bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship of Kidney Injury Biomarkers with Long-Term Cardiovascular Outcomes after Cardiac Surgery
Authors: Parikh Chirag R. , Puthumana Jeremy , Shlipak Michael G. , Koyner Jay L. , Thiessen-Philbrook Heather , McArthur Eric , Kerr Kathleen , Kavsak Peter , Whitlock Richard P. , Garg Amit X. , Coca Steven G.
Published: August 2017

Clinical AKI, measured by serum creatinine elevation, is associated with long-term risks of adverse cardiovascular (CV) events and mortality in patients after cardiac surgery. To evaluate the relative contributions of urine kidney injury biomarkers and plasma cardiac injury biomarkers in adverse events, we conducted a multicenter prospective cohort study of 968 adults undergoing cardiac surgery. On postoperative days 1–3, we measured five urine biomarkers of kidney injury (IL-18, NGAL, KIM-1, L-FABP, and albumin) and five plasma biomarkers of cardiac injury (NT-proBNP, H-FABP, hs-cTnT, cTnI, and CK-MB). The primary outcome was a composite of long-term CV events or death, which was assessed via national health care databases. During a median 3.8 years of follow-up, 219 (22.6%) patients experienced the primary outcome (136 CV events and 83 additional deaths). Compared with patients without postsurgical AKI, patients who experienced AKI Network stage 2 or 3 had an adjusted hazard ratio for the primary composite outcome of 3.52 (95% confidence interval, 2.17 to 5.71). However, none of the five urinary kidney injury biomarkers were significantly associated with the primary outcome. In contrast, four out of five postoperative cardiac injury biomarkers (NT-proBNP, H-FABP, hs-cTnT, and cTnI) strongly associated with the primary outcome. Mediation analyses demonstrated that cardiac biomarkers explained 49% (95% confidence interval, 1% to 97%) of the association between AKI and the primary outcome. These results suggest that clinical AKI at the time of cardiac surgery is indicative of concurrent CV stress rather than an independent renal pathway for long-term adverse CV outcomes.
Identifying Contagion in a Banking Network
Authors: Morrison Alan , Vasios Michalis , Wilson Mungo , Zikes Filip
Published: August 2017

We present the first micro-level evidence of the transmission of shocks through financial networks. Using the network of credit default swap (CDS) transactions between banks, we identify bank CDS returns attributable to counterparty losses. A bank's own CDS spread increases whenever counterparties from whom it has purchased default protection themselves experience losses. We find no such effect from losses of non-counterparties, nor from counterparties to whom the bank has sold protection. The effect on bank CDS returns through this counterparty loss channel is large relative to the direct effect on a bank's CDS returns from its own trading losses.
Estudos Culturais e Comunicação: transversalidades epistemológicas
Authors: RODRIGUES TALLES RANGEL , FERRARI MARIA APARECIDA
Published: August 2017

Este trabalho tem por objetivo geral analisar o estatuto disciplinar da Comunicação no tocante a sua imbricação com os Estudos Culturais a partir da corrente nascida em Birmingham e, posteriormente, da perspectiva latino-americana. O fio condutor analítico deste artigo são as ementas do Programa de Pós-graduação em Ciências da Comunicação da Universidade do Vale do Rio dos Sinos ofertadas entre os anos de 2009 e 2010. Metodologicamente, esta pesquisa realiza uma pesquisa bibliográfica e análise documental. A hipótese geral deste trabalho orienta-se pelo pressuposto de que a Comunicação, sendo uma disciplina que edifica seu estatuto disciplinar na transversalidade, recorre aos estudos da cultura para dar lastro a sua legitimação que se plasma por meio do cotejamento de sua institucionalização, aqui observado nas ementas sob análise.
Epistemologias, Educação e Sociedade (Não Só) de Consumo
Authors: Reimer Ivoni Richter
Published: August 2017

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The power of language in the age of austerity: Volunteers and practitioners reflect on UK civil society
Authors: Clancy Sharon
Published: August 2017

This article is offered as an example of practice-based research, focusing on the concept of praxis: the bringing together of research, theory and action. It does this by exploring the challenges of group work and collaborative thinking, sharing the learning and reflection of
a group of civil society practitioners, from a range of different backgrounds and knowledge practices. The group came together under the auspices of the Raymond Williams Foundation, to reflect on 'keywords' that underpin their work in civil society. Using Raymond Williams's approach to hermeneutics,
they considered how language is used and embedded within society. The approach allowed for the possibility of critiquing and contesting ideas that have become ideologically or politically dominant. The group considered the keywords 'charity', 'philanthropy' and 'voluntarism', and how their
meanings have changed and evolved within society. The debate also brought into focus current concerns about shrinking state provision and consideration of whether the UK is witnessing a renewed focus on charity and corporate philanthropy. Ultimately, the article describes both the tensions
and areas of commonality within the group in response to the debate, as well as opening up the group's learning experience to critical examination.
Collaborative working practices: Imagining better research partnerships
Authors: Rasool Zanib
Published: August 2017

Collaborative research can bring communities to the heart of social research and provide a lens on the everyday experiences of ordinary people living extraordinary lives, capturing the funds of knowledge held in communities that exist outside the corridors of education institutions.
If delivered in an ethical way, co-production can empower communities and elevate voices that traditionally have been on the margins. Through collaboration, we can bridge the knowledge gap that exists between communities and universities and raise community aspirations.
Succeeding with interactive research: How to manage research with and about society
Authors: Krogh Andreas Hagedorn , Nielsen Morten Velsing
Published: August 2017

Increasingly, social science research is carried out in collaboration with partners outside universities, yet research methodology is lacking on how to manoeuvre in a terrain where multiple actors set expectations for research. This article conceptualizes interactive research as research
with and about society, and provides a set of systematic reflections on how to manage opposing pressures, tensions and dilemmas in interactive research projects. We formulate and address three major interactive research management tasks: ensuring continual commitment from external stakeholders,
maintaining the capacity for critique and ensuring that scientific standards are met. Based on our own experience and theories of interactive governance, network management and collaborative leadership, as well as on existing methodological literature, we provide guidance and suggest concrete
tools and methods for performing the tasks in order to avoid the pitfalls and harvest the gains of interactive research.
Does Cyberbullying Prevalence Among Adolescents Relate With Country Socioeconomic and Development Indicators? An Ecological Study of 31 Countries
Authors: Soares Sara , Brochado Sandra , Barros Henrique , Fraga Sílvia
Published: August 2017

Background: In addition to individual characteristics, it is also important to evaluate how the environment may influence the dynamics of cyberbullying. We aim to study the correlation between cyberbullying prevalence among adolescents and selected country-level indicators. Methods: We used two different data sources: data from a previously published literature review, to identify information on cyberbullying prevalence across countries, and data from the World Bank databases, to extract information on country-level indicators. A correlation matrix was used to present the association between the selected country-level indicators and the prevalence of cyberbullying. Results: We observed a statistically significant negative correlation between cyberbullying victimization (cybervictims and cyberbully-victims, respectively) and gross domestic product (r = −.474 and −.842), gross national income (r = −.485 and −.758), enrollment in secondary (r = −.446 and −.898) and tertiary education (r = −.222 and −.881), the number of secure Internet servers (r = −.118 and −.794), and the number of Internet users (r = −.190 and −.818). Conclusions: A country’s educational level seems to be an important contributor to the occurrence of cyberbullying.
The concentration of optimum dissolved oxygen levels for growth of mangrove crab Scylla serrata seed in recirculation system
Authors: Faturrohman Kurnia , Nirmala Kukuh , Djokosetiyanto Daniel , Hastuti Yuni Puji
Published: August 2017

ABSTRACT This study aimed to determine optimum dissolved oxygen (DO) through the addition of aeration and to evaluate the role of dissolved oxygen on production performance and stress responses of mangrove crab Scylla serrata. Experimental design used was complete randomized design with four treatments namely no aeration (A), one point aeration (B), two points aeration (C), and three points aeration (D). All treatments replicated three times. The crab with the average of body weight 45.6±2.1 g/individual cultured in a plastic box (40×30×30 cm3). The stocking densities was 10 crab/box. Crab was cultured within 42 days and were fed two times a day by restricted method (15% of the total biomass). The result showed that C treatment produced 5.51 mg/L dissolved oxygen and gave the best result of mangrove crabs production performance  with 60% survival, 0.83±0.03 g/day absolute growth rate and food conversion ratio 1.1. It also showed good response to the stress that indicated by the cortisol level (10.159 µg/dL). The best results of coefficient of diversity showed by D treatment that was 13.5%. The water quality during study period was fluctuative as affected by different dissolved oxygen value. Keyword: mangrove crabs, dissolved oxygen, production performance  ABSTRAK Penelitian ini bertujuan menentukan kadar oksigen terlarut (OT) atau dissolved oxygen (DO) yang optimum melalui penentuan titik aerasi serta mengevalusi peranan oksigen terlarut terhadap kinerja produksi dan respons stres kepiting bakau Scylla serrata. Rancangan penelitian yang digunakan adalah rancangan acak lengkap dengan empat pelakuan (penambahan titik aerasi dengan rincian A, tidak menggunakan titik aerasi; B, satu titik aerasi; C, dua titik aerasi dan D, tiga titik aerasi) dan tiga ulangan. Kepiting bakau yang digunakan memiliki berat rata-rata 45,6±2,1 g/ekor dengan padat tebar 10 ekor/wadah. Wadah yang digunakan selama pemeliharaan adalah bak fiber plastik yang berukuran 40×30×30 cm3. Pemeliharaan kepiting bakau dilaksanakan selama 42 hari dan diberikan pakan dua kali sehari dengan metode restricted yakni sebesar 15% dari biomassa kepiting. Hasil penelitian menunjukkan bahwa perlakuan C yaitu penambahan dua titik aerasi menghasilkan nilai kelarutan oksigen rata-rata sebesar 5,51 mg/L dan memberikan hasil terbaik terhadap kinerja produksi kepiting bakau (tingkat kelangsungan hidup 60%; laju pertumbuhan mutlak 0,83±0,03 g/hari; dan rasio konversi pakan 1,1). Perlakuan C juga menunjukkan respons stres yang baik dengan memiliki nilai kortisol paling rendah dari perlakuan lain yaitu 10,159 µg/dL. Untuk parameter koefisien keragaman berat, hasil terbaik terjadi pada perlakuan D sebesar 23,3%. Kualitas air selama penelitian memiliki nilai yang fluktuatif di setiap perlakuan sebagai efek adanya perbedaan nilai kelarutan oksigen yang dihasilkan. Kata kunci: kepiting bakau, kelarutan oksigen, kinerja produksi
The application of pigment-protein fraction from Nannochloropsis oculata on β-actin response of Cromileptes altivelis infected with viral nervous necrosis
Authors: Yanuhar Uun , Khumaidi Achmad
Published: August 2017

ABSTRACT  β-actin is a prominent protein in the immune system. An outcome from gene transcription, the protein protects against pathogen infection, such as receptor clustering, antigen internalization, and regulating vesicle for antigen processing. ß - actin expression will determine the success of immune response of the organism. This study aimed to understand the role of pigment-protein fraction (PPF) from Nannochloropsis oculata in the increase of β-actin expression in humpback grouper Cromileptes altivelis infected by viral nervous necrosis (VNN). The experiment was performed with one negative control (A: normal fish) and three PPF treatments (B: fish + PPF, C: fish + VNN, and D: fish + PPF + VNN). PPF was applied through the sonde method and analyzed with immunohistochemistry technique and Immunoratio software. The results showed that PPF was able to increase β-actin expression on all treatments: A (34.9%), B (38.1%), C (39.1%), and D (51.6%). It demonstrated PPF ability to induce the increase of β-actin expression indicating an improved defense of humpback grouper C. altivelis against VNN infection. Keywords: β-actin, pigment-protein fraction, Nannochloropsis oculata, VNN  ABSTRAK β-aktin adalah protein yang berfungsi penting sebagai salah satu sistem pertahanan tubuh. Protein ini merupakan hasil transkripsi dari gen yang memiliki fungsi penting dalam sistem pertahanan tubuh terhadap infeksi patogen, seperti kelompok reseptor, internalisasi antigen, dan mengatur keluar masuknya vesikel untuk pemrosesan antigen. Ekpresi β-aktin menjadi penentu berhasil atau tidaknya respons imun pada tubuh organisme. Penelitian ini bertujuan untuk mengetahui peran fraksi protein pigment (FPP) dari Nannochloropsis oculata dalam meningkatkan respons β-aktin pada ikan kerapu tikus Cromileptes altivelis yang terinfeksi viral nervous necrosis (VNN). Pengamatan dilakukan pada empat percobaan yaitu, satu kontrol (A : ikan normal) dan tiga perlakuan FPP (B : ikan + FPP, C: ikan + VNN, dan D: ikan + VNN + FPP). Pemberian FPP menggunakan metode sonde dan analisis hasil penelitian menggunakan teknik imunohistokimia dan Immunoratio. Hasil penelitian ini menunjukkan bahwa pengiduksian FPP mampu meningkatkan ekpresi β-aktin yaitu A (34,9%), B (38,1%), C (39,1%), dan D (51,6%). Hal tersebut menunjukan FPP mampu menjadi inducer yang baik untuk peningkatan ekpresi β-aktin. Meningkatnya ekspresi β-aktin bisa dijadikan sebagai indikator pertahanan tubuh ikan kerapu tikus C. altivelis terhadap infeksi VNN. Kata kunci: β-aktin, fraksi protein pigmen, Nannochloropsis oculata, VNN
Incremental benefits from the increasing in the production of koi fish Cyprinus carpio var. koi culture
Authors: Diatin Iis , Nuristy Dini F , Teduh Ahmad , Mujahid Muhammad
Published: August 2017

ABSTRACT  Koi fish is one of the species included in the intensification program of ornamental fish production. Production of koi has only reached 82.04% of total national production target thus making it potential for development. The objective of the study was to assess additional financial benefit of production increment through stocking pattern modification. Present research was performed using case study method on Pokdakan PBC Fish Farm (PPFF), koi fish farmers in Sukabumi. Financial analysis consisted of business analysis, investment criteria, and sensitivity. Stocking pattern management could increase ornamental fish production and its benefit margin up to 1.5 times higher. That investment criteria has shown NPV at value of IDR3,824 million, net BCR 4.96, IRR 86.0%, and PP 1.7 years. Koi fish farming was sensitive to a decline in survival rate and insensitive to the rise of formulated feed price. Keywords: business analysis, koi, investment criteria, production pattern, sensitivity  ABSTRAK  Ikan koi merupakan salah satu ikan yang termasuk dalam program penguatan produksi ikan hias Indonesia. Capaian dari target produksi ikan koi yang ditetapkan pemerintah hanya mencapai 82,04 %, sehingga budidaya ikan koi potensial untuk dikembangkan dan ditingkatkan produksinya. Metode yang digunakan adalah studi kasus pada kelompok pembudidaya ikan hias koi PPFF di Sukabumi. Analisis finansial yang digunakan meliputi analisis usaha, kriteria investasi dan sensitivitas. Pengaturan pola tebar dapat meningkatkan jumlah produksi ikan hias dan marjin keuntungan hingga 1,5 kali. Analisis kriteria investasi menghasilkan nilai NPV sebesar Rp3.824 juta, net B/C 4,94, IRR 86,0% dan PP 1,7 tahun. Budidaya ikan koi sensitif terhadap penurunan kelangsungan hidup dan tidak sensitif terhadap peningkatan harga pakan buatan. Kata kunci: analisis usaha, koi, kriteria investasi, pola tebar, produksi
Investigating Students’ Perceptions of Motivating Factors of Online Class Discussions
Authors: Lee Joohi , Martin Leisa
Published: August 2017

One of the goals of teacher education is to prepare our citizens to communicate in a variety of ways. In our present society, communication using digital media has become essential. Although online discussions are a common component of many online courses, engaging students in online discussions has been a challenge. This study queried 86 educators in a math/science teacher education graduate program to examine their perceptions on the factors that motivate them to participate in online discussions.

The results revealed a pragmatic outlook on online education. In terms of intrinsic versus extrinsic motivation, the participants’ main motivation to participate in online class discussions was extrinsic (85.88%), specifically so that they could earn an acceptable participation grade. With regards to discussion grouping formats, they preferred small group discussions (81%) which could facilitate their ability to develop rapport with a small group of fellow classmates over whole class discussion (38.83%). With respect to discussion facilitation, they focused on the practical need to have the instructor to answer their questions about course assignments (67.06%) over online open discussion without a given topic (35.72%). Next, when asked about discussion question types based on Bloom’s taxonomy, their strongest preference reflected a desire for application (89.54%) questions which would facilitate their ability to use theories discussed in class in their daily work as educators. Through collaboration with twenty-first-century learners, online education can use data-driven decision making to help transform online discussion from being the least desirable component of online courses to a more relevant, instructional medium.    
The Use of Social Media in E-Learning: A Metasynthesis
Authors: Mnkandla Ernest , Minnaar Ansie
Published: August 2017

The adoption of social media in e-learning signals the end of distance education as we know it in higher education. However, it appears to have very little impact on the way in which open and distance learning (ODL) institutions are functioning. Earlier research suggests that a significant part of the explanation for the slow uptake of social media in e-learning lies outside of conventional factors attributed to distance learning reforms.

This research used the conceptual framework for online collaborative learning (OCL) in higher education. Social media such as blogs, wikis, Skype or Google Hangout, Facebook; and even mobile apps, such as WhatsApp; could facilitate deep learning and the creation of knowledge in e-learning at higher educational institutions.

This metasynthesis is an interpretative integration of peer-reviewed qualitative research findings on social media in e-learning. It includes a synthesis of data, research methods, and theories used to investigate social media in e-learning. Seven themes emerged from the data which have been recrafted into a framework for social media in e-learning as the final product. The proposed framework could be useful to instructional designers and academics who are interested in using modern learning theories and want to adopt social media in e-learning in higher education as a deep learning strategy.
Openness and Praxis: Exploring the Use of Open Educational Practices in Higher Education
Authors: Cronin Catherine
Published: August 2017

Open educational practices (OEP) is a broad descriptor of practices that include the creation, use, and reuse of open educational resources (OER) as well as open pedagogies and open sharing of teaching practices. As compared with OER, there has been little empirical research on individual educators’ use of OEP for teaching in higher education. This research study addresses that gap, exploring the digital and pedagogical strategies of a diverse group of university educators, focusing on whether, why, and how they use OEP for teaching. The study was conducted at one Irish university; semi-structured interviews were carried out with educators across multiple disciplines. Only a minority of educators used OEP. Using constructivist grounded theory, a model of the concept “Using OEP for teaching” was constructed showing four dimensions shared by open educators: balancing privacy and openness, developing digital literacies, valuing social learning, and challenging traditional teaching role expectations. The use of OEP by educators is complex, personal, and contextual; it is also continually negotiated. These findings suggest that research-informed policies and collaborative and critical approaches to openness are required to support staff, students, and learning in an increasingly complex higher education environment.
Generation of a Chimeric Antibody against a Synthetic Peptide Derived From IL-23p19 with Potential Therapeutic Application
Authors: Diana Pérez-Etcheverry , Carmen Lorenzo-Ferreiro
Published: August 2017

Aim: To construct an express a mouse-human chimeric antibody against IL-23p19 using a
synthetic peptide as immunogen.

Methods: Immunization of mice with a synthetic peptide derived from the IL-23p19 sequence and generation of hybridoma secreting specific antibodies. The chimeric antibody was created using two eukaryotic plasmid constructions; one of them carrying the light mouse-human chain and the other the heavy mouse-human chain. CHO-K1 cells were cotransfected with both plasmids and stable transfectants were grown in selective culture medium.

Results: A chimeric version of anti-IL-23p19 was successfully constructed and expressed in eukaryotic cells. The expressed chimeric antibody showed specific recognition not only of the peptide used as immunogen but also the subunit p19 and the complete interleukin Il-23.

Conclusion: A Chimeric antibody that was developed against a synthetic peptide, which is able to recognize the parent protein IL23 biologically active, could be developed into a targeted therapy in diseases with chronic inflammation.
Adsorption Study of the Removal of Copper (II) Ions using Activated Carbon Based Canarium Schweinfurthii Shells Impregnated with ZnCl2
Authors: Maguie Kammegne Adelaide , Nsami Ndi Julius , Daouda Kouotou , Randy Che Nangah , Mbadcam Ketcha Joseph
Published: August 2017

The adsorption of Cu2+ions on activated carbon based canarium schweinfurthii impregnated with ZnCl2 was studied. The shells of canarium schweinfurthii were impregnated with ZnCl2 at varying ZnCl2 concentrations, temperature, residence time while keeping the heating rate fixed at 10 °C / min and the ratio of impregnation of 1:1. The activated carbon with the highest surface area in term of iodine number of 860,817 mg/g, the highest methylene blue of 741,6 mg/g and 74,66 % of yield of carbon was obtained at 650 °C, 60 % ZnCl 2 and 30min. From the batch adsorption studies, the equilibrium time was found to be 40 min. Analysis of equilibrium isotherm models revealed a good correlation of the experimental data with the Tempkin (R 2 = 0.909) model. This confirms a high affinity of the activated carbon for Cu 2+ ions on the heterogeneous surface. The value of energy obtained from the Tempkin model was 60,606 J/mol and the presence of pics between 487 cm-1 to 871 cm-1 indicating that physisorption and chemisorption were taking place during this sorption. The pseudo-second order kinetics(R 2 = 0.999) governs the adsorption of Cu2+ions on this activated carbon.
Influence of Academics’ Designation and Experience on their Job Satisfaction in Universities in Rift Valley Region of Kenya
Authors: Kiplangat Henry Kiptiony , Kiptiony Gladys Jerobon
Published: August 2017

Institutions of higher learning, universities in particular recognise staffing as a vital part of the management process to ensure the success of universities and the education sector as a whole. The education sector is responsible for developing a sustainable pool of highly trained, skilled and competent human resource capital, and universities are charged with the provision of relevant quality education and ought to foster national cohesion and integration. In fulfilling this mandate however, it is important to have job satisfaction guarantees through correct placements for academics which will ensure committed and stable workforce. It is the aim of this paper to find out the influence that designation and experience of academics’ has on their job satisfaction. The study targeted chartered public and private universities in the Rift Valley Region (RVR), Kenya. The study population consisted of university management, deans and lecturers from the selected universities. The study employed convergent parallel mixed methods design with random and systematic sampling techniques to select the respondents. Purposive sampling was also used to select information-rich cases. Data collection instruments were questionnaires, interview guides and document analysis guide. Analysis was done using descriptive statistics, Pearson correlation coefficient and t-test, One-way Analysis of Variance and regression coefficients.  It was established that the dons with the most experience were highly satisfied in their job. Job designation was a significant determinant on perceived job satisfaction levels among the academic staff with the professors demonstrating the highest job satisfaction.
Demographic Factors Affecting Teachers’ Job Satisfaction and Performance in Private Primary Schools in Yei Town, South Sudan
Authors: Ohide Alyaha Daniel Felix , Mbogo Rosemary Wahu
Published: August 2017

Job satisfaction is an important construct to the field of organizational behavior and the practice of human resource management. Schools are no exception to the list of organizations ensuring teachers’ job satisfaction therefore becomes inevitable if schools have to record good performances. This paper aims at examining some of the demographic factors affecting job satisfaction of teachers in private primary schools and their consequent performance. To attain this objective; the authors carried out a survey study in private schools in Yei town, South Sudan. Simple random sampling technique was used to select the respondents from ten private schools in the town. A total of 110 respondents were considered for the study constituting 10 head teachers and 100 teachers from each of the 10 schools. Questionnaires were used for data collection. Data was then analysed by the use of Statistical Package for Social Science (SPSS) version 12.0 and presented in frequencies and percentages. The factors identified included gender, age bracket, educational level, pay and length of service of teachers.  Based on the findings, it is apparent that certain demographic factors have a significant influence on the level of job satisfaction of teachers in private schools.
Measuring Chern numbers in Hofstadter strips
Authors: Mugel Samuel , Dauphin Alexandre , Massignan Pietro , Tarruell Leticia , Lewenstein Maciej , Lobo Carlos , Celi Alessio
Published: August 2017

Topologically non-trivial Hamiltonians with periodic boundary
conditions are characterized by strictly quantized invariants. Open
questions and fundamental challenges concern their existence, and the
possibility of measuring them in systems with open boundary conditions
and limited spatial extension. Here, we consider transport in Hofstadter
strips, that is, two-dimensional lattices pierced by a uniform magnetic
flux which extend over few sites in one of the spatial dimensions. As we
show, an atomic wave packet exhibits a transverse displacement under the
action of a weak constant force. After one Bloch oscillation, this
displacement approaches the quantized Chern number of the periodic
system in the limit of vanishing tunneling along the transverse
direction. We further demonstrate that this scheme is able to map out
the Chern number of ground and excited bands, and we investigate the
robustness of the method in presence of both disorder and harmonic
trapping. Our results prove that topological invariants can be measured
in Hofstadter strips with open boundary conditions and as few as three
sites along one direction.
Anatomical Responses of Ajwa Dates Sprouts (Phoenix dactylifera L.) to Water Availability and light Intensity
Authors: Triastari Armanda Dian
Published: August 2017

As the biggest Moslem population in the world, Indonesia still has a high dependency on importing date palms from other countries. Ajwa dates (Phoenix dactylifera L.) is one of special date palm cultivar which had cultivated since 5000 BC in arid climate area in Saudi Arabia. Adaptation and optimation of environmental factors for Ajwa dates cultivation in Indonesia are important to be conducted to meet the date palm demand of this country. A study on anatomical responses of Ajwa dates sprouts to water availability and light intensity has been conducted. Ajwa date sprouts had been exposed to combinations of three shade variations (0%, 50%, and 90% shade) and four water availability variations (25%, 50%, 75%, and 100% of the field capacity).  Data were taken from day 0 until day 45 of germination. Morphological parameters which observed and analyzed were the leaf blade length and sprouts root length. Anatomical parameters which observed and analyzed were root radius, stele diameter, leaves numbers, leaves thickness, and stomatal diameter. Variations on water availability and light intensity gave the same effect (not significantly different) in almost every parameters which measured, therefore, the most optimal combination water-light treatment was still unknown. Advanced research and longer duration of experiment need to be conducted to gain the complete information regarding the optimization of environmental factors to increase the Ajwa date productivity in Indonesia.
Analisis Aspek Molekuler Biomarka Alkana Bercabang Core Badak 1/208 Muara Badak, Kutai Kartanegara, Kalimantan Timur
Authors: Firmansyah R. Arizal , Burhan R. Y. Perry
Published: August 2017

Study compound biomarka branched alkanes on core 1/208 Rhinos have done to contribute to the activities of oil exploration wells 1/208 Muara Badak Badak, East Kalimantan's Kutai Kartanegara-through core biomarka profile branched alkanes. Core samples extracted by alternately with solvent mixture of toluene-methanol (3: 1) and chloroform-methanol (3: 1). Then fractionated by Column Chromatography and Thin Layer Chromatography to obtain aliphatic hydrocarbon fraction. Fractions obtained were identified using Gas Chromatography-Mass Spectrometry.The content biomarka aliphatichydrocarbon fraction were identified, among others, iso and anteiso alkanes, mono and trimethyl alkanes. Compounds iso and anteiso alkanes, and alkyl alkane other, providing information that the source of organic material core samples I and II is derived from microorganisms prokaryotic or biogenic precursor derived from cyanobacteria (marine microorganisms) and homologous monomethyl alkanes found in core samples II closer homologous series monomethyl alkanes found in sediments and oil and Precambrian Proterozoic era, so it can be said that the core sample II core samples older than I.
Free vibration analysis of moderately thick isotropic homogeneous open cylindrical shells using improved Fourier series method
Authors: Ahad Fazl e , Shi Dongyan , Hina Zarnab , Anees Ur Rehman
Published: August 2017

In this paper an Improved Fourier series method has been employed to study the free vibrations of isotropic homogeneous moderately thick open cylindrical shells with arbitrary subtended angle and general elastic restraints. In this method, regardless of the boundary conditions, each of the displacement components of open shell is invariably expressed as a simple trigonometric series with accelerated and uniform convergence over the solution domain. Distributed elastic restraints are used to specify the elastic boundary conditions along the shell edges and therefore, arbitrary boundary restraints can be achieved by varying the values of spring’s stiffness. All the unknown expansion coefficients are treated as the generalized coordinates and solved using the Rayleigh-Ritz technique. A considerable number of new vibration results for isotropic open cylindrical shells with various geometric parameters and boundary conditions are presented. The effects of boundary stiffness, thickness to radius ratio and subtended angle on the vibration characteristics are also discussed in detail.
Numerical analysis on dynamic responses of single-storey buildings under seismic effects
Authors: Dong Feng Hui , Lou Can Hong , Liu Yuan , Sun Bao Jiang
Published: August 2017

The paper applies the commercial software ABAQUS to establish numerical models of an original single-storey building and a reinforced building, and conducts experimental test to verify correctness of the computation models. Damages and dynamic characteristics of two kinds of models under seismic effects are studied systematically. X-direction acceleration amplitudes of the wall obviously exceeded those in Y direction. In the same horizontal direction, accelerations of the left wall obviously exceeded those of the right wall. Compared with the original model, the X-direction acceleration amplitude is decreased by 15.4 %, and the Y-direction acceleration amplitude is decreased by 49 % in the left wall of the reinforced model. As for right wall of the reinforced model, the X-direction acceleration amplitude is decreased by 30.4 %, and the Y-direction acceleration amplitude is decreased by 17.6 %. In the X direction, the power amplification factors of the reinforced model were less than those of the original model, and the value was decreased by 30 % for the power amplification factors corresponding to 1.3 g. In the Y direction, the power amplification factors of the reinforce model were less than those of the original model under different seismic effects, wherein the value of the reinforced model was decreased by 33 % for the power amplification factors corresponding to 1.3 g compared with the original model. Under the seismic effect of 0.1 g, damages took place to four wall bodies of the model at earliest, but its value was small. With increased seismic input excitation, damage degree of the wall bodies was also gradually increased. Under the seismic effect of 0.8 g, damages to four wall bodies were serious. Under seismic effect of 1.3 g, damage values of 4 wall bodies reached the maximum value 0.99, and the single-storey building will fail. Damages values of four wall bodies of the original model were relatively concentrated; while damage values of four wall bodies of the reinforced model were disperse. Under each seismic effect, the overall damage value was smaller than that of the reinforced model. This result fully indicates that reinforcement can reduce damages of wall bodies and generate anti-seismic effects.
The research for partitioned algorithm of coupling of elastic pipe and cross-flow in a cylinder
Authors: Yue Qian Bei , Dong Ri Zhi , Liu Ju Bao
Published: August 2017

In the marine flatbed, nuclear power stations and oil fields, the marine risers and heat exchangers are induced vibrations and collision, even caused failure with cross flow. This is a typical problem of bundles vibration in fluid-structure interaction. In this paper, the elastic pipe was separated into several beam elements. And the dynamical equation was adopted to describe the structure. The fluid domain of cylinder was separated into solid elements. And the computational fluid dynamics equation was adopted to describe the fluid. At the fluid-structure coupling interface, the formulas of displacement, velocity and load was derived and the corresponding convergence criterion was also derived. Thus, the partitioned coupling algorithm was established for the elastic pipe and the cross-flow in cylinder. The example showed that, comparing to the results of monolithic coupling algorithm, the error was small. Thus, it proved that the correctness of the partitioned coupling algorithm in this article. And it will provide an effective computational method for vibrations and collision of bundles in a more complex fluid domain.
Shaking table testing and numerical modeling of continuous welded ballast track on bridges under longitudinal seismic loading
Authors: Wang Ping , Liu Hao , Wei Xiankui , Chen Rong , Xiao Jieling , Xu Jingmang
Published: August 2017

In order to confirm the validity of the ideal elasto-plastic resistance model applied to the ballast track under seismic loading, this paper studies the seismic response of continuous welded ballast track on bridges through the shaking table test and presents a process of updating the model based on the test results. The results indicate that the track constraint can improve the low order natural frequency of bridges significantly, and reduce the displacement response of the bridge. When ballast beds are effectively in a dynamic reciprocating state while under seismic loading, a structural change between the granules will occur, wherein some will flow and redistribute. The dynamic hysteretic change of the ballast longitudinal resistance is complex and quite different from that of the ideal elasto-plastic hysteretic route, and the ballast longitudinal resistance performance degenerates. If ballast longitudinal resistance is assumed to be ideal elastic-plastic resistance, the actual beam displacement response will be underestimated and the calculated rail seismic force will be greater than the test result. Moreover, the equivalent stiffness coefficient Ke and damping coefficient Ce of the ballast dynamic resistance characteristics could be obtained by model updating, and the simulation results coincide well with the test results.
Double synchronization states of two exciters with horizontal asymmetric structure in a vibrating system
Authors: Li Lingxuan , Chen Xiaozhe
Published: August 2017

Synchronization of two exciters with asymmetric structure is more widely used in engineering, such as vibrating conveyer, dewatering screen, vibrating screen, however, the synchronization state of two exciters with asymmetric structure in the sub-resonant and super-resonant states is less considered, and it is a valuable research topic. Firstly, we establish a kind of weakly nonlinear vibrating system driven by two exciters with opposite rotation directions and asymmetrical structure. Using Lagrange equations, the differential equations of the vibrating system are obtained. Secondly, we apply Fourier series expansion to obtain the nonlinear elastic force of the nonlinear stiffness. Thirdly, we introduce the modified averaging method of small parameters and Hamilton’s principle to get the criterions of synchronization synchronization stability of two exciters. The theoretical analysis shows that the phase differences are stabilized in the vicinity of Pi phase difference in a super-resonant state when l0 approaches to le, otherwise, in the neighborhood of zero phase difference in a sub-resonant state. Then, the above theory is verified by experiments. The stable phase difference, amplitudes responses and energy consumption are also discussed. This research provides the foundation and guidance for the synchronization of two exciters with horizontal asymmetrical structure and engineering design.
Bending fault evaluation for the HP-IP rotor system of the nuclear steam turbine based on the dynamic model
Authors: Yang Zhang , Jiang Yanlong , Zhang Guoyuan
Published: August 2017

With considering the unbalance mass-fluid film bearings-rotor elements, a dynamics model for the nuclear half-speed 1000 MW saturated steam turbine with No. Dongfang HN1089 is constructed. By solving of the Reynolds Equation and the dynamics model, the oil pressure distribution and dynamic coefficients of the fluid film bearings, and the unbalance response of the rotor, are obtained. The method for evaluating the bending fault based on the dynamics model is proposed, in which the bending parameter is transformed as the unbalance mass. A case on the bending fault evaluation for HN1089 is carried out. The results show that the response sensitivity of HN1089 on the unbalance mass is about 1/6 that of the thermal power units with the same capacity (1000 MW); and it is difficult to decrease the excited response from the bending fault even to add the maximum unbalance mass. In actual, the removing stress in the partial zone and turning method are applied to deal with the HP-IP rotor bending fault, and the response of the repaired rotor is 0.033 m by the actual field test. The results show the model and the method for evaluating the bending fault are accurate and reasonable, which will provide the important theoretical guide for fast and accurately dealing with such bending fault in the steam turbine rotor system.
Dynamic response of water saturated subgrade surface layer under high speed train using moving element method
Authors: Liu Bao , Su Qian , Liu Ting , Li Ting
Published: August 2017

Since the moving element method (MEM) is an elegant method for solving problems involving moving loads. This paper extends the moving element method to the dynamic response of the water-saturated subgrade surface layer under a high-speed train. The track model is described as the Euler beam to simulate the rail, concrete slab layer and elastic medium to simulate the concrete base layer. The water-saturated subgrade surface layer is characterized by Biot’s dynamic poroelastic theory, and the other subgrade components are regarded as elastic medium. The governing equations are formulated in a coordinate system traveling at a constant velocity, and the associated finite element formulation in a moving frame of reference is derived. The proposed computational scheme is applied to investigate the dynamic characteristics of the water-saturated subgrade surface layer subjected to the moving train load. The effects of various key parameters including the train velocity, permeability, drainage boundary, elastic modulus and rail irregularity on hydro-mechanical response of the saturated subgrade surface layer are carefully analyzed.
Prediction of natural frequency of basalt fiber reinforced polymer (FRP) laminated variable thickness plates with intermediate elastic support using artificial neural networks (ANNs) method
Authors: Altabey Wael A.
Published: August 2017

The paper is focused on the application of artificial neural networks (ANNs) in predicting the natural frequency of basalt fiber reinforced polymer (FRP) laminated, variable thickness plates. The author has found that the finite strip transition matrix (FSTM) approach is very effective to study the changes of plate natural frequencies due to intermediate elastic support (IES), but the method difficulty in terms of, a lot of calculations with large number of iterations is the main drawback of the method. For training and testing of the ANN model, a number of FSTM results for different classical boundary conditions (CBCs) with different values of elastic restraint coefficients (KT) for IES have been carried out to training and testing an ANN model. The ANN model has been developed using multilayer perceptron (MLP) Feed-forward neural networks (FFNN). The adequacy of the developed model is verified by the regression coefficient (R2) and Mean Square error (MSE) It was found that the R2 and MSE values are 0.986 and 0.0134 for train and 0.9966 and 0.0122 for test data respectively. The results showed that, the training algorithm of FFNN was sufficient enough in predicting the natural frequency in basalt FRP laminated, variable thickness plates with IES. To judge the ability and efficiency of the developed ANN model, MSE has been used. The results predicted by ANN are in very good agreement with the FSTM results. Consequently, the ANN is show to be effective in predicting the natural frequency of laminated composite plates.
Vibration stimulation effect on biomechanical variation of lower-limb joint according to vibration perception threshold
Authors: Kwak Kiyoung , Kim Huigyun , Song Kyukeun , Kim Dongwook
Published: August 2017

Vibration applied to relaxed muscle or tendon causes tonic reflex contraction in a muscle. Furthermore, when vibration is applied to a muscle, involuntary enhancement of EMG and contraction is induced. Regarding this finding, many studies on the influence of vibration on a muscle and static posture have been performed. However, precedent studies have limitations in applying single characteristic-vibration without any consideration on personal difference on vibration. And studies have been performed to research the change in dynamic state according to the intensity of sensing vibration, but no analysis has been performed on the biomechanical aspect of the lower-limb joints. Nor any consideration was given on the effect of vibration frequency. Therefore, the purpose of this study was to analyze the biomechanical variation in the lower-limb joints according to the characteristics of the mechanical vibration stimulation flowing into Achilles tendon and tibialis anterior tendon during gait, in consideration of the vibration perception threshold and vibration frequency. For this purpose, this study measures the vibration perception threshold according to vibration frequency at each tendon exposed to the stimulation. According to the result, vibration perception threshold varies according to vibrating tendon and vibration frequency. Based on the measurement result of vibration perception threshold, vibration is applied to an Achilles tendon and tibialis anterior tendon during gait. In order to analyze the biomechanical variation in the lower-limb joints according to the characteristics of vibration stimulation applied to each tendon during gait, the angle, moment and power of the lower-limb joints is analyzed using 3D motion analysis system. As a result, biomechanical variation, when vibration lower than a perception threshold is applied, is similar to the variation when vibration at perception threshold is applied. This result implies that vibration stimulation may cause biomechanical variation of lower-limb joints. Furthermore, this means that its biomechanical variation may vary according to the characteristics of the vibration applied.
Invited Review: Recent developments in vibration control of building and bridge structures
Authors: Ghaedi Khaled , Ibrahim Zainah , Adeli Hojjat , Javanmardi Ahad
Published: August 2017

This paper presents a state-of-the-art review of recent articles published on active, passive, semi-active and hybrid vibration control systems for structures under dynamic loadings primarily since 2013. Active control systems include active mass dampers, active tuned mass dampers, distributed mass dampers, and active tendon control. Passive systems include tuned mass dampers (TMD), particle TMD, tuned liquid particle damper, tuned liquid column damper (TLCD), eddy-current TMD, tuned mass generator, tuned-inerter dampers, magnetic negative stiffness device, resetting passive stiffness damper, re-entering shape memory alloy damper, viscous wall dampers, viscoelastic dampers, and friction dampers. Semi-active systems include tuned liquid damper with floating roof, resettable variable stiffness TMD, variable friction dampers, semi-active TMD, magnetorheological dampers, leverage-type stiffness controllable mass damper, semi-active friction tendon. Hybrid systems include shape memory alloys-liquid column damper, shape memory alloy-based damper, and TMD-high damping rubber.