scholarly journals Effects of influent temperature variation on floc blanket behavior and effluent water quality

2020 ◽  
Vol 20 (6) ◽  
pp. 2275-2283
Author(s):  
Wasantha Illangasinghe ◽  
Jagath Manatunge ◽  
Niranjanie Ratnayake ◽  
Niranjali Jayasuriya
Keyword(s):  
Field Experiments ◽  
Settling Velocity ◽  
Effect Of Temperature ◽  
Temperature Phase ◽  
Strong Positive Correlation ◽  
Inertial Forces ◽  
Effluent Water ◽  
Particle Collisions ◽  
Strong Negative Correlation ◽  
Increasing Temperature

Abstract The temperature of the water in clarifier tanks has been shown to have a significant influence on floc blanket stability. The objective of this research was to determine the effects of variations in the influent temperature on a floc blanket using laboratory and field experiments and to assess whether the cohesivity of the blanket expressed as the sludge cohesion coefficient (SCC) can be used to interpret the effect of temperature variations. Effluent turbidity exhibited a strong positive correlation with inflow temperature during the increasing temperature phase and a strong negative correlation during the temperature recession phase. An increment of 2 °C in the influent temperature caused the effluent turbidity to increase by 1 NTU. The SCC of the blanket exhibited a significant relationship with the influent temperature. The optimum blanket cohesivity (SCC of 0.7 mm/sec) was observed at a temperature of 23.2 °C, above which the cohesivity decreased. At higher temperatures, frequent particle collisions owing to high inertial forces cause particle motion with the upward flow and increase the effluent turbidity. No correlation between SCC and blanket settling velocity was observed.

The effect of some environmental conditions on seed development and hard-seededness in subterranean clover (Trifolium subterraneum L.)

1979 ◽  
Vol 30 (1) ◽  
pp. 65 ◽  
Author(s):  
GB Taylor ◽  
MJ Palmer
Keyword(s):  
Seed Development ◽  
Seed Size ◽  
Field Experiments ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Moisture Stress ◽  
Effect Of Temperature ◽  
Temperature Regimes ◽  
Increasing Temperature ◽  
Dry Out

Subterranean clover (cv. Daliak) was grown in boxes with provision for unrestricted lateral growth. At the commencement of flowering, plants were allocated to three day/night temperature regimes of 12/7°, 18/13° and 24/19°C in controlled-temperature glasshouses and well watered until maturity (unstressed). In two additional treatments at 18/13°, plants were either subjected to intermittent moisture stress throughout the flowering period (stressed) or well watered for the first 6 weeks of flowering and then allowed to dry out (droughted). Increasing temperature resulted in more rapid inflorescence production, seed development and earlier plant maturation. The overall mean seed size was lower at 24/19° than at the other two temperatures. The stressed and droughted treatments produced fewer and smaller seeds than the corresponding unstressed treatment. There was a small effect of temperature on the degree of hard-seededness as determined from the mean softening time of seed subjected to daily alternating temperatures of 60/15°. Softening time was not significantly affected by watering treatments. There were small differences in softening time due to the position of the burr on the lateral, with a slight trend for seeds from the first-formed burrs to soften more rapidly. Most of the variation in softening time between seeds was due to variation within burrs. The sequence of seed softening within burrs was related to seed size, the larger seeds generally softening first, but no single regression could be used to describe this relationship for different burr positions or treatments. The absence of major treatment effects on the degree of hard-seededness indicates that varying the length of the seed development period does not necessarily result in differences in hard-seededness, as has been suggested from field experiments.

scholarly journals Theoretical Effect of Temperature on Threshold in the Hodgkin-Huxley Nerve Model

1966 ◽  
Vol 49 (5) ◽  
pp. 989-1005 ◽  
Author(s):  
Richard Fitzhugh
Keyword(s):  
Relaxation Time ◽  
Relaxation Times ◽  
Giant Axon ◽  
Temperature Curve ◽  
Effect Of Temperature ◽  
Threshold Temperature ◽  
Ionic Conductances ◽  
And Shifts ◽  
The Right ◽  
Increasing Temperature

In the squid giant axon, Sjodin and Mullins (1958), using 1 msec duration pulses, found a decrease of threshold with increasing temperature, while Guttman (1962), using 100 msec pulses, found an increase. Both results are qualitatively predicted by the Hodgkin-Huxley model. The threshold vs. temperature curve varies so much with the assumptions made regarding the temperature-dependence of the membrane ionic conductances that quantitative comparison between theory and experiment is not yet possible. For very short pulses, increasing temperature has two effects. (1) At lower temperatures the decrease of relaxation time of Na activation (m) relative to the electrical (RC) relaxation time favors excitation and decreases threshold. (2) For higher temperatures, effect (1) saturates, but the decreasing relaxation times of Na inactivation (h) and K activation (n) factor accommodation and increased threshold. The result is a U-shaped threshold temperature curve. R. Guttman has obtained such U-shaped curves for 50 µsec pulses. Assuming higher ionic conductances decreases the electrical relaxation time and shifts the curve to the right along the temperature axis. Making the conductances increase with temperature flattens the curve. Using very long pulses favors effect (2) over (1) and makes threshold increase monotonically with temperature.

scholarly journals Spatial Variation of the Relationship between PM2.5Concentrations and Meteorological Parameters in China

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Gang Lin ◽  
Jingying Fu ◽  
Dong Jiang ◽  
Jianhua Wang ◽  
Qiao Wang ◽  
...  
Keyword(s):  
Negative Correlation ◽  
Meteorological Parameters ◽  
Semiarid Region ◽  
Strong Positive Correlation ◽  
Annual Average ◽  
Strong Negative Correlation ◽  
Positive Correlation ◽  
Humid Region ◽  
The Relationship ◽  
Warm Temperate

Epidemiological studies around the world have reported that fine particulate matter (PM2.5) is closely associated with human health. The distribution of PM2.5concentrations is influenced by multiple geographic and socioeconomic factors. Using a remote-sensing-derived PM2.5dataset, this paper explores the relationship between PM2.5concentrations and meteorological parameters and their spatial variance in China for the period 2001–2010. The spatial variations of the relationships between the annual average PM2.5, the annual average precipitation (AAP), and the annual average temperature (AAT) were evaluated using the Geographically Weighted Regression (GWR) model. The results indicated that PM2.5had a strong and stable correlation with meteorological parameters. In particular, PM2.5had a negative correlation with precipitation and a positive correlation with temperature. In addition, the relationship between the variables changed over space, and the strong negative correlation between PM2.5and the AAP mainly appeared in the warm temperate semihumid region and northern subtropical humid region in 2001 and 2010, with some localized differences. The strong positive correlation between the PM2.5and the AAT mainly occurred in the mid-temperate semiarid region, the humid, semihumid, and semiarid warm temperate regions, and the northern subtropical humid region in 2001 and 2010.

Development of homogeneous/heterogeneous reaction in flow based through non-Darcy Forchheimer medium

2017 ◽  
Vol 16 (05) ◽  
pp. 1750045 ◽  
Author(s):  
Tasawar Hayat ◽  
Faisal Shah ◽  
Ahmed Alsaedi ◽  
Muhammad Ijaz Khan
Keyword(s):  
Magnetic Parameter ◽  
Heterogeneous Reaction ◽  
Phase Changes ◽  
Heterogeneous Reactions ◽  
Medium Effect ◽  
Effect Of Temperature ◽  
Temperature Phase ◽  
Surface Thermodynamics ◽  
Isothermal Model ◽  
Physical Quantities

The objective here is to analyze the influence of homogeneous and heterogeneous reactions in flow induced by convectively heated sheet with nonlinear velocity and variable thickness. Porous medium effect is characterized by Darcy–Forchheimer consideration. A simple isothermal model of homogeneous–heterogeneous reactions is used to regulate the temperature of stretched surface. Thermodynamics processes of homogeneous–heterogeneous reactions analyze the effect of temperature phase changes. Resulting problems are computed for the convergent solutions of velocity, temperature and concentration. Analysis for the influential variables on the physical quantities is graphically examined. Our computed results interpret that velocity field decays for larger magnetic parameter while temperature field enhances for higher estimation of Biot number.

scholarly journals The effects of cardiac rehabilitation on haemodynamic parameters measured by impedance cardiography in patients with coronary artery disease

2020 ◽  
pp. 126-126
Author(s):  
Milovan Stojanovic ◽  
Marina Deljanin-Ilic ◽  
Stevan Ilic ◽  
Dejan Petrovic ◽  
Bojan Ilic
Keyword(s):  
Coronary Artery Disease ◽  
Negative Correlation ◽  
Impedance Cardiography ◽  
Exercise Stress ◽  
Strong Positive Correlation ◽  
Physical Strain ◽  
Strong Negative Correlation ◽  
Positive Correlation ◽  
Strain Tolerance ◽  
Artery Disease

Background / Aim. Well-organized cardiovascular rehabilitation (CVR) reduces cardiovascular burden by influencing cardiovascular risk factors, improving the quality of life and reducing mortality and hospital readmission. However, its effects on hemodynamic status are largely unknown. The aim of our study was to evaluate the influence of three-week CVR program on hemodynamic status and to investigate if there is a correlation between physical strain tolerance and hemodynamic parameters measured by impedance cardiography (ICG) before and after CVR program in patients with coronary artery disease. Methods. Fifty-two patients attended a three-week CVR program. At the beginning and at the end of rehabilitation program laboratory tests, exercise stress tests (EST) and ICG measurements were taken. Results. Patients showed better strain tolerance on the second exercise stress test (EST2) by achieving higher strain level (Z=2,315; p=0,021) and longer duration of test (Z=2,305; p=0,021). There was a strong positive correlation between the level of EST2 and cardiac output (CO) (r=0,538; p<0,001) and stroke volume (SV) (r=0,380; p=0,017) on the second ICG (ICG2). Also, there was a strong negative correlation between EST2 level and systemic vascular resistance (SVR) (r=-0,472; p=0,002) and SVR index (SSVRI) (r=-0,407; p=0,010) on ICG2. There was a strong positive correlation between EST2 duration and CO (r=0.517; p=0.001) as well as between EST2 duration and SV (r=0.340; p=0.034), and a strong negative correlation between EST2 duration and SVR (r=-0.504; p=0.001) as well as between EST2 duration and SVRI (r=-0.448; p=0.004), according to ICG2. Conclusion. Our study showed that a well-designed CVR program can lead to better physical strain tolerance. Furthermore, CVR led to a significant positive correlation between EST and cardiac output as well as between EST and stroke volume measured by ICG. On the other hand, there was a significant negative correlation between EST and vascular related parameters according to ICG at the end of the CVR program.

scholarly journals DFT calculation for the electronic properties and quantum capacitance of pure and doped Zr2CO2 as electrode of supercapacitors

2021 ◽  
Author(s):  
Shuo Xu ◽  
Shi-Jie Wang ◽  
Li Xiao-Hong ◽  
Hong-Ling Cui
Keyword(s):  
Electronic Properties ◽  
Electrode Materials ◽  
Chemical Properties ◽  
Effect Of Temperature ◽  
Quantum Capacitance ◽  
Substitutional Site ◽  
Level Shifts ◽  
Dirac Distribution ◽  
Increasing Temperature ◽  
Physical And Chemical

Defect and doping are effective methods to modulate the physical and chemical properties of materials. In this report, we investigated the structural stability, electronic properties and quantum capacitance (Cdiff) of Zr2CO2 by changing the dopants of Si, Ge, Sn, N, B, S and F in the substitutional site. The doping of F, N, and S atoms makes the system undergo the semiconductor-to-conductor transition, while the doping of Si, Ge, and Sn maintains the semiconductor characteristics. The Cdiff of the doped systems are further explored. The B-doped system can be used as cathode materials, while the systems doped by S, F, N, Sn atoms are promising anode materials of asymmetric supercapacitors, especially for the S-doped system. The improved Cdiff mainly originates from Fermi-level shifts and Fermi-Dirac distribution by the introduction of the dopant. The effect of temperature on Cdiff is further explored. The result indicates that the maximum Cdiff of the studied systems gradually decreases with the increasing temperature. Our investigation can provide useful theoretical basis for designing and developing the ideal electrode materials for supercapacitors.

scholarly journals SEASONAL VARIATION OF PHENOLS AND FLAVONOIDS IN NON-GALLED AND GALLED LEAVES OF CARYOCAR BRASILIENSE (CARYOCARACEAE)

2021 ◽  
Vol 18 (38) ◽  
pp. 38-46
Author(s):  
Edson Cardoso TEIXEIRA ◽  
Rafaela Oliveira FERREIRA
Keyword(s):  
Secondary Metabolites ◽  
Abiotic Factors ◽  
Complexation Reaction ◽  
Strong Positive Correlation ◽  
Total Phenols ◽  
Leaf Extracts ◽  
Strong Negative Correlation ◽  
Caryocar Brasiliense ◽  
Maximum Temperatures ◽  
Galling Insects

Introduction: Galling insects manipulate the development of their host plants. Galls are rich in secondary metabolites, such as phenolic compounds and terpenes. Caryocar brasiliense acts as a host of galling insects. Few studies report the impacts of this plant-insect interaction on the species' morphology, physiology, and secondary metabolism. Objective: The purpose of this study was to verify if there is a correlation between the levels of total phenols and flavonoids in C. brasiliense leaf extracts and environmental variables, such as temperature and precipitation, throughout the year, and to evaluate how galling insects can interfere in this seasonality. Methods: Ethanol extracts from leaves were obtained by soxhlet extraction. The main classes of secondary metabolites were detected by phytochemical prospecting. The levels of total phenols and flavonoids were quantified by the Folin-Dennis tests and complexation reaction with aluminum chloride, respectively. Pearson 's correlation coefficient shows that the levels of phenols and flavonoids were correlated with the average monthly maximum temperatures and precipitation accumulation, respectively, recorded in Gurupi - Tocantins. Results and Discussion: Phytochemical prospecting indicated flavonoids, saponins, tannins, triterpenes, steroids, and alkaloids in both extracts. In C. brasiliense, the samples of healthy leaves suffered a greater variation in the levels of phenols (68.39±2.3 to 279.34±3.1 mg GAE g-1 extract) and flavonoids (164.06± 3.0 at 269.03±3.6 mg QE g-1 extract) compared to leaf samples with galls. A strong positive correlation was found between the contents of total phenols and maximum temperatures and a strong negative correlation with precipitation through Pearson's correlation. Conclusions: The variations observed in the levels of phenols and flavonoids in the extracts of C. brasiliense seem to be related to abiotic factors and the herbivory promoted by the galling insect.

scholarly journals Effects of the Temperature and the pH on the Main Protease of SARS-CoV-2: A Molecular Dynamics Simulation Study

2021 ◽  
Vol 12 (6) ◽  
pp. 7239-7248
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Root Mean Square ◽  
Dynamics Simulation ◽  
Effect Of Temperature ◽  
Water Molecules ◽  
Mean Square ◽  
Main Protease ◽  
Decreasing Ph ◽  
Increasing Temperature

The novel coronavirus, recognized as COVID-19, is the cause of an infection outbreak in December 2019. The effect of temperature and pH changes on the main protease of SARS-CoV-2 were investigated using all-atom molecular dynamics simulation. The obtained results from the root mean square deviation (RMSD) and root mean square fluctuations (RMSF) analyses showed that at a constant temperature of 25℃ and pH=5, the conformational change of the main protease is more significant than that of pH=6 and 7. Also, by increasing temperature from 25℃ to 55℃ at constant pH=7, a remarkable change in protein structure was observed. The radial probability of water molecules around the main protease was decreased by increasing temperature and decreasing pH. The weakening of the binding energy between the main protease and water molecules due to the increasing temperature and decreasing pH has reduced the number of hydrogen bonds between the main protease and water molecules. Finding conditions that alter the conformation of the main protease could be fundamental because this change could affect the virus’s functionality and its ability to impose illness.

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