Variable pH

Disposable sensors based on a pencil graphite electrode were described for detection of alkyl phenols. The performances of the disposable bare pencil graphite electrode (PGE) and PGE modified with carbon nanotubes, regarding the cyclic and differential pulse voltammetric determination of 4-nonylphenol, 4-octylphenol, and 4-tert-octylphenol, were compared. Some experimental variables of the electrode surface pretreatment and measurement parameters were optimized. Using a phosphate buffer solution (pH 7.

10p langthannam 29-12-2021 13 0   Download

The aim of this study was to examine qualitatively the effect of important electrochemical parameters on the faradaic impedance spectra of oxalic acid electroreduction. The impedance spectrum of a 3-step oxalic acid electroreduction mechanism was simulated by the solution of a faradaic impedance equation based on 3 state variables. Before the solution of the faradaic impedance equation, the electroreduction mechanism was analyzed and it was seen that this mechanism can be represented by an electrical circuit composed of 2 resistors and a capacitance or inductance.

15p langthannam 29-12-2021 17 0   Download

A novel method for the determination of mercury(II) is suggested. The procedure is based on the formation of an ion associate between the bromide complex of Hg(II) and Astrazon Red 6B dye and vortex-assisted liquid–liquid microextraction of the ion associate formed, with subsequent spectrophotometric detection. The variables that affect the procedure, such as pH, the concentration of ligand and dye, the type and volume of extraction solvent, and the rate and time of vortex mixing, were optimized.

9p langthannam 29-12-2021 6 0   Download

ZnO powder was synthesized via a hydrothermally assisted sol-gel method. Synthesis variables including Znprecursor type, pH value, time, and temperature of hydrothermal treatment were analyzed using the Taguchi approach. The experimental procedures were defined based on the L9 array for four variables in three levels. The influences of those variables on the response parameters, i.e. crystallite size, crystallinity, band gap energy (Eg), and degradation constants (k), were evaluated. XRD results and Eg values showed that ZnO wurtzite appeared to be the only crystalline phase in the samples.

12p tudichquannguyet 29-11-2021 14 1   Download

Amorphous cerium phosphate was prepared and characterized. Three-level Box-Behnken design (BBD) was employed to analyze the effect of process variables such as initial pH (2–6), contact time (60–180 min), and sorbent amount (0.05–0.15 g) on the sorption capacity of europium. Analysis of variance (ANOVA) revealed that the main effect of initial pH and sorbent amount has a substantial impact on the sorption of Eu(III). Probability F-value (F = 3 × 10 −3 ) and correlation coefficient (R2 = 0.97) point out that the model is in good accordance with experimental data.

16p tudichquannguyet 29-11-2021 11 1   Download

After oral administration, probiotic lactobacilli meet a number of protection systems in the human body, such as exposure to gastric, pancreatic, and small intestinal juices. Overcoming these detrimental barriers allows living bacteria to adhere to the intestinal epithelium and permanently colonize the gastrointestinal tract (GIT), providing health benefits to the host. Based on this, the transit tolerance of 25 candidate probiotic lactobacilli from katak, yoghurt, and white-brined and yellow cheese to simulated bile and small intestinal juices of variable pH was investigated.

6p thiencuuchu 27-11-2021 11 1   Download

N-terminal pro-brain-type natriuretic peptide (NT-proBNP) is currently used as a surrogate marker for disease severity in pulmonary hypertension (PH). However, NT-proBNP tends to have a high variability and may insufficiently correlate with hemodynamics and exercise capacity.

7p vimaine2711 26-03-2021 7 1   Download

There is little information about vitamin D (Vit D) deficiency in patients with pulmonary hypertension (PH). The objective of this study was: 1) compare Vit D levels between patients with PH, left ventricular failure (LVF) and healthy subjects (HS); 2) correlate, in patients with PH, Vit D levels with prognosis-related variables, such as the 6-min walk test (6MWT).

6p vimaine2711 26-03-2021 7 2   Download

The Knowledge of spatial-variability is critical for site specific nutrient management in soil fertility. Soil sample (149) were gotten from surface from 10 selected sites for preparing precise digital maps using point, line and polygon tools of the GIS (TNTmips 2010) software. Soil spatial variability typically defines variation in soil properties in surface soil such as fertility, pH, EC, soil organic carbon (OC), free CaCO3, mineralizable N,P2O5, K2O and S.

10p chauchaungayxua11 23-03-2021 11 2   Download

Three pectinolytic microbial consortia developed for faster retting of jute (Chorchorus olitorius L. and Chorchorus capsularis L.) were subjected to various pH (4 to 12) and media with variable nitrogen and fixed carbon sources for optimization of fermentation conditions of the consortia for cost-effective pectin degrading enzyme production. All the microbial consortia were active over a wide range of pH from 6 to 10 and recorded maximum polygalacturonase and pectin lyase activities at pH 10.

7p cothumenhmong9 18-01-2021 10 2   Download

Soil pH, EC and Organic Carbon are the essential parameters used as the primary level health status of the soils. In this context, detailed study over soil pH, EC and OC was done for different panchayats of Sabour block of Bhagalpur district. 80 composite surface soil samples (0-15cm) using GPS receiver from different location of fourteen Panchayats of Sabour block were collected during the months of May and June, 2019.

8p trinhthamhodang1216 19-11-2020 18 2   Download

In the present study workouts have been made to develop protein isolate from custard apple seed by using RSM (Response surface methodology). The variable considers percent pH, NaOH concentration and Flour to solvent ratio 15 g of flour. As previous literature was not available preliminary trials were conducted to decide the approximate concentration of pH, NaOH concentration and Flour to solvent ratio 15 g of flour. On the basis of trials ranges of variable decided which were 7 to 11% for pH, 0.6 to 2 (Molar) NaOH concentration and 20 to 60 % Flour to solvent ratio.

11p caygaocaolon8 07-11-2020 17 1   Download

In order to know the dynamics of calcium absorption in sunflower seedlings, an experiment was established under laboratory conditions, at the Universidad Tecnologica de Tehuacan, to evaluate five levels of Ca(CO3)2 in the solution. The variables were: absorbed calcium, pH, electrical conductivity, root length and volume, which were evaluated under a completely randomized design and four replicates (5x4) = 20 experimental units.

6p quenchua8 29-09-2020 10 1   Download

Listeria monocytogenes is an important foodborne pathogen with the ability to survive and grow in different foods and food processing environments. The variability in innate stress tolerance abilities of L. monocytogenes strains (n=104) isolated from clinical (n=35), environment (n=28) and food (n=41) sources was investigated against salt (2.5% to 12.5%), pH (pH 4.0 to 9.5) and low temperature (down to 4⁰C). The stress tolerance abilities were correlated with the source of isolation, serogroups and identifying the prevalent stress tolerant genotype.

13p cothumenhmong7 09-09-2020 16 1   Download

GPS based total 150 surface soil samples (0-15 cm) were collected from each block (30 samples) (namely; Mungaoli, Chanderi, Ishagarh, Ashoknagar and Sadora) of Ashok Nagar district. The samples were prepared and analyzed for different soil properties viz: soil texture (sand silt and clay), pH, EC, soil organic carbon (SOC), Calcium carbonate different forms of potassium (i.e., water soluble, exchangeable, non- exchangeable lattice and total-K) used standard laboratory method.

12p nguaconbaynhay7 15-08-2020 13 1   Download

Antifungal metabolites from rare actinomycetes have been found attractive for application due to its novelty, potency and environmental friendliness. Optimization of process variables for enhanced production of antifungal metabolite in Janibacter sp. RC18 was carried out in this study. One factor at a time (OFAT) was used for preliminary optimization of fermentation variables (time, temperature, initial pH, carbon and nitrogen sources).

19p angicungduoc6 22-07-2020 15 2   Download

In this paper, spatial variability in soil chemical properties and fertility were investigated in Bareli watershed, Seoni district of Madhya Pradesh. Georefened soil samples with a grid spacing of 325×325 m were collected in the study area and analyzed for soil pH, organic carbon, cation exchange capacity, available macronutrients (N, P and K) and micronutrients (Fe, Mn, Cu and Zn). Spatial variability was quantified through semivariogram analysis using geostatistics and kriged maps were generated in Geographic Information System (GIS).

8p angicungduoc5 12-06-2020 11 1   Download

The present study focused on the influence of low pH on growth, specific biochemical parameters and antioxidants amongst Nostoc strains grown under control (pH 7.0) and low pH (pH 4.5) medium. Cell dry weight, chlorophyll content, total soluble proteins and extracellular ammonia release reduced due to low pH stress of growing media compared to control grown cultures. Nitrogenase activity was reduced in two and increased in remaining strains due to low pH.

10p trinhthamhodang5 16-05-2020 16 1   Download

A study was carried out in the Department of Soil Science, DRPCAU, Pusa, Bihar during 2014-15 to evaluate physiological properties of Rhizobium isolated from winged bean, pea, gram, lentil and moong. Production of indole acetic acid (IAA), resistance to antibiotics and tolerance to variable pH are some important key concerns for its adaptability to various soil conditions as inoculants. Rhizobia, in general, followed a similar trend towards pH tolerance in terms of growth (measured as OD) i.e., their growth was higher around neutral pH.

11p kequaidan4 21-04-2020 6 0   Download

A total of thirty isolates of A. alternata were collected from eastern Uttar Pradesh and parts of Bihar, India. All thirty isolates were evaluated for their growth and rate of growth at three different H+ ion concentrations (pH) viz. four, six and eight in PDA medium. Radial growth for all of the isolates of A. alternata was also found significantly maximum at pH 6 followed by pH 8 and pH 4. Also, it was noted that none of the isolate had statistically similar growth in different pH range.

8p nguathienthan4 18-04-2020 15 0   Download