5,169 research outputs found
Energy harvesting Internet of Things health-based paradigm: toward outage probability reduction through inter-wireless body area network cooperation
In today’s healthcare environment, the Internet of Things technology provides suitability among physicians and patients, as it is valuable in numerous medicinal fields. Wireless body sensor network technologies are essential technologies in the growth of Internet of Things healthcare paradigm, where every patient is monitored utilising small-powered and lightweight sensor nodes. A dual-hop, inter–wireless body sensor network cooperation and an incremental inter–wireless body sensor network cooperation with energy harvesting in the Internet of Things health-based paradigm have been investigated and designed in this work. The three protocols have been named and abbreviated as follows: energy harvesting–based dual-hop cooperation, energy harvesting–based inter–wireless body sensor network cooperation and energy harvesting–based incremental inter–wireless body sensor network cooperation. Outage probabilities for the three designed protocols were investigated and inspected, and mathematical expressions of the outage probabilities were derived. The simulation and numerical results showed that the energy harvesting–based incremental inter–wireless body sensor network cooperation provided superior performance over the energy harvesting–based inter–wireless body sensor network cooperation and energy harvesting–based dual-hop cooperation by 1.38 times and 5.72 times, respectively; while energy harvesting–based inter–wireless body sensor network cooperation achieved better performance over energy harvesting–based dual-hop cooperation by 1.87 times
Optimizing the Dynamic Performance of a Wind Driven Standalone DFIG Using an Advanced Control Algorithm
The article seeks to improve the dynamic performance of a standalone doubly fed induction generator (DFIG) which driven by a wind turbine, with the help of an effective control approach. The superiority of the designed predictive controller can be confirmed through evaluating the performance of the DFIG under other control algorithm, which is the model predictive direct torque control (MPDTC), model predictive current control (MPCC) as classic types of control. Firstly, the operating principles of the two controllers are described in details. After that, a comprehensive comparison is performed among the dynamic performances of the designed MPDTC, MPCC techniques and the predictive control strategy, so we can easily present the merits and deficiencies of each control scheme to be able to easily select the most appropriate algorithm to be utilized with the DFIG. The comparison is carried out in terms of system simplicity, dynamic response, ripples’ content, number of performed commutations and total harmonic distortion (THD). The results of the comparison prove the effectiveness and validation of our proposed predictive controller; as it achieves the system simplicity, its dynamic response is faster than that of MPDTC and MPCC, it presents a lower content of ripples compared to MPDTC and MPCC. Moreover, it can minimize the computational burden, remarkably. Furthermore, the numerical results are showing a marked reduction in the THD with a percentage of 2.23 % compared to MPDTC and 1.8 % compared to MPCC. For these reasons, it can be said that the formulated controller is the most convenient to be used with the DFIG to achieve the best dynamic performance
VoroCrust: Voronoi Meshing Without Clipping
Polyhedral meshes are increasingly becoming an attractive option with
particular advantages over traditional meshes for certain applications. What
has been missing is a robust polyhedral meshing algorithm that can handle broad
classes of domains exhibiting arbitrarily curved boundaries and sharp features.
In addition, the power of primal-dual mesh pairs, exemplified by
Voronoi-Delaunay meshes, has been recognized as an important ingredient in
numerous formulations. The VoroCrust algorithm is the first provably-correct
algorithm for conforming polyhedral Voronoi meshing for non-convex and
non-manifold domains with guarantees on the quality of both surface and volume
elements. A robust refinement process estimates a suitable sizing field that
enables the careful placement of Voronoi seeds across the surface circumventing
the need for clipping and avoiding its many drawbacks. The algorithm has the
flexibility of filling the interior by either structured or random samples,
while preserving all sharp features in the output mesh. We demonstrate the
capabilities of the algorithm on a variety of models and compare against
state-of-the-art polyhedral meshing methods based on clipped Voronoi cells
establishing the clear advantage of VoroCrust output.Comment: 18 pages (including appendix), 18 figures. Version without compressed
images available on https://www.dropbox.com/s/qc6sot1gaujundy/VoroCrust.pdf.
Supplemental materials available on
https://www.dropbox.com/s/6p72h1e2ivw6kj3/VoroCrust_supplemental_materials.pd
Frequency of Glomerular Dysfunction in Children with Beta Thalassaemia Major
Objectives: This study investigated the frequency of glomerular dysfunction in children with beta thalassaemia major (β-TM) by using different markers and correlating them with serum ferritin and iron chelation therapy. Methods: The study, carried out between August 2011 and May 2012, included 100 patients with β-TM, in two groups. Group Ia (n = 62) received chelation therapy (deferoxamine). Group Ib (n = 38) received followup care at the Pediatric Hematology Outpatient Clinic, Minia University Children’s Hospital, Egypt. Group II included 50 apparently healthy controls, age- and sex-matched to Group I. All patients underwent a thorough history-taking, clinical examination and laboratory investigations. Results: Compared to Group II, Groups Ia and Ib had significantly higher levels of cystatin C, serum creatinine and serum ferritin, and a higher albumin/ creatinine ratio in their urine, and a significantly lower estimated glomerular filtration rate (eGFR) and creatinine clearance (P <0.05). Moreover, Group Ιa had a significantly lower eGFR and creatinine clearance than Group Ib. Cystatin C had a highly significant strong negative correlation with eGFR and creatinine clearance and a significantly strong positive correlation with serum ferritin, and a higher sensitivity and specificity than serum creatinine and creatinine clearance for small changes in GFR. Conclusion: β-TM patients had a high frequency of glomerular dysfunction—possibly attributable to chronic anaemia, iron overload or chelation therapy. Periodic renal assessment is mandatory to detect renal complications. Cystatin C is a promising marker to monitor glomerular dysfunction, having a higher sensitivity and specificity than serum creatinine and creatinine clearance for small changes in GFR
Hemato-Biochemical studies on Egyptian Buffaloes and Calves naturally infected with Foot and Mouth Disease Virus serotype SAT 2
Foot and mouth disease (FMD) is a highly contagious viral disease of all cloven footed domestic and wild animals. This work was planned to study the different markers for diagnosis of FMDV serotype Sat2 in adult buffaloes and calves including clinical, hematological and biochemical examinations. A total number of sixty animals were divided into four groups. The first group was apparently healthy adult buffaloes, while the second was naturally infected adult buffaloes, a third group was apparently healthy suckling calves and finally the fourth group was naturally infected suckling calves. The recorded clinical signs were fever, salivation, loss of appetite, depression, lameness, blisters or vesicles, erosions and ulcers in the mucosa of the mouth, tongue, lips, gums, pharynx, palate and between the claws. Anemia, leucopenia, lymphopenia and monocytopenia were recorded in infected adult buffaloes and calves. Myocardial injury proved by presence of degenerated myocardial fibers and lymphocyte cell infiltration with a significant increase in cardiac markers like cardiac torponin I, CPK and LDH in addition to a significant hyperkalemia, hypocalcaemia and hypomagnesemia in buffaloe calves. Moreover, electrophoresis showed hyoproteinemia, hypoalbuminemia and hypoglobulinemia in infected animals. It could be concluded that the elevation of cardiac markers emphasized that FMD is more severe in young calves than adult animals. Therefore, it is recommended to evaluate the prognosis of FMD infection in calves by these markers
Math and Science Post-basic Education School Teachers’ Use of As-sessment for Learning and Assessment of Learning Practices in Oman
The present study aimed at investigating math and science post-basic education school teachers’ use of Assessment for Learning (AfL) and Assessment of Learning (AoL) Practices in Oman from teachers’ points of view and as perceived by their educational supervisors. To achieve the objectives of this study, a 31-item of Likert type questionnaire was used. The questionnaire was divided into two subscales. The first subscale contains 12 AoL practices while the second one contains 19 AfL practices. The questionnaire was distributed to 288 math, biology, physics, and chemistry teachers and to 78 math and science educational supervisors. The results show that math and science teachers use AoL practices more than their use of AfL practices from their points of view and based on their educational supervisors perceptions. The study recommends math and science teachers balance between the use of AoL and AfL practices
The Effect of Recombinant Human Bone Morphogenetic Protein-7 on the Osteoblast-like Cells Cultured on Implant
AIM: The aim of the study was to study the effect of recombinant human bone morphogenetic protein-7 (rhBMP-7) on the osteoblast-like cells cultured on implant.
MATERIALS AND METHODS: The osteoblast-like osteo-1 cell line was used in this experiment and derived from the parietal bone tissue of newborn albino rats. The cells were incubated in a humid atmosphere of 95% air and 5% carbon dioxide at 37°C. The medium was changed every 2 days. Four groups were conducted as follows osteoclast-like cell (machined), implanted osteoclast-like cell on titanium (Ti) (modified), osteoclast-like cell supplemented with BMP-7 (Machined + BMP-7), and implanted osteoclast-like cell on Ti and supplemented with BMP-7 (Modified + BMP-7).
RESULTS: Cell proliferation was influenced by rhBMP-7, as demonstrated by a significant increase in collagen content after 7 and 21 days of culture (p = 0.005) and a significant increase in alkaline phosphatase (ALP) activity after 7 days (p < 0.001). The addition of rhBMP-7 influenced ALP activity, and a significant increase was observed after 21 days (p < 0.001).
CONCLUSION: Within the limitations of the study, we concluded that the presence of rhBMP-7 did not influence cell adhesion to chemically modified Ti surfaces but provided an additional stimulus during the differentiation of rat osteo-1 cells cultured on this type of surface
Effect of Yoghourt Starter Culture and Nickel Oxide Nanoparticles on the Activity of Enterotoxigenic Staphylococcus aureus in Domiati Cheese
Domiati cheese is the most popular type of white soft cheese in Egypt. Staphylococcus aureus is a common microorganism that can easily contaminate Domiati cheese during processing and distribution. Enterotoxigenic S. aureus strains produce staphylococcal enterotoxins (SE) that have been involved in food poisoning outbreaks worldwide. The aim of the present study was to examine the inhibitory effect of yoghourt starter culture and nickel oxide nanoparticles (NiO NPs) on the development of the enterotoxigenic S. aureus together with the enterotoxin production during the manufacturing and storage of Domiati cheese. Fresh cow’s milk was inoculated with S. aureus in a count of six log CFU/mL with the addition of either yoghourt starter culture or NiO Nps. The cytotoxicity of NiO NPs on normal human epithelial cells (HEC) was assessed using the MTT assay. In the current study, the inoculated milk was used for making Domiati cheese and the survival Weibull and log-linear models were fitted to the observed data. The obtained results showed that the mean log count of S. aureus decreased one week earlier by using yoghourt starter culture. Staphylococcal enterotoxin A (SEA) was identified only in the control cheese. Notably, Domiati cheese contained MIC of NiO NPs (35 µg/mL), which resulted in a significant decrease in S. aureus counts since at day 21 of cheese ripening it was not detected (<10 CFU/g). Overall, the current study indicated that the addition of yoghourt starter culture and NiO NPs during the processing of Domiati cheese could be useful candidates against S. aureus and enterotoxin production in the dairy industry
- …