers and their application as enantioselective phase transfer catalyst in Michael additions.

    Science.gov (United States)

    Rapi, Zsolt; Nemcsok, Tamás; Pálvölgyi, Ádám; Keglevich, György; Grün, Alajos; Bakó, Péter

    2017-06-01

    A few new l-threitol-based lariat ethers incorporating a monoaza-15-crown-5 unit were synthesized starting from diethyl l-tartrate. These macrocycles were used as phase transfer catalysts in asymmetric Michael addition reactions under mild conditions to afford the adducts in a few cases in good to excellent enantioselectivities. The addition of 2-nitropropane to trans-chalcone, and the reaction of diethyl acetamidomalonate with β-nitrostyrene resulted in the chiral Michael adducts in good enantioselectivities (90% and 95%, respectively). The substituents of chalcone had a significant impact on the yield and enantioselectivity in the reaction of diethyl acetoxymalonate. The highest enantiomeric excess (ee) values (99% ee) were measured in the case of 4-chloro- and 4-methoxychalcone. The phase transfer catalyzed cyclopropanation reaction of chalcone and benzylidene-malononitriles using diethyl bromomalonate as the nucleophile (MIRC reaction) was also developed. The corresponding chiral cyclopropane diesters were obtained in moderate to good (up to 99%) enantioselectivities in the presence of the threitol-based crown ethers. © 2017 Wiley Periodicals, Inc.

  20. Additional calcium carbonate into concentrate diet for sheep fed ensiled king grass as a based-diet

    Directory of Open Access Journals (Sweden)

    I-W Mathius

    1997-10-01

    Full Text Available In order to ascertain the effect of additional calcium carbonate into concentrate diet, on the performance of sheep fed ensiled king grass as a basal diet, a trial was conducted using 28 growing sheep ( average body weight 17 _+ 1 .4 kg. Based on body weight, the animals were grouped and randomized into four dietary treatments in block randomized design . Dietary treatments were (i chopped king grass + 400 g of concentrate, (ii ensiled king grass + 400 g concentrate + 0 % of calcium carbonate, (iii ensiled king grass + 400 g concentrate + 5 % calcium carbonate and (iv ensiled king grass + 400 g concentrate + 10 % calcium carbonate . Results showed that offering 5 % of calcium carbonate into concentrate diet increased (P 0 .05 for all groups . No differences in the apparent digestibility of the nutrient components were observed, but crude protein decreased significantly (P < 0 .05 . A significant relationship ( P < 0 .01 was found between nitrogen intake (NI and nitrogen retention (NR, and the equation was NR = - 0.1848 + 0.3788 NI ( r = 0.9 . Based on data found that feeding only ensiled king grass as a single diet could not meet the maintenance requirement of energy and protein, therefore, additional energy and crude protein sources is needed .

  1. Measures of 'exposure needed for one additional patient to be harmed' in population-based case-control studies

    DEFF Research Database (Denmark)

    Hallas, J.; Christensen, R. D.; Sturmer, T.

    2014-01-01

    Purpose The magnitude of risk for adverse drug reactions may be communicated by a measure of 'exposure needed for one additional patient to be harmed' (ENH). We present four ENH measures, based on four different counterfactual contrasts, as illustrated by the known effects of NSAID use on peptic ...... bleeding. The ultimate choice of ENH measure will depend on epidemiological or clinical considerations and on availability of data. Copyright (C) 2014 John Wiley & Sons, Ltd.......Purpose The magnitude of risk for adverse drug reactions may be communicated by a measure of 'exposure needed for one additional patient to be harmed' (ENH). We present four ENH measures, based on four different counterfactual contrasts, as illustrated by the known effects of NSAID use on peptic...... ulcer bleeding. Methods The four measures were basic ENH (estimating the excess risk when treating the entire source population versus treating no one), age-restricted ENH (the entire source population above, e. g. 50 years old treated versus no one above 50 years old treated), standardised ENH (a...

  2. The addition of medium-chain triglycerides to a purified fish oil-based diet alters inflammatory profiles in mice.

    Science.gov (United States)

    Carlson, Sarah J; Nandivada, Prathima; Chang, Melissa I; Mitchell, Paul D; O'Loughlin, Alison; Cowan, Eileen; Gura, Kathleen M; Nose, Vania; Bistrian, Bruce R; Puder, Mark

    2015-02-01

    Parenteral nutrition associated liver disease (PNALD) is a deadly complication of long term parenteral nutrition (PN) use in infants. Fish oil-based lipid emulsion has been shown in recent years to effectively treat PNALD. Alternative fat sources free of essential fatty acids have recently been investigated for health benefits related to decreased inflammatory response. We hypothesized that the addition of medium-chain triglycerides (MCT) to a purified fish oil-based diet would decrease the response to inflammatory challenge in mice, while allowing for sufficient growth and development. Six groups of ten adult male C57/Bl6 mice were pair-fed different dietary treatments for a period of twelve weeks, varying only in fat source (percent calories by weight): 10.84% soybean oil (SOY), 10% coconut oil (HCO), 10% medium-chain triglycerides (MCT), 3% purified fish oil (PFO), 3% purified fish oil with 3% medium-chain triglycerides (50:50 MCT:PFO) and 3% purified fish oil with 7.59% medium-chain triglycerides (70:30 MCT:PFO). An endotoxin challenge was administered to half of the animals in each group at the completion of dietary treatment. All groups demonstrated normal growth throughout the study period. Groups fed MCT and HCO diets demonstrated biochemical essential fatty acid deficiency and decreased IL-6 and TNF-α response to endotoxin challenge. Groups containing PFO had increased inflammatory response to endotoxin challenge, and the addition of MCT to PFO mitigated this inflammatory response. These results suggest that the addition of MCT to PFO formulations may decrease the host response to inflammatory challenge, which may pose potential for optimized PN formulations. Inclusion of MCT in lipid emulsions given with PN formulations may be of use in therapeutic interventions for disease states resulting from chronic inflammation. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Can homomorphic encryption be practical?

    NARCIS (Netherlands)

    Lauter, K.; Naehrig, M.; Vaikuntanathan, V.

    2011-01-01

    The prospect of outsourcing an increasing amount of data storage and management to cloud services raises many new privacy concerns for individuals and businesses alike. The privacy concerns can be satisfactorily addressed if users encrypt the data they send to the cloud. If the encryption scheme is

  4. 3D composites based on the blends of chitosan and collagen with the addition of hyaluronic acid.

    Science.gov (United States)

    Sionkowska, Alina; Kaczmarek, Beata; Lewandowska, Katarzyna; Grabska, Sylwia; Pokrywczyńska, Marta; Kloskowski, Tomasz; Drewa, Tomasz

    2016-08-01

    3D porous composites based on blends of chitosan, collagen and hyaluronic acid were obtained through the lyophilization process. Mechanical properties, swelling behavior and thermal stability of the blends were studied. Moreover, SEM images were taken and the structure of the blends was studied. Biological properties of the materials obtained were investigated by analyzing of proliferation rate of fibroblast cells incubated with biomaterial extract using MTT assay (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide). The results showed that the properties of 3D composites based on the blends of chitosan and collagen were altered after the addition 1%, 2% and 5% of hyaluronic acid. Mechanical properties and thermal stability of chitosan/collagen blends were improved in the presence of hyaluronic acid in the composite. New 3D materials based on the blends of chitosan, collagen and hyaluronic acid were non-toxic and did not significantly affect cell morphology. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Formulation, Casting, and Evaluation of Paraffin-Based Solid Fuels Containing Energetic and Novel Additives for Hybrid Rockets

    Science.gov (United States)

    Larson, Daniel B.; Desain, John D.; Boyer, Eric; Wachs, Trevor; Kuo, Kenneth K.; Borduin, Russell; Koo, Joseph H.; Brady, Brian B.; Curtiss, Thomas J.; Story, George

    2012-01-01

    This investigation studied the inclusion of various additives to paraffin wax for use in a hybrid rocket motor. Some of the paraffin-based fuels were doped with various percentages of LiAlH4 (up to 10%). Addition of LiAlH4 at 10% was found to increase regression rates between 7 - 10% over baseline paraffin through tests in a gaseous oxygen hybrid rocket motor. Mass burn rates for paraffin grains with 10% LiAlH4 were also higher than those of the baseline paraffin. RDX was also cast into a paraffin sample via a novel casting process which involved dissolving RDX into dimethylformamide (DMF) solvent and then drawing a vacuum on the mixture of paraffin and RDX/DMF in order to evaporate out the DMF. It was found that although all DMF was removed, the process was not conducive to generating small RDX particles. The slow boiling generated an inhomogeneous mixture of paraffin and RDX. It is likely that superheating the DMF to cause rapid boiling would likely reduce RDX particle sizes. In addition to paraffin/LiAlH4 grains, multi-walled carbon nanotubes (MWNT) were cast in paraffin for testing in a hybrid rocket motor, and assorted samples containing a range of MWNT percentages in paraffin were imaged using SEM. The fuel samples showed good distribution of MWNT in the paraffin matrix, but the MWNT were often agglomerated, indicating that a change to the sonication and mixing processes were required to achieve better uniformity and debundled MWNT. Fuel grains with MWNT fuel grains had slightly lower regression rate, likely due to the increased thermal conductivity to the fuel subsurface, reducing the burning surface temperature.

  6. Carbon nanosheets-based supercapacitors: Design of dual redox additives of 1, 4-dihydroxyanthraquinone and hydroquinone for improved performance

    Science.gov (United States)

    Xu, Dong; Sun, Xiao Na; Hu, Wei; Chen, Xiang Ying

    2017-07-01

    Using thiocarbanilide and Mg(OH)2 powders as carbon precursor and template, respectively, novel 2D carbon nanosheets with large area have been produced. Next, based on the cooperative effect, 1, 4-dihydroxyanthraquinone (DQ) and hydroquinone (HQ) regarded as efficient dual redox additives have been incorporated into the electrode carbon material and H2SO4 electrolyte, respectively, to largely elevate the capacitive performance of supercapacitors. More importantly, the cooperative effect results from the redox processes of DQ and HQ consecutively occurring in the electrode carbon material and aqueous H2SO4 electrolyte, respectively. Besides, the molar ratio of DQ and HQ exerts a crucial role in the determination of the electrochemical behaviors and eventually the optimum condition is the mass ratio of 1:1 concerning the DQ and porous carbon within solid electrode while retaining the HQ concentration as 20 mmol L-1 in 1 mol L-1 H2SO4 electrolyte. As a result, the maximum specific capacitance is achieved of 239 F g-1 at 3 A g-1, and furthermore the maximum energy density up to 21.1 Wh kg-1 is almost 3.5 times larger than that of the one without introducing any redox additive.

  7. Real-time interferometric monitoring and measuring of photopolymerization based stereolithographic additive manufacturing process: sensor model and algorithm

    International Nuclear Information System (INIS)

    Zhao, X; Rosen, D W

    2017-01-01

    As additive manufacturing is poised for growth and innovations, it faces barriers of lack of in-process metrology and control to advance into wider industry applications. The exposure controlled projection lithography (ECPL) is a layerless mask-projection stereolithographic additive manufacturing process, in which parts are fabricated from photopolymers on a stationary transparent substrate. To improve the process accuracy with closed-loop control for ECPL, this paper develops an interferometric curing monitoring and measuring (ICM and M) method which addresses the sensor modeling and algorithms issues. A physical sensor model for ICM and M is derived based on interference optics utilizing the concept of instantaneous frequency. The associated calibration procedure is outlined for ICM and M measurement accuracy. To solve the sensor model, particularly in real time, an online evolutionary parameter estimation algorithm is developed adopting moving horizon exponentially weighted Fourier curve fitting and numerical integration. As a preliminary validation, simulated real-time measurement by offline analysis of a video of interferograms acquired in the ECPL process is presented. The agreement between the cured height estimated by ICM and M and that measured by microscope indicates that the measurement principle is promising as real-time metrology for global measurement and control of the ECPL process. (paper)

  8. Enhancing the performance of model-based elastography by incorporating additional a priori information in the modulus image reconstruction process

    International Nuclear Information System (INIS)

    Doyley, Marvin M; Srinivasan, Seshadri; Dimidenko, Eugene; Soni, Nirmal; Ophir, Jonathan

    2006-01-01

    Model-based elastography is fraught with problems owing to the ill-posed nature of the inverse elasticity problem. To overcome this limitation, we have recently developed a novel inversion scheme that incorporates a priori information concerning the mechanical properties of the underlying tissue structures, and the variance incurred during displacement estimation in the modulus image reconstruction process. The information was procured by employing standard strain imaging methodology, and introduced in the reconstruction process through the generalized Tikhonov approach. In this paper, we report the results of experiments conducted on gelatin phantoms to evaluate the performance of modulus elastograms computed with the generalized Tikhonov (GTK) estimation criterion relative to those computed by employing the un-weighted least-squares estimation criterion, the weighted least-squares estimation criterion and the standard Tikhonov method (i.e., the generalized Tikhonov method with no modulus prior). The results indicate that modulus elastograms computed with the generalized Tikhonov approach had superior elastographic contrast discrimination and contrast recovery. In addition, image reconstruction was more resilient to structural decorrelation noise when additional constraints were imposed on the reconstruction process through the GTK method

  9. Influence of reaction products of K-getter fuel additives on commercial vanadia-based SCR catalysts

    DEFF Research Database (Denmark)

    Castellino, Francesco; Jensen, Anker Degn; Johnsson, Jan Erik

    2009-01-01

    , deactivation rates up to 3%/day have been measured. The spent catalysts have been characterized by bulk chemical analysis, Hg-porosimetry and SEM-EDX. NH3-chemisorption tests on the spent elements and activity tests on catalyst powders obtained by crushing the monoliths have also been carried out. The catalyst...... characterization has shown that poisoning by K is the main deactivation mechanism. The results show that binding K in K–P salts will not reduce the rate of catalyst deactivation....... as a K-getter additive. The formed aerosols have been characterized by using both a SMPS system and a low pressure cascade impactor, showing a dual-mode volume-based size distribution with a first peak at around 30 nm and a second one at diameters >1 μm. The different peaks have been associated...

  10. An optimized regulating method for composting phosphorus fractions transformation based on biochar addition and phosphate-solubilizing bacteria inoculation.

    Science.gov (United States)

    Wei, Yuquan; Zhao, Yue; Wang, Huan; Lu, Qian; Cao, Zhenyu; Cui, Hongyang; Zhu, Longji; Wei, Zimin

    2016-12-01

    The study was conducted to investigate the influence of biochar and/or phosphate-solubilizing bacteria (PSB) inoculants on microbial biomass, bacterial community composition and phosphorus (P) fractions during kitchen waste composting amended with rock phosphate (RP). There were distinct differences in the physic-chemical parameters, the proportion of P fractions and bacterial diversity in different treatments. The contribution of available P fractions increased during composting especially in the treatment with the addition of PSB and biochar. Redundancy analysis showed that bacterial compositions were significantly influenced by P content, inoculation and biochar. Variance partitioning further showed that synergy of inoculated PSB and indigenous bacterial communities and the joint effect between biochar and bacteria explained the largest two proportion of the variation in P fractions. Therefore, the combined application of PSB and biochar to improve the inoculation effect and an optimized regulating method were suggested based on the distribution of P fractions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Effect of lithium salts addition on the ionic liquid based extraction of essential oil from Farfarae Flos.

    Science.gov (United States)

    Li, Zhen-Yu; Zhang, Sha-Sha; Jie-Xing; Qin, Xue-Mei

    2015-01-01

    In this study, an ionic liquids (ILs) based extraction approach has been successfully applied to the extraction of essential oil from Farfarae Flos, and the effect of lithium chloride was also investigated. The results indicated that the oil yields can be increased by the ILs, and the extraction time can be reduced significantly (from 4h to 2h), compared with the conventional water distillation. The addition of lithium chloride showed different effect according to the structures of ILs, and the oil yields may be related with the structure of cation, while the chemical compositions of essential oil may be related with the anion. The reduction of extraction time and remarkable higher efficiency (5.41-62.17% improved) by combination of lithium salt and proper ILs supports the suitability of the proposed approach. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Study through potentiodynamic techniques of the corrosion resistance of different aluminium base MMC's with boron additions

    International Nuclear Information System (INIS)

    Abenojar, J.; Bautista, A.; Guzman, S.; Velasco, F.; Martinez, M.A.

    2009-01-01

    This paper compares a wrought aluminium with a PM aluminium and PM aluminium alloys with boron-base additions, containing boron carbide and Fe/B (obtained by mechanical alloying during 36 hours from a Fe-B 50% mixture by weight). The effect of sintering temperature for the Fe/B containing material and the effect of mechanical alloying for the boron carbide containing aluminium alloy on the corrosion resistance of those materials have been studied. Their behaviour is followed through cyclic anodic polarization curves in chloride media. In the Al+20%Fe/B composite, low sintering temperatures (650- 950 deg C) exert a negative effect. However, when the material was sintered at high temperature (1000-1100 deg C) its behaviour was very similar to the PM pure aluminium. The effect of mechanical alloying studied in aluminium with boron carbide was also important in corrosion resistance, finding a lower corrosion rate in the mechanically alloyed material. (author)

  13. Feasibility Study on 3-D Printing of Metallic Structural Materials with Robotized Laser-Based Metal Additive Manufacturing

    Science.gov (United States)

    Ding, Yaoyu; Kovacevic, Radovan

    2016-07-01

    Metallic structural materials continue to open new avenues in achieving exotic mechanical properties that are naturally unavailable. They hold great potential in developing novel products in diverse industries such as the automotive, aerospace, biomedical, oil and gas, and defense. Currently, the use of metallic structural materials in industry is still limited because of difficulties in their manufacturing. This article studied the feasibility of printing metallic structural materials with robotized laser-based metal additive manufacturing (RLMAM). In this study, two metallic structural materials characterized by an enlarged positive Poisson's ratio and a negative Poisson's ratio were designed and simulated, respectively. An RLMAM system developed at the Research Center for Advanced Manufacturing of Southern Methodist University was used to print them. The results of the tensile tests indicated that the printed samples successfully achieved the corresponding mechanical properties.

  14. Cost-effectiveness analysis of additional bevacizumab to pemetrexed plus cisplatin for malignant pleural mesothelioma based on the MAPS trial.

    Science.gov (United States)

    Zhan, Mei; Zheng, Hanrui; Xu, Ting; Yang, Yu; Li, Qiu

    2017-08-01

    Malignant pleural mesothelioma (MPM) is a rare malignancy, and pemetrexed/cisplatin (PC) is the gold standard first-line regime. This study evaluated the cost-effectiveness of the addition of bevacizumab to PC (with maintenance bevacizumab) for unresectable MPM based on a phase III trial that showed a survival benefit compared with chemotherapy alone. To estimate the incremental cost-effectiveness ratio (ICER) of the incorporation of bevacizumab, a Markov model based on the MAPS trial, including the disease states of progression-free survival, progressive disease and death, was used. Total costs were calculated from a Chinese payer perspective, and health outcomes were converted into quality-adjusted life year (QALY). Model robustness was explored in sensitivity analyses. The addition of bevacizumab to PC was estimated to increase the cost by $81446.69, with a gain of 0.112 QALYs, resulting in an ICER of $727202.589 per QALY. In both one-way sensitivity and probabilistic sensitivity analyses, the ICER exceeded the commonly accepted willingness-to-pay threshold of 3 times the gross domestic product per capita of China ($23970.00 per QALY). The cost of bevacizumab had the most important impact on the ICER. The combination of bevacizumab with PC chemotherapy is not a cost-effective treatment option for MPM in China. Given its positive clinical value and extremely low incidence of MPM, an appropriate price discount, assistance programs and medical insurance should be considered to make bevacizumab more affordable for this rare patient population. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Hydrothermally treated chitosan hydrogel loaded with copper and zinc particles as a potential micro-nutrient based antimicrobial feed additive

    Directory of Open Access Journals (Sweden)

    Parthiban eRajasekaran

    2015-11-01

    Full Text Available Large-scale use of antibiotics in food animal farms as growth promoters is considered as one of the driving factors behind increasing incidence of microbial resistance. Several alternatives are under investigation to reduce the amount of total antibiotics used in order to avoid any potential transmission of drug resistant microbes to humans through food chain. Copper sulfate and zinc oxide salts are used as feed supplement as they exhibit antimicrobial properties in addition to being micronutrients. However, higher dosage of copper and zinc (often needed for growth promoting effect to animals is not advisable because of potential environmental toxicity arising from excreta. Innovative strategies are needed to utilize the complete potential of trace minerals as growth promoting feed supplements. To this end, we describe here the development and preliminary characterization of hydrothermally treated chitosan as a delivery vehicle for copper and zinc nanoparticles that could act as a micronutrient based antimicrobial feed supplement. Material characterization studies showed that hydrothermal treatment makes a chitosan hydrogel that re-arranged to capture the copper and zinc metal particles. Systemic antimicrobial assays showed that this chitosan biopolymer matrix embedded with copper (57.6 μg/ml and zinc (800 μg/ml reduced the load of model gut-bacteria (target organisms of growth promoting antibiotics such as Escherichia coli, Enterococcus faecalis, Staphylococcus aureus and Lactobacillus fermentum under in vitro conditions. Particularly, the chitosan/copper/zinc hydrogel exhibited significantly higher antimicrobial effect against L. fermentum, one of the primary targets of antibiotic growth promoters. Additionally, the chitosan matrix ameliorated the cytotoxicity levels of metal supplements when screened against a murine macrophage cell line RAW 264.7 and in TE-71, a murine thymic epithelial cell line. In this proof of concept study, we show

  16. Additive manufacturing.

    Science.gov (United States)

    Mumith, A; Thomas, M; Shah, Z; Coathup, M; Blunn, G

    2018-04-01

    Increasing innovation in rapid prototyping (RP) and additive manufacturing (AM), also known as 3D printing, is bringing about major changes in translational surgical research. This review describes the current position in the use of additive manufacturing in orthopaedic surgery. Cite this article: Bone Joint J 2018;100-B:455-60.

  17. Acid base status in swamp buffaloes (Bubalus Bubalis fed rice straw and concentrate with addition of sodium

    Directory of Open Access Journals (Sweden)

    G Joseph

    2001-12-01

    Full Text Available An experiment was conducted to study the addition of NaHCO3 and Na2CO3 on acid-base status in swamp buffaloes, Three fistulated buffaloes were each introduced to dietary treatment control diett (50% rice straw + 50% concentrate, control + \\0% NaHCO3 and diet control + 10% Na2CO3 in two times Latin Square Design. The diets contained 9,7% crude protein and 53% TDN to achieve maintenance requirements of the animals. Parameters measured include (l Fed consumption, water consumption and urine volume. (2 pH in rumen fluid, saliva, bLood and urine, (3 natrium mineral content in rumen fluid, saliva, blood and urine. The results of the experiment showed higher pH in the rumen fluid, saliva, blood and urine of buffaloes due to supplementation of NaHCO3 and Na2CO3, Water consumption and urine volume was significanly increased as the effect of Na supplement. The acid-base status of buffaloes was apparently normal in all animals.

  18. Influence of Weak Base Addition to Hole-Collecting Buffer Layers in Polymer:Fullerene Solar Cells

    Directory of Open Access Journals (Sweden)

    Jooyeok Seo

    2017-02-01

    Full Text Available We report the effect of weak base addition to acidic polymer hole-collecting layers in normal-type polymer:fullerene solar cells. Varying amounts of the weak base aniline (AN were added to solutions of poly(3,4-ethylenedioxythiophene:poly(styrenesulfonate (PEDOT:PSS. The acidity of the aniline-added PEDOT:PSS solutions gradually decreased from pH = 1.74 (AN = 0 mol% to pH = 4.24 (AN = 1.8 mol %. The electrical conductivity of the PEDOT:PSS-AN films did not change much with the pH value, while the ratio of conductivity between out-of-plane and in-plane directions was dependent on the pH of solutions. The highest power conversion efficiency (PCE was obtained at pH = 2.52, even though all devices with the PEDOT:PSS-AN layers exhibited better PCE than those with the pristine PEDOT:PSS layers. Atomic force microscopy investigation revealed that the size of PEDOT:PSS domains became smaller as the pH increased. The stability test for 100 h illumination under one sun condition disclosed that the PCE decay was relatively slower for the devices with the PEDOT:PSS-AN layers than for those with pristine PEDOT:PSS layers.

  19. Response Surface Optimization of Rotenone Using Natural Alcohol-Based Deep Eutectic Solvent as Additive in the Extraction Medium Cocktail

    Directory of Open Access Journals (Sweden)

    Zetty Shafiqa Othman

    2017-01-01

    Full Text Available Rotenone is a biopesticide with an amazing effect on aquatic life and insect pests. In Asia, it can be isolated from Derris species roots (Derris elliptica and Derris malaccensis. The previous study revealed the comparable efficiency of alcohol-based deep eutectic solvent (DES in extracting a high yield of rotenone (isoflavonoid to binary ionic liquid solvent system ([BMIM]OTf and organic solvent (acetone. Therefore, this study intends to analyze the optimum parameters (solvent ratio, extraction time, and agitation rate in extracting the highest yield of rotenone extract at a much lower cost and in a more environmental friendly method by using response surface methodology (RSM based on central composite rotatable design (CCRD. By using RSM, linear polynomial equations were obtained for predicting the concentration and yield of rotenone extracted. The verification experiment confirmed the validity of both of the predicted models. The results revealed that the optimum conditions for solvent ratio, extraction time, and agitation rate were 2 : 8 (DES : acetonitrile, 19.34 hours, and 199.32 rpm, respectively. At the optimum condition of the rotenone extraction process using DES binary solvent system, this resulted in a 3.5-fold increase in a rotenone concentration of 0.49 ± 0.07 mg/ml and yield of 0.35 ± 0.06 (%, w/w as compared to the control extract (acetonitrile only. In fact, the rotenone concentration and yield were significantly influenced by binary solvent ratio and extraction time (P<0.05 but not by means of agitation rate. For that reason, the optimal extraction condition using alcohol-based deep eutectic solvent (DES as a green additive in the extraction medium cocktail has increased the potential of enhancing the rotenone concentration and yield extracted.

  20. Example-based learning: comparing the effects of additionally providing three different integrative learning activities on physiotherapy intervention knowledge.

    Science.gov (United States)

    Dyer, Joseph-Omer; Hudon, Anne; Montpetit-Tourangeau, Katherine; Charlin, Bernard; Mamede, Sílvia; van Gog, Tamara

    2015-03-07

    Example-based learning using worked examples can foster clinical reasoning. Worked examples are instructional tools that learners can use to study the steps needed to solve a problem. Studying worked examples paired with completion examples promotes acquisition of problem-solving skills more than studying worked examples alone. Completion examples are worked examples in which some of the solution steps remain unsolved for learners to complete. Providing learners engaged in example-based learning with self-explanation prompts has been shown to foster increased meaningful learning compared to providing no self-explanation prompts. Concept mapping and concept map study are other instructional activities known to promote meaningful learning. This study compares the effects of self-explaining, completing a concept map and studying a concept map on conceptual knowledge and problem-solving skills among novice learners engaged in example-based learning. Ninety-one physiotherapy students were randomized into three conditions. They performed a pre-test and a post-test to evaluate their gains in conceptual knowledge and problem-solving skills (transfer performance) in intervention selection. They studied three pairs of worked/completion examples in a digital learning environment. Worked examples consisted of a written reasoning process for selecting an optimal physiotherapy intervention for a patient. The completion examples were partially worked out, with the last few problem-solving steps left blank for students to complete. The students then had to engage in additional self-explanation, concept map completion or model concept map study in order to synthesize and deepen their knowledge of the key concepts and problem-solving steps. Pre-test performance did not differ among conditions. Post-test conceptual knowledge was higher (P example and completion example strategies to foster intervention selection.

  1. Food additives

    Science.gov (United States)

    ... GO About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Food additives URL of this page: //medlineplus.gov/ency/article/ ...

  2. Additively manufactured metallic porous biomaterials based on minimal surfaces: A unique combination of topological, mechanical, and mass transport properties.

    Science.gov (United States)

    Bobbert, F S L; Lietaert, K; Eftekhari, A A; Pouran, B; Ahmadi, S M; Weinans, H; Zadpoor, A A

    2017-04-15

    Porous biomaterials that simultaneously mimic the topological, mechanical, and mass transport properties of bone are in great demand but are rarely found in the literature. In this study, we rationally designed and additively manufactured (AM) porous metallic biomaterials based on four different types of triply periodic minimal surfaces (TPMS) that mimic the properties of bone to an unprecedented level of multi-physics detail. Sixteen different types of porous biomaterials were rationally designed and fabricated using selective laser melting (SLM) from a titanium alloy (Ti-6Al-4V). The topology, quasi-static mechanical properties, fatigue resistance, and permeability of the developed biomaterials were then characterized. In terms of topology, the biomaterials resembled the morphological properties of trabecular bone including mean surface curvatures close to zero. The biomaterials showed a favorable but rare combination of relatively low elastic properties in the range of those observed for trabecular bone and high yield strengths exceeding those reported for cortical bone. This combination allows for simultaneously avoiding stress shielding, while providing ample mechanical support for bone tissue regeneration and osseointegration. Furthermore, as opposed to other AM porous biomaterials developed to date for which the fatigue endurance limit has been found to be ≈20% of their yield (or plateau) stress, some of the biomaterials developed in the current study show extremely high fatigue resistance with endurance limits up to 60% of their yield stress. It was also found that the permeability values measured for the developed biomaterials were in the range of values reported for trabecular bone. In summary, the developed porous metallic biomaterials based on TPMS mimic the topological, mechanical, and physical properties of trabecular bone to a great degree. These properties make them potential candidates to be applied as parts of orthopedic implants and/or as bone

  3. Design and analysis of a piezoelectric material based touch screen with additional pressure and its acceleration measurement functions

    International Nuclear Information System (INIS)

    Chu, Xiang-Cheng; Liu, Jia-Yi; Gao, Ren-Long; Chang, Jie; Li, Long-Tu

    2013-01-01

    Touch screens are becoming more and more prevalent in everyday environments due to their convenience and humanized operation. In this paper, a piezoelectric material based touch screen is developed and investigated. Piezoelectric ceramics arrayed under the touch panel at the edges or corners are used as tactile sensors to measure the touch positioning point similarly to conventional touch screens. However, additional touch pressure and its acceleration performance can also be obtained to obtain a higher-level human–machine interface. The piezoelectric ceramics can also be added to a traditional touch screen structure, or they can be used independently to construct a novel touch screen with a high light transmittance approach to a transparent glass. The piezoelectric ceramics were processed from PZT piezoelectric ceramic powder into a round or rectangular shape. According to the varied touch position and physical press strength of a finger, or even a gloved hand or fingernail, the piezoelectric tactile sensors will have different output voltage responses. By calculating the ratio of different piezoelectric tactile sensors’ responses and summing up all piezoelectric tactile sensors’ output voltages, the touch point position, touch pressure and touch force acceleration can be detected. A prototype of such a touch screen is manufactured and its position accuracy, touch pressure and response speed are measured in detail. The experimental results show that the prototype has many advantages such as high light transmittance, low energy cost and high durability. (paper)

  4. Investigation of maltodextrin-based synergistic system with amino acid chiral ionic liquid as additive for enantioseparation in capillary electrophoresis.

    Science.gov (United States)

    Chen, Jiaquan; Du, Yingxiang; Sun, Xiaodong

    2017-12-01

    The combined use of chiral ionic liquids (ILs) and chiral selectors in capillary electrophoresis (CE) to establish a synergistic system has proven to be an effective approach for enantioseparation. In this article, tetramethylammonium-L-arginine, a kind of amino acid chiral IL, was applied to investigate its potential synergistic effect with maltodextrin in CE enantioseparation. The established maltodextrin-based synergistic system showed markedly improved enantioseparations compared with the single maltodextrin system. Parameters such as the chiral IL concentration, maltodextrin concentration, buffer pH, applied voltage, and capillary temperature were optimized. Satisfactory enantioseparation of the five studied drugs, including nefopam, duloxetine, ketoconazole, cetirizine, and citalopram was achieved in 50 mM Tris-H 3 PO 4 buffer solution (pH 3.0) containing 7.0% (m/v) maltodextrin and 60 mM tetramethylammonium-L-arginine. In addition, the chiral configuration of tetramethylammonium-L-arginine was also investigated to demonstrate the existence of a synergistic effect between chiral ILs and maltodextrin. © 2017 Wiley Periodicals, Inc.

  5. Effects of calcium hydroxide addition on the physical and chemical properties of a calcium silicate-based sealer.

    Science.gov (United States)

    Kuga, Milton Carlos; Duarte, Marco Antonio Hungaro; Sant'anna-Júnior, Arnaldo; Keine, Kátia Cristina; Faria, Gisele; Dantas, Andrea Abi Rached; Guiotti, Flávia Angélica

    2014-06-01

    Recently, various calcium silicate-based sealers have been introduced for use in root canal filling. The MTA Fillapex is one of these sealers, but some of its physicochemical properties are not in accordance with the ISO requirements. The aim of this study was to evaluate the flowability, pH level and calcium release of pure MTA Fillapex (MTAF) or containing 5% (MTAF5) or 10% (MTAF10) calcium hydroxide (CH), in weight, in comparison with AH Plus sealer. The flowability test was performed according to the ISO 6876:2001 requirements. For the pH level and calcium ion release analyses, the sealers were placed individually (n=10) in plastic tubes and immersed in deionized water. After 24 hours, 7 and 14 days, the water in which each specimen had been immersed was evaluated to determine the pH level changes and calcium released. Flowability, pH level and calcium release data were analyzed statistically by the ANOVA test (α=5%). In relation to flowability: MTAF>AH Plus>MTAF5>MTAF10. In relation to the pH level, for 24 h: MTAF5=MTAF10=MTAF>AH Plus; for 7 and 14 days: MTAF5=MTAF10>MTAF>AH Plus. For the calcium release, for all periods: MTAF>MTAF5=MTAF10>AH Plus. The addition of 5% CH to the MTA Fillapex (in weight) is an alternative to reduce the high flowability presented by the sealer, without interfering in its alkalization potential.

  6. Tribological Behaviors of Graphene and Graphene Oxide as Water-Based Lubricant Additives for Magnesium Alloy/Steel Contacts

    Directory of Open Access Journals (Sweden)

    Hongmei Xie

    2018-01-01

    Full Text Available The tribological behaviors of graphene and graphene oxide (GO as water-based lubricant additives were evaluated by use of a reciprocating ball-on-plate tribometer for magnesium alloy-steel contacts. Three sets of test conditions were examined to investigate the effect of concentration, the capacity of carrying load and the endurance of the lubrication film, respectively. The results showed that the tribological behaviors of water can be improved by adding the appropriate graphene or GO. Compared with pure deionized water, 0.5 wt.% graphene nanofluids can offer reduction of friction coefficient by 21.9% and reduction of wear rate by 13.5%. Meanwhile, 0.5 wt.% GO nanofluids were found to reduce the friction coefficient and wear rate up to 77.5% and 90%, respectively. Besides this, the positive effect of the GO nanofluids was also more pronounced in terms of the load-carrying capacity and the lubrication film endurance. The wear mechanisms have been tentatively proposed according to the observation of the worn surfaces by field emission scanning electron microscope-energy dispersive spectrometer (FESEM-EDS and Raman spectrum as well as the wettability of the nanofluids on the magnesium alloy surface by goniometer.

  7. Tribological Behaviors of Graphene and Graphene Oxide as Water-Based Lubricant Additives for Magnesium Alloy/Steel Contacts.

    Science.gov (United States)

    Xie, Hongmei; Jiang, Bin; Dai, Jiahong; Peng, Cheng; Li, Chunxia; Li, Quan; Pan, Fusheng

    2018-01-29

    The tribological behaviors of graphene and graphene oxide (GO) as water-based lubricant additives were evaluated by use of a reciprocating ball-on-plate tribometer for magnesium alloy-steel contacts. Three sets of test conditions were examined to investigate the effect of concentration, the capacity of carrying load and the endurance of the lubrication film, respectively. The results showed that the tribological behaviors of water can be improved by adding the appropriate graphene or GO. Compared with pure deionized water, 0.5 wt.% graphene nanofluids can offer reduction of friction coefficient by 21.9% and reduction of wear rate by 13.5%. Meanwhile, 0.5 wt.% GO nanofluids were found to reduce the friction coefficient and wear rate up to 77.5% and 90%, respectively. Besides this, the positive effect of the GO nanofluids was also more pronounced in terms of the load-carrying capacity and the lubrication film endurance. The wear mechanisms have been tentatively proposed according to the observation of the worn surfaces by field emission scanning electron microscope-energy dispersive spectrometer (FESEM-EDS) and Raman spectrum as well as the wettability of the nanofluids on the magnesium alloy surface by goniometer.

  8. Ceramic-Based 4D Components: Additive Manufacturing (AM) of Ceramic-Based Functionally Graded Materials (FGM) by Thermoplastic 3D Printing (T3DP).

    Science.gov (United States)

    Scheithauer, Uwe; Weingarten, Steven; Johne, Robert; Schwarzer, Eric; Abel, Johannes; Richter, Hans-Jürgen; Moritz, Tassilo; Michaelis, Alexander

    2017-11-28

    In our study, we investigated the additive manufacturing (AM) of ceramic-based functionally graded materials (FGM) by the direct AM technology thermoplastic 3D printing (T3DP). Zirconia components with varying microstructures were additively manufactured by using thermoplastic suspensions with different contents of pore-forming agents (PFA), which were co-sintered defect-free. Different materials were investigated concerning their suitability as PFA for the T3DP process. Diverse zirconia-based suspensions were prepared and used for the AM of single- and multi-material test components. All of the samples were sintered defect-free, and in the end, we could realize a brick wall-like component consisting of dense (<1% porosity) and porous (approx. 5% porosity) zirconia areas to combine different properties in one component. T3DP opens the door to the AM of further ceramic-based 4D components, such as multi-color, multi-material, or especially, multi-functional components.

  9. An additional role for the Brønsted acid-base catalysts of mandelate racemase in transition state stabilization.

    Science.gov (United States)

    Nagar, Mitesh; Bearne, Stephen L

    2015-11-10

    Mandelate racemase (MR) catalyzes the interconversion of the enantiomers of mandelate and serves as a paradigm for understanding the enzyme-catalyzed abstraction of an α-proton from a carbon acid substrate with a high pKa. The enzyme utilizes a two-base mechanism with Lys 166 and His 297 acting as Brønsted acid and base catalysts, respectively, in the R → S reaction direction. In the S → R reaction direction, their roles are reversed. Using isothermal titration calorimetry (ITC), MR is shown to bind the intermediate/transition state (TS) analogue inhibitor benzohydroxamate (BzH) in an entropy-driven process with a value of ΔCp equal to -358 ± 3 cal mol(-1) K(-1), consistent with an increased number of hydrophobic interactions. However, MR binds BzH with an affinity that is ∼2 orders of magnitude greater than that predicted solely on the basis of hydrophobic interactions [St. Maurice, M., and Bearne, S. L. (2004) Biochemistry 43, 2524], suggesting that additional specific interactions contribute to binding. To test the hypothesis that cation-π/NH-π interactions between the side chains of Lys 166 and His 297 and the aromatic ring and/or the hydroxamate/hydroximate moiety of BzH contribute to the binding of BzH, site-directed mutagenesis was used to generate the MR variants K166M, K166C, H297N, and K166M/H297N and their binding affinity for various ligands determined using ITC. Comparison of the binding affinities of these MR variants with the intermediate/TS analogues BzH and cyclohexanecarbohydroxamate revealed that cation-π/NH-π interactions between His 297 and the hydroxamate/hydroximate moiety and the phenyl ring of BzH contribute approximately 0.26 and 0.91 kcal/mol to binding, respectively, while interactions with Lys 166 contribute approximately 1.74 and 1.74 kcal/mol, respectively. Similarly, comparison of the binding affinities of these mutants with substrate analogues revealed that Lys 166 contributes >2.93 kcal/mol to the binding of (R

  10. Well-to-Wheels analysis of landfill gas-based pathways and their addition to the GREET model.

    Energy Technology Data Exchange (ETDEWEB)

    Mintz, M.; Han, J.; Wang, M.; Saricks, C.; Energy Systems

    2010-06-30

    Today, approximately 300 million standard cubic ft/day (mmscfd) of natural gas and 1600 MW of electricity are produced from the decomposition of organic waste at 519 U.S. landfills (EPA 2010a). Since landfill gas (LFG) is a renewable resource, this energy is considered renewable. When used as a vehicle fuel, compressed natural gas (CNG) produced from LFG consumes up to 185,000 Btu of fossil fuel and generates from 1.5 to 18.4 kg of carbon dioxide-equivalent (CO{sub 2}e) emissions per million Btu of fuel on a 'well-to-wheel' (WTW) basis. This compares with approximately 1.1 million Btu and 78.2 kg of CO{sub 2}e per million Btu for CNG from fossil natural gas and 1.2 million Btu and 97.5 kg of CO{sub 2}e per million Btu for petroleum gasoline. Because of the additional energy required for liquefaction, LFG-based liquefied natural gas (LNG) requires more fossil fuel (222,000-227,000 Btu/million Btu WTW) and generates more GHG emissions (approximately 22 kg CO{sub 2}e /MM Btu WTW) if grid electricity is used for the liquefaction process. However, if some of the LFG is used to generate electricity for gas cleanup and liquefaction (or compression, in the case of CNG), vehicle fuel produced from LFG can have no fossil fuel input and only minimal GHG emissions (1.5-7.7 kg CO{sub 2}e /MM Btu) on a WTW basis. Thus, LFG-based natural gas can be one of the lowest GHG-emitting fuels for light- or heavy-duty vehicles. This report discusses the size and scope of biomethane resources from landfills and the pathways by which those resources can be turned into and utilized as vehicle fuel. It includes characterizations of the LFG stream and the processes used to convert low-Btu LFG into high-Btu renewable natural gas (RNG); documents the conversion efficiencies and losses of those processes, the choice of processes modeled in GREET, and other assumptions used to construct GREET pathways; and presents GREET results by pathway stage. GREET estimates of well-to-pump (WTP

  11. Do Simulation-Based Skill Exercises and Post-Encounter Notes Add Additional Value to a Standardized Patient-Based Clinical Skills Examination?

    Directory of Open Access Journals (Sweden)

    Michael D. Prislin

    2011-01-01

    Full Text Available Background. Standardized patient (SP clinical assessments have limited utility in assessing higher-level clinical competencies. This study explores the value of including simulation exercises and postencounter notes in an SP clinical skills examination. Methods. Two exercises involving cardiac auscultation and ophthalmic funduscopy simulations along with written post encounter notes were added to an SP-based performance examination. Descriptive analyses of students' performance and correlations with SP-based performance measures were obtained. Results. Students' abilities to detect abnormalities on physical exam were highly variable. There were no correlations between SP-based and simulation-derived measures of physical examination competency. Limited correlations were found between students' abilities to perform and document physical examinations and their formulation of appropriate differential diagnoses. Conclusions. Clinical simulation exercises add depth to SP-based assessments of performance. Evaluating the content of post encounter notes offers some insight into students' integrative abilities, and this appears to be improved by the addition of simulation-based post encounter skill exercises. However, further refinement of this methodology is needed.

  12. Design and development of a layer-based additive manufacturing process for the realization of metal parts of designed mesostructure

    Science.gov (United States)

    Williams, Christopher Bryant

    Low-density cellular materials, metallic bodies with gaseous voids, are a unique class of materials that are characterized by their high strength, low mass, good energy absorption characteristics, and good thermal and acoustic insulation properties. In an effort to take advantage of this entire suite of positive mechanical traits, designers are tailoring the cellular mesostructure for multiple design objectives. Unfortunately, existing cellular material manufacturing technologies limit the design space as they are limited to certain part mesostructure, material type, and macrostructure. The opportunity that exists to improve the design of existing products, and the ability to reap the benefits of cellular materials in new applications is the driving force behind this research. As such, the primary research goal of this work is to design, embody, and analyze a manufacturing process that provides a designer the ability to specify the material type, material composition, void morphology, and mesostructure topology for any conceivable part geometry. The accomplishment of this goal is achieved in three phases of research: (1) Design---Following a systematic design process and a rigorous selection exercise, a layer-based additive manufacturing process is designed that is capable of meeting the unique requirements of fabricating cellular material geometry. Specifically, metal parts of designed mesostructure are fabricated via three-dimensional printing of metal oxide ceramic powder followed by post-processing in a reducing atmosphere. (2) Embodiment ---The primary research hypothesis is verified through the use of the designed manufacturing process chain to successfully realize metal parts of designed mesostructure. (3) Modeling & Evaluation ---The designed manufacturing process is modeled in this final research phase so as to increase understanding of experimental results and to establish a foundation for future analytical modeling research. In addition to an analysis of

  13. Improved Efficiency and Stability of Perovskite Solar Cells Induced by CO Functionalized Hydrophobic Ammonium-Based Additives.

    Science.gov (United States)

    Wu, Zhifang; Raga, Sonia R; Juarez-Perez, Emilio J; Yao, Xuyang; Jiang, Yan; Ono, Luis K; Ning, Zhijun; Tian, He; Qi, Yabing

    2018-01-01

    Because of the rapid rise of the efficiency, perovskite solar cells are currently considered as the most promising next-generation photovoltaic technology. Much effort has been made to improve the efficiency and stability of perovskite solar cells. Here, it is demonstrated that the addition of a novel organic cation of 2-(6-bromo-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)ethan-1-ammonium iodide (2-NAM), which has strong Lewis acid and base interaction (between CO and Pb) with perovskite, can effectively increase crystalline grain size and reduce charge carrier recombination of the double cation FA 0.83 MA 0.17 PbI 2.51 Br 0.49 perovskite film, thus boosting the efficiency from 17.1 ± 0.8% to 18.6 ± 0.9% for the 0.1 cm 2 cell and from 15.5 ± 0.5% to 16.5 ± 0.6% for the 1.0 cm 2 cell. The champion cell shows efficiencies of 20.0% and 17.6% with active areas of 0.1 and 1.0 cm 2 , respectively. Moreover, the hysteresis behavior is suppressed and the stability is improved. The result provides a promising route to further elevate efficiency and stability of perovskite solar cells by the fine tuning of triple organic cations. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Modification of asphaltic concrete with a mineral polymeric additive based on butadiene-styrene rubber and chemically precipitated calcium carbonate

    Directory of Open Access Journals (Sweden)

    S. I. Niftaliev

    2016-01-01

    Full Text Available Modification of asphaltic concrete with a mineral polymeric additive based on butadiene – styrene rubber and chemically precipitated calcium carbonate. This paper presents the results of the study of physical – mechanical and service properties of the asphaltic concrete modified with the mineral polymeric composition. Calcium carbonate is used both as a filler and a coagulant. The chalk was preliminarily ground and hydrophobizated by stearic acid. These operations contribute to even distribution of the filler and interfere with lump coagulation. As a result of the experiments, it was found that the best results were obtained by combining the operations of dispersion and hydrophobization. The optimal amount of stearic acid providing the finest grinding in a ball mill is a content from 3 to 5% by weight. The optimal grinding time of the filler was found (4–6 hours. With increasing dispersion time the particles form agglomerates. Filling the butadiene styrene latex with the hydrophobic fine-grained calcium carbonate was carried out in the laboratory mixer. As a result of the experimental works, it was found that the best distribution of the filler takes place with ratio of rubber: chalk – 100:400. The resulting modifier was subjected to the thermal analysis on the derivatograph to determine its application temperature interval. A marked reduction in weight of the mineral polymeric modifier begins at 350 °C. Thus, high temperature of the modifier destruction allows to use it at the temperature of the technological process of asphaltic concrete preparation (up to 170 °C. It was found that an increase in the amount of the carbonate filler in the rubber SKS 30АRК significantly increases its thermal resistance and connection of the polymer with the chalk in the composition.

  15. Speckle Reduction on Ultrasound Liver Images Based on a Sparse Representation over a Learned Dictionary

    Directory of Open Access Journals (Sweden)

    Mohamed Yaseen Jabarulla

    2018-05-01

    Full Text Available Ultrasound images are corrupted with multiplicative noise known as speckle, which reduces the effectiveness of image processing and hampers interpretation. This paper proposes a multiplicative speckle suppression technique for ultrasound liver images, based on a new signal reconstruction model known as sparse representation (SR over dictionary learning. In the proposed technique, the non-uniform multiplicative signal is first converted into additive noise using an enhanced homomorphic filter. This is followed by pixel-based total variation (TV regularization and patch-based SR over a dictionary trained using K-singular value decomposition (KSVD. Finally, the split Bregman algorithm is used to solve the optimization problem and estimate the de-speckled image. The simulations performed on both synthetic and clinical ultrasound images for speckle reduction, the proposed technique achieved peak signal-to-noise ratios of 35.537 dB for the dictionary trained on noisy image patches and 35.033 dB for the dictionary trained using a set of reference ultrasound image patches. Further, the evaluation results show that the proposed method performs better than other state-of-the-art denoising algorithms in terms of both peak signal-to-noise ratio and subjective visual quality assessment.

  16. Sensitization to Food Additives in Patients with Allergy: A Study Based on Skin Test and Open Oral Challenge.

    Science.gov (United States)

    Moghtaderi, Mozhgan; Hejrati, Zinatosadat; Dehghani, Zahra; Dehghani, Faranak; Kolahi, Niloofar

    2016-06-01

    There has been a great increase in the consumption of various food additives in recent years. The purpose of this study was to identify the incidence of sensitization to food additives by using skin prick test in patients with allergy and to determine the concordance rate between positive skin tests and oral challenge in hypersensitivity to additives. This cross-sectional study included 125 (female 71, male 54) patients aged 2-76 years with allergy and 100 healthy individuals. Skin tests were performed in both patient and control groups with 25 fresh food additives. Among patients with allergy, 22.4% showed positive skin test at least to one of the applied materials. Skin test was negative to all tested food additives in control group. Oral food challenge was done in 28 patients with positive skin test, in whom 9 patients showed reaction to culprit (Concordance rate=32.1%). The present study suggested that about one-third of allergic patients with positive reaction to food additives showed positive oral challenge; it may be considered the potential utility of skin test to identify the role of food additives in patients with allergy.

  17. Performance Simulation and Verification of Vat Photopolymerization Based, Additively Manufactured Injection Molding Inserts with Micro-Features

    DEFF Research Database (Denmark)

    Mischkot, Michael; Hofstätter, Thomas; Michailidou, Ifigeneia

    2017-01-01

    Injection molding soft tooling inserts manufactured additively with vat photopolymerization represent a valid technology for prototyping and pilot production of polymer parts. However, a significant drawback is the low heat conductivity of photopolymers influencing cycletime and part quality...

  18. Certification of Additive Manufacturing Processing Parameters through Physics-Based Predictive Simulation of Process-Defects-Microstructure

    Data.gov (United States)

    National Aeronautics and Space Administration — Additive manufacturing (AM), also known as 3D printing, is a next generation technology for cost-effective and accelerated way of manufacturing complex-shaped...

  19. Understanding the interactions of phosphonate-based flame-retarding additives with graphitic anode for lithium ion batteries

    International Nuclear Information System (INIS)

    Feng, Jinkui; Ma, Peng; Yang, Hanxi; Lu, Li

    2013-01-01

    Highlights: •Diethyl ethylphosphonate (DEEP) and dimethyl methylphosphonate are tested as flame retardants for lithium ion batteries. •The DMMP shows a destructive reaction with graphitic anode while DEEP shows a self-reduction mechanism. •DEEP is reported for the first time as flame-retardant additive for lithium ion batteries and demonstrates a much better compatibility with graphitic anode. -- Abstract: The compatibility with graphitic anode has been one key problem in developing flame-retarding additives for lithium ion batteries. To understand the interactions between flame-retarding additives and graphitic anode, two phosphonate esters (dimethyl methylphosphonate DMMP and diethyl ethylphosphonate DEEP) are selected and characterized as flame retardant addtives. DEEP is reported as a flame-retarding additive for the first time. Their interactions with graphite anode are characterized via current-static charge–discharge, ex-situ XRD, FE-SEM and AC impedance. The results reveal that the two phosphonate esters demonstrate different reaction mechanisms with graphitic anode, which result in different anode compatibility. These findings may be useful for designing better flame-retarding additives for lithium ion batteries

  20. Effect of addition of different nano-clays on the fumed silica-polyethylene glycol based shear-thickening fluids

    Science.gov (United States)

    Singh, Mansi; Mehta, Rajeev; Verma, Sanjeev K.; Biswas, Ipsita

    2018-01-01

    A comparative study of the rheology of shear thickening suspensions of 20% fumed silica in polyethylene glycol (PEG200) with different nano clays as additives has been done. The nano-clays used are montmorillonite (MMT), Closite15A, Kaolin and Halloysite clay. The objective was to study the effect of relatively cost-effective clays as a partial substitute of silica. Specifically, the effect of type, concentration, temperature and frequency were considered. The results indicate that the shear thickening properties of Closite15A as additive in temperature ranges of 25 °C-45 °C performs the best and Halloysite performs best at higher (55 °C) and lower temperatures (5, 15 °C). The elasticity effects in dynamic experiments were markedly enhanced by Halloysite clay addition. Addition of MMT, however, led to insignificant enhancement in critical viscosity in steady-state as well as dynamic state-rheology. Interestingly, shear thickening fluid (STF) with all clay except MMT was stable after storing for more than a month. These findings indicate that the introduction of nano-clay as additives is a promising and cost effective method for enhancing the STF behavior which can be utilized in high impact resistant (about 3000% strain and 300 rad s-1 frequency) applications.

  1. A Fluorescent Molecular Probe for the Detection of Hydrogen Based on Oxidative Addition Reactions with Crabtree-Type Hydrogenation Catalysts.

    Science.gov (United States)

    Kos, Pavlo; Plenio, Herbert

    2015-11-02

    A Crabtree-type Ir(I) complex tagged with a fluorescent dye (bodipy) was synthesized. The oxidative addition of H2 converts the weakly fluorescent Ir(I) complex (Φ=0.038) into a highly fluorescent Ir(III) species (Φ=0.51). This fluorogenic reaction can be utilized for the detection of H2 and to probe the oxidative addition step in the catalytic hydrogenation of olefins. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Starch-Glycerol Based Edible Film and Effect of Rosella (Hibiscus Sabdariffa Linn Extract and Surimi Dumbo Catfish (Clarias gariepinus Addition on Its Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Endaruji Sedyadi

    2016-10-01

    Full Text Available Effect of Rosella (Hibiscus Sabdariffa Linn Extract and Surimi Dumbo catfish (Clarias gariepinus addition on Starch-Based Edible Film-Glycerol Mechanical Properties has been done. The purpose of this study is to create an active environment-friendly packaging material. Surimi additions are intended to improve the mechanical properties of bioplastics and additions of Rosella extract intended as a bio-indicator of acidity. The method used was Solvent Casting. An amount of surimi and rosella extract varied to obtain the best mechanical properties. The results shows that the addition of surimi and rosella flower extract significantly effect the elongation of Edible films produced up to 27%.

  3. Casein addition to a whey-based formula has limited effects on gut function in preterm pigs

    DEFF Research Database (Denmark)

    Thymann, T.; Støy, Ann Cathrine Findal; Bering, S. B.

    2012-01-01

    Preterm infants are susceptible to necrotizing enterocolitis (NEC). Using preterm pigs, we determined whether a whey–casein-based formula would be superior to a formula based on whey protein alone. Twenty cesarean-derived preterm pigs (92% gestation) were given total parenteral nutrition for 36 h...... followed by 30 h of enteral feeding with whey [protein fraction of milk formula based on whey (WHEY); n = 11] or casein and/or whey [protein fraction of milk formula based on a combination of casein and whey (CASEIN); n = 9]-based formulas. Sugar absorptive function was investigated at 6 and 30 h after...... studied in gut contents. Severity of NEC lesions was similar between diet groups but galactose absorption was markedly higher in CASEIN than in WHEY (P

  4. Atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry of friction modifier additives analyzed directly from base oil solutions.

    Science.gov (United States)

    Widder, Lukas; Brennerb, Josef; Huttera, Herbert

    2014-01-01

    To develop new products and to apply measures of quality control quick and simple accessibility of additive composition in automo- tive lubrication is important. The aim of this study was to investigate the possibility of analyzing organic friction modifier additives by means of atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry [AP-MALDI-MS] from lubricant solu- tions without the use of additional separation techniques. Analyses of selected friction modifier ethoxylated tallow amines and oleic acid amide were compared using two ionization methods, positive-ion electrospray ionization (ESI) and AP-MALDI, using a LTQ Orbitrap mass spectrometer. Pure additives were characterized from solvent solutions, as well as from synthetic and mineral base oil mixtures. Detected ions of pure additive samples consisted mainly of [M + H]+, but also alkaLi metal adducts [M + Na]+ and [M + K]+ could be seen. Characterizations of blends of both friction modifiers from the base oil mixtures were carried out as well and showed significant inten- sities for several additive peaks. Thus, this work shows a method to directly analyze friction modifier additives used in the automotive industry from an oil blend via the use of AP-MALDI without any further separation steps. The method presented will further simplify the acquisition of data on lubricant composition and additives. Furthermore, it allows the perspective of analyzing additive reaction products directly from formulated oil blends.

  5. Improved tribological properties of the synthesized copper/carbon nanotube nanocomposites for rapeseed oil-based additives

    Science.gov (United States)

    Wang, Zhiqiang; Ren, Ruirui; Song, Haojie; Jia, Xiaohua

    2018-01-01

    Carbon nanotubes (CNTs) decorated with uniform copper nanoparticles (Cu NPs) were successfully prepared via a facile approach towards surface modification of CNTs with spontaneous polydopamine (PDA). The structures and morphologies of the nanocomposites were investigated by different kinds of techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Cu/PDA/CNTs nanocomposites were fabricated by growing the Cu NPs with an average diameter of 5 nm on the surfaces of PDA-modified CNTs. The CNTs functionalized with PDA layer not only provide an anchoring platform for the Cu NPs immobilization, but also endow Cu/PDA/CNTs with good dispersion stability when Cu/PDA/CNTs nanocomposites were used as lubricant additive. The tribological performance of the nanocomposites as the rapeseed oil lubricant additive, as well as Cu NPs, CNTs, and Cu/CNTs, was also investigated using a MS-T3000 ball-on-disk tribometer. Results show that the 0.2 wt% Cu/PDA/CNTs nanoadditive simultaneously reduce the friction and wear by 33.5% and 23.7%, respectively, outperformed the tribological performance of Cu NPs, CNTs, and Cu/CNTs nanoadditives. In addition, the presence of active sites in Cu/PDA/CNTs was beneficial to reduce the time of running-in period, give rise to the fastest speed to be stable of the friction coefficient curve as compared to the other nanoadditives. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy of the worn surfaces lubricated by the soybean oil with Cu/PDA/CNTs nanocomposites showed that formation of low shear strength tribofilms containing Cu/PDA/CNTs nanocomposites and its self-lubricating property was key factor in reduction of the friction and protection against wear and deformation.

  6. Microstructure and thermal stability of nickel layers electrodeposited from an additive-free sulphamate-based electrolyte

    DEFF Research Database (Denmark)

    Rasmussen, Anette Alsted; Møller, Per; Somers, Marcel A. J.

    2006-01-01

    and scanning electron microscopy and X-ray diffraction; the Vickers hardness was measured in cross sections. The present is meant as a reference for forthcoming articles on the investigation of various strengthening mechanisms on the microstructure, hardness and thermal stability of Ni (alloys) electrodeposits.......The influences of the current density and the temperature on the microstructure and hardness of Ni layers electrodeposited from an additive-free sulphamate bath were investigated. The microstructure and thermal stability of the electrodeposits was investigated with a combination of transmission...

  7. Lewis base activation of Lewis acids: catalytic, enantioselective addition of glycolate-derived silyl ketene acetals to aldehydes.

    Science.gov (United States)

    Denmark, Scott E; Chung, Won-Jin

    2008-06-20

    A catalytic system involving silicon tetrachloride and a chiral, Lewis basic bisphosphoramide catalyst is effective for the addition of glycolate-derived silyl ketene acetals to aldehydes. It was found that the sense of diastereoselectivity could be modulated by changing the size of the substituents on the silyl ketene acetals. In general, the trimethylsilyl ketene acetals derived from methyl glycolates with a large protecting group on the alpha-oxygen provide enantiomerically enriched alpha,beta-dihydroxy esters with high syn-diastereoselectivity, whereas the tert-butyldimethylsilyl ketene acetals derived from bulky esters of alpha-methoxyacetic acid provide enantiomerically enriched alpha,beta-dihydroxy esters with high anti-diastereoselecitvity.

  8. Effect of strontium addition and chitosan concentration variation on cytotoxicity of chitosan-alginate-carbonate apatite based bone scaffold

    Science.gov (United States)

    Perkasa, Rilis Eka; Umniati, B. Sri; Sunendar, Bambang

    2017-09-01

    Bone scaffold is one of the most important component in bone tissue engineering. Basically, bone scaffold is a biocompatible structure designed to replace broken bone tissue temporarily. Unlike conventional bone replacements, an advanced bone scaffold should be bioactive (e.g: supporting bone growth) and biodegradable as new bone tissue grow, while retain its mechanical properties similarity with bone. It is also possible to add more bioactive substrates to bone scaffold to further support its performance. One of the substrate is strontium, an element that could improve the ability of the bone to repair itself. However, it must be noted that excessive consumption of strontium could lead to toxicity and diseases, such as osteomalacia and hypocalcemia. This research aimed to investigate the effect of strontium addition to the cytotoxic property of chitosan-alginate-carbonate apatite bone scaffold. The amount of strontium added to the bone scaffold was 5% molar of the carbonate apatite content. As a control, bone scaffold without stronsium (0% molar) were also made. The effect of chitosan concentration variation on the cytotoxicity were also observed, where the concentration varies on 1% and 3% w/v of chitosan solution. The results showed an optimum result on bone scaffold sample with 5% molar of strontium and 3% chitosan, where 87.67% cells in the performed MTS-Assay cytotoxicity testing survived. This showed that the use of up to 5% molar addition of strontium and 3% chitosan could enhance the survivability of the cell.

  9. Environmental Assessment for the National Museum of the United States Air Force Addition, Wright-Patterson Air Force Base, Ohio

    Science.gov (United States)

    2013-02-01

    AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) United States Air Force 88th...Air Base Wing Wright-Patterson Air Force Base, Ohio 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES...visitors nationwide and from foreign countries. Softball and soccer fields are located adjacent to the Museum grounds and are operated by the 88 Air

  10. Estimation of Frost Resistance of the Tile Adhesive on a Cement Based with Application of Amorphous Aluminosilicates as a Modifying Additive

    Science.gov (United States)

    Ivanovna Loganina, Valentina; Vladimirovna Zhegera, Christina

    2017-10-01

    In the article given information on the possibility of using amorphous aluminosilicates as a modifying additive in the offered tile cement adhesive. In the article, the data on the preparation of an additive based on amorphous aluminosilicates, on its microstructure and chemical composition. Presented information on the change in the porosity of cement stone when introduced of amorphous aluminosilicates in the his composition. The formulation of a dry building mix on a cement base is proposed with use of an additive based on amorphous aluminosilicates as a modifying additive. Recipe of dry adhesive mixes include Portland cement M400, mineral aggregate in proportion fraction 0.63-0.315:0.315-0.14 respectively 80:20 (%) and filling density of 1538.2 kg/m3, a plasticizer Kratasol, redispersible powder Neolith P4400 and amorphous alumnosilicates. The developed formulation can be used as a tile adhesive for finishing walls of buildings and structure with tiles. Presented results of the evaluation of frost resistance of adhesives based on cement with using of amorphous aluminosilicates as a modifying additive. Installed the mark on the frost resistance of tile glue and frost resistance of the contact zone of adhesive. Established, that the adhesive layer based on developed formulation dry mixture is crack-resistant and frost-resistant for conditions city Penza and dry humidity zone - zone 3 and climatic subarea IIB (accordance with Building codes and regulations 23-01-99Ȋ) cities Russia’s.

  11. Example-based learning: comparing the effects of additionally providing three different integrative learning activities on physiotherapy intervention knowledge

    NARCIS (Netherlands)

    J.-O. Dyer (Joseph-Omer); A. Hudon (Anne); K. Montpetit-Tourangeau (Katherine); B. Charlin (Bernard); S. Mamede (Silvia); T.A.J.M. van Gog (Tamara)

    2015-01-01

    textabstractBACKGROUND: Example-based learning using worked examples can foster clinical reasoning. Worked examples are instructional tools that learners can use to study the steps needed to solve a problem. Studying worked examples paired with completion examples promotes acquisition of

  12. Effect of amphiphilic additives on the behavior of water-based acrylic pressure-sensitive adhesives during paper recycling

    Science.gov (United States)

    Jihui Guo; Steven J. Severtson; Larry E. Gwin; Carl J. Houtman

    2008-01-01

    Pressure-sensitive adhesives (PSAs) in recovered paper reduce efficiency and increase operating costs for paper recycling mills. Increased PSA fragmentation during pulping and the corresponding reduction in screening efficiency are indications that a PSA will likely interfere with paper recycling. Water-based PSAs, which dominate the label market, have complex...

  13. Hepatitis B virus vaccination booster does not provide additional protection in adolescents: a cross-sectional school-based study.

    Science.gov (United States)

    Chang, Yung-Chieh; Wang, Jen-Hung; Chen, Yu-Sheng; Lin, Jun-Song; Cheng, Ching-Feng; Chu, Chia-Hsiang

    2014-09-23

    Current consensus does not support the use of a universal booster of hepatitis B virus (HBV) vaccine because there is an anamnestic response in almost all children 15 years after universal infant HBV vaccination. We aimed to provide a booster strategy among adolescents as a result of their changes in lifestyle and sexual activity. This study comprised a series of cross-sectional serological surveys of HBV markers in four age groups between 2004 and 2012. The seropositivity rates of hepatitis B surface antigen (HBsAg) and its reciprocal antibody (anti-HBs) for each age group were collected. There were two parts to this study; age-specific HBV seroepidemiology and subgroup analysis, including effects of different vaccine types, booster response for immunogenicity at 15 years of age, and longitudinal follow-up to identify possible additional protection by HBV booster. Within the study period, data on serum anti-HBs and HBsAg in a total of 6950 students from four age groups were collected. The overall anti-HBs and HBsAg seropositivity rates were 44.3% and 1.2%, respectively. The anti-HBs seropositivity rate in the plasma-derived subgroup was significantly higher in both 15- and 18-year age groups. Overall response rate in the double-seronegative recipients at 15 years of age was 92.5% at 6 weeks following one recombinant HBV booster dose. Among the 24 recipients showing anti-HBs seroconversion at 6 weeks after booster, seven subjects (29.2%) had lost their anti-HBs seropositivity again within 3 years. Increased seropositivity rates and titers of anti-HBs did not provide additional protective effects among subjects comprehensively vaccinated against HBV in infancy. HBV booster strategy at 15 years of age was the main contributor to the unique age-related phenomenon of anti-HBs seropositivity rate and titer. No increase in HBsAg seropositivity rates within different age groups was observed. Vaccination with plasma-derived HBV vaccines in infancy provided higher

  14. Improvement of food packaging related properties in whey protein isolate‑based nanocomposite films and coatings by addition of montmorillonite nanoplatelets

    Science.gov (United States)

    Schmid, Markus; Merzbacher, Sarah; Brzoska, Nicola; Müller, Kerstin; Jesdinszki, Marius

    2017-11-01

    In the present study the effects of the addition of montmorillonite (MMT) nanoplatelets on whey protein isolate (WPI)-based nanocomposite films and coatings were investigated. The main objective was the development of WPI-based MMT-nanocomposites with enhanced barrier and mechanical properties. WPI-based nanocomposite cast-films and coatings were prepared by dispersing 0 % (reference sample), 3 %, 6 %, 9 % (w/w protein) MMT, or, depending on the protein concentration, also 12 % and 15 % (w/w protein) MMT into native WPI-based dispersions, followed by subsequent denaturation during the drying and curing process. The natural MMT nanofillers could be randomly dispersed into film-forming WPI-based nanodispersions, displaying good compatibility with the hydrophilic biopolymer matrix. As a result, by addition of 15 % (w/w protein) MMT into 10 % (w/w dispersion) WPI-based cast-films or coatings, the oxygen permeability (OP) was reduced by 91 % for glycerol-plasticized and 84 % for sorbitol-plasticized coatings, water vapor transmission rate (WVTR) was reduced by 58 % for sorbitol-plasticized cast-films. Due to the addition of MMT- nanofillers the Young’s modulus and tensile strength improved by 315 % and 129 %, respectively, whereas elongation at break declined by 77 % for glycerol-plasticized cast-films. In addition, comparison of plasticizer type revealed that sorbitol-plasticized cast-films were generally stiffer and stronger, but less flexible compared glycerol-plasticized cast-films. Viscosity measurements demonstrated good processability and suitability for up-scaled industrial processes of native WPI-based nanocomposite dispersions, even at high nanofiller-loadings. These results suggest that the addition of natural MMT- nanofillers into native WPI-based matrices to form nanocomposite films and coatings holds great potential to replace well-established, fossil-based packaging materials for at least certain applications such as oxygen barriers as part of

  15. Effect of the addition of expanded vermiculite in the technological properties of ceramic materials of clay base

    International Nuclear Information System (INIS)

    Lins, R.R.F.; Peixoto, R.S. Dutra; Macedo, D.A.; Nascimento, R.M.; Oliveira, G.V.M.; Universidade Federal da Paraiba

    2016-01-01

    This paper discusses the effects of adding expanded vermiculite ceramic block made from two different types of clay and analysis of the properties for three compositions at different sintering temperatures. Samples pressed at 40 MPa were sintered between 800 and 1100 ° C. The technological properties were determined according to the sintering temperature. The evaluation of the crystalline phases and microstructure was carried out by X-ray diffraction results indicated that with the addition of expanded vermiculite in the specimens there was an increase in porosity of the blocks together with the water absorption, therefore a reduction in apparent density, as well as the breakdown voltage of the three-point bending. This study demonstrates the possibility of formulating ceramic blocs order to improve the insulating properties of these materials. (author)

  16. Poly(vinylbenzylchloride) Based Anion-Exchange Blend Membranes (AEBMs): Influence of PEG Additive on Conductivity and Stability.

    Science.gov (United States)

    Kerres, Jochen A; Krieg, Henning M

    2017-06-16

    In view of the many possible applications such as fuel cells and electrolysers, recent interest in novel anion exchange membranes (AEMs) has increased significantly. However, their low conductivity and chemical stability limits their current suitability. In this study, the synthesis and characterization of several three- and four-component anion exchange blend membranes (AEBMs) is described, where the compositions have been systematically varied to study the influence of the AEBM's composition on the anion conductivities as well as chemical and thermal stabilities under strongly alkaline conditions. It was shown that the epoxide-functionalized poly(ethylene glycol)s that were introduced into the four-component AEBMs resulted in increased conductivity as well as a marked improvement in the stability of the AEBMs in an alkaline environment. In addition, the thermal stability of the novel AEBMs was excellent showing the suitability of these membranes for several electrochemical applications.

  17. Synthesis of Novel E-2-Chlorovinyltellurium Compounds Based on the Stereospecific Anti-addition of Tellurium Tetrachloride to Acetylene

    Directory of Open Access Journals (Sweden)

    Svetlana V. Amosova

    2012-05-01

    Full Text Available The reaction of tellurium tetrachloride with acetylene proceeds in a stereospecific anti-addition manner to afford the novel products E-2-chlorovinyltellurium trichloride and E,E-bis(2-chlorovinyltellurium dichloride. Reaction conditions for the selective preparation of each of these products were found. The latter was obtained in 90% yield in CHCl3 under a pressure of acetylene of 10–15 atm, whereas the former product was formed in up to 72% yield in CCl4 under a pressure of acetylene of 1–3 atm. Synthesis of the previously unknown E,E-bis(2-chlorovinyl telluride, E,E-bis(2-chlorovinyl ditelluride, E-2-chlorovinyl 1,2,2-trichloroethyl telluride and E,E-bis(2-chlorovinyl-tellurium dibromide is described.

  18. Effect of addition of lignin in physical-chemical properties of a polyesters based on glycerol, phthalic and adipic acids

    International Nuclear Information System (INIS)

    Guimaraes, D.H.; Viana, A.P.M.; Lima, A.S.C.; Goncalves, A.P.B.; Miranda, C.S.; Jose, N.M.

    2014-01-01

    In this paper the study of different addition amounts of lignin in the physicochemical properties of polyesters made from glycerol and different amounts of phthalic and adipic acids have been proposed. The following characterizations were made: XRD, FTIR, TGA, DSC and SEM. The variation in the percentage of adipic and phthalic acids had a direct effect on thermal and morphological properties. The thermal analysis showed that there was miscibility between the polyester and lignin, by means of displacement related to the temperature of thermal degradation events. In FTIR analysis was noted displacements of characteristic bands of hydrogen bonds and specific carbonyl ester groups. These shifts were more pronounced as it has larger amounts of phthalic acid as monomer and larger amounts of lignin in the compositions. (author)

  19. Forced and natural carbonation of lime-based mortars with and without additives: Mineralogical and textural changes

    International Nuclear Information System (INIS)

    Cultrone, G.; Sebastian, E.; Huertas, M. Ortega

    2005-01-01

    We have studied the carbonation process in different types of mortars, with and without pozzolana or air-entraining additives, subject to a CO 2 -rich atmosphere and compared the results with those of similar naturally carbonated mortars. We used X-ray diffraction technique to demonstrate that high CO 2 concentrations favour a faster, more complete carbonation process with 8 days being sufficient to convert portlandite into 90 wt.% calcite. Full carbonation, however, is not reached during the life-span of the tests, not even in forced carbonation experiments. This could be due to at least one of the following phenomena: a premature drying of samples during carbonation reaction, the temperature at which the carbonation process was carried out or the reduction of pore volume occupied by newly formed calcite crystals. This last option seems to be the least probable. We observed a more prolific development of calcite crystals in the pores and fissures through which the carbonic anhydride flows. Under natural conditions, carbonation is much slower and similar levels are not reached for 6 months. These differences suggest that the carbonation process is influenced by the amount of CO 2 used. Both the mineralogy and texture of mortars vary depending on the type of additive used but the speed of the portlandite-calcite transformation does not change significantly. Pozzolana produces hydraulic mortars although the quantity of calcium aluminosilicate crystals is low. The air-entraining agent significantly alters the texture of the mortars creating rounded pores and eliminating or reducing the drying cracks

  20. Prediction of the enthalpies of vaporization for room-temperature ionic liquids: Correlations and a substitution-based additive scheme

    International Nuclear Information System (INIS)

    Kabo, Gennady J.; Paulechka, Yauheni U.; Zaitsau, Dzmitry H.; Firaha, Alena S.

    2015-01-01

    Highlights: • The available literature data on Δ l g H for ionic liquids were analyzed. • Correlation equations for Δ l g H were derived using symbolic regression. • A substitution-based incremental scheme for Δ l g H was developed. • The proposed scheme has an advantage over the existing predictive procedures. - Abstract: The literature data on the enthalpies of vaporization for aprotic ionic liquids (ILs) published by the end of May 2014 were analyzed and the most reliable Δ l g H m values were derived for 68 ILs. The selected enthalpies of vaporization were correlated with density and surface tension using symbolic regression and a number of effective correlation equations were proposed. The substitution-based incremental scheme for prediction of the enthalpies of vaporization of imidazolium, pyridinium and pyrrolidinium ILs was developed. The standard error of the regression for the developed scheme is significantly lower than that for the atom-based group-contribution schemes proposed earlier

  1. Estimation of daily aluminum intake in Japan based on food consumption inspection results: impact of food additives

    Science.gov (United States)

    Sato, Kyoko; Suzuki, Ippei; Kubota, Hiroki; Furusho, Noriko; Inoue, Tomoyuki; Yasukouchi, Yoshikazu; Akiyama, Hiroshi

    2014-01-01

    Dietary aluminum (Al) intake by young children, children, youths, and adults in Japan was estimated using the market basket method. The Al content of food category (I–VII) samples for each age group was determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The Al content in processed foods and unprocessed foods ranged from 0.40 to 21.7 mg/kg and from 0.32 to 0.54 mg/kg, respectively. For processed foods in all age groups, the Al content in food category VI samples, sugar and confections/savories, was the highest, followed by those in category II, cereals. The daily dietary Al intake from processed foods was much larger than that from unprocessed foods. The mean weekly percentages of the provisional tolerable weekly intake (PTWI, established by the joint FAO/WHO Expert Committee on Food Additives in 2011) from processed foods for all age groups are 43.1, 22.4, 17.6 and 15.1%, respectively. Only the highest consumer Al exposure value (>P95) of the young children group exceeded the PTWI. PMID:25473496

  2. Manufacture of a UO2-Based Nuclear Fuel with Improved Thermal Conductivity with the Addition of BeO

    Science.gov (United States)

    Garcia, Chad B.; Brito, Ryan A.; Ortega, Luis H.; Malone, James P.; McDeavitt, Sean M.

    2017-12-01

    The low thermal conductivity of oxide nuclear fuels is a performance-limiting parameter. Enhancing this property may provide a contribution toward establishing accident-tolerant fuel forms. In this study, the thermal conductivity of UO2 was increased through the fabrication of ceramic-ceramic composite forms with UO2 containing a continuous BeO matrix. Fuel with a higher thermal conductivity will have reduced thermal gradients and lower centerline temperatures in the fuel pin. Lower operational temperatures will reduce fission gas release and reduce fuel restructuring. Additions of BeO were made to UO2 fuel pellets in 2.5, 5, 7.5, and 10 vol pct concentrations with the goals of establishing reliable lab-scale processing procedures, minimizing porosity, and maximizing thermal conductivity. The microstructure was characterized with electron probe microanalysis, and the thermal properties were assessed by light flash analysis and differential scanning calorimetry. Reliable, high-density samples were prepared using compaction pressure between 200 and 225 MPa and sintering times between 4 and 6 hours. It was found that the thermal conductivity of UO2 improved approximately 10 pct for each 1 vol pct BeO added over the measured temperature range 298.15 K to 523.15 K (25 °C to 250 °C) with the maximum observed improvement being ˜ 100 pct, or doubled, at 10 vol pct BeO.

  3. Catalytic effect of additional metallic phases on the hydrogen absorption behavior of a Zr-Based alloy

    International Nuclear Information System (INIS)

    Ruiz, F; Peretti, H; Castro, E; Real, S; Visitin, A; Triaca, W

    2005-01-01

    The electrochemical hydrogen absorption of electrodes containing Zr 0 .9Ti 0 .1(Ni 0 .5Mn 0 .25Cr 0 .20V 0 .05) 2 is studied in alkaline media by monitoring the activation and discharge capacity along charge-discharge cycling.The considered alloy is tested in both as melted and annealed condition in order to investigate the catalytic effect of small amounts of micro segregated secondary phases of the Zr-Ni system. Since these catalytic phases are only present in the as melted alloys, tests are also carried out using a composite material elaborated from powders of the annealed alloy with the addition of 18 wt.% of the suspected catalytic phases, melted separately.The hydrogen absorption-desorption behavior for the different cases is discussed and correlated with the metallurgical characterization of the materials.The catalytic effects are studied employing cyclic voltammetry and electrochemical impedance techniques. The results are analyzed in terms of a developed physicochemical model

  4. Plant essential oils and allied volatile fractions as multifunctional additives in meat and fish-based food products: a review.

    Science.gov (United States)

    Patel, Seema

    2015-01-01

    Essential oils are concentrated aromatic volatile compounds derived from botanicals by distillation or mechanical pressing. They play multiple, crucial roles as antioxidants, food pathogen inhibitors, shelf-life enhancers, texture promoters, organoleptic agents and toxicity-reducing agents. For their versatility, they appear promising as food preservatives. Several research findings in recent times have validated their potential as functional ingredients in meat and fish processing. Among the assortment of bioactive compounds in the essential oils, p-cymene, thymol, eugenol, carvacrol, isothiocyanate, cinnamaldehyde, cuminaldehyde, linalool, 1,8-cineol, α-pinene, α-terpineol, γ-terpinene, citral and methyl chavicol are most familiar. These terpenes (monoterpenes and sesquiterpenes) and phenolics (alcohols, esters, aldehydes and ketones) have been extracted from culinary herbs such as oregano, rosemary, basil, coriander, cumin, cinnamon, mint, sage and lavender as well as from trees such as myrtle, fir and eucalyptus. This review presents essential oils as alternatives to conventional chemical additives. Their synergistic actions with modified air packaging, irradiation, edible films, bacteriocins and plant byproducts are discussed. The decisive roles of metabolic engineering, microwave technology and metabolomics in quality and quantity augmentation of essential oil are briefly mooted. The limitations encountered and strategies to overcome them have been illuminated to pave way for their enhanced popularisation. The literature has been mined from scientific databases such as Pubmed, Pubchem, Scopus and SciFinder.

  5. Variability and relationship among Mixolab and Falling Number evaluation based on influence of fungal α-amylase addition.

    Science.gov (United States)

    Codina, Georgiana Gabriela; Mironeasa, Silvia; Mironeasa, Costel

    2012-08-15

    In bread-making technology, α-amylase activity is routinely measured with a Falling Number device to predict wheat flour quality. The aim of this study was to determine the possibility of using Mixolab parameters to assess the Falling Number (FN) index. The effects of different doses of fungal α-amylase addition on the Mixolab characteristics and FN index values were investigated. Principal component analysis was performed in order to illustrate the relationships between the Mixolab parameters and the FN index. To highlight the linear combination between the FN index values and the Mixolab parameters used to evaluate starch pasting properties (C3, C4, C5 and point differences C34 and C54), a multivariate prediction model was developed. Greatest precision (R = 0.728) was obtained for the linear regression FN = f(C4, C54) model. This model was tested on a different sample set than the one on which it was built. A high correlation was obtained between predictive model and measured FN index values (r = 0.896, P = 0.01). The model provides a framework to predict the evolution of the FN index, which is predicted by the torque for cooking stability (C4) and the difference between points C5 and C4 (C54). The obtained results suggested that the Mixolab device could be a reliable instrument for evaluation of the FN index values. Copyright © 2012 Society of Chemical Industry.

  6. Aerosol based direct-write micro-additive fabrication method for sub-mm 3D metal-dielectric structures

    Science.gov (United States)

    Rahman, Taibur; Renaud, Luke; Heo, Deuk; Renn, Michael; Panat, Rahul

    2015-10-01

    The fabrication of 3D metal-dielectric structures at sub-mm length scale is highly important in order to realize low-loss passives and GHz wavelength antennas with applications in wearable and Internet-of-Things (IoT) devices. The inherent 2D nature of lithographic processes severely limits the available manufacturing routes to fabricate 3D structures. Further, the lithographic processes are subtractive and require the use of environmentally harmful chemicals. In this letter, we demonstrate an additive manufacturing method to fabricate 3D metal-dielectric structures at sub-mm length scale. A UV curable dielectric is dispensed from an Aerosol Jet system at 10-100 µm length scale and instantaneously cured to build complex 3D shapes at a length scale  <1 mm. A metal nanoparticle ink is then dispensed over the 3D dielectric using a combination of jetting action and tilted dispense head, also using the Aerosol Jet technique and at a length scale 10-100 µm, followed by the nanoparticle sintering. Simulation studies are carried out to demonstrate the feasibility of using such structures as mm-wave antennas. The manufacturing method described in this letter opens up the possibility of fabricating an entirely new class of custom-shaped 3D structures at a sub-mm length scale with potential applications in 3D antennas and passives.

  7. GLASS FORMATION AND PROPERTIES OF CORDIERITE COMPOSITIONS FROM TALC-BASED NATURAL RAW MATERIALS WITH BORON OXIDE ADDITION

    Directory of Open Access Journals (Sweden)

    Esin GÜNAY

    2010-12-01

    Full Text Available In this study, the glass forming behaviour of cordierite compositions in MAS (MgO-Al2O3-SiO2 system with added B2O3 content up to 3% were studied by melting the natural raw materials such as; talc, kaolin, alumina and boric acid as the source of MgO, SiO2, Al2O3 and B2O3 respectively. XRD analysis revealed the glass formation. Optical properties of the glasses were measured using UV-VIS spectrophotometer and structural changes were monitored by using FT-IR spectrometer. Physical properties such as density, colour, thermal expansion coefficients and hardness were measured according to the standard test methods. Glasses with a green colour were produced and this was attributed to the Fe content in the glass up to 0.5% coming from talc and kaolin. The addition of B2O3 to the glasses increased the glass transition temperatures (Tg values and reduced the thermal expansion coefficient values of the glasses from 5.2226 to 5.0072ºCx10-6, for MAS-T-0 and MAS-T-3, respectively.

  8. Aerosol based direct-write micro-additive fabrication method for sub-mm 3D metal-dielectric structures

    International Nuclear Information System (INIS)

    Rahman, Taibur; Panat, Rahul; Renaud, Luke; Heo, Deuk; Renn, Michael

    2015-01-01

    The fabrication of 3D metal-dielectric structures at sub-mm length scale is highly important in order to realize low-loss passives and GHz wavelength antennas with applications in wearable and Internet-of-Things (IoT) devices. The inherent 2D nature of lithographic processes severely limits the available manufacturing routes to fabricate 3D structures. Further, the lithographic processes are subtractive and require the use of environmentally harmful chemicals. In this letter, we demonstrate an additive manufacturing method to fabricate 3D metal-dielectric structures at sub-mm length scale. A UV curable dielectric is dispensed from an Aerosol Jet system at 10–100 µm length scale and instantaneously cured to build complex 3D shapes at a length scale  <1 mm. A metal nanoparticle ink is then dispensed over the 3D dielectric using a combination of jetting action and tilted dispense head, also using the Aerosol Jet technique and at a length scale 10–100 µm, followed by the nanoparticle sintering. Simulation studies are carried out to demonstrate the feasibility of using such structures as mm-wave antennas. The manufacturing method described in this letter opens up the possibility of fabricating an entirely new class of custom-shaped 3D structures at a sub-mm length scale with potential applications in 3D antennas and passives. (technical note)

  9. Analysis of habitat characteristics of small pelagic fish based on generalized additive models in Kepulauan Seribu Waters

    Science.gov (United States)

    Rivai, A. A.; Siregar, V. P.; Agus, S. B.; Yasuma, H.

    2018-03-01

    One of the required information for sustainable fisheries management is about the habitat characteristics of a fish species. This information can be used to map the distribution of fish and map the potential fishing ground. This study aimed to analyze the habitat characteristics of small pelagic fishes (anchovy, squid, sardine and scads) which were mainly caught by lift net in Kepulauan Seribu waters. Research on habitat characteristics had been widely done, but the use of total suspended solid (TSS) parameters in this analysis is still lacking. TSS parameter which was extracted from Landsat 8 along with five other oceanographic parameters, CPUE data and location of fishing ground data from lift net fisheries in Kepulauan Seribu were included in this analysis. This analysis used Generalized Additive Models (GAMs) to evaluate the relationship between CPUE and oceanographic parameters. The results of the analysis showed that each fish species had different habitat characteristics. TSS and sea surface height had a great influence on the value of CPUE from each species. All the oceanographic parameters affected the CPUE of each species. This study demonstrated the effective use of GAMs to identify the essential habitat of a fish species.

  10. Improvement of Dimensional Accuracy of 3-D Printed Parts using an Additive/Subtractive Based Hybrid Prototyping Approach

    Science.gov (United States)

    Amanullah Tomal, A. N. M.; Saleh, Tanveer; Raisuddin Khan, Md.

    2017-11-01

    At present, two important processes, namely CNC machining and rapid prototyping (RP) are being used to create prototypes and functional products. Combining both additive and subtractive processes into a single platform would be advantageous. However, there are two important aspects need to be taken into consideration for this process hybridization. First is the integration of two different control systems for two processes and secondly maximizing workpiece alignment accuracy during the changeover step. Recently we have developed a new hybrid system which incorporates Fused Deposition Modelling (FDM) as RP Process and CNC grinding operation as subtractive manufacturing process into a single setup. Several objects were produced with different layer thickness for example 0.1 mm, 0.15 mm and 0.2 mm. It was observed that pure FDM method is unable to attain desired dimensional accuracy and can be improved by a considerable margin about 66% to 80%, if finishing operation by grinding is carried out. It was also observed layer thickness plays a role on the dimensional accuracy and best accuracy is achieved with the minimum layer thickness (0.1 mm).

  11. Physics-Based Preconditioning of a Compressible Flow Solver for Large-Scale Simulations of Additive Manufacturing Processes

    Science.gov (United States)

    Weston, Brian; Nourgaliev, Robert; Delplanque, Jean-Pierre

    2017-11-01

    We present a new block-based Schur complement preconditioner for simulating all-speed compressible flow with phase change. The conservation equations are discretized with a reconstructed Discontinuous Galerkin method and integrated in time with fully implicit time discretization schemes. The resulting set of non-linear equations is converged using a robust Newton-Krylov framework. Due to the stiffness of the underlying physics associated with stiff acoustic waves and viscous material strength effects, we solve for the primitive-variables (pressure, velocity, and temperature). To enable convergence of the highly ill-conditioned linearized systems, we develop a physics-based preconditioner, utilizing approximate block factorization techniques to reduce the fully-coupled 3×3 system to a pair of reduced 2×2 systems. We demonstrate that our preconditioned Newton-Krylov framework converges on very stiff multi-physics problems, corresponding to large CFL and Fourier numbers, with excellent algorithmic and parallel scalability. Results are shown for the classic lid-driven cavity flow problem as well as for 3D laser-induced phase change. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  12. Effect of Bauxite addition on Adhesion Strength and Surface Roughness of Fly ash based Plasma Sprayed Coatings

    Science.gov (United States)

    Bhuyan, S. K.; Samal, S.; Pattnaik, D.; Sahu, A.; Swain, B.; Thiyagarajan, T. K.; Mishra, S. C.

    2018-03-01

    The environment is being contaminated with advancement of new technology, day by day. One of the primary sources for this contamination is the industrial waste. Industrialization is the prime reason behind the prosperity of any country to meet the materialistic demand. To run the industries, a huge amount of (electric) power is needed and hence need for thermal power plants to serve the purpose. In present scenario, coal fired thermal power plants are set up which generates a huge quantity of Fly ash. Consumption of industrial waste (Fly ash), continually a major concern for human race. In recent years, fly ash is being utilized for various purposes i.e. making bricks, mine reclamation, production of cements etc. The presence of Silica and Alumina in fly ash makes it useful for thermal barrier applications also. The plasma spray technology has the advantage of being able to process any types of metal/ceramic mineral, low-grade-ore minerals etc. to make value-added products and also to deposit ceramics, metals and a combination of these to deposit composite coatings with desired microstructure and required properties on a range of substrate materials. The present work focuses on utilization of fly ash mixing with bauxite (ore mineral) for a high valued application. Fly ash with 10 and 20% bauxite addition is used to deposit plasma spray overlay coatings at different power levels (10-20kW) on aluminum and mild steel substrates. Adhesion strength and surface roughness of the coatings are evaluated. Phase composition analysis of the coatings were done using X-ray diffraction analysis. Surface morphology of the coatings was studied using a scanning electron microscope (SEM). Maximum adhesion strength of 4.924 MPa is obtained for the composition fly ash and bauxite (10%), coated on mild steel at 16kW torch power level. The surface roughness (Ra) of the coatings is found to vary between 10.0102 to 17.2341 micron.

  13. THE INFLUENCE OF PHOSPHORUS SLAG ADDITION ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF METAKAOLIN-BASED GEOPOLYMER PASTES

    Directory of Open Access Journals (Sweden)

    M. A. SOLEIMANI

    2013-03-01

    Full Text Available In this study, metakaolin plus different weight percent of phosphorus slag (10-100 wt. % were used in preparation of geopolymer. The compressive strength, phase analysis and microstructure changes were compared with a metakaolin based geopolymer control sample. Results showed that the substitution of slag up to 40 wt. % instead of metakaolin increase the 28 days compressive strength (14.5 % compared with control sample. This enhancement of strength is related to coexistence of geopolymeric gel and C‒S‒H gel or C‒A‒S‒H phase by XRD and FTIR study. In slag containing geopolymer samples some microcracks were observed at microstructure that established by volume change during formation of new phase or mismatching of unreacted particle with geopolymeric gel. These microcrack can dominate at high content of slag (above 40 wt. % substitution and decrease the strength of samples. These results show that it is possible to produce geopolymer cement from waste phosphorus slages.

  14. The effect of addition of various elements on properties of NiTi-based shape memory alloys for biomedical application

    Science.gov (United States)

    Kök, Mediha; Ateş, Gonca

    2017-04-01

    In biomedical applications, NiTi and NiTi-based alloys that show their shape memory effects at body temperature are preferred. In this study, the purpose is to produce NiTi and NiTi-based alloys with various chemical rates and electron concentrations and to examine their various physical properties. N45Ti55, Ni45Ti50Cr2.5Cu2.5, Ni48Ti51X (X=Mn, Sn, Co) alloys were produced in an arc melter furnace in this study. After the homogenization of these alloys, the martensitic phase transformation temperatures were determined with differential-scanner calorimeter. The transformation temperature was found to be below the 37 ° C (body temperature) in Ni45Ti50Cr2.5Cu2.5, Ni48Ti51X (X=Mn, Co) alloys; and the transformation temperature of the N45Ti55, Ni48Ti51Sn alloys was found to be over 37 ° C . Then, the micro and crystal structure analyses of the alloys were made, and it was determined that Ni45Ti50Cr2.5Cu2.5, Ni48Ti51X (X=Mn, Co) alloys, which were in austenite phase at room temperature, included B2 (NiTi) phase and Ti2Ni precipitation phase, and the alloys that were in the martensite phase at room temperature included B19ı (NiTi) phase and Ti2Ni phase. The common phase in both alloy groups is the Ti2Ni phase, and this type of phase is generally seen in NiTi alloys that are rich in titanium (Ti-rich).

  15. Radiation Vulcanization of Polymeric Blends Based on Ethylene Propylene Diene Monomer Rubber/ Waste Materials in Presence of Different Additives

    International Nuclear Information System (INIS)

    MOHAMED, R.M.

    2015-01-01

    In this investigation, the mechanical blending technique was applied for preparation of elastomeric blend of ethylene propylene diene monomer rubber (EPDM)and nitrile butadiene rubber (NBR) having a fixed ratio of (50/50) by weight. The prepared blend of EPDM/NBR (50/50) was used as a rubber matrix to be loaded with waste materials, namely rice husk (RH) as a natural waste filler and then with ground tire rubber (GTR) as an artificial one. The degree of loading varied from 5 p hr to 20 p hr. Ionizing radiation, namely ,gamma rays were applied for inducing vulcanization of prepared and loaded rubber blends, in the range from 5 kGy to 250 kGy. Different properties of prepared composites were followed up as a function of degree of loading with the waste material and dose of irradiation. The mechanical properties, namely tensile strength and elongation at break percent of the composites slightly decreased as the filler loading increased over the whole range of irradiation .Tensile modulus and hardness, on the other hand, showed an opposite trend, i.e. the increased. Other properties, namely physical, thermal and morphological confirmed the mechanical ones. Obtained results were affiliated with lack of interface adhesion between the waste materials and the rubber matrix elastomers. The lack of interface adhesion was improved by filling the composite with a limited content, up to 7 p hr, of the compatibilizer, namely, maleic anhydride (MAH). Measurements of different properties was carried out for composite loaded with 10 p hr of waste material. It has been found that the tensile properties were significantly improved with addition of the compatibilizing agent Further and significant improvement was attained in properties of prepared later composite by its loading with 40 p hr of either HAF- carbon black or Hisil as reinforcing fillers that participates in chemical as well as physical bonding. Similarly and lastly 8 p hr of N, N- methylene di acrylamide (MDA) were loaded

  16. The influence of nitrogen and oxygen additions on the thermal characteristics of aluminium-based thin films

    Energy Technology Data Exchange (ETDEWEB)

    Borges, J., E-mail: joelborges@fisica.uminho.pt [Centro de Física, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Department of Control Engineering, Faculty of Electrical Engineering, Czech Technical University in Prague, Technická 2, Prague 6 (Czech Republic); Macedo, F. [Centro de Física, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Couto, F.M. [Physics Sciences Laboratory, Norte Fluminense State University, 28013-602 Campos–RJ (Brazil); Rodrigues, M.S.; Lopes, C. [Centro de Física, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Instituto Pedro Nunes, Laboratório de Ensaios, Desgaste e Materiais, Rua Pedro Nunes, 3030-199 Coimbra (Portugal); Pedrosa, P. [Centro de Física, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, 3030-788 Coimbra (Portugal); Universidade do Porto, Faculdade de Engenharia, Departamento de Engenharia Metalúrgica e de Materiais, Rua Dr. Roberto Frias, s/n, 4200-465 Porto (Portugal); Polcar, T. [Department of Control Engineering, Faculty of Electrical Engineering, Czech Technical University in Prague, Technická 2, Prague 6 (Czech Republic); Engineering Materials & nCATS, FEE, University of Southampton, Highfield Campus, SO17 1BJ, Southampton (United Kingdom); Marques, L.; Vaz, F. [Centro de Física, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal)

    2015-08-01

    The ternary aluminium oxynitride (AlN{sub x}O{sub y}) system offers the possibility to obtain a wide range of properties by tailoring the ratio between pure Al, AlN{sub x} and AlO{sub y} and therefore opening a significant number of possible applications. In this work the thermal behaviour of AlN{sub x}O{sub y} thin films was analysed by modulated infrared radiometry (MIRR), taking as reference the binary AlO{sub y} and AlN{sub x} systems. MIRR is a non-contact and non-destructive thermal wave measurement technique based on the excitation, propagation and detection of temperature oscillations of very small amplitudes. The intended change of the partial pressure of the reactive gas (N{sub 2} and/or O{sub 2}) influenced the target condition and hence the deposition characteristics which, altogether, affected the composition and microstructure of the films. Based on the MIRR measurements and their qualitative and quantitative interpretation, some correlations between the thermal transport properties of the films and their chemical/physical properties have been found. Furthermore, the potential of such technique applied in this oxynitride system, which present a wide range of different physical responses, is also discussed. The experimental results obtained are consistent with those reported in previous works and show a high potential to fulfil the demands needed for the possible applications of the systems studied. They are clearly indicative of an adequate thermal response if this particular thin film system is aimed to be applied in small sensor devices or in electrodes for biosignal acquisition, such as those for electroencephalography or electromyography as it is the case of the main research area that is being developed in the group. - Highlights: • AlN{sub x}, AlO{sub y} and AlN{sub x}O{sub y} films were deposited by magnetron sputtering. • Discharge characteristics were compared between systems. • Different x and y coefficients were obtained.

  17. Effect of COOH-functionalized SWCNT addition on the electrical and photovoltaic characteristics of Malachite Green dye based photovoltaic cells

    International Nuclear Information System (INIS)

    Chakraborty, S.; Manik, N. B.

    2014-01-01

    We report the effect of COOH-functionalized single walled carbon nanotubes (COOH-SWCNT) on the electrical and photovoltaic characteristics of Malachite Green (MG) dye based photovoltaic cells. Two different types of photovoltaic cells were prepared, one with MG dye and another by incorporating COOH-SWCNT with this dye. Cells were characterized through different electrical and photovoltaic measurements including photocurrent measurements with pulsed radiation. From the dark current—voltage (I–V) characteristic results, we observed a certain transition voltage (V th ) for both the cells beyond which the conduction mechanism of the cells change sharply. For the MG dye, V th is 3.9 V whereas for COOH-SWCNT mixed with this dye, V th drops to 2.7 V. The device performance improves due to the incorporation of COOH-SWCNT. The open circuit voltage and short circuit current density change from 4.2 to 97 mV and from 108 to 965 μA/cm 2 respectively. Observations from photocurrent measurements show that the rate of growth and decay of the photocurrent are quite faster in the presence of COOH-SWCNT. This observation indicates a faster charge separation processes due to the incorporation of COOH-SWCNT in the MG dye cells. The high aspect ratio of COOH-SWCNT allows efficient conduction pathways for the generated charge carriers. (semiconductor devices)

  18. Dry sliding wear behaviour of heat treated iron based powder metallurgy steels with 0.3% Graphite + 2% Ni additions

    International Nuclear Information System (INIS)

    Tekeli, S.; Gueral, A.

    2007-01-01

    To determine the effect of various heat treatments on the microstructure and dry sliding wear behaviour of iron based powder metallurgy (PM) steels, atomized iron powder was mixed with 0.3% graphite + 2% Ni. The mixed powders were cold pressed at 700 MPa and sintered at 1200 deg. C for 30 min under pure Ar gas atmosphere. One of the sintered specimens was quenched from 890 deg. C and then tempered at 200 deg. C for 1 h. The other sintered specimens were annealed at different intercritical heat treatment temperatures of 728 and 790 deg. C and water quenched. Through this intercritical annealing heat treatment, the specimens with various ferrite + martensite volume fractions were produced. Wear tests were carried out on the quenched + tempered and intercritically annealed specimens under dry sliding conditions using a pin-on-disk type machine at constant load and speed and the results were compared in terms of microstructure, hardness and wear strength. It was seen that hardness and wear strength in intercritically annealed specimens were higher than that of quenched + tempered specimen

  19. Processing of recognition information and additional cues: A model-based analysis of choice, confidence, and response time

    Directory of Open Access Journals (Sweden)

    Andreas Glockner

    2011-02-01

    Full Text Available Research on the processing of recognition information has focused on testing the recognition heuristic (RH. On the aggregate, the noncompensatory use of recognition information postulated by the RH was rejected in several studies, while RH could still account for a considerable proportion of choices. These results can be explained if either a a part of the subjects used RH or b nobody used it but its choice predictions were accidentally in line with predictions of the strategy used. In the current study, which exemplifies a new approach to model testing, we determined individuals' decision strategies based on a maximum-likelihood classification method, taking into account choices, response times and confidence ratings simultaneously. Unlike most previous studies of the RH, our study tested the RH under conditions in which we provided information about cue values of unrecognized objects (which we argue is fairly common and thus of some interest. For 77.5% of the subjects, overall behavior was best explained by a compensatory parallel constraint satisfaction (PCS strategy. The proportion of subjects using an enhanced RH heuristic (RHe was negligible (up to 7.5%; 15% of the subjects seemed to use a take the best strategy (TTB. A more-fine grained analysis of the supplemental behavioral parameters conditional on strategy use supports PCS but calls into question process assumptions for apparent users of RH, RHe, and TTB within our experimental context. Our results are consistent with previous literature highlighting the importance of individual strategy classification as compared to aggregated analyses.

  20. Evaluation of some natural water-insoluble cellulosic material as lost circulation control additives in water-based drilling fluid

    Directory of Open Access Journals (Sweden)

    Ahmed Mohamed Alsabagh

    2015-12-01

    In this work, three natural water-insoluble cellulosic materials; peanut hulls, bagasse and sawdust were investigated as lost circulation control materials. One hundred and eight different LCM samples made of various materials were tested with mud. The experiments were conducted in a permeability plugging apparatus (PPA at a differential pressure of 100 psi and 300 psi, using 10, 60 and 90 ceramic discs. The performance of each LCM sample was determined based on the amount of spurt loss and total fluid loss of the mud according to the American Petroleum Institute (API standard. The obtained results showed that, the amount of the fluid loss depends on the LCM material, concentration and size distribution, testing results show that, the peanut gives the best results among the bagasse and sawdust, especially fine size which exhibited better results in the filtration characteristics due to the better filling properties of this size. Peanut hulls, bagasse and sawdust show a slight effect on the rheological properties of the mud. The results were discussed on light of particle size distribution.

  1. Group additivity calculations of the thermodynamic properties of unfolded proteins in aqueous solution: a critical comparison of peptide-based and HKF models.

    Science.gov (United States)

    Hakin, A W; Hedwig, G R

    2001-02-15

    A recent paper in this journal [Amend and Helgeson, Biophys. Chem. 84 (2000) 105] presented a new group additivity model to calculate various thermodynamic properties of unfolded proteins in aqueous solution. The parameters given for the revised Helgeson-Kirkham-Flowers (HKF) equations of state for all the constituent groups of unfolded proteins can be used, in principle, to calculate the partial molar heat capacity, C(o)p.2, and volume, V2(0), at infinite dilution of any polypeptide. Calculations of the values of C(o)p.2 and V2(0) for several polypeptides have been carried out to test the predictive utility of the HKF group additivity model. The results obtained are in very poor agreement with experimental data, and also with results calculated using a peptide-based group additivity model. A critical assessment of these two additivity models is presented.

  2. Effects of stocking density of freshwater prawn Macrobrachium rosenbergii and addition of different levels of tilapia Oreochromis niloticus on production in C/N controlled periphyton based system

    NARCIS (Netherlands)

    Asaduzzaman, M.; Wahab, M.A.; Verdegem, M.C.J.; Mondal, M.N.; Azim, M.E.

    2009-01-01

    An on-station trial was conducted to evaluate the effect of stocking density of freshwater prawn and addition of different levels of tilapia on production in carbon/nitrogen (C/N) controlled periphyton based system. The experiment had a 2 × 3 factorial design, in which two levels of prawn stocking

  3. Effect of SiC whisker addition on the microstructures and mechanical properties of Ti(C, N)-based cermets

    International Nuclear Information System (INIS)

    Wu, Peng; Zheng, Yong; Zhao, Yongle; Yu, Haizhou

    2011-01-01

    Ti(C, N)-based cermets with addition of SiC whisker (SiC w ) were prepared by vacuum sintering. The microstructures of the prepared cermets were investigated by using X-ray diffractometry (XRD) and scanning electron microscopy (SEM). Mechanical properties such as transverse rupture strength (TRS), fracture toughness (K IC ) and hardness (HRA) were also measured. It was found that the grain size of the cermets was affected by the SiC whisker addition. The cermets with 1.0 wt.% SiC whisker addition exhibited the smallest grain size. The porosities of the cermets increased with increasing SiC whisker additions. The addition of the SiC whisker had no influence on the phase constituents of the cermets. Compared with the cermets with no whisker addition, the highest TRS and fracture toughness for cermets with 1.0 wt.% SiC whisker addition increased by about 24% and 29%, respectively. The strengthening mechanisms were attributed to finer grain size, homogeneous microstructure and moderate thickness of rim phase. The toughening mechanisms were characterized by crack deflection, whisker bridging and whisker pulling-out.

  4. Pedigree-based estimation of covariance between dominance deviations and additive genetic effects in closed rabbit lines considering inbreeding and using a computationally simpler equivalent model.

    Science.gov (United States)

    Fernández, E N; Legarra, A; Martínez, R; Sánchez, J P; Baselga, M

    2017-06-01

    Inbreeding generates covariances between additive and dominance effects (breeding values and dominance deviations). In this work, we developed and applied models for estimation of dominance and additive genetic variances and their covariance, a model that we call "full dominance," from pedigree and phenotypic data. Estimates with this model such as presented here are very scarce both in livestock and in wild genetics. First, we estimated pedigree-based condensed probabilities of identity using recursion. Second, we developed an equivalent linear model in which variance components can be estimated using closed-form algorithms such as REML or Gibbs sampling and existing software. Third, we present a new method to refer the estimated variance components to meaningful parameters in a particular population, i.e., final partially inbred generations as opposed to outbred base populations. We applied these developments to three closed rabbit lines (A, V and H) selected for number of weaned at the Polytechnic University of Valencia. Pedigree and phenotypes are complete and span 43, 39 and 14 generations, respectively. Estimates of broad-sense heritability are 0.07, 0.07 and 0.05 at the base versus 0.07, 0.07 and 0.09 in the final generations. Narrow-sense heritability estimates are 0.06, 0.06 and 0.02 at the base versus 0.04, 0.04 and 0.01 at the final generations. There is also a reduction in the genotypic variance due to the negative additive-dominance correlation. Thus, the contribution of dominance variation is fairly large and increases with inbreeding and (over)compensates for the loss in additive variation. In addition, estimates of the additive-dominance correlation are -0.37, -0.31 and 0.00, in agreement with the few published estimates and theoretical considerations. © 2017 Blackwell Verlag GmbH.

  5. TRX-LOGOS - a graphical tool to demonstrate DNA information content dependent upon backbone dynamics in addition to base sequence.

    Science.gov (United States)

    Fortin, Connor H; Schulze, Katharina V; Babbitt, Gregory A

    2015-01-01

    It is now widely-accepted that DNA sequences defining DNA-protein interactions functionally depend upon local biophysical features of DNA backbone that are important in defining sites of binding interaction in the genome (e.g. DNA shape, charge and intrinsic dynamics). However, these physical features of DNA polymer are not directly apparent when analyzing and viewing Shannon information content calculated at single nucleobases in a traditional sequence logo plot. Thus, sequence logos plots are severely limited in that they convey no explicit information regarding the structural dynamics of DNA backbone, a feature often critical to binding specificity. We present TRX-LOGOS, an R software package and Perl wrapper code that interfaces the JASPAR database for computational regulatory genomics. TRX-LOGOS extends the traditional sequence logo plot to include Shannon information content calculated with regard to the dinucleotide-based BI-BII conformation shifts in phosphate linkages on the DNA backbone, thereby adding a visual measure of intrinsic DNA flexibility that can be critical for many DNA-protein interactions. TRX-LOGOS is available as an R graphics module offered at both SourceForge and as a download supplement at this journal. To demonstrate the general utility of TRX logo plots, we first calculated the information content for 416 Saccharomyces cerevisiae transcription factor binding sites functionally confirmed in the Yeastract database and matched to previously published yeast genomic alignments. We discovered that flanking regions contain significantly elevated information content at phosphate linkages than can be observed at nucleobases. We also examined broader transcription factor classifications defined by the JASPAR database, and discovered that many general signatures of transcription factor binding are locally more information rich at the level of DNA backbone dynamics than nucleobase sequence. We used TRX-logos in combination with MEGA 6.0 software

  6. The influence of kind of coating additive on the compressive strength of RCA-based concrete prepared by triple-mixing method

    Science.gov (United States)

    Urban, K.; Sicakova, A.

    2017-10-01

    The paper deals with the use of alternative powder additives (fly ash and fine fraction of recycled concrete) to improve the recycled concrete aggregate and this occurs directly in the concrete mixing process. Specific mixing process (triple mixing method) is applied as it is favourable for this goal. Results of compressive strength after 2 and 28 days of hardening are given. Generally, using powder additives for coating the coarse recycled concrete aggregate in the first stage of triple mixing resulted in decrease of compressive strength, comparing the cement. There is no very important difference between samples based on recycled concrete aggregate and those based on natural aggregate as far as the cement is used for coating. When using both the fly ash and recycled concrete powder, the kind of aggregate causes more significant differences in compressive strength, with the values of those based on the recycled concrete aggregate being worse.

  7. Synthesis of polymeric additives based on itaconic acid and their evaluation as pour point depressants for lube oil in relation to rheological flow properties

    Directory of Open Access Journals (Sweden)

    A.M. Al-Sabagh

    2012-06-01

    Full Text Available Modification of the wax crystal habit practical interest during transportation processing of lube oil at low temperature. Various pour point depressant (PPD additives can facilitate this modification by different mechanisms. Comb shaped polymer additives are known to depress the pour point of lube oil by providing different nucleation sites for the precipitation of wax. This paper describes performance based design, synthesis, characterization and evaluation of comb shaped polymeric additives. Alkyl itaconates were prepared by the esterification of itaconic acid with different saturated alcohols C16/C18/NAFOL 20+A (Cav = 20/NAFOL 1822 B (Cav = 22. The four synthesized monomers were characterized and copolymerized with styrene in different molar ratios. All the products were characterized by infra-red (FTIR, Nuclear Magnetic Resonance (NMR Spectroscopy and Gel permeation chromatography (GPC. Rheological properties of lube oil (with and without additives were studied by Brookfield viscometer. In this study the additives based on itaconic acid were evaluated as good PPD and rheology modifiers.

  8. Freeze-Thaw Performance and Moisture-Induced Damage Resistance of Base Course Stabilized with Slow Setting Bitumen Emulsion-Portland Cement Additives

    Directory of Open Access Journals (Sweden)

    Mojtaba Shojaei Baghini

    2015-01-01

    Full Text Available Freeze-thaw (FT cycles and moisture susceptibility are important factors influencing the geotechnical characteristics of soil-aggregates. Given the lack of published information on the behavior of cement-bitumen emulsion-treated base (CBETB under environmental conditions, especially freezing and thawing, this study investigated the effects of these additives on the CBETB performance. The primary goal was to evaluate the resistance of CBETB to moisture damage by performing FT, Marshall conditioning, and AASHTO T-283 tests and to evaluate the long-term stripping susceptibility of CBETB while also predicting the liquid antistripping additives to assess the mixture’s durability and workability. Specimens were stabilized with Portland cement (0%–6%, bitumen emulsion (0%–5%, and Portland cement-bitumen emulsion mixtures and cured for 7 days, and their short- and long-term performances were studied. Evaluation results of both the Marshall stability ratio and the tensile strength ratio show that the additions of additives increase the resistance of the mixtures to moisture damage. Results of durability tests performed for determining the resistance of compacted specimens to repeated FT cycles indicate that the specimen with the 4% cement-3% bitumen emulsion mixture significantly improves water absorption, volume changes, and weight losses. This indicates the effectiveness of this additive as a road base stabilizer with excellent engineering properties for cold regions.

  9. Effects of nano TiN addition on the microstructure and mechanical properties of TiC based steel bonded carbides

    Institute of Scientific and Technical Information of China (English)

    WANG Zhi'an; DAI Haiyang; ZOU Yu

    2008-01-01

    TiC based steel bonded carbides with the addition of nano TiN were prepared by vicuum sintering techniques.The microstructure was investigated using scanning electron microscopy(SEM)and transmission electron microscopy (TEM),and the mechanical properties,such as bending strength,impact toughness,hardness,and density,were measured.The results indicate that the grain size becomes small and there is uniformity in the steel bonded carbide with nano addition;several smaller carbide particles are also found to be inlaid in the rim of the larger carbide grains and prevent the coalescence of TiC grains.The smaller and larger carbide grains joint firmly,and then the reduction of the average size of the grains leads to the increase in the mechanical properties of the steel bonded carbides with nano addition.But the mechanical properties do not increase monotonously with an increase in nano addition.When the nano TiN addition accounts for 6-8 wt.% of the amount of steel bonded carbides.the mechanical properties reach the maximum values and then decrease with further increase in nano TiN addition.

  10. Characterization on the coatings of Ni-base alloy with nano- and micron-size Sm2O3 addition prepared by laser deposition

    International Nuclear Information System (INIS)

    Zhang Shihong; Li Mingxi; Yoon, Jae Hong; Cho, Tong Yul

    2008-01-01

    The coating materials are the powder mixture of micron-size Ni-base alloy powders with both 1.5 wt.% micron-size and nano-size Sm 2 O 3 powders, which are prepared on Q235 steel plate by 2.0 kW CO 2 laser deposition. The results indicate that with rare earth oxide Sm 2 O 3 addition, the width of planar crystallization is smaller than that of the Ni-base alloy coatings. Micron- and nano-Sm 2 O 3 /Ni-base alloy coatings have similar microstructure showing the primary phase of γ-Ni dendrite and eutectic containing γ-Ni and Cr 23 C 6 phases. However, compared to micron-Sm 2 O 3 /Ni-base alloy, preferred orientation of γ-Ni dendrite of nano-Sm 2 O 3 /Ni-base alloy is weakened. Planar crystal of several-μm thickness is first grown and then dendrite growth is observed at 1.5% micron-Sm 2 O 3 /Ni-base alloy coating whereas equiaxed dendrite is grown at 1.5% nano-Sm 2 O 3 /Ni-base alloy coating. Hardness and wear resistance of the coating improves with decreasing Sm 2 O 3 size from micron to nano. The improvement on tribological property of nano-Sm 2 O 3 /Ni-base alloy over micron-Sm 2 O 3 /Ni-base alloy coatings can be attributed to the better resistance of equiaxed dendrite to adhesion interactions during the wear process. In 6 M HNO 3 solution, the corrosion resistance is greatly improved with nano-Sm 2 O 3 addition since the decrease of corrosion ratio along grain-boundary in nano-Sm 2 O 3 /Ni-base alloy coating contributes to harmonization of corrosion potential

  11. The virucidal effects against murine norovirus and feline calicivirus F4 as surrogates for human norovirus by the different additive concentrations of ethanol-based sanitizers.

    Science.gov (United States)

    Akasaka, Tempei; Shimizu-Onda, Yuko; Hayakawa, Satoshi; Ushijima, Hiroshi

    2016-03-01

    Since human norovirus is non-cultivable, murine norovirus and feline calicivirus have been used as surrogates. In this study, the virucidal effects of ethanol-based sanitizers with different concentrations of additives (malic acid/sodium malate, glycerin-fatty acid ester) against murine norovirus and feline calicivirus F4 were examined. The ethanol-based sanitizers at pH 7 showed sufficient virucidal effects, but glycerin-fatty acid ester included in ethanol-based sanitizers at pH 4 or 6 reduced the virucidal effects against murine norovirus. The ethanol-based sanitizers containing malic acid/sodium malate inactivated feline calicivirus F4 in shorter time, but there is no difference between ethanol-based sanitizers with and without glycerin-fatty acid ester. Traditionally, feline calicivirus has been used for long time as a surrogate virus for human norovirus. However, this study suggested that murine norovirus and feline calicivirus F4 had different sensitivity with the additive components of ethanol-based sanitizers. Therefore, using feline calicivirus alone as a surrogate for human norovirus may not be sufficient to evaluate the virucidal effect of sanitizers on food-borne infections caused by human norovirus. Sanitizers having virucidal effects against at least both murine norovirus and feline calicivirus may be more suitable to inactivate human norovirus. Copyright © 2015. Published by Elsevier Ltd.

  12. Comparison of additional boundary conditions based on thermoreflectance spectra of the Asub(n=1)-exciton in CdS crystals at oblique incidence

    International Nuclear Information System (INIS)

    Stoessel, W.; Wagner, H.J.

    1978-01-01

    Thermoreflectance spectra of the Asub(n=1)-exciton in CdS are measured at 8 K for angles of incidence of the light ranging from 5 0 to 85 0 , using three different spatial arrangements between the c-axis, the E- and k-vector of light. Additional boundary conditions of Pekar, Ting et al. Agarwal et al. are discussed for the first time in terms of optical constants. The refractive indices for these additional boundary conditions are derived, considering special features of CdS, such as optical anisotropy, exciton symmetry, and effective exciton mass anisotropy. Fitting calculations based on the experimental data show that Pekar's additional boundary condition gives the best agreement between theory and experiment. (author)

  13. Estimate of the benefits of a population-based reduction in dietary sodium additives on hypertension and its related health care costs in Canada.

    Science.gov (United States)

    Joffres, Michel R; Campbell, Norm R C; Manns, Braden; Tu, Karen

    2007-05-01

    Hypertension is the leading risk factor for mortality worldwide. One-quarter of the adult Canadian population has hypertension, and more than 90% of the population is estimated to develop hypertension if they live an average lifespan. Reductions in dietary sodium additives significantly lower systolic and diastolic blood pressure, and population reductions in dietary sodium are recommended by major scientific and public health organizations. To estimate the reduction in hypertension prevalence and specific hypertension management cost savings associated with a population-wide reduction in dietary sodium additives. Based on data from clinical trials, reducing dietary sodium additives by 1840 mg/day would result in a decrease of 5.06 mmHg (systolic) and 2.7 mmHg (diastolic) blood pressures. Using Canadian Heart Health Survey data, the resulting reduction in hypertension was estimated. Costs of laboratory testing and physician visits were based on 2001 to 2003 Ontario Health Insurance Plan data, and the number of physician visits and costs of medications for patients with hypertension were taken from 2003 IMS Canada. To estimate the reduction in total physician visits and laboratory costs, current estimates of aware hypertensive patients in Canada were used from the Canadian Community Health Survey. Reducing dietary sodium additives may decrease hypertension prevalence by 30%, resulting in one million fewer hypertensive patients in Canada, and almost double the treatment and control rate. Direct cost savings related to fewer physician visits, laboratory tests and lower medication use are estimated to be approximately $430 million per year. Physician visits and laboratory costs would decrease by 6.5%, and 23% fewer treated hypertensive patients would require medications for control of blood pressure. Based on these estimates, lowering dietary sodium additives would lead to a large reduction in hypertension prevalence and result in health care cost savings in Canada.

  14. Soil solution and sugar maple response to NH(4)NO (3) additions in a base-poor northern hardwood forest of Québec, Canada.

    Science.gov (United States)

    Moore, Jean-David; Houle, Daniel

    2009-08-01

    Nitrogen additions (NH4NO3) at rates of three- and ten-fold ambient atmospheric deposition (8.5 kg ha(-1) year(-1)) were realised in an acid- and base-poor northern hardwood forest of Québec, Canada. Soil solution chemistry, foliar chemistry, crown dieback and basal area growth of sugar maple (Acer saccharum Marsh.) were measured. Except for a transitory increase of NO3 and NH4 concentrations, there was no persistent increase in their level in soil solution 3 years after N treatments, with the exception of one plot out of three, that received the highest N addition, beginning to show persistent and high NO3 concentrations after 2 years of N additions. Three years of N additions have significantly increased the N DRIS index of sugar maple but not N foliar concentration. Potassium, Ca and Mn foliar concentrations, as well as P and Ca DRIS indices, decreased in treated plots after 3 years. No treatment effect was observed for basal area growth and dieback rate. One unexpected result was the significant decrease in foliar Ca even in the treated plots that received low N rates, despite the absence of significant NO3-induced leaching of Ca. The mechanism responsible for the decrease in foliar Ca is not known. Our results, however, clearly demonstrate that increased N deposition at sites with low base saturation may affect Ca nutrition even when clear signs of N saturation are not observed.

  15. Predicting acute and chronic effects of wood preservative products in Daphnia magna and Pseudokirchneriella subcapitata based on the concept of concentration addition.

    Science.gov (United States)

    Coors, Anja; Weisbrod, Barbara; Schoknecht, Ute; Sacher, Frank; Kehrer, Anja

    2014-02-01

    The current European legislation requires that combined effects of the active substances and any substance of concern contained in biocidal products are taken into account in environmental risk assessment. The hypothesis whether the consideration of active substances together with all formulation additives that are labeled as presenting an environmental hazard is sufficient for a reliable environmental risk assessment was tested in the present study by investigating 3 wood preservative products. Relevant single substances in the products, some of their generic mixtures, the biocidal products themselves, and aqueous eluates prepared from the products (representing potential environmental mixtures) were tested for effects on algal growth and Daphnia acute immobilization as well as reproduction. Predictions for the products and the eluates were based on the concept of concentration addition and were mostly found to provide reliable or at least protective estimates for the observed acute and chronic toxicity of the mixtures. The mixture toxicity considerations also indicated that the toxicity of each product was dominated by just 1 of the components, and that assessments based only on the dominating substance would be similarly protective as a full-mixture risk assessment. Yet, there remained uncertainty in some cases that could be related to the toxicity of transformation products, the impact of unidentified formulation additives, or synergistic interaction between active substances and formulation additives. © 2013 SETAC.

  16. Temporal Drivers of Liking Based on Functional Data Analysis and Non-Additive Models for Multi-Attribute Time-Intensity Data of Fruit Chews.

    Science.gov (United States)

    Kuesten, Carla; Bi, Jian

    2018-06-03

    Conventional drivers of liking analysis was extended with a time dimension into temporal drivers of liking (TDOL) based on functional data analysis methodology and non-additive models for multiple-attribute time-intensity (MATI) data. The non-additive models, which consider both direct effects and interaction effects of attributes to consumer overall liking, include Choquet integral and fuzzy measure in the multi-criteria decision-making, and linear regression based on variance decomposition. Dynamics of TDOL, i.e., the derivatives of the relative importance functional curves were also explored. Well-established R packages 'fda', 'kappalab' and 'relaimpo' were used in the paper for developing TDOL. Applied use of these methods shows that the relative importance of MATI curves offers insights for understanding the temporal aspects of consumer liking for fruit chews.

  17. Effect of tartarate and citrate based food additives on the micellar properties of sodium dodecylsulfate for prospective use as food emulsifier.

    Science.gov (United States)

    Banipal, Tarlok S; Kaur, Harjinder; Kaur, Amanpreet; Banipal, Parampaul K

    2016-01-01

    Citrate and tartarate based food preservatives can be used to enhance the emulsifying properties of sodium dodecylsulfate (SDS) based micellar system and thus making it appropriate for food applications. Exploration of interactions between the two species is the key constraint for execution of such ideas. In this work various micellar and thermodynamic parameters of SDS like critical micellar concentration (CMC), standard Gibbs free energy of micellization (ΔG(0)mic.) etc. have been calculated in different concentrations of disodium tartarate (DST) and trisodium citrate (TSC) in the temperature range (288.15-318.15)K from the conductivity and surface tension measurements. The parameters obtained from these studies reveal the competitive nature of both the additives with SDS for available positions at the air/water interface. TSC is found to be more effective additive in order to make SDS micellar system better for its potential applications as food emulsifier. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. [Determination of the Plant Origin of Licorice Oil Extract, a Natural Food Additive, by Principal Component Analysis Based on Chemical Components].

    Science.gov (United States)

    Tada, Atsuko; Ishizuki, Kyoko; Sugimoto, Naoki; Yoshimatsu, Kayo; Kawahara, Nobuo; Suematsu, Takako; Arifuku, Kazunori; Fukai, Toshio; Tamura, Yukiyoshi; Ohtsuki, Takashi; Tahara, Maiko; Yamazaki, Takeshi; Akiyama, Hiroshi

    2015-01-01

    "Licorice oil extract" (LOE) (antioxidant agent) is described in the notice of Japanese food additive regulations as a material obtained from the roots and/or rhizomes of Glycyrrhiza uralensis, G. inflata or G. glabra. In this study, we aimed to identify the original Glycyrrhiza species of eight food additive products using LC/MS. Glabridin, a characteristic compound in G. glabra, was specifically detected in seven products, and licochalcone A, a characteristic compound in G. inflata, was detected in one product. In addition, Principal Component Analysis (PCA) (a kind of multivariate analysis) using the data of LC/MS or (1)H-NMR analysis was performed. The data of thirty-one samples, including LOE products used as food additives, ethanol extracts of various Glycyrrhiza species and commercially available Glycyrrhiza species-derived products were assessed. Based on the PCA results, the majority of LOE products was confirmed to be derived from G. glabra. This study suggests that PCA using (1)H-NMR analysis data is a simple and useful method to identify the plant species of origin of natural food additive products.

  19. Lime-based restoration paints: characterization and evaluation of formulations using a native species from the Amazon flora and PVA-based glue as additives

    Directory of Open Access Journals (Sweden)

    Mayra Martins Silva

    Full Text Available Abstract Based on historic documents, two lime-based paint formulations were produced in laboratory in order to evaluate their basic characteristics as restoration materials for historic buildings with lime-based components. The paints were made basically with hydrated lime, clay, water and linseed (Linum usitatissimum L. oil, and one formulation had PVA (polyvinyl acetate-based glue as fixative, and the other one, Couma guianensis' latex. Each paint component was characterized by XRD and FTIR, and color and specular gloss measurements were performed on both paints. A preliminary assessment of the paints was conducted using the Pipe Method, the salt crystallization test, visual analysis for dustiness, and analysis of microbiological growth. The results showed that the laboratory-produced paints are theoretically and technologically compatible with lime-based coatings, however, their superficial performance can be improved to achieve greater durability. This study also brings to light local materials from the Amazon region that have great potential to be used and recognized as raw materials for paints and which could also be investigated for other uses.

  20. Influence of Zr and nano-Y{sub 2}O{sub 3} additions on thermal stability and improved hardness in mechanically alloyed Fe base ferritic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kotan, Hasan, E-mail: hkotan@konya.edu.tr [Department of Metallurgical Engineering and Materials Science, Necmettin Erbakan University, Dere Aşıklar Mah. Demet Sokak, Meram, Konya 42140 (Turkey); Darling, Kris A. [U.S. Army Research Laboratory, Weapons and Materials Research Directorate, RDRL-WMM-F, Aberdeen Proving Ground, MD 21005-5069 (United States); Scattergood, Ronald O.; Koch, Carl C. [Department of Materials Science and Engineering, NC State University, 911 Partners Way, Room 3078, Raleigh, NC 27695-7907 (United States)

    2014-12-05

    The motivation of this work was driven to improve the thermal stability in systems where polymorphic transformations can result in an additional driving force, upsetting the expected thermodynamic stability. In this study, Fe{sub 92}Ni{sub 8} alloys with Zr and nano-Y{sub 2}O{sub 3} additions were produced by ball milling and then annealed at high temperatures. Emphasis was placed on understanding the effects of dispersed nano-Y{sub 2}O{sub 3} particle additions and their effect on microstructural stability at and above the bcc-to-fcc transformation occurring at 700 °C in Fe–Ni systems. Results reveal that microstructural stability and hardness can be promoted by a combination of Zr and Y{sub 2}O{sub 3} additions, that being mostly effective for stability before and after phase transition, respectively. The mechanical strength of these alloys is achieved by a unique microstructure comprised a ultra-fine grain Fe base matrix, which contains dispersions of both nano-scale in-situ formed Zr base intermetallics and ex-situ added Y{sub 2}O{sub 3} secondary oxide phases. Both of these were found to be essential for a combination of high thermal stability and high mechanical strength properties. - Highlights: • Polymorphic transformations can limit the processing of nanostructured powders. • It causes a rapid grain growth and impairs the improved mechanical properties. • We aim to improve the hardness and thermal stability above the phase transformation. • Thermal stability is achieved by a combination of Zr and Y{sub 2}O{sub 3} additions. • Hardness is promoted by in-situ formed and ex-situ added secondary nano phases.

  1. Designed synergetic effect of electrolyte additives to improve interfacial chemistry of MCMB electrode in propylene carbonate-based electrolyte for enhanced low and room temperature performance.

    Science.gov (United States)

    Wotango, Aselefech Sorsa; Su, Wei-Nien; Haregewoin, Atetegeb Meazah; Chen, Hung-Ming; Cheng, Ju-Hsiang; Lin, Ming-Hsien; Wang, Chia-Hsin; Hwang, Bing-Joe

    2018-05-09

    The performance of lithium ion batteries rapidly falls at lower temperatures due to decreasing conductivity of electrolytes and Solid Electrolyte Interphase (SEI) on graphite anode. Hence, it limits the practical use of lithium ion batteries at sub-zero temperatures and also affects the development of lithium ion batteries for widespread applications. The SEI formed on the graphite surface is very influential in determining the performance of the battery. Herein, a new electrolyte additive, 4-Chloromethyl-1,3,2-dioxathiolane-2-oxide (CMDO), is prepared to improve the properties of commonly used electrolyte constituents - ethylene carbonate (EC), and fluoroethylene carbonate (FEC). The formation of an efficient passivation layer in propylene carbonate (PC) -based electrolyte for MCMB electrode was investigated. The addition of CMDO resulted in a much less irreversible capacity loss and induces thin SEI formation. However, the combination of the three additives played a key role to enhance reversible capacity of MCMB electrode at lower or ambient temperature. The electrochemical measurement analysis showed that the SEI formed from a mixture of the three additives gave better intercalation-deintercalation of lithium ions.

  2. Characterization on the coatings of Ni-base alloy with nano- and micron-size Sm{sub 2}O{sub 3} addition prepared by laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Shihong [School of Materials Science and Engineering, Anhui University of Technology, Maanshan City, Anhui Province 243002 (China); School of Nano and Advanced Materials Engineering, Changwon National University, 9, Sarim-Dong, Changwon, Gyeongnam 641-773 (Korea, Republic of)], E-mail: zsh10110903@hotmail.com; Li Mingxi [School of Materials Science and Engineering, Anhui University of Technology, Maanshan City, Anhui Province 243002 (China); Yoon, Jae Hong; Cho, Tong Yul [School of Nano and Advanced Materials Engineering, Changwon National University, 9, Sarim-Dong, Changwon, Gyeongnam 641-773 (Korea, Republic of)

    2008-12-01

    The coating materials are the powder mixture of micron-size Ni-base alloy powders with both 1.5 wt.% micron-size and nano-size Sm{sub 2}O{sub 3} powders, which are prepared on Q235 steel plate by 2.0 kW CO{sub 2} laser deposition. The results indicate that with rare earth oxide Sm{sub 2}O{sub 3} addition, the width of planar crystallization is smaller than that of the Ni-base alloy coatings. Micron- and nano-Sm{sub 2}O{sub 3}/Ni-base alloy coatings have similar microstructure showing the primary phase of {gamma}-Ni dendrite and eutectic containing {gamma}-Ni and Cr{sub 23}C{sub 6} phases. However, compared to micron-Sm{sub 2}O{sub 3}/Ni-base alloy, preferred orientation of {gamma}-Ni dendrite of nano-Sm{sub 2}O{sub 3}/Ni-base alloy is weakened. Planar crystal of several-{mu}m thickness is first grown and then dendrite growth is observed at 1.5% micron-Sm{sub 2}O{sub 3}/Ni-base alloy coating whereas equiaxed dendrite is grown at 1.5% nano-Sm{sub 2}O{sub 3}/Ni-base alloy coating. Hardness and wear resistance of the coating improves with decreasing Sm{sub 2}O{sub 3} size from micron to nano. The improvement on tribological property of nano-Sm{sub 2}O{sub 3}/Ni-base alloy over micron-Sm{sub 2}O{sub 3}/Ni-base alloy coatings can be attributed to the better resistance of equiaxed dendrite to adhesion interactions during the wear process. In 6 M HNO{sub 3} solution, the corrosion resistance is greatly improved with nano-Sm{sub 2}O{sub 3} addition since the decrease of corrosion ratio along grain-boundary in nano-Sm{sub 2}O{sub 3}/Ni-base alloy coating contributes to harmonization of corrosion potential.

  3. NASA/ORNL/AFRL Project Work on EBM LSHR: Additive Manufacturing of High-Temperature Gamma-Prime Strengthened Ni-Based Superalloys

    Science.gov (United States)

    Sudbrack, Chantal K.; Kirka, Michael M.; Dehoff, Ryan R.; Carter, Robert W.; Semiatin, Sheldon L.; Gabb, Timothy P.

    2016-01-01

    Powder-bed fabrication of aerospace alloys may revolutionize production by eliminating the need for extensive machining and expensive tooling. Heated-bed electron-beam melting (EBM) offers advantages over non-heated laser additive manufacturing (AM) methods, including lower residual stress, reduced risk of contamination, slower cooling rates, and faster build times. NASA Glenn Research Center has joint project work with Oak Ridge National Lab and the Air Force Research Laboratory to explore the feasibility of fabricating advanced Ni-based gamma-prime superalloys with EBM AM.

  4. Determination of migration of phosphorus-based additives from food packaging material into food-simulating solvents by neutron activation/Cerenkov counting

    International Nuclear Information System (INIS)

    Lickly, T.D.; Quinn, T.; Blanchard, F.A.; Murphy, P.G.

    1988-01-01

    Samples of food-simulating solvents exposed to food-packaging materials that contain phosphorus-based additives have been examined for migration of phosphorus-containing compounds from the packaging material, using neutron activation/Cerenkov counting. This method has the advantage that commercially produced packaging materials can be used (no elaborate sample preparation as with other radiotracer methods) and no elaborate sample processing techniques are needed to reach the desired levels (low ng/mL) as is usual with most chromatographic or spectroscopic techniques. (author)

  5. Effect of rare earth addition on ionic conductivity on ZrO2:3 mol % Y2O3 based ceramics

    International Nuclear Information System (INIS)

    Munoz, M.R.A.; Silva, C.R.M.; Narvaez, S.J.L.

    2010-01-01

    Zirconia based solid electrolytes were sintered with 5.39, 10.54, 15.45 wt % of REO as sintering aids. Characterization was made by X-Ray diffractometry, infrared spectroscopy, laser particle size and transmission electron microscopy. Samples were prepared by uniaxial cold press and sintered at 1400 deg C, followed by electric properties determination via impedance spectroscopy. Complimentary characterization was made by X-Ray diffractometry, density by the Archimedes method and scanning electron microscopy. The ionic conductivity is affected by the amount of REO additive and this effect is correlated to the existing tetragonal and cubic phases for each composition. (author)

  6. Spray-Dried Cellulose Nanofibril-Reinforced Polypropylene Composites for Extrusion-Based Additive Manufacturing: Nonisothermal Crystallization Kinetics and Thermal Expansion

    Directory of Open Access Journals (Sweden)

    Lu Wang

    2018-02-01

    Full Text Available Isotactic polypropylene (iPP is a versatile polymer. It accounts for the second-largest polymer consumption worldwide. However, iPP is difficult to 3D print via extrusion-based processing. This is attributable to its rapid crystallization rate. In this study, spray-dried cellulose nanofibrils (SDCNF and maleic anhydride polypropylene (MAPP were investigated to reveal their effects on the nonisothermal crystallization kinetics and thermal expansion of iPP. SDCNF at 3 wt % and 30 wt % accelerated the crystallization rate of iPP, while SDCNF at 10 wt % retarded the crystallization rate by restricting crystal growth and moderately increasing the nucleation density of iPP. Additionally, adding MAPP into iPP/SDCNF composites accelerated the crystallization rate of iPP. The effective activation energy of iPP increased when more than 10 wt % SDCNF was added. Scanning electron microscopy and polarized light microscopy results indicated that high SDCNF content led to a reduced gap size among SDCNF, which hindered the iPP crystal growth. The coefficient of thermal expansion of iPP/SDCNF10% was 11.7% lower than the neat iPP. In summary, SDCNF, at 10 wt %, can be used to reduce the warping of iPP during extrusion-based additive manufacturing.

  7. Effect of carbon additions on the as-cast microstructure and defect formation of a single crystal Ni-based superalloy

    International Nuclear Information System (INIS)

    Al-Jarba, K.A.; Fuchs, G.E.

    2004-01-01

    In an effort to reduce grain defects in large single crystal Ni-base superalloy components, carbon is intentionally added. In this study, the effect of carbon additions on the microstructure and solidification defect formation of a model Ni-based superalloy, LMSX-1, was examined. The results show that the tendency of the alloy to form all types of solidification defects decreased as the carbon content increased. The as-cast microstructures also exhibited a decrease in the amount of γ-γ' eutectic structure and an increase in the volume fraction of carbides and porosity, as the carbon content was increased. The carbides formed in these alloys were mostly of script-type MC carbides which formed continuous, dendritic networks in the interdendritic region. Microprobe analysis of the as-cast structures showed that the partitioning coefficients did not change with carbon additions. Therefore, the reduction in defect formation with increasing carbon content could not be attributed to changes in segregation behavior of alloying elements. Instead, the presence of these carbides in the interdendritic regions of the alloy appeared to have prevented the thermosolutal fluid flow

  8. Wire-based laser metal deposition for additive manufacturing of TiAl6V4: basic investigations of microstructure and mechanical properties from build up parts

    Science.gov (United States)

    Klocke, Fritz; Arntz, Kristian; Klingbeil, Nils; Schulz, Martin

    2017-02-01

    The wire-based laser metal deposition (LMD-W) is a new technology which enables to produce complex parts made of titanium for the aerospace and automotive industry. For establishing the LMD-W as a new production process it has to be proven that the properties are comparable or superior to conventional produced parts. The mechanical properties were investigated by analysis of microstructure and tensile test. Therefore, specimens were generated using a 4.5 kW diode laser cladding system integrated in a 5-Axis-machining center. The structural mechanical properties are mainly influence by crystal structure and thereby the thermal history of the work piece. Especially the high affinity to oxide, distortion and dual phase microstructure make titanium grade 5 (TiAl6V4) one of the most challenging material for additive manufacturing. By using a proper local multi-nozzle shielding gas concept the negative influence of oxide in the process could be eliminated. The distortion being marginal at a single bead, accumulated to a macroscopic effect on the work piece. The third critical point for additive processing of titanium, the bimodal microstructure, could not be cleared by the laser process alone. All metallurgical probes showed α-martensitic-structure. Therefore, a thermal treatment became a necessary production step in the additive production chain. After the thermal treatment the microstructure as well as the distortion was analyzed and compared with the status before. Although not all technical issues could be solved, the investigation show that LMD-W of titanium grade 5 is a promising alternative to other additive techniques as electronic beam melting or plasma deposition welding.

  9. Additive influence of genetic predisposition and conventional risk factors in the incidence of coronary heart disease: a population-based study in Greece

    Science.gov (United States)

    Yiannakouris, Nikos; Katsoulis, Michail; Trichopoulou, Antonia; Ordovas, Jose M; Trichopoulos, Dimitrios

    2014-01-01

    Objectives An additive genetic risk score (GRS) for coronary heart disease (CHD) has previously been associated with incident CHD in the population-based Greek European Prospective Investigation into Cancer and nutrition (EPIC) cohort. In this study, we explore GRS-‘environment’ joint actions on CHD for several conventional cardiovascular risk factors (ConvRFs), including smoking, hypertension, type-2 diabetes mellitus (T2DM), body mass index (BMI), physical activity and adherence to the Mediterranean diet. Design A case–control study. Setting The general Greek population of the EPIC study. Participants and outcome measures 477 patients with medically confirmed incident CHD and 1271 controls participated in this study. We estimated the ORs for CHD by dividing participants at higher or lower GRS and, alternatively, at higher or lower ConvRF, and calculated the relative excess risk due to interaction (RERI) as a measure of deviation from additivity. Results The joint presence of higher GRS and higher risk ConvRF was in all instances associated with an increased risk of CHD, compared with the joint presence of lower GRS and lower risk ConvRF. The OR (95% CI) was 1.7 (1.2 to 2.4) for smoking, 2.7 (1.9 to 3.8) for hypertension, 4.1 (2.8 to 6.1) for T2DM, 1.9 (1.4 to 2.5) for lower physical activity, 2.0 (1.3 to 3.2) for high BMI and 1.5 (1.1 to 2.1) for poor adherence to the Mediterranean diet. In all instances, RERI values were fairly small and not statistically significant, suggesting that the GRS and the ConvRFs do not have effects beyond additivity. Conclusions Genetic predisposition to CHD, operationalised through a multilocus GRS, and ConvRFs have essentially additive effects on CHD risk. PMID:24500614

  10. Comparison of Thermodynamic Predictions and Experimental Observations on B Additions in Powder-Processed Ni-Based Superalloys Containing Elevated Concentrations of Nb

    Science.gov (United States)

    Antonov, Stoichko; Huo, Jiajie; Feng, Qiang; Isheim, Dieter; Seidman, David N.; Sun, Eugene; Tin, Sammy

    2018-03-01

    Boron additions to Ni-based superalloys are considered to be beneficial to the creep properties of the alloy, as boron has often been reported to increase grain boundary cohesion, increase ductility, and promote the formation of stable boride phases. Despite the importance, it is not well understood whether these improvements are associated with the presence of elemental boron or stable borides along the grain boundaries. In this investigation, two experimental powder-processed Ni-based superalloys containing elevated levels of Nb were found to exhibit increased solubility for B in the γ matrix when compared to similar commercial Ni-based superalloys. This resulted in an overall lower B concentration at grain boundaries that suppressed boride formation. As the predictive capability of CALPHAD database models for Ni-based superalloys have improved over the years, some discrepancies may still persist around compositionally heterogeneous features such as grain boundaries. Improved quantification of the characteristic partitioning of B as a function of the bulk alloy composition is required for understanding and predicting the stability of borides.

  11. ROV-based Underwater Vision System for Intelligent Fish Ethology Research

    Directory of Open Access Journals (Sweden)

    Rui Nian

    2013-09-01

    Full Text Available Fish ethology is a prospective discipline for ocean surveys. In this paper, one ROV-based system is established to perform underwater visual tasks with customized optical sensors installed. One image quality enhancement method is first presented in the context of creating underwater imaging models combined with homomorphic filtering and wavelet decomposition. The underwater vision system can further detect and track swimming fish from the resulting images with the strategies developed using curve evolution and particular filtering, in order to obtain a deeper understanding of fish behaviours. The simulation results have shown the excellent performance of the developed scheme, in regard to both robustness and effectiveness.

  12. Mechanical and Combustion Performance of Multi-Walled Carbon Nanotubes as an Additive to Paraffin-Based Solid Fuels for Hybrid Rockets

    Science.gov (United States)

    Larson, Daniel B.; Boyer, Eric; Wachs, Trevor; Kuo, Kenneth, K.; Koo, Joseph H.; Story, George

    2012-01-01

    Paraffin-based solid fuels for hybrid rocket motor applications are recognized as a fastburning alternative to other fuel binders such as HTPB, but efforts to further improve the burning rate and mechanical properties of paraffin are still necessary. One approach that is considered in this study is to use multi-walled carbon nanotubes (MWNT) as an additive to paraffin wax. Carbon nanotubes provide increased electrical and thermal conductivity to the solid-fuel grains to which they are added, which can improve the mass burning rate. Furthermore, the addition of ultra-fine aluminum particles to the paraffin/MWNT fuel grains can enhance regression rate of the solid fuel and the density impulse of the hybrid rocket. The multi-walled carbon nanotubes also present the possibility of greatly improving the mechanical properties (e.g., tensile strength) of the paraffin-based solid-fuel grains. For casting these solid-fuel grains, various percentages of MWNT and aluminum particles will be added to the paraffin wax. Previous work has been published about the dispersion and mixing of carbon nanotubes.1 Another manufacturing method has been used for mixing the MWNT with a phenolic resin for ablative applications, and the manufacturing and mixing processes are well-documented in the literature.2 The cost of MWNT is a small fraction of single-walled nanotubes. This is a scale-up advantage as future applications and projects will require low cost additives to maintain cost effectiveness. Testing of the solid-fuel grains will be conducted in several steps. Dog bone samples will be cast and prepared for tensile testing. The fuel samples will also be analyzed using thermogravimetric analysis and a high-resolution scanning electron microscope (SEM). The SEM will allow for examination of the solid fuel grain for uniformity and consistency. The paraffin-based fuel grains will also be tested using two hybrid rocket test motors located at the Pennsylvania State University s High Pressure

  13. In-situ formation of Ni4Ti3 precipitate and its effect on pseudoelasticity in selective laser melting additive manufactured NiTi-based composites

    Science.gov (United States)

    Gu, Dongdong; Ma, Chenglong

    2018-05-01

    Selective laser melting (SLM) additive manufacturing technology was applied to synthesize NiTi-based composites via using ball-milled Ti, Ni, and TiC mixed powder. By transmission electron microscope (TEM) characterization, it indicated that the B2 (NiTi) matrix was obtained during SLM processing. In spite of more Ti content (the Ti/Ni ratio >1), a mass of Ni-rich intermetallic compounds containing Ni4Ti3 with nanostructure features and eutectic Ni3Ti around in-situ Ti6C3.75 dendrites were precipitated. Influence of the applied laser volume energy density (VED) on the morphology and content of Ni4Ti3 precipitate was investigated. Besides, nanoindentation test of the matrix was performed in order to assess pseudoelastic recovery behavior of SLM processed NiTi-based composites. At a relatively high VED of 533 J/mm3, the maximum pseudoelastic recovery was obtained due to the lowest content of Ni4Ti3 precipitates. Furthermore, the precipitation mechanism of in-situ Ni4Ti3 was present based on the redistribution of titanium element and thermodynamics analysis, and then the relationship of Ni4Ti3 precipitate, VED and pseudoelastic recovery behavior was also revealed.

  14. Effects of HfB2 and HfN Additions on the Microstructures and Mechanical Properties of TiB2-Based Ceramic Tool Materials

    Science.gov (United States)

    An, Jing; Song, Jinpeng; Liang, Guoxing; Gao, Jiaojiao; Xie, Juncai; Cao, Lei; Wang, Shiying; Lv, Ming

    2017-01-01

    The effects of HfB2 and HfN additions on the microstructures and mechanical properties of TiB2-based ceramic tool materials were investigated. The results showed that the HfB2 additive not only can inhibit the TiB2 grain growth but can also change the morphology of some TiB2 grains from bigger polygons to smaller polygons or longer ovals that are advantageous for forming a relatively fine microstructure, and that the HfN additive had a tendency toward agglomeration. The improvement of flexural strength and Vickers hardness of the TiB2-HfB2 ceramics was due to the relatively fine microstructure; the decrease of fracture toughness was ascribed to the formation of a weaker grain boundary strength due to the brittle rim phase and the poor wettability between HfB2 and Ni. The decrease of the flexural strength and Vickers hardness of the TiB2-HfN ceramics was due to the increase of defects such as TiB2 coarse grains and HfN agglomeration; the enhancement of fracture toughness was mainly attributed to the decrease of the pore number and the increase of the rim phase and TiB2 coarse grains. The toughening mechanisms of TiB2-HfB2 ceramics mainly included crack bridging and transgranular fracture, while the toughening mechanisms of TiB2-HfN ceramics mainly included crack deflection, crack bridging, transgranular fracture, and the core-rim structure. PMID:28772821

  15. Effects of HfB2 and HfN Additions on the Microstructures and Mechanical Properties of TiB2-Based Ceramic Tool Materials

    Directory of Open Access Journals (Sweden)

    Jing An

    2017-04-01

    Full Text Available The effects of HfB2 and HfN additions on the microstructures and mechanical properties of TiB2-based ceramic tool materials were investigated. The results showed that the HfB2 additive not only can inhibit the TiB2 grain growth but can also change the morphology of some TiB2 grains from bigger polygons to smaller polygons or longer ovals that are advantageous for forming a relatively fine microstructure, and that the HfN additive had a tendency toward agglomeration. The improvement of flexural strength and Vickers hardness of the TiB2-HfB2 ceramics was due to the relatively fine microstructure; the decrease of fracture toughness was ascribed to the formation of a weaker grain boundary strength due to the brittle rim phase and the poor wettability between HfB2 and Ni. The decrease of the flexural strength and Vickers hardness of the TiB2-HfN ceramics was due to the increase of defects such as TiB2 coarse grains and HfN agglomeration; the enhancement of fracture toughness was mainly attributed to the decrease of the pore number and the increase of the rim phase and TiB2 coarse grains. The toughening mechanisms of TiB2-HfB2 ceramics mainly included crack bridging and transgranular fracture, while the toughening mechanisms of TiB2-HfN ceramics mainly included crack deflection, crack bridging, transgranular fracture, and the core-rim structure.

  16. Radiation effects on cancer mortality among A-bomb survivors, 1950-72. Comparison of some statistical models and analysis based on the additive logit model

    Energy Technology Data Exchange (ETDEWEB)

    Otake, M [Hiroshima Univ. (Japan). Faculty of Science

    1976-12-01

    Various statistical models designed to determine the effects of radiation dose on mortality of atomic bomb survivors in Hiroshima and Nagasaki from specific cancers were evaluated on the basis of a basic k(age) x c(dose) x 2 contingency table. From the aspects of application and fits of different models, analysis based on the additive logit model was applied to the mortality experience of this population during the 22year period from 1 Oct. 1950 to 31 Dec. 1972. The advantages and disadvantages of the additive logit model were demonstrated. Leukemia mortality showed a sharp rise with an increase in dose. The dose response relationship suggests a possible curvature or a log linear model, particularly if the dose estimated to be more than 600 rad were set arbitrarily at 600 rad, since the average dose in the 200+ rad group would then change from 434 to 350 rad. In the 22year period from 1950 to 1972, a high mortality risk due to radiation was observed in survivors with doses of 200 rad and over for all cancers except leukemia. On the other hand, during the latest period from 1965 to 1972 a significant risk was noted also for stomach and breast cancers. Survivors who were 9 year old or less at the time of the bomb and who were exposed to high doses of 200+ rad appeared to show a high mortality risk for all cancers except leukemia, although the number of observed deaths is yet small. A number of interesting areas are discussed from the statistical and epidemiological standpoints, i.e., the numerical comparison of risks in various models, the general evaluation of cancer mortality by the additive logit model, the dose response relationship, the relative risk in the high dose group, the time period of radiation induced cancer mortality, the difference of dose response between Hiroshima and Nagasaki and the relative biological effectiveness of neutrons.

  17. The Influence of Brewer’s Yeast Autolysate and Lactic Acid Bacteria on the Production of a Functional Food Additive Based on Beetroot Juice Fermentation

    Directory of Open Access Journals (Sweden)

    Josip Baras

    2004-01-01

    Full Text Available The importance of »functional foods« in the world is increasing, and the procedures for their production are under intense development. The goal of this paper is to optimise the production of a functional food additive based on beetroot juice (Beta vulgaris L. using brewer’s yeast autolysate. In order to improve the nutritive properties of the product and to preserve it, the possibility of beetroot juice fermentation using a Lactobacillus species has been investigated. Comparative investigations of three bacteria cultures (L. plantarum A112, L. acidophilus BGSJ15-3 and L. acidophilus NCDO1748 during fermentation in two media, beetroot juice and a mixture of beetroot juice with an autolysate of brewer´s yeast, have been performed. The poorest fermentative activity and growth in both substrates was observed using the L. acidophilus NCDO1748 culture. The two cultures demonstrated better fermentative activity in the mixture of tested substrates, while acidifying activity (production of lactic acid and a decrease in pH of the L. acidophilus BGSJ15-3 culture was considerably better than that of the L. plantarum A112 culture. L. plantarum A112 culture showed better growth than L. acidophilus BGSJ15-3. From the results obtained, it has been concluded that the L. plantarum A112 and L. acidophilus BGSJ15-3 can be successfully used for fermentation of the mixture of beetroot juice and brewer’s yeast autolysate in order to obtain a functional food additive.

  18. Structural modification of swai-fish (Pangasius hypophthalmus)-based emulsions containing non-meat protein additives by ultra-high pressure and thermal treatments

    Science.gov (United States)

    Techarang, Jiranat; Apichartsrangkoon, Arunee; Phanchaisri, Boonrak; Pathomrungsiyoungkul, Pattavara; Sriwattana, Sujinda

    2017-07-01

    Swai-fish emulsions containing fermented soybeans (thua nao and rice-koji miso) were pressurized at 600 MPa for 20 min or heated at 72°C for 30 min. The fish batters were blended with soy protein isolate (SPI) or whey protein concentrate (WPC) to stabilize the emulsions. The processed fish emulsions were then subjected to physical, chemical and microbiological examinations. The results of gel strength and water-holding potential showed that SPI addition yielded higher impact on these properties than WPC addition, which was also confirmed by the interactions between SPI and native fish proteins depicted by electrophoregrams. The frequency profiles suggested that the heated gels had a greater storage and loss moduli than pressurized gels, while pressurized WPC set-gel displayed larger loss tangent (the predominance of viscous moiety) than those pressurized SPI set-gel. High bacteria and spore counts of B. subtilis (residual of the thua nao) were observed in both pressurized and heated fish-based emulsions.

  19. Effect of Si and Mn additions on ferrite and austenite phase fractions in 25Cr-7Ni-1.5Mo-3W base super duplex stainless steels

    International Nuclear Information System (INIS)

    Jeong, S.W.; Lee, Z.-H.; Lee, H.M.

    2000-01-01

    The effect of heat treatment and Si and Mn additions on the ferrite and austenite phase fractions of the super duplex stainless steel (SDSS), Fe-25Cr-7Ni-1.5Mo-3W-Si-Mn-0.25N (numbers are all in wt.% unless specified otherwise), was investigated. The thermodynamic calculations of phase equilibria and phase fractions were performed using the Thermo-Calc program. Based on the calculated results, specific compositions of Si and Mn were selected and alloys with these compositions were analysed by Feritscope, X-ray diffractometry and scanning electron microscopy. The calculated phase fractions and experimentally analysed ones were compared and there was a good agreement between calculations and measurements. The optimum heat treatment condition for Fe-25Cr-7Ni-1.5Mo-3W-0.5Si-0.5Mn-0.25N is to hold at 1050 to 1100 C for 2 h in considering the ferrite to austenite ratio of 50:50 and to avoid second phase precipitation such as the σ phase. It was suggested that an excessive addition of more than 0.8Si and 1.0Mn may induce the σ phase precipitation. (orig.)

  20. A screening method based on UV-Visible spectroscopy and multivariate analysis to assess addition of filler juices and water to pomegranate juices.

    Science.gov (United States)

    Boggia, Raffaella; Casolino, Maria Chiara; Hysenaj, Vilma; Oliveri, Paolo; Zunin, Paola

    2013-10-15

    Consumer demand for pomegranate juice has considerably grown, during the last years, for its potential health benefits. Since it is an expensive functional food, cheaper fruit juices addition (i.e., grape and apple juices) or its simple dilution, or polyphenols subtraction are deceptively used. At present, time-consuming analyses are used to control the quality of this product. Furthermore these analyses are expensive and require well-trained analysts. Thus, the purpose of this study was to propose a high-speed and easy-to-use shortcut. Based on UV-VIS spectroscopy and chemometrics, a screening method is proposed to quickly screening some common fillers of pomegranate juice that could decrease the antiradical scavenging capacity of pure products. The analytical method was applied to laboratory prepared juices, to commercial juices and to representative experimental mixtures at different levels of water and filler juices. The outcomes were evaluated by means of multivariate exploratory analysis. The results indicate that the proposed strategy can be a useful screening tool to assess addition of filler juices and water to pomegranate juices. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Towards Additive Manufacture of Functional, Spline-Based Morphometric Models of Healthy and Diseased Coronary Arteries: In Vitro Proof-of-Concept Using a Porcine Template

    Directory of Open Access Journals (Sweden)

    Rachel Jewkes

    2018-02-01

    Full Text Available The aim of this study is to assess the additive manufacture of morphometric models of healthy and diseased coronary arteries. Using a dissected porcine coronary artery, a model was developed with the use of computer aided engineering, with splines used to design arteries in health and disease. The model was altered to demonstrate four cases of stenosis displaying varying severity, based on published morphometric data available. Both an Objet Eden 250 printer and a Solidscape 3Z Pro printer were used in this analysis. A wax printed model was set into a flexible thermoplastic and was valuable for experimental testing with helical flow patterns observed in healthy models, dominating the distal LAD (left anterior descending and left circumflex arteries. Recirculation zones were detected in all models, but were visibly larger in the stenosed cases. Resin models provide useful analytical tools for understanding the spatial relationships of blood vessels, and could be applied to preoperative planning techniques, but were not suitable for physical testing. In conclusion, it is feasible to develop blood vessel models enabling experimental work; further, through additive manufacture of bio-compatible materials, there is the possibility of manufacturing customized replacement arteries.

  2. Cooperative redox-active additives of anthraquinone-2,7-disulphonate and K4Fe(CN)6 for enhanced performance of active carbon-based capacitors

    Science.gov (United States)

    Tian, Ying; Liu, Ming; Che, Ruxing; Xue, Rong; Huang, Liping

    2016-08-01

    Two redox additives of anthraquinone-2,7-disulphonate (AQDS) and K4Fe(CN)6 are introduced into the neutral medium of KNO3 for enhanced performance of active carbon-based (AC) capacitor. The Faradaic redox reactions of AQ/H2AQ and Fe(CN)63-/Fe(CN)64- are diffusion-controlled and occurred on the negative electrode and the positive electrode respectively and simultaneously, resulting in the enhancement of specific capacitance, power density and energy density of 240 F g-1, 527 W kg-1 and 26.3 Wh kg-1, respectively at a current density of 1.0 A g-1 for a symmetric AC capacitor in the electrolyte of 1 M KNO3-0.017 M K4Fe(CN)6-0.017 M AQDS. These values are much higher than those in the controls of either 1 M KNO3-0.017 M K4Fe(CN)6 or 1 M KNO3-0.017 M AQDS with only one pair of redox additives. These results demonstrate the cooperative K4Fe(CN)6 and AQDS for enhanced performance of AC capacitor, and thus provide an alternative approach for efficient capacitors.

  3. Towards Additive Manufacture of Functional, Spline-Based Morphometric Models of Healthy and Diseased Coronary Arteries: In Vitro Proof-of-Concept Using a Porcine Template.

    Science.gov (United States)

    Jewkes, Rachel; Burton, Hanna E; Espino, Daniel M

    2018-02-02

    The aim of this study is to assess the additive manufacture of morphometric models of healthy and diseased coronary arteries. Using a dissected porcine coronary artery, a model was developed with the use of computer aided engineering, with splines used to design arteries in health and disease. The model was altered to demonstrate four cases of stenosis displaying varying severity, based on published morphometric data available. Both an Objet Eden 250 printer and a Solidscape 3Z Pro printer were used in this analysis. A wax printed model was set into a flexible thermoplastic and was valuable for experimental testing with helical flow patterns observed in healthy models, dominating the distal LAD (left anterior descending) and left circumflex arteries. Recirculation zones were detected in all models, but were visibly larger in the stenosed cases. Resin models provide useful analytical tools for understanding the spatial relationships of blood vessels, and could be applied to preoperative planning techniques, but were not suitable for physical testing. In conclusion, it is feasible to develop blood vessel models enabling experimental work; further, through additive manufacture of bio-compatible materials, there is the possibility of manufacturing customized replacement arteries.

  4. Exploration of the viscosity temperature dependences and microstructure of magnesium-based commercial alloy AZ91D with small additions of calcium

    International Nuclear Information System (INIS)

    Abaturov, I S; Popel, P S; Brodova, I G; Astafiev, V V; Li Peijie

    2008-01-01

    The technique of rotating oscillation damping of a crucible filled in with the melt under investigation was used for measurement of viscosity of the Mg-based AZ91D commercial alloy with various additions of calcium. The viscosity was measured in liquid state in temperature interval from 600 up to 840 deg. C. The comparative metallographic investigation of the structure of samples with calcium content of 0.0, 0.4, 0.6 and 0.8 wt.% which were crystallized just after re-melting at the temperature of 640 deg. C and after heating in liquid state up to 850 deg. C were made. It was shown that the thermal treatment of samples in liquid state is accompanied by considerable changes in the cast structure that forms after the crystallization of the samples

  5. Asymmetric synthesis of α-amino acids via homologation of Ni(II) complexes of glycine Schiff bases. Part 3: Michael addition reactions and miscellaneous transformations.

    Science.gov (United States)

    Aceña, José Luis; Sorochinsky, Alexander E; Soloshonok, Vadim

    2014-09-01

    The major goal of this review is a critical discussion of the literature data on asymmetric synthesis of α-amino acids via Michael addition reactions involving Ni(II)-complexes of amino acids. The material covered is divided into two conceptually different groups dealing with applications of: (a) Ni(II)-complexes of glycine as C-nucleophiles and (b) Ni(II)-complexes of dehydroalanine as Michael acceptors. The first group is significantly larger and consequently subdivided into four chapters based on the source of stereocontrolling element. Thus, a chiral auxiliary can be used as a part of nucleophilic glycine Ni(II) complex, Michael acceptor or both, leading to the conditions of matching vs. mismatching stereochemical preferences. The particular focus of the review is made on the practical aspects of the methodology under discussion and mechanistic considerations.

  6. Increased charge transfer of Poly (ethylene oxide) based electrolyte by addition of small molecule and its application in dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Muthuraaman, B.; Will, Geoffrey; Wang, Hongxia; Moonie, Paul; Bell, John

    2013-01-01

    A Poly (ethylene oxide) based polymer electrolyte impregnated with 2-Mercapto benzimidazole was comprehensively characterized by XRD, UV–visible spectroscopy, FTIR as well as electrochemical impedance spectroscopy. It was found that the crystallization of PEO was dramatically reduced and the ionic conductivity of the electrolyte was increased 4.5 fold by addition of 2-Mercapto benzimidazole. UV–visible and FTIR spectroscopes indicated the formation of charge transfer complex between 2-Mercapto benzimidazole and iodine of the electrolyte. Dye-sensitized solar cells with the polymer electrolytes were assembled. It was found that both the photocurrent density and photovoltage were enhanced with respect to the DSC without 2-Mercapto benzimidazole, leading to a 60% increase of the performance of the cell.

  7. Synchrotron-based FTIR microspectroscopy for the mapping of photo-oxidation and additives in acrylonitrile-butadiene-styrene model samples and historical objects.

    Science.gov (United States)

    Saviello, Daniela; Pouyet, Emeline; Toniolo, Lucia; Cotte, Marine; Nevin, Austin

    2014-09-16

    Synchrotron-based Fourier transform infrared micro-spectroscopy (SR-μFTIR) was used to map photo-oxidative degradation of acrylonitrile-butadiene-styrene (ABS) and to investigate the presence and the migration of additives in historical samples from important Italian design objects. High resolution (3×3 μm(2)) molecular maps were obtained by FTIR microspectroscopy in transmission mode, using a new method for the preparation of polymer thin sections. The depth of photo-oxidation in samples was evaluated and accompanied by the formation of ketones, aldehydes, esters, and unsaturated carbonyl compounds. This study demonstrates selective surface oxidation and a probable passivation of material against further degradation. In polymer fragments from design objects made of ABS from the 1960s, UV-stabilizers were detected and mapped, and microscopic inclusions of proteinaceous material were identified and mapped for the first time. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Establishment of data base files of thermodynamic data developed by OECD/NEA. Part 4. Addition of thermodynamic data for iron, tin and thorium

    International Nuclear Information System (INIS)

    Yoshida, Yasushi; Kitamura, Akira

    2014-12-01

    Thermodynamic data for compounds and complexes of elements with auxiliary species specialized in modeling requirements for safety assessments of radioactive waste disposal systems have been developed by the Thermochemical Data Base (TDB) project of the Nuclear Energy Agency in the Organization for Economic Co-operation and Development (OECD/NEA). Recently, thermodynamic data for aqueous complexes, solids and gases of thorium, tin and iron (Part 1) have been published in 2008, 2012 and 2013, respectively. These thermodynamic data have been selected on the basis of NEA’s guidelines which describe peer review and data selection, extrapolation to zero ionic strength, assignment of uncertainty, and temperature correction; therefore the selected data are considered to be reliable. The reliability of selected thermodynamic data of TDB developed by Japan Atomic Energy Agency (JAEA-TDB) has been confirmed by comparing with selected data by the NEA. For this comparison, text files of the selected data on some geochemical calculation programs are required. In the present report, the database files for the NEA’s TDB with addition of selected data for iron, tin and thorium to the previous files have been established for use of PHREEQC, Geochemist’s Workbench and EQ3/6. In addition, as an example of confirmation of quality, dominant species in iron TDB were compared in Eh-pH diagram and differences between JAEA-TDB and NEA-TDB were shown. Data base files established in the present study will be at the Website of thermodynamic, sorption and diffusion database in JAEA (http://migrationdb.jaea.go.jp/). A CD-ROM is attached as an appendix. (J.P.N.)

  9. Digital Image Deblurring by Nonlinear Homomorphic Filtering

    Science.gov (United States)

    1974-08-01

    Noise Film Grain Noise Impulse Noise Nois» and the ReVlection Scanner Page iv vii viii 1 1 2 4 5 7 8 11 11 12 IB 20 25...1. "^ bCx.y), n(x,y) Diagram 1 a(x,y) le the impulse response, or point-spread function, of the system, and la assumed to be unknown. All noise ... deblurring problem. This inadequacy results from the fact that the high frequency noise floor in the pouer spectrum of a blurred imaga U about 60 dbt

  10. implementation of spatial domain homomorphic filtering

    African Journals Online (AJOL)

    eobe

    on a Java-enabled mobile phone and form a low cost embedded image processing enhancement system. Keywords: Spatial ... important because of the wide range of applications that can ..... Co our Image Processi g” Ph D thesis U iversity of.

  11. Investigations of Fully Homomorphic Encryption (IFHE)

    Science.gov (United States)

    2015-05-01

    27000 1057 900 2.69 2 15 23 ≈ 1.02 · 107 32767 28 + 1 62419 51840 1687 1440 2.72 1 3 40 ≈ 4.6 · 106 4243648 91149 58080 1321 1320 1.28 1 3 39 ≈ 2.3...complexity of the protocol isO (|ckt| · (n·td +κ) ·κ 2), BC ( |ckt| · n·t·κ2d , n ) and BC ( |ckt| · κ3, κ ) . PROOF (COMMUNICATION COMPLEXITY): We analyze each...invocations to the protocol Π[·]→〈·〉. The communication complexity of this step isO (n · c · inl · κ) and BC ( n · c · inl · κ, n ) ; this follows from

  12. Multiparty Computation from Somewhat Homomorphic Encryption

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Pastro, Valerio; Smart, Nigel

    2011-01-01

    independent of the function to be computed and of the inputs, and a much more efficient online phase where the actual computation takes place. The online phase is unconditionally secure and has total computational (and communication) complexity linear in $n$, the number of players, where earlier work......We propose a general multiparty computation protocol secure against an active adversary corrupting up to $n-1$ of the $n$ players. The protocol may be used to compute securely arithmetic circuits over any finite field $\\F_{p^k}$. Our protocol consists of a preprocessing phase that is both...... was quadratic in $n$. Hence, the work done by each player in the online phase is independent of $n$ and moreover is only a small constant factor larger than what one would need to compute the circuit in the clear. It is the first protocol in the preprocessing model with these properties. We show a lower bound...

  13. Pyrrolidinium-based ionic liquid electrolyte with organic additive and LiTFSI for high-safety lithium-ion batteries

    International Nuclear Information System (INIS)

    Yang, Binbin; Li, Cuihua; Zhou, Junhui; Liu, Jianhong; Zhang, Qianling

    2014-01-01

    Highlights: • New ionic liquid electrolytes composed by PYR 13 TFSI and EC/DMC-5%VC. • Mixed electrolyte for use in high-safety lithium-ion batteries. • LiTFSI concentration in IL electrolyte greatly affects the rate capability of the cell. • The optimal mixed electrolyte is ideal for applications at high temperature. - Abstract: In this paper, we report on the physicochemical properties of mixed electrolytes based on an ionic liquid N-propyl-N-methylpyrrolidiniumbis (trifluoromethanesulfonyl) imide (PYR 13 TFSI), organic additives, and lithium bis (trifluoromethanesulfonyl) imide (LiTFSI) for high safety lithium-ion batteries. The proposed optimal content of ionic liquid in the mixed electrolyte is 65 vol%, which results in non- flammability, high thermal stability, a wide electrochemical window of 4.8 V, low viscosity, low bulk resistance and the lowest interface resistance to lithium anode. The effects of the concentration of LiTFSI in the above electrolyte are critical to the rate performance of the LiFePO 4 -based battery. We have found the suitable LiTFSI concentration (0.3 M) for good capacity retention and rate capability

  14. Improving nutrient management practices in agriculture: The role of risk-based beliefs in understanding farmers' attitudes toward taking additional action

    Science.gov (United States)

    Wilson, Robyn S.; Howard, Gregory; Burnett, Elizabeth A.

    2014-08-01

    A recent increase in the amount of dissolved reactive phosphorus (DRP) entering the western Lake Erie basin is likely due to increased spring storm events in combination with issues related to fertilizer application and timing. These factors in combination with warmer lake temperatures have amplified the spread of toxic algal blooms. We assessed the attitudes of farmers in northwest Ohio toward taking at least one additional action to reduce nutrient loss on their farm. Specifically, we (1) identified to what extent farm and farmer characteristics (e.g., age, gross farm sales) as well as risk-based beliefs (e.g., efficacy, risk perception) influenced attitudes, and (2) assessed how these characteristics and beliefs differ in their predictive ability based on unobservable latent classes of farmers. Risk perception, or a belief that negative impacts to profit and water quality from nutrient loss were likely, was the most consistent predictor of farmer attitudes. Response efficacy, or a belief that taking action on one's farm made a difference, was found to significantly influence attitudes, although this belief was particularly salient for the minority class of farmers who were older and more motivated by profit. Communication efforts should focus on the negative impacts of nutrient loss to both the farm (i.e., profit) and the natural environment (i.e., water quality) to raise individual perceived risk among the majority, while the minority need higher perceived efficacy or more specific information about the economic effectiveness of particular recommended practices.

  15. Characterization of geopolymer fly-ash based foams obtained with the addition of Al powder or H{sub 2}O{sub 2} as foaming agents

    Energy Technology Data Exchange (ETDEWEB)

    Ducman, V., E-mail: vilma.ducman@zag.si; Korat, L.

    2016-03-15

    Recent innovations in geopolymer technology have led to the development of various different types of geopolymeric products, including highly porous geopolymer-based foams, which are formed by the addition of foaming agents to a geopolymer fly-ash based matrix. These agents decompose, or react with the liquid matrix or oxygen in the matrix, resulting in the release of gases which form pores prior to the hardening of the gel. The hardened structure has good mechanical and thermal properties, and can therefore be used for applications in acoustic panels and in lightweight pre-fabricated components for thermal insulation purposes. This study presents the results of the pore-forming process in the case when two different foaming agents, i.e. aluminium powder amounting to 0.07, 0.13 and 0.20 mass. % and H{sub 2}O{sub 2} amounting to 0.5, 1.0, 1.5 and 2.0 mass. %, were added to a fly-ash geopolymer matrix. The physical, mechanical, and microstructural properties of the thus obtained foams, and the effects of the type and amount of the added foaming agent, are presented and discussed. Highly porous structures were obtained in the case of both of the investigated foaming agents, with overall porosities up to 59% when aluminium powder was added, and of up 48% when H{sub 2}O{sub 2} was added. In the latter case, when 2% of the H{sub 2}O{sub 2} foaming agent was added, finer pores (with diameters up to 500 μm) occurred in the structure, whereas somewhat larger pores (some had diameters greater than 1 mm) occurred when the same amount of aluminium powder was added. The mechanical properties of the investigated foams depended on their porosity. In the case of highly porous structures a compressive strength of 3.3 MPa was nevertheless achieved for the samples containing 0.2% of aluminium powder, and 3.7 MPa for those containing 2.0% of H{sub 2}O{sub 2}. - Highlights: • Preparation of geopolymer foams based on fly ash with the addition of Al powder or H{sub 2}O{sub 2} as

  16. Use of an additive canthaxanthin based and annatto extract in diets of laying hens and its effect on the color of the yolk and the egg shelf life

    Directory of Open Access Journals (Sweden)

    Víctor Rojas V.

    2015-09-01

    Full Text Available The aim of this study was to evaluate the use of an additive canthaxanthin based and annatto extract (Bixa orellana L. in diets of laying hens and its effect on the color of the yolk and the egg shelf life. Position 864 hens 34 to 45 weeks old, distributed in a completely randomized design with six replicates per treatment were used. Treatments were T0 (control diet, T1 (T0 + 30 g of canthaxanthin and annatto extract and T2 (T0 + 60 g of canthaxanthin and annatto extract. The results were 88.6; 91.9 and 90.8% for laying percentage; 60.5; 61.6 and 61.5 g for egg weight; 53.6; 56.4 and 55.7 g for egg mass. The yolk color temperature 7 °C for Roche scale was 6, 9 and 12 and colorimetric Minolta was to "L" of 42.10; 40.24 and 39.65; for "a" of 0.07; 3.68 and 6.44 and for "b" of 19.35; 18.36 and 18.18. Shelf life at room temperature 7 °C was 81, 86 and 90 UH. Lipid peroxidation was 0.10; 0.07 and 0.05 μmol MDA.g-1 yolk; for T0, T1 and T2 respectively. In all variables indicated statistically significant differences between treatments (p < 0.05. Food consumption was 103.9; 109.2 and 107.5 g and feed conversion of 1.94; 1.93 and 1.92. It is concluded that the addition of canthaxanthin and annatto extract to 30 and 60 g t-1 feed than the control, improved performance parameters, yolk color and egg shelf life.

  17. Genetic predisposition to coronary heart disease and stroke using an additive genetic risk score: A population-based study in Greece

    Science.gov (United States)

    Yiannakouris, N.; Katsoulis, M.; Dilis, V.; Parnell, L.D.; Trichopoulos, D.; Ordovas, J.M.; Trichopoulou, A.

    2012-01-01

    Objective To determine the extent to which the risk for incident coronary heart disease (CHD) increases in relation to a genetic risk score (GRS) that additively integrates the influence of high-risk alleles in nine documented single nucleotide polymorphisms (SNPs) for CHD, and to examine whether this GRS also predicts incident stroke. Methods Genotypes at nine CHD-relevant SNPs were determined in 494 cases of incident CHD, 320 cases of incident stroke and 1345 unaffected controls drawn from the population-based Greek component of the European Prospective Investigation into Cancer and nutrition (EPIC) cohort. An additive GRS was calculated for each study participant by adding one unit for the presence of each high-risk allele multiplied by the estimated effect size of that allele in the discovery samples. Statistical analysis was performed using logistic regression. Results The GRS was significantly associated with the incidence of CHD where the odds of CHD incidence in the highest quintile of the GRS were 1.74 times higher (95% confidence interval [CI] = 1.25–2.43, p for trend = 0.0004), compared to the lowest quintile. With respect to stroke, a weaker and non-significant positive association with GRS was apparent as the odds of stroke incidence in the highest quintile of the GRS were 1.36 times higher (95% CI = 0.90–2.06, p for trend = 0.188), compared to the lowest quintile. Conclusion A GRS relying on nine documented “CHD-specific” SNPs is significantly predictive of CHD but it was not found to be statistically significantly associated with incident stroke. PMID:22429504

  18. Effect of silver and indium addition on mechanical properties and indentation creep behavior of rapidly solidified Bi–Sn based lead-free solder alloys

    International Nuclear Information System (INIS)

    Shalaby, Rizk Mostafa

    2013-01-01

    Mechanical properties and indentation creep of the melt-spun process Bi–42 wt%Sn, Bi–40 wt%Sn–2 wt%In, Bi–40 wt%Sn–2 wt%Ag and Bi–38 wt%Sn–2 wt%In–2 wt%Ag were studied by dynamic resonance technique and Vickers indentation testing at room temperature and compared to that of the traditional Sn–37 wt%Pb eutectic alloy. The results show that the structure of Bi–42 wt%Sn alloy is characterized by the presence of rhombohedral Bi and body centered tetragonal β-Sn. The two ternary alloys exhibit additional constituent phases of intermetallic compounds SnIn 19 for Bi–40 wt%Sn–2 wt%In and ε-Ag 3 Sn for Bi–40 wt%Sn–2 wt%Ag alloys. Attention has been paid to the role of intermetallic compounds on mechanical and creep behavior. The In and Ag containing solder alloy exhibited a good combination of higher creep resistance, good mechanical properties and lower melting temperature as compared with Pb–Sn eutectic solder alloy. This was attributed to the strengthening effect of Bi as a strong solid solution element in the Sn matrix and formation of intermetallic compounds β-SnBi, ε-Ag 3 Sn and InSn 19 which act as both strengthening agent and grain refiner in the matrix of the material. Addition of In and Ag decreased the melting temperature of Bi–Sn lead-free solder from 143 °C to 133 °C which was possible mainly due to the existence of InSn 19 and Ag 3 Sn intermetallic compounds. Elastic constants, internal friction and thermal properties of Bi–Sn based alloys have been studied and analyzed.

  19. Effect of an organic acids based feed additive and enrofloxacin on the prevalence of antibiotic-resistant E. coli in cecum of broilers.

    Science.gov (United States)

    Roth, Nataliya; Mayrhofer, Sigrid; Gierus, Martin; Weingut, Christine; Schwarz, Christiane; Doupovec, Barbara; Berrios, Roger; Domig, Konrad J

    2017-09-01

    Increasing antibiotic resistance is a major public health concern. Fluoroquinolones are used to treat and prevent poultry diseases worldwide. Fluoroquinolone resistance rates are high in their countries of use. The aim of this study was to evaluate the effect of an acids-based feed additive, as well as fluoroquinolone antibiotics, on the prevalence of antibiotic-resistant E. coli. A total of 480 broiler chickens (Ross 308) were randomly assigned to 3 treatments: a control group receiving a basal diet; a group receiving a feed additive (FA) based on formic acid, acetic acid and propionic acid; and an antibiotic enrofloxacin (AB) group given the same diet, but supplemented with enrofloxacin in water. A pooled fecal sample of one-day-old chicks was collected upon arrival at the experimental farm. On d 17 and d 38 of the trial, cecal samples from each of the 8 pens were taken, and the count of E. coli and antibiotic-resistant E. coli was determined.The results of the present study show a high prevalence of antibiotic-resistant E. coli in one-day-old chicks. Supplementation of the diet with FA and treatment of broilers with AB did not have a significant influence on the total number of E. coli in the cecal content on d 17 and d 38 of the trial. Supplementation with FA contributed to better growth performance and to a significant decrease (P ≤ 0.05) in E. coli resistant to ampicillin and tetracycline compared to the control and AB groups, as well as to a decrease (P ≤ 0.05) in sulfamethoxazole and ciprofloxacin-resistant E. coli compared to the AB group. Treatment with AB increased (P ≤ 0.05) the average daily weight compared to the control group and increased (P ≤ 0.05) the number of E. coli resistant to ciprofloxacin, streptomycin, sulfamethoxazole and tetracycline; it also decreased (P ≤ 0.05) the number of E. coli resistant to cefotaxime and extended spectrum beta-lactamase- (ESBL-) producing E. coli in the ceca of broilers. © 2017 Poultry Science

  20. Does additional support provided through e-mail or SMS in a Web-based Social Marketing program improve children's food consumption? A Randomized Controlled Trial.

    Science.gov (United States)

    Rangelov, Natalie; Della Bella, Sara; Marques-Vidal, Pedro; Suggs, L Suzanne

    2018-02-16

    The FAN Social Marketing program was developed to improve dietary and physical activity habits of families with children in Ticino, Switzerland. The aim of this study was to examine if the effects of the program on children's food intake differed by intervention group. Effects of the FAN program were tested through a Randomized Controlled Trial. The program lasted 8 weeks, during which participants received tailored communication about nutrition and physical activity. Families were randomly allocated to one of three groups, where the parent received the intervention by the Web (G1), Web + e-mail (G2) or Web + SMS (G3). Children in all groups received tailored print letters by post. Children's food consumption was assessed at baseline and immediate post intervention using a 7-day food diary. Generalized linear mixed models with child as a random effect and with time, treatment group, and the time by treatment interaction as fixed effects were used to test the impact of the intervention. Analyses were conducted with a sample of 608 children. After participating in FAN the marginal means of daily consumption of fruit changed from 0.95 to 1.12 in G1, from 0.82 to 0.94 in G2, and from 0.93 to 1.18 in G3. The margins of the daily consumption of sweets decreased in each group (1.67 to 1.56 in G1, 1.71 to 1.49 in G2, and 1.72 to 1.62 in G3). The change in vegetable consumption observed from pre to post intervention in G3 (from 1.13 to 1.21) was significantly different from that observed in G1 (from 1.21 to 1.17). A well-designed Web-based Social Marketing intervention complemented with print letters can help improve children's consumption of water, fruit, soft drinks, and sweets. The use of SMS to support greater behavior change, in addition to Web-based communication, resulted only in a small significant positive change for vegetables, while the use of e-mail in addition to Web did not result in any significant difference. The trial was retrospectively registered in the

  1. Optimising the concentration of LiNO3 additive in C4mpyr-TFSI electrolyte-based Li-S battery

    International Nuclear Information System (INIS)

    Barghamadi, Marzieh; Best, Adam S.; Hollenkamp, Anthony F.; Mahon, Peter; Musameh, Mustafa; Rüther, Thomas

    2016-01-01

    In the context of lithium-sulfur (Li-S) battery technology, LiNO 3 is known to improve performance by protecting the lithium anode via the formation of an optimized solid electrolyte interphase (SEI) as well as suppressing the associated lithium polysulfides shuttle effect during cycling. Herein, the concentration of added LiNO 3 (0.05–0.4 mol kg −1 ) in a C 4 mpyr-TFSI- organic mixed electrolyte has been varied, with any changes in cell performance monitored against the physical (viscosity) and ion-transport (NMR-based ion diffusion and conductivity) properties of each variant. We find that an electrolyte with 0.1 mol kg −1 LiNO 3 shows the best performance and that this is because this electrolyte has the highest conductivity, lowest viscosity and shows the lowest glass transition temperature (T g ), measured with differential scanning calorimetry (DSC). While the long-term benefits of adding lithium nitrate to the electrolyte of Li-S cells are known to be related to effects centred on the lithium anode, the short-term influence of this additive on capacity performance is clearly related to promoting better access to the porous cathode. The range of concentration over which this effect is operative (0.05–0.20 mol kg −1 ) overlaps with the range recommended for optimum performance of the lithium anode.

  2. Additive effect of congenital heart disease and early developmental disorders on attention-deficit/hyperactivity disorder and autism spectrum disorder: a nationwide population-based longitudinal study.

    Science.gov (United States)

    Tsao, Pei-Chen; Lee, Yu-Sheng; Jeng, Mei-Jy; Hsu, Ju-Wei; Huang, Kai-Lin; Tsai, Shih-Jen; Chen, Mu-Hong; Soong, Wen-Jue; Kou, Yu Ru

    2017-11-01

    In this retrospective nationwide population-based case-control study, we investigated the impact of congenital heart disease (CHD) on the development of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD), which remains unclear. Children aged disorders (EDD) that were diagnosed before ADHD and ASD diagnosis were also analyzed. The incidence rates of perinatal comorbidities, EDD, ADHD, and ASD were higher in the CHD group than in the control group. Multivariate Cox regression analysis revealed that the CHD group had an increased risk of developing ADHD (adjusted hazard ratio [aHR] 2.52, 95% confidence interval CI 1.96-3.25) and ASD (aHR 1.97, 95% CI 1.11-3.52) after adjusting for confounding comorbidities. EDD, but not perinatal comorbidities were also independent risk factors for ADHD and ASD after adjustment. Subgroup analysis indicated that the risk for ADHD (HR 16.59, 95% CI 12.17-22.60) and ASD (HR 80.68, 95% CI 39.96-176.12) was greatly increased in CHD subjects with EDD than in non-CHD subjects without EDD. These findings suggested that CHD at birth and EDD during early childhood were two independent risk factors for ADHD and ASD and that concurrent CHD and EDD might additively increase these risks.

  3. Resilience of Soil Microbial Communities to Metals and Additional Stressors: DNA-Based Approaches for Assessing “Stress-on-Stress” Responses

    Directory of Open Access Journals (Sweden)

    Hamed Azarbad

    2016-06-01

    Full Text Available Many microbial ecology studies have demonstrated profound changes in community composition caused by environmental pollution, as well as adaptation processes allowing survival of microbes in polluted ecosystems. Soil microbial communities in polluted areas with a long-term history of contamination have been shown to maintain their function by developing metal-tolerance mechanisms. In the present work, we review recent experiments, with specific emphasis on studies that have been conducted in polluted areas with a long-term history of contamination that also applied DNA-based approaches. We evaluate how the “costs” of adaptation to metals affect the responses of metal-tolerant communities to other stress factors (“stress-on-stress”. We discuss recent studies on the stability of microbial communities, in terms of resistance and resilience to additional stressors, focusing on metal pollution as the initial stress, and discuss possible factors influencing the functional and structural stability of microbial communities towards secondary stressors. There is increasing evidence that the history of environmental conditions and disturbance regimes play central roles in responses of microbial communities towards secondary stressors.

  4. A novel baseline-correction method for standard addition based derivative spectra and its application to quantitative analysis of benzo(a)pyrene in vegetable oil samples.

    Science.gov (United States)

    Li, Na; Li, Xiu-Ying; Zou, Zhe-Xiang; Lin, Li-Rong; Li, Yao-Qun

    2011-07-07

    In the present work, a baseline-correction method based on peak-to-derivative baseline measurement was proposed for the elimination of complex matrix interference that was mainly caused by unknown components and/or background in the analysis of derivative spectra. This novel method was applicable particularly when the matrix interfering components showed a broad spectral band, which was common in practical analysis. The derivative baseline was established by connecting two crossing points of the spectral curves obtained with a standard addition method (SAM). The applicability and reliability of the proposed method was demonstrated through both theoretical simulation and practical application. Firstly, Gaussian bands were used to simulate 'interfering' and 'analyte' bands to investigate the effect of different parameters of interfering band on the derivative baseline. This simulation analysis verified that the accuracy of the proposed method was remarkably better than other conventional methods such as peak-to-zero, tangent, and peak-to-peak measurements. Then the above proposed baseline-correction method was applied to the determination of benzo(a)pyrene (BaP) in vegetable oil samples by second-derivative synchronous fluorescence spectroscopy. The satisfactory results were obtained by using this new method to analyze a certified reference material (coconut oil, BCR(®)-458) with a relative error of -3.2% from the certified BaP concentration. Potentially, the proposed method can be applied to various types of derivative spectra in different fields such as UV-visible absorption spectroscopy, fluorescence spectroscopy and infrared spectroscopy.

  5. Effect of homogenization heat treatments on the cast structure and tensile properties of nickel-base superalloy ATI 718Plus in the presence of boron and zirconium additions

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini, Seyed Ali, E-mail: saliho3ini@gmail.com; Madar, Karim Zangeneh; Abbasi, Seyed Mehdi

    2017-03-24

    The effect of homogenization heat treatment on cast structure, hardness, and tensile properties of the nickel-based superalloy 718plus in the presence of boron and zirconium additives were investigated. For this purpose, five alloys with different contents of boron (0.00–0.016 wt%) and zirconium (0.0–0.1 wt%) were cast by double vacuum process VIM/VAR and then were homogenized at 1075–1175 °C for 5–25 h. Microstructural investigation by OM and SEM and phase analysis by XRD were done and then hardness and high temperature tensile tests were performed on the homogenized alloys. The results show that the amount of the Laves phase is reduced by increases in time and temperature of homogenization. It was also found that increases in duration of homogenization at 1075 °C results in improving strength and ductility, while duration increase at 1175 °C is accompanied with degradation of them, which caused the reduction of needle-like delta phase on grain boundaries. Boron and zirconium had negative effects on the strength and ductility of the alloy by increasing the amount of Laves in the cast structure. By increasing these elements in alloy composition, more time is needed in order to fully eliminate the Laves by homogenization treatment.

  6. In vitro evaluation of salinomycin addition in wheat straw based total mixed diets on rumen fermentation, methanogenesis and dry matter degradability in buffalo

    Directory of Open Access Journals (Sweden)

    Sunil K. Sirohi

    Full Text Available Aim: The aim of the current study was to evaluate the effect of salinomycin in vitro on methanogenesis and rumen fermentation. Materials and Methods: Different levels of (0,10, 15 and 20 ppm salinomycin were checked for their effect on in vitro methanogenesis and rumen fermentation on three wheat straw based diets i.e. low fiber diet (LFD, 40R:60C, medium fiber diet (MFD, 50R:50C and high fiber diet (HFD, 60R:40C. Evaluation of salinomycin was carried out using in vitro gas production technique. Methane production and individual fatty acids were estimated by Gas Chromatography. Results: Results of different levels of salinomycin on in vitro methanogenesis indicated that the maximum methane reduction (38.14% in term of mM/gDM was noticed in HFD at 20 ppm level. IVDMD showing increasing trend with an increasing concentration of salinomycin with HFD and LFD, while shown decreasing trend with MFD respectively. Protozoal population significantly decreased by addition of salinomycin in all diets. Conclusion: The results of salinomycin evaluation in the current study can be implicated to mitigate the methane production, thus saving the feed energy loss and the accumulation of green house gases in environment. [Vet World 2012; 5(10.000: 609-613

  7. RNA-sequencing-based transcriptome and biochemical analyses of steroidal saponin pathway in a complete set of Allium fistulosum—A. cepa monosomic addition lines

    Science.gov (United States)

    Abdelrahman, Mostafa; El-Sayed, Magdi; Sato, Shusei; Hirakawa, Hideki; Ito, Shin-ichi; Tanaka, Keisuke; Mine, Yoko; Sugiyama, Nobuo; Suzuki, Minoru; Yamauchi, Naoki

    2017-01-01

    The genus Allium is a rich source of steroidal saponins, and its medicinal properties have been attributed to these bioactive compounds. The saponin compounds with diverse structures play a pivotal role in Allium’s defense mechanism. Despite numerous studies on the occurrence and chemical structure of steroidal saponins, their biosynthetic pathway in Allium species is poorly understood. The monosomic addition lines (MALs) of the Japanese bunching onion (A. fistulosum, FF) with an extra chromosome from the shallot (A. cepa Aggregatum group, AA) are powerful genetic resources that enable us to understand many physiological traits of Allium. In the present study, we were able to isolate and identify Alliospiroside A saponin compound in A. fistulosum with extra chromosome 2A from shallot (FF2A) and its role in the defense mechanism against Fusarium pathogens. Furthermore, to gain molecular insight into the Allium saponin biosynthesis pathway, high-throughput RNA-Seq of the root, bulb, and leaf of AA, MALs, and FF was carried out using Illumina's HiSeq 2500 platform. An open access Allium Transcript Database (Allium TDB, http://alliumtdb.kazusa.or.jp) was generated based on RNA-Seq data. The resulting assembled transcripts were functionally annotated, revealing 50 unigenes involved in saponin biosynthesis. Differential gene expression (DGE) analyses of AA and MALs as compared with FF (as a control) revealed a strong up-regulation of the saponin downstream pathway, including cytochrome P450, glycosyltransferase, and beta-glucosidase in chromosome 2A. An understanding of the saponin compounds and biosynthesis-related genes would facilitate the development of plants with unique saponin content and, subsequently, improved disease resistance. PMID:28800607

  8. RNA-sequencing-based transcriptome and biochemical analyses of steroidal saponin pathway in a complete set of Allium fistulosum-A. cepa monosomic addition lines.

    Science.gov (United States)

    Abdelrahman, Mostafa; El-Sayed, Magdi; Sato, Shusei; Hirakawa, Hideki; Ito, Shin-Ichi; Tanaka, Keisuke; Mine, Yoko; Sugiyama, Nobuo; Suzuki, Yutaka; Yamauchi, Naoki; Shigyo, Masayoshi

    2017-01-01

    The genus Allium is a rich source of steroidal saponins, and its medicinal properties have been attributed to these bioactive compounds. The saponin compounds with diverse structures play a pivotal role in Allium's defense mechanism. Despite numerous studies on the occurrence and chemical structure of steroidal saponins, their biosynthetic pathway in Allium species is poorly understood. The monosomic addition lines (MALs) of the Japanese bunching onion (A. fistulosum, FF) with an extra chromosome from the shallot (A. cepa Aggregatum group, AA) are powerful genetic resources that enable us to understand many physiological traits of Allium. In the present study, we were able to isolate and identify Alliospiroside A saponin compound in A. fistulosum with extra chromosome 2A from shallot (FF2A) and its role in the defense mechanism against Fusarium pathogens. Furthermore, to gain molecular insight into the Allium saponin biosynthesis pathway, high-throughput RNA-Seq of the root, bulb, and leaf of AA, MALs, and FF was carried out using Illumina's HiSeq 2500 platform. An open access Allium Transcript Database (Allium TDB, http://alliumtdb.kazusa.or.jp) was generated based on RNA-Seq data. The resulting assembled transcripts were functionally annotated, revealing 50 unigenes involved in saponin biosynthesis. Differential gene expression (DGE) analyses of AA and MALs as compared with FF (as a control) revealed a strong up-regulation of the saponin downstream pathway, including cytochrome P450, glycosyltransferase, and beta-glucosidase in chromosome 2A. An understanding of the saponin compounds and biosynthesis-related genes would facilitate the development of plants with unique saponin content and, subsequently, improved disease resistance.

  9. First Reprocessing of Southern Hemisphere Additional Ozonesondes (SHADOZ) Ozone Profiles (1998-2016): 2. Comparisons With Satellites and Ground-Based Instruments

    Science.gov (United States)

    Thompson, Anne M.; Witte, Jacquelyn C.; Sterling, Chance; Jordan, Allen; Johnson, Bryan J.; Oltmans, Samuel J.; Fujiwara, Masatomo; Vömel, Holger; Allaart, Marc; Piters, Ankie; Coetzee, Gert J. R.; Posny, Françoise; Corrales, Ernesto; Diaz, Jorge Andres; Félix, Christian; Komala, Ninong; Lai, Nga; Ahn Nguyen, H. T.; Maata, Matakite; Mani, Francis; Zainal, Zamuna; Ogino, Shin-ya; Paredes, Francisco; Penha, Tercio Luiz Bezerra; da Silva, Francisco Raimundo; Sallons-Mitro, Sukarni; Selkirk, Henry B.; Schmidlin, F. J.; Stübi, Rene; Thiongo, Kennedy

    2017-12-01

    The Southern Hemisphere ADditional OZonesonde (SHADOZ) network was assembled to validate a new generation of ozone-monitoring satellites and to better characterize the vertical structure of tropical ozone in the troposphere and stratosphere. Beginning with nine stations in 1998, more than 7,000 ozone and P-T-U profiles are available from 14 SHADOZ sites that have operated continuously for at least a decade. We analyze ozone profiles from the recently reprocessed SHADOZ data set that is based on adjustments for inconsistencies caused by varying ozonesonde instruments and operating techniques. First, sonde-derived total ozone column amounts are compared to the overpasses from the Earth Probe/Total Ozone Mapping Spectrometer, Ozone Monitoring Instrument, and Ozone Mapping and Profiler Suite satellites that cover 1998-2016. Second, characteristics of the stratospheric and tropospheric columns are examined along with ozone structure in the tropical tropopause layer (TTL). We find that (1) relative to our earlier evaluations of SHADOZ data, in 2003, 2007, and 2012, sonde-satellite total ozone column offsets at 12 stations are 2% or less, a significant improvement; (2) as in prior studies, the 10 tropical SHADOZ stations, defined as within ±19° latitude, display statistically uniform stratospheric column ozone, 229 ± 3.9 DU (Dobson units), and a tropospheric zonal wave-one pattern with a 14 DU mean amplitude; (3) the TTL ozone column, which is also zonally uniform, masks complex vertical structure, and this argues against using satellites for lower stratospheric ozone trends; and (4) reprocessing has led to more uniform stratospheric column amounts across sites and reduced bias in stratospheric profiles. As a consequence, the uncertainty in total column ozone now averages 5%.

  10. Efeito da adição de ácidos graxos em filmes à base de pectina The effect of addition of fatty acids on pectin films

    Directory of Open Access Journals (Sweden)

    Juliana A. Batista

    2005-12-01

    Full Text Available Os objetivos deste trabalho foram desenvolver filmes à base de pectina de baixo teor de esterificação, amidada, com adição dos ácidos graxos láurico (AL, palmítico (AP e esteárico (AE e caracterizá-los quanto às propriedades de permeabilidade ao vapor de água (PVA e ao oxigênio, propriedades mecânicas (tensão de ruptura e elongação, solubilidade em água e opacidade, além de observar a morfologia da superfície dos filmes utilizando microscopia eletrônica de varredura (MEV. A adição de 12 e 18% dos ácidos promoveu aumento da PVA e da elongação e redução da tensão de ruptura, em relação aos filmes com 6% de ácido graxo. Todos os filmes apresentaram-se 100% solúveis em água e mais opacos quando os ácidos graxos foram adicionados. A partir da MEV, foi observado que os ácidos graxos não se incorporaram à matriz filmogênica.The purposes of this research were to develop and characterize composite biofilms produced with low methoxyl amidated pectin plus lauric, palmitic and stearic acids. Water vapor permeability, oxigen permeability, mechanical properties (tensile strength and elongation, water solubility, opacity and, surface morphology were evaluated. The increase of fatty acids addition to 12 and 18% resulted in an increase in water vapor permeability and elongation and a decrease in tensile strength compared to the level of 6% of fatty acids. All formulations produced films showing 100% water solubility. As observed by scanning electronic microscopy the fatty acids were not homogeneously incorporated on the filmogenic matrices.

  11. Benefit of the addition of hormone therapy to neoadjuvant anthracycline-based chemotherapy for breast cancer: comparison of predicted and observed pCR.

    Science.gov (United States)

    Generali, Daniele; Corona, Silvia Paola; Pusztai, Lajos; Rouzier, Roman; Allevi, Giovanni; Aguggini, Sergio; Milani, Manuela; Strina, Carla; Frati, Albane

    2018-03-01

    Neoadjuvant hormonal therapy is generally considered a valid option for hormone receptor positive breast cancer (BC) patients who are unfit for chemotherapy or surgery. Whilst numerous studies analyzed efficacy of neoadjuvant chemotherapy (CT) or endocrine therapy (HT) alone in hormone receptor positive patients, there is a lack of research looking at the usefulness of a preoperative combinatorial approach of CT and HT in this patient subgroup. Using a predictive model previously described in the literature, developed to analyze the probability of benefit from preoperative chemotherapy, we were able to compare pathological complete response (pCR) rates expected with the use of CT alone with the pCR rates reported in a population of 192 patients treated with the combination of tamoxifen plus anthracycline-based CT at Cremona Hospital between 2003 and 2006. Even with a relatively small patient population, this approach provided insightful information for the selection of hormone receptor positive BC patients most likely to benefit from the use of preoperative HT and CT in combination. Whilst no statistically significant benefit was obtained with the addition of tamoxifen to neoadjuvant chemotherapy in the entire population, or in any of the molecular stratification subgroups, the analysis of the calibration curve showed that a combinatorial approach may improve pCR in patients with luminal B tumors. More specific trials should be designed to confirm our initial results. To the best of our knowledge, this is the first report investigating the efficacy of the combination of CT and HT in the neoadjuvant treatment of hormone receptor positive BC.

  12. Continuous anaerobic digestion of swine manure: ADM1-based modelling and effect of addition of swine manure fibers pretreated with aqueous ammonia soaking

    International Nuclear Information System (INIS)

    Jurado, E.; Antonopoulou, G.; Lyberatos, G.; Gavala, H.N.; Skiadas, I.V.

    2016-01-01

    Highlights: • Aqueous ammonia soaking (AAS) effect on methane yield: verification in continuously fed digesters. • AAS resulted in 98% increase of the methane yield of swine manure fibers in continuously fed digesters. • ADM1 was successfully adapted to simulating anaerobic digestion of swine manure. • Modification of hydrolysis kinetics was necessary for an adequate simulation of the digestion of AAS-treated fibers. - Abstract: Anaerobic digestion of manure fibers presents challenges due to their low biodegradability. Aqueous ammonia soaking (AAS) has been tested as a simple method to disrupt the lignocellulose and increase the methane yield of manure fibers. In the present study, mesophilic anaerobic digestion of AAS pretreated manure fibers was performed in CSTR-type digesters, fed with swine manure and/or a mixture of swine manure and AAS pretreated manure fibers (at a total solids based ratio of 0.52 manure per 0.48 fibers). Two different simulations were performed. In the first place, the Anaerobic Digestion Model 1 (ADM1) was fitted to a manure-fed, CSTR-type digester and validated by simulating the performance of a second reactor digesting manure. It was shown that disintegration and hydrolysis of the solid matter of manure was such a slow process that the organic particulate matter did not significantly contribute to the methane production. In the second place, ADM1 was used to describe biogas production from the codigestion of manure and AAS pretreated manure fibers. The model predictions regarding biogas production and methane content were in good agreement with the experimental data. It was shown that, AAS treatment significantly increased the disintegration and hydrolysis rate of the carbohydrate compounds of the fibers. The effect of the addition of AAS treated fibers on the kinetics of the conversion of other key compounds such as volatile fatty acids was negligible.

  13. Molybdenum-based additives to mixed-metal oxides for use in hot gas cleanup sorbents for the catalytic decomposition of ammonia in coal gases

    Science.gov (United States)

    Ayala, Raul E.

    1993-01-01

    This invention relates to additives to mixed-metal oxides that act simultaneously as sorbents and catalysts in cleanup systems for hot coal gases. Such additives of this type, generally, act as a sorbent to remove sulfur from the coal gases while substantially simultaneously, catalytically decomposing appreciable amounts of ammonia from the coal gases.

  14. Increased risk of schizophrenia from additive interaction between infant motor developmental delay and obstetric complications: evidence from a population-based longitudinal study.

    LENUS (Irish Health Repository)

    Clarke, Mary C

    2011-12-01

    Obstetric complications and developmental delay are well-established risk factors for schizophrenia. The authors investigated whether these risk factors interact in an additive manner to further increase risk for schizophrenia.

  15. [Carbon storage of forest vegetation and allocation for main forest types in the east of Da-xing'an Mountains based on additive biomass model].

    Science.gov (United States)

    Peng, Wei; Dong, Li Hu; Li, Feng Ri

    2016-12-01

    Based on the biomass investigation data of main forest types in the east of Daxing'an Mountains, the additive biomass models of 3 main tree species were developed and the changes of carbon storage and allocation of forest community of tree layer, shrub layer, herb layer and litter layer from different forest types were discussed. The results showed that the carbon storage of tree layer, shrub layer, herb layer and litter layer for Rhododendron dauricum-Larix gmelinii forest was 71.00, 0.34, 0.05 and 11.97 t·hm -2 , respectively. Similarly, the carbon storage of the four layers of Ledum palustre-L. gmelinii forest was 47.82, 0.88, 0, 5.04 t·hm -2 , 56.56, 0.44, 0.04, 8.72 t·hm -2 for R. dauricum-mixed forest of L. gmelinii-Betula platyphylla, 46.21, 0.66, 0.07, 6.16 t·hm -2 for L. palustre-mixed forest of L. gmelinii-B. platyphylla, 40.90, 1.37, 0.04, 3.67 t·hm -2 for R. dauricum-B. platyphylla forest, 36.28, 1.12, 0.18, 4.35 t·hm -2 for L. palustre-B. platyphylla forest. The carbon storage of forest community for the understory vegetation of R. dauricum was higher than that of the forest with L. palustre. In the condition of similar circumstances for the understory, the order of carbon storage for forest community was L. gmelinii forest > the mixed forest of L. gmelinii-B. platyphylla > B. platyphylla forest. The carbon storage of different forest types was different with the order of R. dauricum-L. gmelinii forest (83.36 t·hm -2 )> R. dauricum-mixed forest of L. gmelinii-B. platyphylla (65.76 t·hm -2 ) > L. palustre-L. gmelinii forest (53.74 t·hm -2 )> L. palustre-mixed forest of L. gmelinii-B. platyphylla (53.10 t·hm -2 )> R. dauricum-B. platyphylla forest (45.98 t·hm -2 ) > L. palustre-B. platyphylla forest (41.93 t·hm -2 ). The order of carbon storage for the vertical distribution in forest communities with diffe-rent forest types was the tree layer (85.2%-89.0%) > litter layer (8.0%-14.4%) > shrub layer (0.4%-2.7%) > herb layer (0-0.4%).

  16. Additional collection devices used in conjunction with the SurePath Liquid-Based Pap Test broom device do not enhance diagnostic utility

    Directory of Open Access Journals (Sweden)

    O'Connor Jason C

    2004-09-01

    Full Text Available Abstract Background We have previously shown that use of an EC brush device in combination with the Rovers Cervex-Brush (SurePath broom offered no significant improvement in EC recovery. Here we determine if use of additional collection devices enhance the diagnostic utility of the SurePath Pap for gynecologic cytology. Methods After informed consent, 37 women ages 18–56 receiving their routine cervical examinations were randomized into four experimental groups. Each group was first sampled with the SurePath broom then immediately re-sampled with an additional collection device or devices. Group 1: Rover endocervix brush (n = 8. Group 2: Medscand CytoBrush Plus GT (n = 7. Group 3: Rover spatula + endocervix brush (n = 11. Group 4: Medscand spatula + CytoBrush Plus GT (n = 11. Results Examination of SurePath broom-collected cytology yielded the following abnormal diagnoses: atypia (n = 2, LSIL (n = 5 and HSIL (n = 3. Comparison of these diagnoses to those obtained from paired samples using the additional collection devices showed that use of a second and or third device yielded no additional abnormal diagnoses. Importantly, use of additional devices did not improve upon the abnormal cell recovery of the SurePath broom and in 4/10 cases under-predicted or did not detect the SurePath broom-collected lesion as confirmed by cervical biopsy. Finally, in 36/37 cases, the SurePath broom successfully recovered ECs. Use of additional devices, in Group 3, augmented EC recovery to 37/37. Conclusions Use of additional collection devices in conjunction with the SurePath broom did not enhance diagnostic utility of the SurePath Pap. A potential but not significant improvement in EC recovery might be seen with the use of three devices.

  17. Study Modules for Calculus-Based General Physics. [Includes Modules 1 and 2: Dimensions and Vector Addition; Rectilinear Motion; plus a Trigonometry and Calculus Review].

    Science.gov (United States)

    Fuller, Robert G., Ed.; And Others

    This is part of a series of 42 Calculus Based Physics (CBP) modules totaling about 1,000 pages. The modules include study guides, practice tests, and mastery tests for a full-year individualized course in calculus-based physics based on the Personalized System of Instruction (PSI). The units are not intended to be used without outside materials;…

  18. Effects of the sp element additions on the microstructure and mechanical properties of NiCoFeCr based high entropy alloys

    International Nuclear Information System (INIS)

    Vida, Adam; Varga, Lajos K.; Chinh, Nguyen Quang; Molnar, David; Huang, Shuo; Vitos, Levente

    2016-01-01

    The effects of the sp (Al, Ga, Ge, Sn) element additions on the microstructure and mechanical properties of equimolar NiCoFeCr High Entropy Alloys (HEAs) are investigated. The results of X-ray diffraction measurements combined with scanning electron microscopy SEM investigations, as well as the results of nanoindentation test revealed that while the structure of the basic alloy is full FCC, the addition of sp elements has changed it to a multiphase containing both FCC and BCC components, but in different scales. Accordingly, the addition of sp elements strongly increases the strength of the basic state, especially in the case of alloys where the BCC phase is dominant in the microstructure. The physical properties as the Young’s- and shear moduli of the investigated HEAs were also determined using ultrasound methods. The correlation between these two moduli suggests a general relationship for metallic alloys.

  19. Evidence-Based Communication Practices for Children with Visual Impairments and Additional Disabilities: An Examination of Single-Subject Design Studies

    Science.gov (United States)

    Parker, Amy T.; Grimmett, Eric S.; Summers, Sharon

    2008-01-01

    This review examines practices for building effective communication strategies for children with visual impairments, including those with additional disabilities, that have been tested by single-subject design methodology. The authors found 30 studies that met the search criteria and grouped intervention strategies to align any evidence of the…

  20. Additive Manufacturing Infrared Inspection

    Science.gov (United States)

    Gaddy, Darrell; Nettles, Mindy

    2015-01-01

    The Additive Manufacturing Infrared Inspection Task started the development of a real-time dimensional inspection technique and digital quality record for the additive manufacturing process using infrared camera imaging and processing techniques. This project will benefit additive manufacturing by providing real-time inspection of internal geometry that is not currently possible and reduce the time and cost of additive manufactured parts with automated real-time dimensional inspections which deletes post-production inspections.