scholarly journals Comprehensive Analytical Modelling of an Absolute pH Sensor

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5190
Author(s):  
Cristina Medina-Bailon ◽  
Naveen Kumar ◽  
Rakshita Pritam Singh Dhar ◽  
Ilina Todorova ◽  
Damien Lenoble ◽  
...  
Keyword(s):  
Silicon Dioxide ◽  
Numerical Experiments ◽  
Ph Sensor ◽  
Hafnium Dioxide ◽  
Matlab Code ◽  
Oxide Degradation ◽  
Depletion Width ◽  
Ion Activity ◽  
The Absolute ◽  
The Impact

In this work, we present a comprehensive analytical model and results for an absolute pH sensor. Our work aims to address critical scientific issues such as: (1) the impact of the oxide degradation (sensing interface deterioration) on the sensor’s performance and (2) how to achieve a measurement of the absolute ion activity. The methods described here are based on analytical equations which we have derived and implemented in MATLAB code to execute the numerical experiments. The main results of our work show that the depletion width of the sensors is strongly influenced by the pH and the variations of the same depletion width as a function of the pH is significantly smaller for hafnium dioxide in comparison to silicon dioxide. We propose a method to determine the absolute pH using a dual capacitance system, which can be mapped to unequivocally determine the acidity. We compare the impact of degradation in two materials: SiO2 and HfO2, and we illustrate the acidity determination with the functioning of a dual device with SiO2.

Prognostic value of absolute monocyte count in chronic lymphocytic leukaemia

2015 ◽  
Vol 156 (15) ◽  
pp. 592-597
Author(s):  
László Szerafin ◽  
János Jakó ◽  
Ferenc Riskó
Keyword(s):  
Chronic Lymphocytic Leukaemia ◽  
Prognostic Value ◽  
Lymphocytic Leukaemia ◽  
Treatment Time ◽  
Monocyte Count ◽  
Time To Treatment ◽  
Causes Of Mortality ◽  
The Absolute ◽  
The Impact ◽  
Overal Survival

Introduction: The low peripheral absolute lymphocyte and high monocyte count have been reported to correlate with poor clinical outcome in various lymphomas and other cancers. However, a few data known about the prognostic value of absolute monocyte count in chronic lymphocytic leukaemia. Aim: The aim of the authors was to investigate the impact of absolute monocyte count measured at the time of diagnosis in patients with chronic lymphocytic leukaemia on the time to treatment and overal survival. Method: Between January 1, 2005 and December 31, 2012, 223 patients with newly-diagnosed chronic lymphocytic leukaemia were included. The rate of patients needing treatment, time to treatment, overal survival and causes of mortality based on Rai stages, CD38, ZAP-70 positivity and absolute monocyte count were analyzed. Results: Therapy was necessary in 21.1%, 57.4%, 88.9%, 88.9% and 100% of patients in Rai stage 0, I, II, III an IV, respectively; in 61.9% and 60.8% of patients exhibiting CD38 and ZAP-70 positivity, respectively; and in 76.9%, 21.2% and 66.2% of patients if the absolute monocyte count was <0.25 G/l, between 0.25–0.75 G/l and >0.75 G/l, respectively. The median time to treatment and the median overal survival were 19.5, 65, and 35.5 months; and 41.5, 65, and 49.5 months according to the three groups of monocyte counts. The relative risk of beginning the therapy was 1.62 (p<0.01) in patients with absolute monocyte count <0.25 G/l or >0.75 G/l, as compared to those with 0.25–0.75 G/l, and the risk of overal survival was 2.41 (p<0.01) in patients with absolute monocyte count lower than 0.25 G/l as compared to those with higher than 0.25 G/l. The relative risks remained significant in Rai 0 patients, too. The leading causes of mortality were infections (41.7%) and the chronic lymphocytic leukaemia (58.3%) in patients with low monocyte count, while tumours (25.9–35.3%) and other events (48.1 and11.8%) occurred in patients with medium or high monocyte counts. Conclusions: Patients with low and high monocyte counts had a shorter time to treatment compared to patients who belonged to the intermediate monocyte count group. The low absolute monocyte count was associated with increased mortality caused by infectious complications and chronic lymphocytic leukaemia. The absolute monocyte count may give additional prognostic information in Rai stage 0, too. Orv. Hetil., 2015, 156(15), 592–597.

The Impact of Age and Gender on Hematopoietic Stem Cells and Immune Contexture of the Bone Marrow Microenvironment

2020 ◽  
pp. 1-6
Author(s):  
Rebar N. Mohammed
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Hematopoietic Stem Cells ◽  
Immune Cells ◽  
Absolute Number ◽  
Cell Number ◽  
Hematopoietic Stem ◽  
The Absolute ◽  
And Gender ◽  
The Impact

Hematopoietic stem cells (HSCs) are a rare population of cells that reside mainly in the bone marrow and are capable of generating and fulfilling the entire hematopoietic system upon differentiation. Thirty-six healthy donors, attending the HSCT center to donate their bone marrow, were categorized according to their age into child (0–12 years), adolescence (13–18 years), and adult (19–59 years) groups, and gender into male and female groups. Then, the absolute number of HSCs and mature immune cells in their harvested bone marrow was investigated. Here, we report that the absolute cell number can vary considerably based on the age of the healthy donor, and the number of both HSCs and immune cells declines with advancing age. The gender of the donor (male or female) did not have any impact on the number of the HSCs and immune cells in the bone marrow. In conclusion, since the number of HSCs plays a pivotal role in the clinical outcome of allogeneic HSC transplantations, identifying a younger donor regardless the gender is critical.

scholarly journals The Picard-HSS-SOR iteration method for absolute value equations

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Lin Zheng
Keyword(s):  
Iteration Method ◽  
Numerical Experiments ◽  
Absolute Value Equation ◽  
Absolute Value Equations ◽  
Absolute Value ◽  
Convergence Results ◽  
Hss Iteration ◽  
The Absolute ◽  
Hss Iteration Method

AbstractIn this paper, we present the Picard-HSS-SOR iteration method for finding the solution of the absolute value equation (AVE), which is more efficient than the Picard-HSS iteration method for AVE. The convergence results of the Picard-HSS-SOR iteration method are proved under certain assumptions imposed on the involved parameter. Numerical experiments demonstrate that the Picard-HSS-SOR iteration method for solving absolute value equations is feasible and effective.

Speciation and Geochemical Implications of Carcass Burial Leachate

2018 ◽  
Vol 61 (2) ◽  
pp. 559-570
Author(s):  
Dyan L. Pratt ◽  
Terrance A. Fonstad
Keyword(s):  
Chemical Composition ◽  
Ionic Strength ◽  
Activity Coefficient ◽  
Swine Manure ◽  
Burial Site ◽  
Mass Mortality Event ◽  
Ammonium N ◽  
Ion Activity ◽  
Common Activity ◽  
The Impact

Abstract. In the event of a mass livestock mortality situation, disposal routes such as burial are commonly chosen. The impact of burial on the environment could be substantial, but the composition of the leachate arising from a burial site has not been well documented. This study was performed to determine the chemical composition of leachate arising from animal mortalities in a burial setting. Three species of livestock were used: bovine, swine, and poultry. Leachate collected from lined burial pits over two years of decomposition was analyzed for major and minor ions. Analysis indicated that livestock mortality leachate contains, on average, concentrations of 46,000 mg L-1 of alkalinity (as bicarbonate), 12,600 mg L-1 of ammonium-N, 2600 mg L-1 of chloride, 3600 mg L-1 of sulfate, 2300 mg L-1 of potassium, 1800 mg L-1 of sodium, and 1500 mg L-1 of phosphorus, along with lesser amounts of iron, calcium, and magnesium. Select samples had maximum concentrations of ammonium-N and bicarbonate up to 50% higher than these average values. In comparison to earthen swine manure storages and landfills, the ionic strength of the leachate was 2 to 4 times higher, and therefore its impact on water resources could be greater. Following the study of the chemical composition of livestock mortality leachate, the potential impacts of this leachate on the soil/water systems below a burial site were investigated. The ionic strength of the leachate presents its own set of challenges. Basic modeling of ion activity using the five most common activity coefficient equations (Debye-Hückel, extended Debye-Hückel, Truesdell-Jones, Davies, and Pitzer) were considered to assess the sensitivity of these methods for calculated ion activity as impacted by the ionic strength of the leachate. This was completed to further enhance the modeling and speciation efforts. Based on the results and the applicability of the Truesdell-Jones equation, PHREEQC was used to assess the chemical speciation of the leachate. The speciation of this leachate provides evidence of phosphate and sulfate compounds available for potential unattenuated transport. Understanding the geochemical implications of livestock mortality burial will give scientists and regulators more information for performing future risk analyses when considering mortality burial as a management option, either routinely or during a mass mortality event. Keywords: Ion activity coefficient, Ionic strength, Leachate chemical composition, Livestock burial leachate, Speciation.

scholarly journals Failure to collectively assess security surveillance technologies will inevitably lead to an absolute surveillance society.

2013 ◽  
Vol 12 (1) ◽  
pp. 73-88 ◽  
Author(s):  
Timothy Mitchener-Nissen
Keyword(s):  
New Technology ◽  
Security Technology ◽  
Security Technologies ◽  
Small Rise ◽  
The Absolute ◽  
Waking Up ◽  
Surveillance Society ◽  
The Individual ◽  
Security Surveillance ◽  
The Impact

When assessing any security technology which impacts upon privacy, whether this constitutes a new technology or the novel application of existing technologies, we should do so by examining the combined effect of all security interventions currently employed within a society. This contrasts with the prevailing system whereby the impact of a new security technology is predominantly assessed on an individual basis by a subjective balancing of the security benefits of that technology against any reductions in concomitant rights, such as privacy and liberty. I contend that by continuing to focus on the individual effect, as opposed to the combined effects, of security technologies within a society the likelihood of sleep-walking into (or indeed waking-up in) an absolute surveillance society moves from a possible future to the logically inevitable future. This conclusion is based on two underlying assertions. Firstly that assessing a technology often entails a judgement of whether any loss in privacy is legitimised by a justifiable increase in security; however one fundamental difference between these two rights is that privacy is a finite resource with identifiable end-states (i.e. absolute privacy through to the absolute absence of privacy) whereas security does not have two finite end-states (while there exists the absolute absence of security, absolute security is an unobtainable yet desired goal). The second assertion, which relies upon the validity of the first, holds that one consequence of absolute security being unobtainable yet desirable is that new security interventions will continuously be developed, each potentially trading a small measure of privacy for a small rise in security. Examined individually each intervention may constitute a justifiable trade-off. However this approach of combining interventions in the search for ever greater security will ultimately reduce privacy to zero.

scholarly journals The impact of rheological uncertainty on dynamic topography predictions

Solid Earth ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 2167-2178 ◽  
Author(s):  
Ömer F. Bodur ◽  
Patrice F. Rey
Keyword(s):  
Mantle Convection ◽  
Numerical Experiments ◽  
Mantle Flow ◽  
Dynamic Topography ◽  
Density Anomaly ◽  
Low Viscosity ◽  
Local Reduction ◽  
Dynamic Components ◽  
Mantle Rheology ◽  
The Impact

Abstract. Much effort is being made to extract the dynamic components of the Earth's topography driven by density heterogeneities in the mantle. Seismically mapped density anomalies have been used as an input into mantle convection models to predict the present-day mantle flow and stresses applied on the Earth's surface, resulting in dynamic topography. However, mantle convection models give dynamic topography amplitudes generally larger by a factor of ∼2, depending on the flow wavelength, compared to dynamic topography amplitudes obtained by removing the isostatically compensated topography from the Earth's topography. In this paper, we use 3-D numerical experiments to evaluate the extent to which the dynamic topography depends on mantle rheology. We calculate the amplitude of instantaneous dynamic topography induced by the motion of a small spherical density anomaly (∼100 km radius) embedded into the mantle. Our experiments show that, at relatively short wavelengths (<1000 km), the amplitude of dynamic topography, in the case of non-Newtonian mantle rheology, is reduced by a factor of ∼2 compared to isoviscous rheology. This is explained by the formation of a low-viscosity channel beneath the lithosphere and a decrease in thickness of the mechanical lithosphere due to induced local reduction in viscosity. The latter is often neglected in global mantle convection models. Although our results are strictly valid for flow wavelengths less than 1000 km, we note that in non-Newtonian rheology all wavelengths are coupled, and the dynamic topography at long wavelengths will be influenced.

scholarly journals ENHANCED MASS LOSS RATES IN RED SUPERGIANTS AND THEIR IMPACT ON THE CIRCUMSTELLAR MEDIUM

2019 ◽  
Vol 55 (2) ◽  
pp. 161-175
Author(s):  
L. Hernández-Cervantes ◽  
B. Pérez-Rendón ◽  
A. Santillán ◽  
G. García-Segura ◽  
C. Rodríguez-Ibarra
Keyword(s):  
Mass Loss ◽  
Stellar Evolution ◽  
Gas Dynamics ◽  
Numerical Experiments ◽  
Evolutionary Models ◽  
Solar Composition ◽  
Red Supergiants ◽  
The Impact ◽  
Circumstellar Medium ◽  
Loss Rates

In this work, we present models of massive stars between 15 and 23 M⊙ , with enhanced mass loss rates during the red supergiant phase. Our aim is to explore the impact of extreme red supergiant mass-loss on stellar evolution and on their circumstellar medium. We computed a set of numerical experiments, on the evolution of single stars with initial masses of 15, 18, 20 and, 23 M⊙ , and solar composition (Z = 0.014), using the numerical stellar code BEC. From these evolutionary models, we obtained time-dependent stellar wind parameters, that were used explicitly as inner boundary conditions in the hydrodynamical code ZEUS-3D, which simulates the gas dynamics in the circumstellar medium (CSM), thus coupling the stellar evolution to the dynamics of the CSM. We found that stars with extreme mass loss in the RSG phase behave as a larger mass stars.

Metaheuristic- and Statistical-Based Sampling in Optimization

2018 ◽  
pp. 84-104
Author(s):  
Yoel Tenne
Keyword(s):  
Computer Simulations ◽  
Real World ◽  
Computational Intelligence ◽  
Numerical Experiments ◽  
Strong Impact ◽  
Initial Sample ◽  
Modern Engineering ◽  
Computationally Intensive ◽  
The Impact ◽  
Optimization Search

Modern engineering often uses computer simulations as a partial substitute to real-world experiments. As such simulations are often computationally intensive, metamodels, which are numerical approximations of the simulation, are often used. Optimization frameworks which use metamodels require an initial sample of points to initiate the main optimization process. Two main approaches for generating the initial sample are the ‘design of experiments' method which is statistically based, and the more recent metaheuristic-based sampling which uses a metaheuristic or a computational intelligence algorithm. Since the initial sample can have a strong impact on the overall optimization search and since the two sampling approaches operate based only widely different mechanisms this study analyzes the impact of these two approaches on the overall search effectiveness in an extensive set of numerical experiments which covers a wide variety of scenarios. A detailed analysis is then presented which highlights which method was the most beneficial to the search depending on the problem settings.

Optimization of Tuned Mass Dampers to Improve the Earthquake Resistance of High Buildings

2015 ◽  
pp. 511-548
Author(s):  
Rolf Steinbuch
Keyword(s):  
Detailed Analysis ◽  
Earthquake Resistance ◽  
Reduced Model ◽  
Earthquake Loading ◽  
Efficient Design ◽  
Tuned Mass Dampers ◽  
Good Design ◽  
Local Maxima ◽  
The Absolute ◽  
The Impact

To prevent high buildings in endangered zones suffering from seismic attack, TMD are applied successfully. In many applications the dampers are placed along the height of the edifice to reduce the damage during the earthquake. The dimensioning of TMD is a multidimensional optimisation problem with many local maxima. To find the absolute best or a very good design, advanced optimization strategies have to be applied. Bionic optimization proposes different methods to deal with such tasks but requires many repeated studies of the buildings and dampers design. To improve the speed of the analysis, the authors propose a reduced model of the building including the dampers. A series of consecutive generations shows a growing capacity to reduce the impact of an earthquake on the building. The proposals found help to dimension the dampers. A detailed analysis of the building under earthquake loading may yield an efficient design.

scholarly journals Mathematical Modeling of Impact of Possible Shock Dynamic Loads on the Modern Composite Materials

2019 ◽  
Vol 224 ◽  
pp. 02012
Author(s):  
Eugenе Sosenushkin ◽  
Oksana Ivanova ◽  
Elena Yanovskaya ◽  
Yuliya Vinogradova
Keyword(s):  
Composite Materials ◽  
Friction Force ◽  
Equations Of Motion ◽  
Elastic Fiber ◽  
Dynamic Loads ◽  
Friction Forces ◽  
Absolute Value ◽  
A Value ◽  
The Absolute ◽  
The Impact

In this paper, we study the dynamic processes in materials reinforced with fibers, that can be represented as composite rods. There has been developed a mathematical model of wave propagation under the impact of a shock pulse in semi-infinite composite rods. It is believed that the considered composite rod consists of two layers formed by simpler rods of different isotropic materials with different mechanical properties. The cross sections of such rods are considered to be constant and identical. When such composite materials are impacted by dynamic loads, a significant part of the energy is dissipated due to the presence of friction forces between the contact surfaces of the rods. In this regard, we study the propagation of waves in an elastic fiber-rod, the layers of which interact according to Coulomb law of dry friction. The case of instantaneous excitation of rods by step pulses is investigated. The blow is applied to a rod made of a harder material. In the absence of slippage, the friction force gets a value not exceeding the absolute value of the limit. In the absence of slippage, the friction force takes a value not exceeding the absolute value of the limit. Let us consider the value of the friction force constant. Normal stresses and velocities satisfy the equations of motion and Hooke’s law. The problem statement results in the solution of inhomogeneous wave equations by the method of characteristics in different domains, which are the lines of discontinuities of the solution. Solutions are found in all constructed domains. On the basis of the analysis of the obtained solution, qualitative conclusions are made and curves are constructed according to the obtained ratios. From the found analytical solution of the problem it is possible to obtain ratios for stresses and strain rates in composite rods and composite materials.

Sign in / Sign up

Export Citation Format

Share Document