Finite element computation of transient dissipative double diffusive magneto-convective nanofluid flow from a rotating vertical porous surface in porous media

This paper aimed to investigate the transient dissipative MHD double diffusive free convective boundary layer flow of electrically-conducting nanofluids from a stationary or moving vertical porous surface in a rotating high permeability porous medium, considering buoyancy, thermal radiation and first order chemical reaction. Thermo-diffusion (Soret) and diffuso-thermal (Dufour) effects are also considered. Darcy’s law is employed. The mathematical model is formulated by considering water-based nanofluids containing metallic nano-particles for both stationary and moving plate cases. Three nanofluids are examined, namely copper, aluminium oxide or titanium oxide in water. The transformed non-linear, coupled, dimensionless partial differential equations describing the flow are solved with physically appropriate boundary conditions by using Galerkin weighted residual scheme. For prescribed permeability, numerical results are presented graphically for the influence of a number of emerging parameters. Validation of finite element solutions for skin friction and Nusselt number is achieved via comparison with the previously published work as special cases of the present investigation and very good correlation obtained. Increasing rotational parameter is observed to reduce both primary and secondary velocity components. Primary and secondary velocities are consistently elevated with increasing Soret, Dufour, thermal Grashof and solutal Grashof numbers. Increasing Schmidt number, chemical reaction and suction parameter both suppress nano - particle concentration whereas the converse behavior is computed with increasing Soret number. The study is relevant to high temperature rotating chemical engineering systems exploiting magnetized nanofluids and also electromagnetic nanomaterial manufacturing processes

A framework for the probabilistic analysis of meteotsunamis

This paper is not subject to U.S. copyright. The definitive version was published in Natural Hazards 74 (2014): 123-142, doi:10.1007/s11069-014-1294-1.A probabilistic technique is developed to assess the hazard from meteotsunamis. Meteotsunamis are unusual sea-level events, generated when the speed of an atmospheric pressure or wind disturbance is comparable to the phase speed of long waves in the ocean. A general aggregation equation is proposed for the probabilistic analysis, based on previous frameworks established for both tsunamis and storm surges, incorporating different sources and source parameters of meteotsunamis. Parameterization of atmospheric disturbances and numerical modeling is performed for the computation of maximum meteotsunami wave amplitudes near the coast. A historical record of pressure disturbances is used to establish a continuous analytic distribution of each parameter as well as the overall Poisson rate of occurrence. A demonstration study is presented for the northeast U.S. in which only isolated atmospheric pressure disturbances from squall lines and derechos are considered. For this study, Automated Surface Observing System stations are used to determine the historical parameters of squall lines from 2000 to 2013. The probabilistic equations are implemented using a Monte Carlo scheme, where a synthetic catalog of squall lines is compiled by sampling the parameter distributions. For each entry in the catalog, ocean wave amplitudes are computed using a numerical hydrodynamic model. Aggregation of the results from the Monte Carlo scheme results in a meteotsunami hazard curve that plots the annualized rate of exceedance with respect to maximum event amplitude for a particular location along the coast. Results from using multiple synthetic catalogs, resampled from the parent parameter distributions, yield mean and quantile hazard curves. Further refinements and improvements for probabilistic analysis of meteotsunamis are discussed

Intelligent Sensor Positioning and Orientation Through Constructive Neural Network-Embedded INS/GPS Integration Algorithms

Mobile mapping systems have been widely applied for acquiring spatial information in applications such as spatial information systems and 3D city models. Nowadays the most common technologies used for positioning and orientation of a mobile mapping system include a Global Positioning System (GPS) as the major positioning sensor and an Inertial Navigation System (INS) as the major orientation sensor. In the classical approach, the limitations of the Kalman Filter (KF) method and the overall price of multi-sensor systems have limited the popularization of most land-based mobile mapping applications. Although intelligent sensor positioning and orientation schemes consisting of Multi-layer Feed-forward Neural Networks (MFNNs), one of the most famous Artificial Neural Networks (ANNs), and KF/smoothers, have been proposed in order to enhance the performance of low cost Micro Electro Mechanical System (MEMS) INS/GPS integrated systems, the automation of the MFNN applied has not proven as easy as initially expected. Therefore, this study not only addresses the problems of insufficient automation in the conventional methodology that has been applied in MFNN-KF/smoother algorithms for INS/GPS integrated systems proposed in previous studies, but also exploits and analyzes the idea of developing alternative intelligent sensor positioning and orientation schemes that integrate various sensors in more automatic ways. The proposed schemes are implemented using one of the most famous constructive neural networks—the Cascade Correlation Neural Network (CCNNs)—to overcome the limitations of conventional techniques based on KF/smoother algorithms as well as previously developed MFNN-smoother schemes. The CCNNs applied also have the advantage of a more flexible topology compared to MFNNs. Based on the experimental data utilized the preliminary results presented in this article illustrate the effectiveness of the proposed schemes compared to smoother algorithms as well as the MFNN-smoother schemes

Impact of severity, duration, and etiology of hyperthyroidism on bone turnover markers and bone mineral density in men

<p>Abstract</p> <p>Background</p> <p>Hyperthyroidism is accompanied by osteoporosis with higher incidence of fracture rates. The present work aimed to study bone status in hyperthyroidism and to elucidate the impact of severity, duration, and etiology of hyperthyroidism on biochemical markers of bone turnover and bone mineral density (BMD).</p> <p>Methods</p> <p>Fifty-two male patients with hyperthyroidism, 31 with Graves' disease (GD) and 21 with toxic multinodular goiter (TNG), with an age ranging from 23 to 65 years were included, together with 25 healthy euthyroid men with matched age as a control group. In addition to full clinical examination, patients and controls were subjected to measurement of BMD using dual-energy X-ray absorptiometery scanning of the lower half of the left radius. Also, some biochemical markers of bone turnover were done for all patients and controls.</p> <p>Results</p> <p>Biochemical markers of bone turnover: included serum bone specific alkaline phosphatase, osteocalcin, carboxy terminal telopeptide of type l collagen also, urinary deoxypyridinoline cross-links (DXP), urinary DXP/urinary creatinine ratio and urinary calcium/urinary creatinine ratio were significantly higher in patients with GD and TNG compared to controls (P < 0.01). However, there was non-significant difference in these parameters between GD and TNG patients (P > 0.05). BMD was significantly lower in GD and TNG compared to controls, but the Z-score of BMD at the lower half of the left radius in patients with GD (-1.7 ± 0.5 SD) was not significantly different from those with TNG (-1.6 ± 0.6 SD) (>0.05). There was significant positive correlation between free T3 and free T4 with biochemical markers of bone turnover, but negative correlation between TSH and those biochemical markers of bone turnover. The duration of the thyrotoxic state positively correlated with the assessed bone turnover markers, but it is negatively correlated with the Z-score of BMD in the studied hyperthyroid patients (r = -0.68, P < 0.0001).</p> <p>Conclusion</p> <p>Men with hyperthyroidism have significant bone loss with higher biochemical markers of bone turnover. The severity and the duration of the thyrotoxic state are directly related to the derangement of biochemical markers of bone turnover and bone loss.</p

Diurnal rhythms of bone turnover markers in three ethnic groups

Context: Ethnic groups differ in fragility fracture risk and bone metabolism. Differences in diurnal rhythms (DRs) of bone turnover and PTH may play a role.  Objective: We investigated the DRs of plasma bone turnover markers (BTMs), PTH, and 1,25(OH)2D in three groups with pronounced differences in bone metabolism and plasma PTH.  Participants: Healthy Gambian, Chinese, and white British adults (ages 60–75 years; 30 per country).  Interventions: Observational study with sample collection every 4 hours for 24 hours.  Main Outcomes: Levels of plasma C-terminal telopeptide of type I collagen, procollagen type-1 N-propeptide, N-mid osteocalcin, bone alkaline phosphatase, PTH, and 1,25-dihydroxyvitamin D were measured. DRs were analyzed with random-effects Fourier regression and cross-correlation and regression analyses to assess associations between DRs and fasting and 24-hour means of BTMs and PTH.  Results: Concentrations of BTMs, PTH, and 1,25-dihydroxyvitamin D were higher in Gambians compared to other groups (P < .05). The DRs were significant for all variables and groups (P < .03) and were unimodal, with a nocturnal peak and a daytime nadir for BTMs, whereas PTH had two peaks. The DRs of BTMs and PTH were significantly cross-correlated for all groups (P < .05). There was a significant positive association between C-terminal telopeptide of type I collagen and PTH in the British and Gambian groups (P = .03), but not the Chinese group.  Conclusions: Despite ethnic differences in plasma BTMs and PTH, DRs were similar. This indicates that alteration of rhythmicity and loss of coupling of bone resorption and formation associated with an elevated PTH in other studies may not uniformly occur across different populations and needs to be considered in the interpretation of PTH as a risk factor of increased bone loss

Preserved emotional awareness of pain in a patient with extensive bilateral damage to the insula, anterior cingulate, and amygdala

Functional neuroimaging investigations of pain have discovered a reliable pattern of activation within limbic regions of a putative "pain matrix" that has been theorized to reflect the affective dimension of pain. To test this theory, we evaluated the experience of pain in a rare neurological patient with extensive bilateral lesions encompassing core limbic structures of the pain matrix, including the insula, anterior cingulate, and amygdala. Despite widespread damage to these regions, the patient's expression and experience of pain was intact, and at times excessive in nature. This finding was consistent across multiple pain measures including self-report, facial expression, vocalization, withdrawal reaction, and autonomic response. These results challenge the notion of a "pain matrix" and provide direct evidence that the insula, anterior cingulate, and amygdala are not necessary for feeling the suffering inherent to pain. The patient's heightened degree of pain affect further suggests that these regions may be more important for the regulation of pain rather than providing the decisive substrate for pain's conscious experience

The epidemiology of chronic pain in Libya: a cross-sectional telephone survey.

BACKGROUND: Chronic pain is a public health problem although there is a paucity of prevalence data from countries in the Middle East and North Africa. The aim of this study was to estimate the prevalence of chronic pain and neuropathic pain in a sample of the general adult population in Libya. METHODS: A cross-sectional telephone survey was conducted before the onset of the Libyan Civil War (February 2011) on a sample of self-declared Libyans who had a landline telephone and were at least 18 years of age. Random sampling of household telephone number dialling was undertaken in three major cities and interviews conducted using an Arabic version of the Structured Telephone Interviews Questionnaire on Chronic Pain previously used to collect data in Europe. In addition, an Arabic version of S-LANSS was used. 1212 individuals were interviewed (response rate = 95.1 %, mean age = 37.8 ± 13.9 years, female = 54.6 %). RESULTS: The prevalence of chronic pain ≥ 3 months was 19.6 % (95 % CI 14.6 % to 24.6 %) with a mean ± SD duration of pain of 6 · 5 ± 5 · 7 years and a higher prevalence for women. The prevalence of neuropathic pain in the respondents reporting chronic pain was 19 · 7 % (95 % CI 14 · 6-24 · 7), equivalent to 3 · 9 % (95 % CI 2 · 8 to 5 · 0 %) of the general adult population. Only, 71 (29 · 8 %) of respondents reported that their pain was being adequately controlled. CONCLUSIONS: The prevalence of chronic pain in the general adult population of Libya was approximately 20 % and comparable with Europe and North America. This suggests that chronic pain is a public health problem in Libya. Risk factors are being a woman, advanced age and unemployment. There is a need for improved health policies in Libya to ensure that patients with chronic pain receive effective management

Dissolution Enhancement and Formulation of Rapid-Release Lornoxicam Mini-Tablets

The aim was to enhance the dissolution of lornoxicam (LOR) and to produce mini-tablets with an optimised system to provide a rapid-release multi-particulate formulation. LOR systems were prepared through co-evaporation with either polyethylene glycol 6000 or Pluronic® F-68 (PLU) and adsorption onto Neusilin® US2 alone or co-adsorption in the presence of different amounts of polysorbate 80. All systems were characterised by FT-IR, differential scanning calorimetry, X-ray diffraction, flowability and dissolution techniques. Mini-tablets were prepared using the system with the optimum dissolution profile and flowability. Tensile strengths, content uniformity and dissolution profiles of the mini-tablets were evaluated. The effects of different excipients and storage conditions on mini-tablet properties were also studied. The optimised rapid-release LOR mini-tablets were further evaluated for their in vivo pharmacokinetic profile. The co-evaporate of LOR with PLU showed significantly faster dissolution and superior flowability and was evaluated together with three directly compressible excipients (Cellactose® 80, StarLac® (STA) and Emcompress®) for mini-tablet formulation. The formulation with STA provided the optimum results in terms of tensile strength content uniformity and rapid drug release following a 3-month stability study and was selected for further in vivo evaluation. The pharmacokinetic profile indicated the potential of the mini-tablets achieving rapid release and increased absorption of LO