scholarly journals OSCILLATIONS OF FREEZING FRONT IN EXTERNAL ENCLOSURES

2003 ◽  
Vol 9 (2) ◽  
pp. 88-91
Author(s):  
Natalija Parfentjeva ◽  
Oleg Samarin ◽  
Sabina Paulauskaitė
Keyword(s):  
Air Temperature ◽  
Quantitative Estimation ◽  
Time Lag ◽  
Temperature Oscillation ◽  
Wall Material ◽  
Freezing Front ◽  
External Temperature ◽  
Temperature Oscillations ◽  
Approximate Procedure

An approximate procedure is proposed for calculating of the temperature field in a one-layer wall under harmonic variations of the external air temperature with regard to phase transitions of moisture within the wall. The trend of the freezing front displacement within the wall is researched as time goes on depending on relative thermal stability of the wall material and average thermal lag of the freezing layer. The engineering formulae are obtained for quantitative estimation of the front displacement offering determination of the peak value of its waves and their time lag with respect to the external temperature oscillations. The estimation of accuracy of the proposed calculation procedure is carried out and the limits of its suitability are detected. It has been shown that the error of the procedure falls in the limits of initial data under the magnitudes of the air temperature and thermal properties of employed materials meeting with in practice if the freezing front lays beyond the bounds of the violent temperature oscillation layer.

A comparative technique using as Joint studying to prove structure and determination the Quantitative estimation of organic compound (Irbesartan) as drug in multicomponent tablet form

2019 ◽  
Vol 9 (o3) ◽  
Author(s):  
Imad Tarek Hanoon ◽  
Abed Mohammed Daheir AL-Joubory 2 ◽  
Marwa Mohamed Saied 3
Keyword(s):  
Mobile Phase ◽  
Chemical Structure ◽  
Quantitative Estimation ◽  
Potassium Phosphate ◽  
Hplc Method ◽  
Pharmaceutical Dosage Forms ◽  
Tablet Form ◽  
Rp Hplc ◽  
Percent Recovery

A simple , specific, accurate and precise RP-HPLC method was developed for determination of Irbesartan (IRB) in pharmaceutical dosage forms in tablets products and sachet using symmetry (L 1 ) column at 30°C . The signal was detected at 225 nm. A mobile phase dissolve 0.5 g of buffer potassium phosphate in 100 ml distilled water and adjust pH 2.7 , methanol and acetonitrile at ratio (40 :30 :30 ) . and flow rate 1.2ml/min -1 at pH=7.2 a mobile phase The percent recovery was detected 101 % and the linearity of concentration was 10-50 µg.ml -1 and supported this method by using (FT.I.R.) spectrum method for organic spectrophotometer to prove the chemical structure of this drug and some physical properties . we are obtained the result is identical of other literature . The proposed method was applied successfully for determination of the IRB in tablets products.

HPLC/Tandem Mass Spectrometric Studies on Steroidal Saponins: An Example of Quantitative Determination of Shatavarin IV from Dietary Supplements Containing Asparagus racemosus

2014 ◽  
Vol 97 (6) ◽  
pp. 1497-1502 ◽  
Author(s):  
Dada Patil ◽  
Manish Gautam ◽  
Sunil Gairola ◽  
Suresh Jadhav ◽  
Bhushan Patwardhan
Keyword(s):  
Acetic Acid ◽  
Dietary Supplements ◽  
Quantitative Estimation ◽  
Multiple Reaction Monitoring ◽  
Asparagus Racemosus ◽  
Steroidal Saponin ◽  
Esi Ms ◽  
Tandem Mass Spectrometric ◽  
Positive Ion

Abstract Asparagus racemosus (AR) is a popular botanical present in several Ayurvedic medicines and nutritional and dietary supplements with immunomodulatory, galactogogue, and anticancer activity. A steroidal saponin known as shatavarin IV is one of the active constituents of AR. A new, selective, and rapid HPLC/MS/MS method has been developed and validated for quantitative estimation of shatavarin IV in crude, processed, and marketed samples of AR. The analytes were separated on a Luna C18 column using simple isocratic elution with water (0.1% acetic acid)–acetonitrile (0.1% acetic acid; 70 + 30, v/v) at a flow rate of 0.8 mL/min. The analytes were detected by electrospray ionization (ESI)-MS/MS and quantified using multiple reaction monitoring techniques in the positive ion mode. The method showed excellent linearity (r2 > 0.998) over the concentration range of 7.5 to 254 ng/mL with LOD of 2.5 ng/mL. Precision (RSD) and accuracy (recovery) were found in the ranges of 2.00 to 5.15 and 102 to 110%, respectively. The validated HPLC/ESI-MS/MS method was successfully applied to the quantification of shatavarin IV in crude, processed, and marketed (single or multiherb) AR samples. Therefore, this method could be used for QC and standardization of pharmaceutical or nutritional products containing AR.

Quantitative estimation of the effect of noxious substances in atmosphere air on the sickness rate of children

1997 ◽  
Vol 78 (5) ◽  
pp. 388-390
Author(s):  
A. B. Galyamov
Keyword(s):  
Environmental Factors ◽  
Sulphur Dioxide ◽  
Quantitative Estimation ◽  
Anthropogenic Load ◽  
Sickness Rate ◽  
Quantitative Characteristics ◽  
The City ◽  
Noxious Substances

The sikness rate of children living in the territories of the city with various levels of anthropogenic load is studied. The informativity of the multifactor dispersed analysis for determination of quantitative characteristics of the effect of environmental factors on the population sickness rate is noted. The effect of six inassociated factors (dust, sulphur dioxide etc.) on the sickness rate of children aged 4 to 7 is studied by this method.

scholarly journals Spatiotemporal Response of Vegetation to Rainfall and Temperature fluctuations in the Sahel. Case study in the Forest Reserve of Fina, Mali

2021 ◽  
Author(s):  
Karamoko Sanogo ◽  
Birhanu B. Zemadim ◽  
Souleymane Sanogo ◽  
Ashatu Abdulkadiri ◽  
Abdramane BA
Keyword(s):  
Air Temperature ◽  
Arid Zone ◽  
Time Lag ◽  
Temperature Fluctuations ◽  
Vegetation Response ◽  
Forest Reserve ◽  
Forest Reserves ◽  
Climate Fluctuation ◽  
Spatiotemporal Response

Forests constitute a key component of the Earth system but the sustainability of the forest reserves in the semi-arid zone is a real concern since its vegetation is very sensitive to the climate fluctuation. The understanding of the mechanisms for the interaction vegetation-climate is poorly studied in the context of African Sahel. In this study, the characteristics of the vegetation response to the fluctuations of precipitation and temperature is determined for the forest reserve of Fina. Rainfall estimates, air temperature and NDVI are used to establish the lag correlations between fluctuations of vegetation and climate variables at both seasonal and interannual bases. Results shows increasing tendency of NDVI started from the 1990s coinciding the recovery of the rainfall from the 1980s drought and the obtained correlation(r=0.66) is statistically significant (pvalue<0.01). The strongest responses of vegetation to rainfall and temperature fluctuations were found after 30 and 15 days, respectively. Moreover, at shorter time lag (e.g. 15 days) more pronounced vegetation responses to both rainfall and temperature were found in agricultural dominated land while at longer time lag (e.g. 30 days) stronger response was observed in Bare dominated land. The vegetation response to the climate fluctuation is modulated by the land use/cover dynamics. Keywords: NDVI, Rainfall, Air temperature, vegetation response, Fina Forest Reserve, Mali.

scholarly journals RESEARCH OF THE TENSELY-DEFORMED STATE OF ELEMENTS OF MOBILE HEAT STORAGE

2020 ◽  
Vol 42 (2) ◽  
pp. 68-75
Author(s):  
V.G. Demchenko ◽  
А.S. Тrubachev ◽  
A.V. Konyk
Keyword(s):  
Mathematical Model ◽  
Heat Storage ◽  
Quantitative Estimation ◽  
The Real ◽  
State Of The Union ◽  
Real Geometry ◽  
Deformed State ◽  
The Mathematical Model ◽  
Minimization Of Functional

Worked out methodology of determination of the tensely-deformed state of elements of mobile heat storage of capacity type, that works in the real terms of temperature and power stress on allows to estimate influence of potential energy on resilient deformation that influences on reliability of construction and to give recommendations on planning of tank (capacities) of accumulator. For determination possibly of possible tension of construction of accumulator kinematics maximum terms were certain. As a tank of accumulator shows a soba the difficult geometrical system, the mathematical model of calculation of coefficient of polynomial and decision of task of minimization of functional was improved for determination of tension for Міzеs taking into account the real geometry of equipment. Conducted quantitative estimation of the tensely-deformed state of the union coupling, corps and bottom of thermal accumulator and the resource of work of these constructions is appraised. Thus admissible tension folds 225 МРа.

scholarly journals Qualitative and quantitative determination of phytochemicals from flowers of Spanish Cherry tree

2018 ◽  
Vol 8 (6-s) ◽  
pp. 182-186
Author(s):  
Vineeta Singh ◽  
Anita Rao ◽  
Shipra Pandey ◽  
Vaibhav Sharan Pandey ◽  
Vageshwari Vageshwari ◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Quantitative Estimation ◽  
Standard Procedure ◽  
Tannin Content ◽  
Cherry Tree ◽  
Qualitative And Quantitative ◽  
Standard Curve ◽  
Soxhlet Apparatus ◽  
Percentage Yield

The present enquiry was intended to analyze the phytochemicals qualitatively and quantitatively from flowers of Spanish cherry tree. Flower powder was extracted using polar and nonpolar solvent by soxhlet apparatus. Percentage yield of crude extracts was determined and further the extracts were subjected to analyze the phytochemicals qualitatively and quantitatively by standard procedure. Qualitative analysis showed the absence of alkaloids while presences of tannins, saponins, terpenoids, steroids, glycosides, flavonoids, phenols. Quantitative estimation of phytochemicals was determined using standard curve. Result revealed that the tannin content was 4.3±0.01 (mgTAE /gm), flavanols content was 0.28±0.05 (mgQE/gm). Saponins content was 3.6±0.7 % and terpenoids content was 1.47±0.37 %. A well conducted studies on phytochemicals revealed that they are vital for humans because they provide protection against a variety of ailments. Therefore, the present study is aimed to analyze phytochemicals qualitatively and quantitatively. Keywords: Phytochemicals, Tannins, Saponins, Flavanols, Terpenoids

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