1,555 research outputs found
Behaviour of polymer grouted splices under increasing tensile load
This paper presents the behavior and performance of polymer grouted splices under increasing direct tensile load. A spiral is utilized to confine the splicing of two discontinued bars which are interlocked within the spiral through the utilization of high strength polymer grout. The bar embedded lengths and the spiral diameters of the grouted splices were varied in order to investigate their effects on the performance of the polymer grouted splices. The performance was evaluated based on the load-displacement relationship, ultimate loading capacity and failure mode. The best performance of polymer grouted splices was obtained with the spiral diameter of 23mm and embedment length of 125mm in which with these parameters the grouted spiral is able to develop the full tensile strength of the spliced bars
Radiation Protection in an Interventional Laboratory: A Comparative Study of Australian and Saudi Arabian Hospitals
This study aimed to investigate whether the use of protection devices and attitudes of interventional professionals (including radiologists, cardiologists, vascular surgeons, medical imaging technicians and nurses) towards radiation protection will differ between Saudi Arabian and Australian hospitals. Hard copies of an anonymous survey were distributed to 10 and 6 clinical departments in the Eastern province of Saudi Arabia and metropolitan hospitals in Western Australia, respectively. The overall response rate was 43 % comprising 110 Australian participants and 63 % comprising 147 Saudi participants. Analysis showed that Australian respondents differed significantly from Saudi respondents with respect to their usages of leaded glasses (p < 0.001), ceiling-suspended lead screen (p < 0.001) and lead drape suspended from the table (p < 0.001). This study indicates that the trained interventional professionals in Australia tend to adhere to benefit from having an array of tools for personal radiation protection than the corresponding group in Saudi Arabi
Survival Probability for Open Spherical Billiards
We study the survival probability for long times in an open spherical
billiard, extending previous work on the circular billiard. We provide details
of calculations regarding two billiard configurations, specifically a sphere
with a circular hole and a sphere with a square hole. The constant terms of the
long-term survival probability expansions have been derived analytically. Terms
that vanish in the long time limit are investigated analytically and
numerically, leading to connections with the Riemann hypothesis
Pore-GNN: A graph neural network-based framework for predicting flow properties of porous media from micro-CT images
This paper presents a hybrid deep learning framework that combines graph neural networks with convolutional neural networks to predict porous media properties. This approach capitalizes on the capabilities of pre-trained convolutional neural networks to extract n-dimensional feature vectors from processed three dimensional micro computed tomography porous media images obtained from seven different sandstone rock samples. Subsequently, two strategies for embedding the computed feature vectors into graphs were explored: extracting a single feature vector per sample (image) and treating each sample as a node in the training graph, and representing each sample as a graph by extracting a fixed number of feature vectors, which form the nodes of each training graph. Various types of graph convolutional layers were examined to evaluate the capabilities and limitations of spectral and spatial approaches. The dataset was divided into 70/20/10 for training, validation, and testing. The models were trained to predict the absolute permeability of porous media. Notably, the proposed architectures further reduce the selected objective loss function to values below 35 mD, with improvements in the coefficient of determination reaching 9%. Moreover, the generalizability of the networks was evaluated by testing their performance on unseen sandstone and carbonate rock samples that were not encountered during training. Finally, a sensitivity analysis is conducted to investigate the influence of various hyperparameters on the performance of the models. The findings highlight the potential of graph neural networks as promising deep learning-based alternatives for characterizing porous media properties. The proposed architectures efficiently predict the permeability, which is more than 500 times faster than that of numerical solvers.Document Type: Original articleCited as: Alzahrani, M. K., Shapoval, A., Chen, Z., Rahman, S. S. Pore-GNN: A graph neural network-based framework for predicting flow properties of porous media from micro-CT images. Advances in Geo-Energy Research, 2023, 10(1):39-55. https://doi.org/10.46690/ager.2023.10.0
Organizational Justice and Job Satisfaction Among Nurses
Organizations should enhance justice in the workplace to increase the satisfaction among employees. The purpose of this study was to examine the impact of organizational justice on job satisfaction among nurses. The study cohort was composed of nurses from 2 public hospitals. A stratified sampling technique was employed to ensure better representation of samples from the 2 hospitals. A total of 184 valid questionnaires from 2 public hospitals were analyzed by structural equation modeling. The results showed that the 3 dimensions of organizational justice, namely distributive justice, procedural justice, and interactional justice, have a positive and significant impact on the nurses' job satisfaction. Distributive justice showed a greater impact on job satisfaction than procedural justice and interactional justice. The supervisors and administrators should be provided with information on how improvement in organizational justice leads to job satisfaction and on-the-job facilitation of employee innovation. The results of this study provide a clear image for hospital administrations about the substantial role of justice in the workplace
Effect of mixing period, water and sugar on the sesame cracker dough stickiness
Sesame Cracker or Kuih Bijan is a popular traditional Malays snack in Malaysia. The simplest formulation of Sesame Cracker dough includes glutinous rice flour, sugar, and water. In order to reduce the negative effect caused by dough stickiness, the effect of mixing period (3 to 7 minutes), water (41.6 to 45.6%) and sugar (1 to 9%) on dough stickiness of sesame cracker dough were studied using Texture Analyzer and Chen-Hoseney methodologies (i.e. Chen-Hoseney Dough Stickiness Cell). The result obtained showing that the increment of mixing time, water and sugar addition, increased the dough stickiness, work of adhesion/adhesiveness and dough strength/cohesiveness. However, overmixing of dough had led to the decrease of these parameters
The Relationship between National Culture and Succession Planning in Malaysian Public Universities
This study investigates the role of national culture in succession planning. Higher education institutions ought to learn from corporate succession planning practices; nevertheless, succession planning principles must be adapted as needed to meet the unique needs of each institution. Studies of the influence of culture on succession planning in higher education institutions have not yet revealed the specific impact of national culture on succession planning. We use Hofstede’s national culture dimensions, which are power distance, collectivism, masculinity, uncertainty avoidance and long-term orientation. Data were gathered from five universities in Malaysia, and were analyzed using structural equation modeling. Our findings show that the national culture of university employees influences succession planning. This study contributes to existing understanding of factors affecting succession planning, points towards further research, helps practitioners by demonstrating the importance of taking national culture into account and indicates the importance of implementing succession planning in public universities in Malaysia
Modelling Multilayer Communication Channel in Terahertz Band for Medical Applications
In this work we present a multi-layer channel model for terahertz communication that incorporates both layers of human body tissues and textile layers. Many research works tackled communication channel modelling in human body alone while some other research focused on textile characterization/modelling alone. There is a real gap in connecting these different models. To investigate this, a multi-layer channel model for terahertz communication is developed, this model assumes external textile layer stacked over layers of human body tissues. The electromagnetic properties of the different layers are extracted from previous works that used time domain spectroscopy (TDS) in the terahertz band to characterize each of the considered layers. The model is implemented as a flexible MATLAB/Octave program that enables the simulation of layers with either fixed or random depths. This paper aims to pave the way to connecting patients’ in-body nano-nodes with off-body (on-cloth) nano-nodes by building such a combined channel model. This helps in many applications especially in the medical field. For example, having connected nano-nodes can help in diagnosing diseases, monitoring health by sending information to the external environment, treatment (e.g., increasing or decreasing a certain dose depending on the monitoring), etc. The obtained results show how the THz signal can be affected when it propagates through heterogeneous mediums (i.e., human body tissues and textile). Various types of path-loss has been calculated for this purpose and verified by comparison with results from previous research on separate models of human body and textile
Recommended from our members
Design and Characterization of Porous Core Polarization Maintaining Photonic Crystal Fiber for THz Guidance
An improved design of Teflon photonic crystal fiber with a porous air-core is presented for low-loss terahertz guidance. Optimization of total power confinement in the air-holes, together both in the cladding and core regions, is carried out for both quasi-TE and quasi-TM polarizations by using a full-vectorial finite element method. To achieve the polarization maintenance, modal birefringence is enhanced by destroying the circular symmetry with the introduction of unequal size air-holes in the first ring
Prevalence of Behavioral and Emotional Disorders among the Orphans and Factors Associated with these Disorders
Background: Orphans are the special group of children who are generally deprived and prone to develop psychiatric disorders even reared in well run institution. Objectives: To find out the prevalence of the behavioral and emotional disorder among the children living in orphanage in Dhaka city, and to assess the possible factors associated with the presence of disorders among this study population. Methods: It was a cross sectional descriptive study conducted in selected orphanages. A Total 342 cases were included. One stage structured assessment of psychopathology was carried out by using a valid Bangla version of DAWBA (The Development and Well-Being Assessment). Data analysis was done by SPSS for windows 16.0 version. Results: The results indicate that overall prevalence of behavioral and emotional disorders were 40.35%, in which Behavioral disorder was 26.9%, Emotional disorder was 10.2% and both Behavioral and Emotional disorder were 3.2%. Higher length of stay and low level of education of foster mother were significantly associated with psychiatric morbidity of the respondents. Conclusions: It can be concluded that behavioral and emotional disorders are highly prevalent among orphan children and adolescents with residential care that needs to be addressed. Moreover, measure for early identification and intervention will improve the quality of life of the orphan population.DOI: http://dx.doi.org/10.3329/bsmmuj.v5i1.10997 BSMMU J 2012; 5(1):29-3
- …