scholarly journals Effect of temperature on the determination of available phosphorus in soil in northern China

2020 ◽  
Vol 514 ◽  
pp. 022070
Author(s):  
Haiou Zhang ◽  
Chengdi Shi ◽  
Yangjie Lu
Keyword(s):  
Northern China ◽  
Effect Of Temperature ◽  
Available Phosphorus

Cortical reaction as an egg quality indicator in artificial reproduction of pikeperch, Sander lucioperca

2012 ◽  
Vol 24 (6) ◽  
pp. 843 ◽  
Author(s):  
Daniel Żarski ◽  
Sławomir Krejszeff ◽  
Katarzyna Palińska ◽  
Katarzyna Targońska ◽  
Krzysztof Kupren ◽  
...  
Keyword(s):  
Quality Evaluation ◽  
Egg Quality ◽  
Effect Of Temperature ◽  
Artificial Reproduction ◽  
Female Fish ◽  
Sander Lucioperca ◽  
Embryo Survival ◽  
Hormonal Stimulation ◽  
Cortical Reaction

The aim of this study was to investigate the process of the cortical reaction in eggs of pikeperch, Sander lucioperca (L.), as well as the application of microscopic assessment of this process in egg quality evaluation. The analysis was carried out with eggs obtained from 10 females by artificial reproduction, in which hormonal stimulation with hCG was applied. Subsequently, each sample of eggs (separately from each female fish) was analysed. The analysis included observation of the cortical reaction and the process of egg swelling, and determination of the effect of temperature (12, 14 and 16°C) and the presence of spermatozoa on the cortical reaction. The results indicate that the cortical reaction in pikeperch eggs is quite violent, resulting in visible deformation of eggs between 3 and 5 min after activation. No effect of temperature or the presence of spermatozoa on the cortical reaction was observed. A strong correlation was recorded for the percentage of egg deformations observed and embryo survival rate. The described method of determination of pikeperch egg quality (based on egg deformation rate between 3 and 5 min after activation) may be highly useful, both in scientific research (where high-quality eggs are required) and in hatchery practice.

scholarly journals SYNTHESIS OF NEW SUBSTITUTED PROCAINE HYDROCHLORIDE COMPOUNDS AND THEIR USE IN SPECTROPHOTOMETRIC DETERMINATION OF TETRACYCLINE HYDROCHLORIDE THROUGH DIAZOTIZATION-COUPLING REACTIONS

2021 ◽  
Vol 18 (39) ◽  
pp. 14-32
Author(s):  
Hind Sadiq Al-WARD ◽  
Mouayed Qassssim AL-ABACHI ◽  
Mohammed Rifaat AHMED
Keyword(s):  
Stability Constant ◽  
Thermodynamic Parameters ◽  
Coupling Reaction ◽  
Water Soluble ◽  
Procaine Hydrochloride ◽  
Effect Of Temperature ◽  
Basic Medium ◽  
Fast Method ◽  
The Stability

Background: Tetracycline is one of the most important antibiotics. It is used to treat many different bacterial infections. It is often used in treating severe acne, or sexually transmitted diseases such as syphilis, gonorrhea, or chlamydia. In some cases, tetracycline is used when penicillin or another antibiotic cannot be used to treat serious infections such as the ones caused by Bacillus anthracis, Listeria, Clostridium, Actinomyces. Aim: synthesized a new novel reagent used to determine TCH spectrophotometrically by using diazonium and coupling reaction. Methods: Four new substituted procaine derivatives were prepared by simple organic methods using aniline derivatives. A spectrophotometric approach was established for the micro-determination of TCH. The stoichiometry was investigated using mole ratio and continuous variation methods, and the stability constant was also estimated. The ΔG, ΔH, and ΔS were determined as thermodynamic parameters for evaluating the effect of temperature on the reaction. Results: Substituted procaine derivatives were prepared, and o-hydroxy procaine seems to be the best reagent used to determine TCH by diazotization and coupling reaction. The result was a yellow water-soluble dye with a maximum absorbance of 380 nm. The reaction conditions were studied and optimized. Beers law was obeyed over a concentration range (2.5–50) μg.mL-1 for TCH. The molar absorptivity was (14.4669.103) L.mol-1.cm-1, and the detection limit was (0.5052) μg.mL-1. The stoichiometry of the formed product was found 1:1 (o-hydroxyprocaine: TCH). The stability constant indicated that the product formed was stable, and the thermodynamic parameters showed that the diazonium salt reaction was preferred to occur at a low temperature. Conclusions: a simple, accurate, and fast method was developed to determine TCH in pure form and pharmaceuticals by coupling the TCH with a newly synthesized procaine derivative reagent (o-hydroxy procaine) in a basic medium.

TEMPERATURE DEPENDENCE OF ELECTRICAL RESISTANCE OF INDIVIDUAL CARBON NANOTUBES AND CARBON NANOTUBES NETWORK

2012 ◽  
Vol 26 (21) ◽  
pp. 1250136 ◽  
Author(s):  
SAJJAD DEHGHANI ◽  
MOHAMMAD KAZEM MORAVVEJ-FARSHI ◽  
MOHAMMAD HOSSEIN SHEIKHI
Keyword(s):  
Carbon Nanotubes ◽  
Temperature Dependence ◽  
Electric Fields ◽  
Electrical Resistance ◽  
Electrode Materials ◽  
Effect Of Temperature ◽  
Electrode Spacing ◽  
Single Wall Carbon Nanotubes ◽  
Tube Metal

We present a model to understand the effect of temperature on the electrical resistance of individual semiconducting single wall carbon nanotubes (s-SWCNTs) of various diameters under various electric fields. The temperature dependence of the resistance of s-SWCNTs and metallic SWCNTs (m-SWCNTs) are compared. These results help us to understand the temperature dependence of the resistance of SWCNTs network. We experimentally examine the temperature dependence of the resistance of random networks of SWCNTs, prepared by dispersing CNTs in ethanol and drop-casting the solution on prefabricated metallic electrodes. Examining various samples with different electrode materials and spacings, we find that the dominant resistance in determination of the temperature dependence of resistance of the network is the resistance of individual tubes, rather than the tube–tube resistance or tube–metal contact resistance. It is also found that the tube–tube resistance depends on the electrode spacing and it is more important for larger electrode spacings. By applying high electric field to burn the all-metallic paths of the SWCNTs network, the temperature dependence of the resistance of s-SWCNTs is also examined. We also investigate the effect of acid treatment of CNTs on the temperature dependence of the resistance of SWCNTs and also multi-wall CNTs (MWCNTs) networks.

Rapid Ammonium Citrate Extraction Method for Determination of Available Phosphorus

1967 ◽  
Vol 50 (6) ◽  
pp. 1273-1279
Author(s):  
Gordon O Guerrant ◽  
J D Hunter ◽  
C H Mcbride
Keyword(s):  
Quality Control ◽  
Extraction Method ◽  
Direct Determination ◽  
Ammonium Citrate ◽  
Available Phosphorus ◽  
Gooch Crucible

Abstract Available phosphorus has been determined in fertilizers by a quick extraction method useful for screening or quality control purposes. Samples were extracted in a Gooch crucible with a jet of 65 °C neutral ammonium citrate in 10—20 mill. A single direct determination of available phosphorus was made by the alkalimetric quimociac method, modified for speed and for use in high citrate concentrations. The results compare favorably in accviracy to the gravimetric quimociac results reported on 20 Magruder check fertilizer samples

Spectrophotometric Method for the Direct Determination of Available Phosphorus in Fertilizers: Use of Dry Ashing to Destroy Citrate

1965 ◽  
Vol 48 (4) ◽  
pp. 859-865
Author(s):  
Wallace S Brammell
Keyword(s):  
Spectrophotometric Method ◽  
Direct Determination ◽  
Available Phosphorus ◽  
Hot Plate ◽  
Erlenmeyer Flask ◽  
White Ash ◽  
Heat Stable ◽  
Dry Ashing ◽  
Acid Reagent

Abstract A simple, rapid spectrophotometry method has been developed for direct determination of available phosphorus in fertilizers. Citrate and other organic materials are destroyed by dry ashing. The combined water and citrate extracts are diluted, a 5 ml aliquot is pipetted into a 25 ml Erlenmeyer flask, and 2 ml of ashing reagent (dilute HNO3, sucrose, and MgO) is added. During evaporation to dryness on a hot plate, nonorthophosphates are hydrolyzed to orthophosphates which react with Mg to form heat-stable compounds. During the subsequent ashing, phosphorus remains in the ortho form. Due to sucrose, the dry residue has a very porous structure and can be converted to a white ash in about 30 minutes in a pre-heated 550°C muffle. Color is developed with vanadomolybdic acid reagent. Absorbance is read on a spectrophotometer at 400 mμ.

Influence of temperature on blood pH of the human adult and newborn

1964 ◽  
Vol 19 (5) ◽  
pp. 897-900 ◽  
Author(s):  
Karlis Adamsons ◽  
Salha S. Daniel ◽  
Gillian Gandy ◽  
L. Stanley James
Keyword(s):  
Cell Concentration ◽  
Effect Of Temperature ◽  
Red Cell ◽  
Acid Base ◽  
Blood Ph ◽  
Influence Of Temperature On ◽  
The Mean ◽  
Ph Range ◽  
Two Populations

The effect of temperature upon pH of blood from adult and newborn humans was investigated. Although the mean ΔpH/ΔT values for the two populations differed, 0.0144/ °C for adults versus 0.0128 for the newborn, this was not peculiar to the source since the temperature-induced pH changes were identical when comparison was made between samples of similar pH and CO2 content. It was shown that even over the physiologic pH range ΔpH/ΔT is not constant but is a function of pH and CO2. No significant changes in ΔpH/ΔT were observed with oxygenation of hemoglobin. The influence of red cell concentration was detectable only when hematocrit values fell below 20%. A graph and an equation for the determination of ΔpH/ΔT of blood with a given pH and CO2 content is presented. acid base Submitted on December 9, 1963

Sign in / Sign up

Export Citation Format

Share Document