Synthesis and characterization of poly (styrene-g-ethylene oxide)

Imperial Users onl

Data-driven Balanced Truncation for Predictive Model Order Reduction of Aeroacoustic Response

Rapid prediction of the aeroacoustic response is a key component in the design of aircraft and turbomachinery. While it is possible to achieve accurate predictions using direct solution of the compressible Navier-Stokes equations, applications of such solvers is not feasible in design optimization due to the high cost of resolving wave phenomena in an Eulerian setting. In this work, we propose a technique for highly accelerated predictions of aeroacoustic response using a data-driven model reduction approach based on the eigensystem realization algorithm (ERA), as a non-intrusive balanced truncation method. Specifically, we create and compare ERA ROMs based on the training data generated by solving the linearized and nonlinear Euler equations with Gaussian pulse inputs, and use them for prediction of the aeroacoustic response of an airfoil subject to different types of gust loading. The results show that both ROMs are in good agreement with the full-order model (FOM) solution in a purely predictive setting, while achieving orders of magnitude reduction in the online computation time. Using ERA for prediction of the acoustic response requires activating each input channel separately in the FOM for training ROMs, and operating on a large Hankel matrix, that can become computationally infeasible. We address this bottleneck in two steps: first, we propose a multi-fidelity gappy POD method to identify the most impactful input channels based on a coarser grid. Therefore, we reduce the computation cost on the FOM and ROM levels as we build the Markov sequence by querying the high-resolution FOM only for the input channels identified by gappy POD. Second, we use tangential interpolation at the ROM level to reduce the size of the Hankel matrix. The proposed methods enable application of ERA for highly accurate online acoustic response prediction and reduce the offline computation cost of ROMs

Non-intrusive Balancing Transformation of Highly Stiff Systems with Lightly-damped Impulse Response

Balanced truncation (BT) is a model reduction method that utilizes a coordinate transformation to retain eigen-directions that are highly observable and reachable. To address realizability and scalability of BT applied to highly stiff and lightly-damped systems, a non-intrusive data-driven method is developed for balancing discrete-time systems via the eigensystem realization algorithm (ERA). The advantage of ERA for balancing transformation makes full-state outputs tractable. Further, ERA enables balancing despite stiffness, by eliminating computation of balancing modes and adjoint simulations. As a demonstrative example, we create balanced ROMs for a one-dimensional reactive flow with pressure forcing, where the stiffness introduced by the chemical source term is extreme (condition number $10^{13}$), preventing analytical implementation of BT. We investigate the performance of ROMs in prediction of dynamics with unseen forcing inputs and demonstrate stability and accuracy of balanced ROMs in truly predictive scenarios whereas without ERA, POD-Galerkin and Least-squares Petrov-Galerkin projections fail to represent the true dynamics. We show that after the initial transients under unit impulse forcing, the system undergoes lightly-damped oscillations, which magnifies the influence of sampling properties on predictive performance of the balanced ROMs. We propose an output domain decomposition approach and couple it with tangential interpolation to resolve sharp gradients at reduced computational costs

Mood-tracking application as persuasive technology for reduction of occupational stress

Occupational stress is a major concern in the job performance of employees. The use of persuasive technologies is one way to prevent or reduce this stress. The present study developed a mood tracking application and tested its effect on stress reduction of employees. Twenty-six employees of a petrochemical company were divided into equally-sized groups of married and single participants. Employees' accommodations are different based on their marital status. Other variables effecting stress were same for both groups. An OSI-R questionnaire was used to collect data before and after four weeks of application use. In present pilot study, data analysis shows that this kind of persuasive technology can have a significant positive effect on single employees and help them to decrease and manage their stress; however, no meaningful results were recorded for the married group because they did not use the application as much as participants in the single group

Congenital absence of the dens of axis

Embryological aetiology of anomaly of the dens of the axis discussed. The previous literature of this subject is briefly reviewed. A case of complete absence of dens of the axis with severe torticollis and spastic tetraplegia is presented. This 6-year-old patient recovered fully following occipito-cervical fusion. © 1974, International Spinal Cord Society. All right reserved

Replicative intermediates of Tomato leaf curl virus and its satellite DNAs

AbstractSeveral plant geminiviruses have been shown recently to utilize both rolling-circle replication (RCR) and recombination-dependent replication (RDR) strategies. A highly specific binding of the viral replication-associated protein (Rep) to its cognate DNA is essential for initiation of viral DNA replication and for the recognition of DNA components of the bipartite geminiviruses of the Begomovirus genus. We have extended the replication analysis to the monopartite Australian Tomato leaf curl virus (ToLCV), its Rep binding deficient mutants, and the satellite DNAs it supports. Analyses of viral DNA by two-dimensional agarose gel electrophoresis after fractionation by single-stranded (ss) DNA-selective cellulose chromatography revealed that DNA intermediates of ToLCV and its mutant were identical. Both RCR and RDR intermediates were identified. New ToLCV DNA forms were observed and characterized as subgenomic topoisomers, heterogeneous open circular double-stranded (ds) DNA, and degradation products. A 1350-nt DNA β satellite associated with the unrelated Cotton leaf curl Multan virus (CLCuMV) was supported by ToLCV and produced intermediates of both RCR and RDR, suggesting that replication strategies of satellites are determined by the helper virus. Replicative intermediates of the 682 nt ToLCV satellite DNA could not be resolved; however, concatemers of up to octamer were detected, together with a field of hybridizing material suggestive of complementary strand replication on heterogeneous circular ssDNA templates

Success factors for hospital information system implementation in public university hospitals

Hospital Information System (HIS) could help the delivery of high quality health services and improve patient care and patient safety. The development and the adoption of the system need to commence if high quality patient care is to be provided. However, successful HIS implementation is not an easy task and it depends on multiple factors such as adequate computer skills, lack of training and education. Despite the presence of a literature on nurse’s satisfaction on HIS, there is still a controversy over the success of HIS implementation. The input from the Information and Organisation culture, Trust and the nurses themselves, have not been considered. The aim of this study therefore, is to identify the success factors that influence a successful HIS implementation and to propose a research model which could fulfil the objective. Based on DeLone and Mc Lean's information, a success model system with an addition of four additional factors namely the Information culture, Organisational cultures, Trust and User quality was developed in this study. Employing a quantitative research methodology, this study began by conducting a pilot study involving 160 nurses from a university hospital to validate the reliability of the questionnaire to be used. Then, 1200 questionnaires were distributed to seven public university hospitals in Iran and 1028 (86%) usable responses were used for analysis. The covariance-based on structural equation modelling using STATA was employed to evaluate the model. Findings revealed that fourteen out of sixteen proposed hypotheses are significant on successful HIS implementation. The Information quality, Service quality, Organisation culture and the Information culture were among the most influential constructs in the final model. As the study was empirically tested in the Iranian setting, it contributes to theoretical and practical aspect of research especially in the Iranian public university hospital context

Hegemonic masculinity represented in Mukhtar Ma'i's In The Name of Honor

ENGLISH: Hegemonic masculinity is a gendered practice that has become an accepted acknowledgment problem of the practice legitimacy, which occurs when there is a dominant position of men and women's subordination. This study aims to find the forms of hegemonic masculinity in the novel In The Name of Honor by Mukhtar Mai. The researcher focuses on analyzing the portrayal of hegemonic masculinity in the novel. This study was analyzed with the theory of hegemonic masculinity, The type of research used by the researcher is descriptive qualitative. The data source used in this research is the novel In The Name of Honor by Mukhtar Mai. The collection technique in this study used reading and note-taking strategies. Then to analyze in this study, namely by analyzing the data, describing the analyzed data, and making conclusions regarding the analysis results. This research shows that there are acts of male domination against the repressed character (female), which shows hegemonic masculinity The result of this study portrayed the hegemonic masculinity of the five male characters in the novel. The five characters were Abdul Khaliq, Ghulam Farid, Faiz Muhammed, and Allah Dita who carried out acts of intimidation, rape, and violence against marginalized women and men, while the police forced Mukhtar to dismiss the case involving Mastoi as a suspect and spoke falsely during the trial. Then the factors that cause hegemonic masculinity are positivist view and the normative approach. INDONESIA: Hegemoni maskulinitas merupakan praktik gender yang menjadi menjelma menjadi pengakuan yang diterima masyarakat terhadap masalah patriarki, yang menjamin posisi dominasi laki-laki dan subordinasi perempuan. Bentuk dominasi terhadap perempuan juga terjadi dalam novel ini. Pembahasan dalam penelitian ini bertujuan untuk menemukan gambaran hegemoni maskulinitas dalam novel In The Name of Honor karya Mukhtar Mai. Peneliti berfokus pada menganalisis bentuk-bentuk hegemoni maskulinitas dalam novel. Penelitian ini dianalisis dengan teori maskulinitas hegemoni, Jenis penelitian yang digunakan peneliti bersifat deskriptif kualitatif. Dengan sumber data yang digunakan dalam penelitian ini adalah novel In The Name of Honor karya Mukhtar Mai. Teknik pengumpulan dalam penelitian ini menggunakan teknik baca dan catat. Kemudian untuk menganalisis dalam penelitian ini yaitu dengan menganalisis data, mendeskripsikan data yang teranalisis, dan membuat kesimpulan terkait hasil analisis. Hasil dari penelitian ini adalah gambaran tindakan hegemoni maskulinitas pada lima karakter laki-laki dalam novel. Kelima tokoh tersebut Abdul Khaliq, Ghulam Farid, Faiz Muhammed, Allah Dita yang melakukan tindakan intimindasi, pemerkosaan, kekerasan terhdap perempuan dan laki-laki yang termajinalkan sedangkan polisi melakukan pemaksaan terhadap Mukhtar untuk memberhentikan kasus yang menyangkut Mastoi sebagai tersangka dan berbicara tidak sebenarnya ketika pengadilan. Kemudian factor penyebab terjadinya hegemoni maskulinitas karena pandangan positivis dan pendekatan normative. ARABIC: إن الذكورية المهيمنة هي ممارسة جندرية تتحول إلى اعتراف مقبول من المجتمع بقضايا السلطة الأبوية ، مما يضمن هيمنة الذكور وتبعية المرأة. يظهر شكل الهيمنة على المرأة أيضًا في هذه الرواية. تهدف المناقشة في هذه الدراسة إلى إيجاد صورة للذكورية المهيمنة في رواية باسم الشرف لمختار مي. يركز الباحث على تحليل أشكال الذكورية المهيمنة في الرواية. تم تحليل هذا البحث من خلال نظرية الذكورية المهيمنة ، وكان نوع البحث الذي استخدمه الباحث وصفي نوعي. مصدر البيانات الأساسي المستخدم في هذا البحث هي رواية باسم الشرف لمختار مي. وبالنسبة لمصادر البيانات الثانوية المستخدمة فهي المجلات أو الأطروحات أو المراجع التي تناقش نظرية الرجولة المهيمنة ، وخاصة رأي راوين كونيل. استخدمت تقنية الجمع في هذه الدراسة تقنيات القراءة وتدوين الملاحظات. ثم التحليل في هذه الدراسة ، أي من خلال تحليل البيانات ، ووصف البيانات التي تم تحليلها ، والتوصل إلى استنتاجات بشأن نتائج التحليل. كانت نتيجة هذه الدراسة وصفًا للذكورية المهيمنة للشخصيات الخمسة الذكورية في الرواية. الشخصيات الخمسة هم عبد الخالق ، وغلام فريد ، وفايز محمد ، والله ديتا الذين ارتكبوا أعمال ترهيب واغتصاب وعنف ضد المهمشين من النساء والرجال ، ثم إن العوامل التي تسبب الهيمنة الذكورية هي النظرة الوضعية والنهج المعياري

Rapid Detection of Toxoplasma gondii Antigen in Experimentally Infected Mice by Dot- ELISA

Background: Toxoplasmosis is a worldwide endemic disease. In congenitally infected infants and AIDS patients, toxoplasmosis causes high rates of morbidity and mortality. In these cases antibody detection is difficult; so detection of parasite or its components could be useful tool for early detection and following treatment of the infection.Methods: Sixty-three BALB/c mice were injected intra-peritoneal with 5×103 tachyzoites of Toxoplasma gondii RH strain, nine mice were sacrificed daily for 7 days. Fourteen mice were in­jected with phosphate buffer saline as control group. Dot-ELISA was performed for detection of T.gondii antigen in mice sera and capture - ELISA was done as golden standard assay too.Results : Toxoplasma gondii antigen was detected from day 2 in mice sera ; 22% of mice sera on day 2, 33% on day 3,77% on day 4 and 100% on day 5 till their death on day 7 had shown antigene­mia by dot - ELISA, no positive result was detected in control mice by dot- ELISA.Conclusion: Dot-ELISA is a sensitive method for diagnosis of T. gondii infection in the animal model; also, this technique is more rapid and easy to perform method in comparison with cap­ture-ELISA