Cation Migration in Mortar with Different Volume Fractions of Aggregate Affected by Electric Field

2011 ◽  
Vol 99-100 ◽  
pp. 711-714
Author(s):  
Wen Ten Kuo ◽  
Chih Chien Liu ◽  
Wei Chien Wang
Keyword(s):  
Constant Current ◽  
Type I ◽  
Negative Effects ◽  
Constant Current Density ◽  
Ion Migration ◽  
Volume Fractions ◽  
Cation Migration ◽  
Percolation Effect ◽  
Negative Effect ◽  
Pass Through

This study used Type I Portland cement with Na2Oeq of 0.67% to fabricate a mortar specimen with w/c ratio of 0.5 and a dimension of φ10  3 cm. The 7 volume fractions of aggregate (Vf) were adjusted to 0, 10, 20, 30, 40, 50 and 60%, and Acceleration Lithium Migration Technique (ALMT) experiments with 9 A/m2 constant current density were performed. The results show that for specimen with Vf of 10%, the negative effects on ion migration generated by aggregate dilution and tortuosity effects were the greatest; therefore, the removal times of Na + and K+, the time it took for Li+ to pass through the specimen and the time for Li+ to reach steady state were all longer than in the other experiments. When Vf was increased to 20 and 30%, the negative effect from the dilution and the tortuosity effects generated by the increase in Vf was cancelled the positive effect from ITZ on ion migration. When Vf was increased to over 30%, the percolation effect from ITZ controlled the behavior of ion migration. During the ALMT experiment, the anode steadily produced a large amount of O2, while the cathode produced a small amount of H2.

Effect of Electric Field on Cation Migration and Electrode Reactions of Mortar with Different W/C Ratios

2011 ◽  
Vol 399-401 ◽  
pp. 1320-1325
Author(s):  
Chih Chien Liu ◽  
Wen Ten Kuo ◽  
Shu Wang Hsu
Keyword(s):  
Constant Current ◽  
Type I ◽  
Constant Current Density ◽  
Mortar Specimen ◽  
Electrode Reactions ◽  
Increase With Increase ◽  
Cation Migration ◽  
And Migration ◽  
Lithium Migration ◽  
Migration Technique

This study used Type I Portland cement with Na2Oeq of 0.67 % to fabricate a mortar specimen with a w/c ratio of 0.5 and a dimension of φ10 × 3 cm, adjusted to the 6 w/c ratios of 0.35, 0.40, 0.45, 0.50, 0.55 and 0.60. The specimen was applied constant current density of 9 A/m2 during the Accelerated Lithium Migration Technique (ALMT) experiment. The results show that during the application of the current, over 86.4% of the electricity applied used in the production of gas through electrode reactions, and about 3.9-4.6% in cation migration. The required time of removal for Na+ and K+ decreased with increases in w/c ratio. The average removal percentage of Na+ and K+ increasing with the increase in w/c ratio. There was a good linear relationship between the steSuperscript textSuperscript textady-state flux and migration coefficient of Li+ and w/c ratio, and the steady flux of migration coefficient increase with increase in the w/c ratio.

Influence of Aggregate Volume Ratio of Mortar on the Migration of Cations Using the Accelerated Lithium Migration Technique

2011 ◽  
Vol 230-232 ◽  
pp. 400-404
Author(s):  
Wei Chien Wang ◽  
Chih Chien Liu ◽  
Chau Lee
Keyword(s):  
Steady State ◽  
Current Density ◽  
Linear Correlation ◽  
Volume Ratio ◽  
Constant Current ◽  
Constant Current Density ◽  
Pass Through ◽  
And Migration ◽  
Lithium Migration ◽  
Migration Technique

This study utilizes mortar specimens, to design 3 different a/c ratios of 2.25, 2.75, and 3.25. The aggregate volume ratios (Vf) are 46 %, 52 %, and 57 %, respectively, while the w/c ratio is 0.5, and undergoing a 9, 12, and 15 A/m2 constant current density Accelerated Lithium Migration Technique after curing for 3 months. Results show that, on specimens applied with the same current density, the time of Li+ to pass through the specimen, and steady state flux and migration coefficient all exhibit a positive linear correlation with Vf. At the same time, the non-steady state migration coefficient for Li+ have a negative linear correlation with Vf.

scholarly journals Impact of Cigarette Smoking on Sperm Parameters of Infertile Men in Center of Algiers (Capital of Algeria)

2020 ◽  
Vol 10 (4-s) ◽  
pp. 193-196
Author(s):  
Amina Itatahine ◽  
Abbassia Demmouche ◽  
H Maï ◽  
Z.C. Khalloua ◽  
D. Ferrag ◽  
...  
Keyword(s):  
Cigarette Smoking ◽  
Male Infertility ◽  
Sperm Count ◽  
Sperm Concentration ◽  
Sperm Parameters ◽  
Semen Parameters ◽  
Negative Effects ◽  
Negative Effect ◽  
Pass Through ◽  
And Function

Background : Cigarette smoking has negative effects on male fertility. Toxins from tobacco smoking can potentially affect sperm development and function, with a negative effect on semen parameters. In fact, the components of cigarette smoke pass through the blood-testis barrier and thus induce an alteration of sperm parameters and nucleus quality of the spermatozoa. The aim is to determine a diffence between tobbaco and no tobbaco patient and semen parameters. This article aimed to assess the relationship between smoking and male infertility. Subject and Methods : this is retrospective study focused on the effects of smoking on semen analyses.  377 men (165 non-smokers, 212  smokers) with infertility for at least 1 year were evaluated between  Mars  and  November 2018, in center of algiers (capital of Algeria). Sperm characteristics (concentration, motility, morphology, and volume) were detemined. Results: Sperm concentration, percentage motility and morphology were significantly lower in an infertile Smokers group than the infertile Nonsmokers group. We also observed that the infertility duration were significantly increased (p<0.05) in accordance with the age in an infertile Smokers group.  Our study shows that cigarette smoking is associated with reduced sperm count and motility. Conclusions: Our results suggest that cigarette smoking has an overall negative effect on semen parameters. Our study suggests that men should be advised to abstain from smoking in order to improve reproductive outcomes. Keywords: smoking, semen, male infertility, sperm, humans

An old friend is better than two new ones? Approaches to market research in the context of digital transformation for the antitrust laws enforcement

2020 ◽  
pp. 37-55 ◽  
Author(s):  
A. E. Shastitko ◽  
O. A. Markova
Keyword(s):  
Business Models ◽  
Rapid Development ◽  
Digital Transformation ◽  
Market Definition ◽  
Type I ◽  
Type Ii ◽  
Digital Platforms ◽  
Advantages And Disadvantages ◽  
Pass Through ◽  
Type Ii Errors

Digital transformation has led to changes in business models of traditional players in the existing markets. What is more, new entrants and new markets appeared, in particular platforms and multisided markets. The emergence and rapid development of platforms are caused primarily by the existence of so called indirect network externalities. Regarding to this, a question arises of whether the existing instruments of competition law enforcement and market analysis are still relevant when analyzing markets with digital platforms? This paper aims at discussing advantages and disadvantages of using various tools to define markets with platforms. In particular, we define the features of the SSNIP test when being applyed to markets with platforms. Furthermore, we analyze adjustment in tests for platform market definition in terms of possible type I and type II errors. All in all, it turns out that to reduce the likelihood of type I and type II errors while applying market definition technique to markets with platforms one should consider the type of platform analyzed: transaction platforms without pass-through and non-transaction matching platforms should be tackled as players in a multisided market, whereas non-transaction platforms should be analyzed as players in several interrelated markets. However, if the platform is allowed to adjust prices, there emerges additional challenge that the regulator and companies may manipulate the results of SSNIP test by applying different models of competition.

Reducing the Ecotoxicity of Pesticide Polluted Waters by Electrochemical Methods

2019 ◽  
Vol 70 (5) ◽  
pp. 1574-1578
Author(s):  
Cristian Neamtu ◽  
Bogdan Tutunaru ◽  
Adriana Samide ◽  
Alexandru Popescu
Keyword(s):  
Nitrogen Atmosphere ◽  
Constant Current ◽  
Polluted Water ◽  
Gaseous Nitrogen ◽  
Constant Current Density ◽  
Electrochemical Approach ◽  
Saline Waters ◽  
Thermal Combustion ◽  
Polluted Waters ◽  
Thermal Stability Of

Electrochlorination constitutes an electrochemical approach for the treatment of pesticide-containing wastewaters. This study evaluated the electrochemical and thermal stability of four pesticides and the efficiency of electrochlorination to remove and detoxify the simulated polluted water with: Acetamiprid, Emamectin, Imidacloprid and Propineb. This study reports the experimental results obtained by cyclic voltammetry and electrolysis at constant current density in association with UV-Vis spectrophotometry. In saline waters this pesticides are electrochemical active and anodic peaks are registered in the corresponding voltammograms. After thermal combustion, in a gaseous nitrogen atmosphere, a residue ranging from 15 to 45 % is observed at 500 �C.

60 GHz-Band Low-Noise Amplifier

2017 ◽  
Vol 26 (05) ◽  
pp. 1750075 ◽  
Author(s):  
Najam Muhammad Amin ◽  
Lianfeng Shen ◽  
Zhi-Gong Wang ◽  
Muhammad Ovais Akhter ◽  
Muhammad Tariq Afridi
Keyword(s):  
Transmission Line ◽  
Quality Factor ◽  
Noise Figure ◽  
Cmos Technology ◽  
Low Noise ◽  
Constant Current ◽  
60 Ghz ◽  
Frequency Range ◽  
Constant Current Density ◽  
Chip Area

This paper presents the design of a 60[Formula: see text]GHz-band LNA intended for the 63.72–65.88[Formula: see text]GHz frequency range (channel-4 of the 60[Formula: see text]GHz band). The LNA is designed in a 65-nm CMOS technology and the design methodology is based on a constant-current-density biasing scheme. Prior to designing the LNA, a detailed investigation into the transistor and passives performances at millimeter-wave (MMW) frequencies is carried out. It is shown that biasing the transistors for an optimum noise figure performance does not degrade their power gain significantly. Furthermore, three potential inductive transmission line candidates, based on coplanar waveguide (CPW) and microstrip line (MSL) structures, have been considered to realize the MMW interconnects. Electromagnetic (EM) simulations have been performed to design and compare the performances of these inductive lines. It is shown that the inductive quality factor of a CPW-based inductive transmission line ([Formula: see text] is more than 3.4 times higher than its MSL counterpart @ 65[Formula: see text]GHz. A CPW structure, with an optimized ground-equalizing metal strip density to achieve the highest inductive quality factor, is therefore a preferred choice for the design of MMW interconnects, compared to an MSL. The LNA achieves a measured forward gain of [Formula: see text][Formula: see text]dB with good input and output impedance matching of better than [Formula: see text][Formula: see text]dB in the desired frequency range. Covering a chip area of 1256[Formula: see text][Formula: see text]m[Formula: see text]m including the pads, the LNA dissipates a power of only 16.2[Formula: see text]mW.

scholarly journals Asthma patients experience increased symptoms of anxiety, depression and fear during the COVID-19 pandemic

2021 ◽  
Vol 18 ◽  
pp. 147997312110296
Author(s):  
Geertje M de Boer ◽  
Laura Houweling ◽  
Rudi W Hendriks ◽  
Jan H Vercoulen ◽  
Gerdien A Tramper-Stranders ◽  
...  
Keyword(s):  
Online Survey ◽  
Anxiety And Depression ◽  
Negative Effects ◽  
Cross Sectional ◽  
Healthcare Facilities ◽  
Care Workers ◽  
Asthma Patients ◽  
Negative Effect ◽  
Patients Experience ◽  
Anxiety Depression

Population studies showed a decrease in psychological wellbeing during the COVID-19 pandemic. Asthma is associated with a negative effect on anxiety and depression, which might worsen during the COVID-19 lockdown. The aim of the study was to compare fear, anxiety and depression between asthma patients and patients wit hout asthma pre-COVID-19 and during COVID-19 pandemic. This study compares fear, anxiety and depression in asthma patients and controls between pre-COVID-19 and during COVID-19 lockdown with a cross-sectional online survey. Participants were invited to fill out several questionnaires pertaining to fear, anxiety, depression, asthma control and quality of life. Asthma patients (N = 37) displayed, during the course of the pandemic, a clinically relevant increase in anxiety (3.32 ± 2.95 vs. 6.68 ± 3.78; p < 0.001) and depression (1.30 ± 1.15 vs. 3.65 ± 3.31; p < 0.001), according to the hospital anxiety and depression levels (HADS) compared to pre-COVID-19 assessment. This was not seen in controls. Also, asthma patients displayed more anxiety about acquiring COVID-19 disease compared to controls ((5.11 ± 1.99 vs. 3.50 ± 2.79), p = 0.006). Patients with asthma experienced an increase in anxiety and depression levels and were more afraid of acquiring COVID-19 disease compared to controls. Also, patients with asthma were more likely to avoid healthcare facilities due to fear of acquiring COVID-19 disease compared to controls. Therefore, we advise health care workers to address these possible negative effects on mental health by phone or e-consults.

scholarly journals Impact of “non-lethal” tarsal clipping on bumble bees (Bombus vosnesenskii) may depend on queen stage and worker size

2021 ◽  
Author(s):  
John M. Mola ◽  
Clara Stuligross ◽  
Maureen L. Page ◽  
Danielle Rutkowski ◽  
Neal M. Williams
Keyword(s):  
Genetic Material ◽  
Population Monitoring ◽  
First Year ◽  
Negative Effects ◽  
Worker Size ◽  
Monitoring Tools ◽  
Individual Survival ◽  
Body Sizes ◽  
Negative Effect ◽  
Worker Caste

Abstract Recent bumble bee declines have prompted the development of novel population monitoring tools, including the use of putatively non-lethal tarsal clipping to obtain genetic material. However, the potential side effects of tarsal clipping have only been tested in the worker caste of a single domesticated species, prompting the need to more broadly test whether tarsal clipping negatively affects sampled individuals. To determine if tarsal clipping reduces queen survivorship and colony establishment, we collected wild queens of Bombus vosnesenskii and clipped tarsi from a single leg of half the individuals. We reared captive queens and estimated survivorship and nest establishment success. We also clipped tarsi of workers from a subset of colonies across a range of body sizes. We found no consistent negative effect of clipping on queen survival. In the first year, clipped nest-searching queens suffered heavy mortality, but there was no effect on foraging queens. The following year, we found no effect of clipping on queen survival or establishment. Clipping did not reduce overall worker survival but reduced survivorship for those in the smallest size quartile. Implications for insect conservation Our findings suggest tarsal clipping does not have consistent negative effects on individual survival. However, our results varied with queen behavioral state, year, and worker size, suggesting differences within and among species and interactions with landscape stressors warrant further study. In the interim, we recommend researchers and conservationists minimize the use of tarsal clipping for sensitive species, populations, or small workers except in cases of exceptional scientific need.

scholarly journals Long-term subjective memory after electroconvulsive therapy

BJPsych Open ◽  
2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Robert Sigström ◽  
Axel Nordenskjöld ◽  
Anders Juréus ◽  
Caitlin Clements ◽  
Erik Joas ◽  
...  
Keyword(s):  
Electroconvulsive Therapy ◽  
Memory Impairment ◽  
Rating Scale ◽  
Final Analysis ◽  
Negative Effects ◽  
Subjective Memory ◽  
Subjective Memory Impairment ◽  
Negative Effect ◽  
Negative Expectations

Background There have been reports of long-term subjective memory worsening after electroconvulsive therapy (ECT). Aims To study the prevalence and risk factors of long-term subjective memory worsening among patients receiving ECT in routine clinical practice. Method Patients (n = 535, of whom 277 were included in the final analysis) were recruited from eight Swedish hospitals. Participants' subjective memory impairment was assessed before ECT and a median of 73 days after ECT using the memory item from the Comprehensive Psychopathological Rating Scale. Participants also rated their pre-ECT expectations and post-ECT evaluations of the effect of ECT on memory on a 7-point scale. We used ordinal regression to identify variables associated with subjective memory worsening and negative evaluations of the effect of ECT on memory. Results Comparisons of pre- and post-ECT assessments showed that subjective memory worsened in 16.2% of participants, remained unchanged in 52.3% and improved in 31.4%. By contrast, when asked to evaluate the effect of ECT on memory after treatment 54.6% reported a negative effect. Subjective memory worsening was associated with negative expectations before ECT, younger age and shorter duration of follow-up. Conclusions Although subjective memory improved more often than it worsened when assessed before and after ECT, a majority of patients reported that ECT had negative effects on their memory when retrospectively asked how ECT had affected it. This might suggest that some patients attribute pre-existing subjective memory impairment to ECT. Clinicians should be aware that negative expectations are associated with subjective worsening of memory after ECT.

Sign in / Sign up

Export Citation Format

Share Document