scholarly journals Application of Vacuum Infiltration in Cryopreservation of Isolated Grape Buds

2021 ◽  
Vol 31 (1) ◽  
pp. 51-57
Author(s):  
Anton Prystalov ◽  
◽  
Olena Bobrova ◽  
Larisa Kuleshova ◽  
◽  
...  
Keyword(s):  
Free Water ◽  
Vacuum Infiltration ◽  
The Novel ◽  
Temperature Differential ◽  
Scanning Calorimetry ◽  
Heterogeneous Samples ◽  
Heat Capacity Jump ◽  
Cryoprotective Solution ◽  
Vegetatively Propagated Plants ◽  
Complicated Task

Preserving the gene pool of grapes, referred to the vegetatively propagated plants is a complicated task, which can be also solved by cryopreservation of the buds. To saturate such bulk and heterogeneous samples with cryoprotectants the novel methods are required. The effectiveness of vacuum infiltration and 60 min standard passive saturation (soaking) of isolated grape buds of the Russian Concord variety with a cryoprotective solution PVS 2 were compared in this research. To saturate by vacuum infiltration the buds were incubated in cryoprotective solution for 15 min at 40 kPa, afterwards, the pressure was gradually increased to atmospheric level. The efficiency of bud saturation was evaluated with low-temperature differential scanning calorimetry by changing the enthalpies and temperatures of phase transitions as well as the intensity of heat capacity jump at glass transition. The use of vacuum in the saturation of isolated grape buds were found to lead to a strong rise in cryoprotectant concentration in them and a significant decrease in the amount of free water crystallized during cooling compared to passive soaking in a PVS 2 vitrification solution.

scholarly journals DSC reveals variation in enthalpy associated with free water molecules in water-ethanol solution exposed to x-rays and magnetic field

2021 ◽  
Vol 17 (1) ◽  
pp. 07-07
Author(s):  
Nirmal Chandra Sukul ◽  
Tandra Sarkar ◽  
Atheni Konar ◽  
Md. Amir Sohel ◽  
Asmita Sengupta ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Aqueous Ethanol ◽  
Free Water ◽  
Ethanol Solution ◽  
Water Molecules ◽  
X Rays ◽  
Standard Medium ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Homeopathic Drugs

Aqueous ethanol is the standard medium for all drugs used in homeopathy. X-ray and Magnetispoli ambo are 2 homeopathic drugs prepared by exposure of aqueous ethanol to x-rays and static magnetic field, respectively.Mother tinctures (MT)weresuccessively diluted with solvent 1:100 and succussed in several steps to prepare centesimal potencies 8 cH, 14 cH and 32 cH. The solvent was processed in the same way. Although identical in chemical composition (0.03 molar ethanol) and water content (96%) these preparations like the Mother tinctures and three potencies of X-ray and Magnetispoli amboexhibit different therapeutic pathological effects. Potency 8cH of each preparation was diluted with water to reach concentrations 4%, 20%, 40% and 80% ethanol. The aim of the study was to establish whether these potencies exhibited variation in free water molecules. Differential Scanning Calorimetry (DSC) of MT and potencies exhibited almost similar freezing and melting points, but they remarkably differed in freezing and melting enthalpy and free water molecules. The various dilutions of potency 8cH exhibited variation in enthalpies and free water molecules, being this variation independent of the amount of water added. We conclude that exposure of aqueous ethanol to x-rays and magnetic field, with subsequent dilution and agitation induces changes in the solvent involving free water molecules. All X-ray and Magnetispoli ambo potencies were analyzed by means of Raman spectroscopy for free water molecules. The results were compared to the ones of DSC, being more or less similar.

Synthesis, characterization, and structures of zircona- and boracyclosiloxanes with ferrocenyl substituents

2002 ◽  
Vol 80 (11) ◽  
pp. 1469-1480 ◽  
Author(s):  
Karena Thieme ◽  
Sara C Bourke ◽  
Juan Zheng ◽  
Mark J MacLachlan ◽  
Fojan Zamanian ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
The Novel ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Multinuclear Nmr Spectroscopy

The novel zirconatetraferrocenylcyclotrisiloxane Cp2Zr(OSiFc2)2O (6), dizirconatetraferrocenylcyclotetrasiloxane [Cp2Zr(OSiFc2)O]2 (7), boratetraferrocenylcyclotrisiloxane (C6H5)B(OSiFc2)2O (8), and diboratetraferrocenylcyclotetrasiloxane [(C6H5)B(OSiFc2)O]2 (9) with ferrocenyl (Fc = Fe(η-C5H4)(η-C5H5)) substituents at silicon have been prepared from the reactions of Cp2Zr(NMe2)2 and PhBCl2 with diferrocenylsilanediol Fc2Si(OH)2 (3) and tetraferrocenyldisiloxanediol [Fc2SiOH]2O (5). The compounds were characterized by mass spectrometry, elemental analysis, UV–vis, IR, Raman, and multinuclear NMR spectroscopy, as well as single crystal X-ray diffraction. Thermogravimetric analysis and differential scanning calorimetry investigation of 6–9 showed that the cycles decompose before they can undergo any thermal ring-opening polymerization. In addition, no polymerization was detected in the presence of either KOSiMe3 or HOTf. The bulky ferrocenyl substituents on the Si atoms are likely to be at least partially responsible for the inability of these heterocycles to undergo ring-opening polymerization. Key words: heterocyclosiloxanes, ferrocenyl.

scholarly journals Swelling properties of chitosan hydrogels

2004 ◽  
Vol 22 (1) ◽  
pp. 32 ◽  
Author(s):  
David R Rohindra ◽  
Ashveen V Nand ◽  
Jagjit R Khurma
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Glass Transition ◽  
Free Water ◽  
Scanning Calorimetry ◽  
Swelling Behaviour ◽  
Swelling Properties ◽  
Different Temperatures ◽  
Ft Ir ◽  
Chitosan Hydrogels

Chitosan hydrogels were prepared by crosslinking chitosan with glutaraldehyde. The swelling behaviour of the crosslinked and uncross-linked hydrogels was measured by swelling the gels in media of different pH and at different temperatures. The swelling behavior was observed to be dependent on pH, temperature and the degree of crosslinking. The gel films were characterized by Fourier transform Infrared spectroscopy (FT-IR) and Differential Scanning Calorimetry (DSC). The glass transition temperature (Tg) and the amount of free water in the hydrogels decreased with increasing crosslinking in the hydrogels.

Determination of Total and Free Water in Triple Superphosphate Fertilizers by Using Thermal Analysis

1985 ◽  
Vol 68 (4) ◽  
pp. 788-793
Author(s):  
Krystyna Kostyrko ◽  
Malgorzata Skoczylas ◽  
Andrzej Klee
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Free Water ◽  
Total Water ◽  
Triple Superphosphate ◽  
Scanning Calorimetry ◽  
Thermal Methods ◽  
Dehydration Processes ◽  
Derivatographic Analysis

Abstract Thermal analysis methods were used to study dehydration of triple superphosphate. A redrying procedure followed by Q-derivatographic analysis (under quasiisobaric and quasiisothermal conditions) as well as differential scanning calorimetry (DSC) was applied. Attempts were made to establish the correct drying-oven temperature for determination of water content, i.e., the temperature at which free or total water is removed from the fertilizer. Thermal decomposition of monocalcium orthophosphate monohydrate, the major component of triple superphosphate, was studied and a model was advanced for the reactions that occur during decomposition of this salt. The free water was completely released when superphosphate was heated at a constant temperature of 85°C. The total water was entirely released at 160°C. At 150°C, the process of removing the water of crystallization from the orthophosphate was disturbed by other concomitant dehydration processes which result in irreversible decomposition of this salt. The results obtained indicate that the thermal methods of analysis used are complementary.

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