Effect on Cs removal of solid-phase metal oxidation in metal ferrocyanides

2017 ◽  
Vol 105 (12) ◽  
Author(s):  
Keun-Young Lee ◽  
Jimin Kim ◽  
Maengkyo Oh ◽  
Eil-Hee Lee ◽  
Kwang-Wook Kim ◽  
...  
Keyword(s):  
Treatment Process ◽  
Solid Phase ◽  
Storage Conditions ◽  
Radioactive Cesium ◽  
Metal Oxidation ◽  
Aging Period ◽  
Higher Temperature ◽  
Increasing Temperature ◽  
And Storage ◽  
Cobalt And Nickel

AbstractMetal ferrocyanides (MFCs) have been studied for many years and are regarded as efficient adsorbents for the selective removal of radioactive cesium (Cs) from contaminated aqueous solutions. Although their efficiency has been demonstrated, various investigations on the physicochemical, thermal, and radiological stability of the solids of MFCs are required to enhance the applicability of MFCs in the treatment process. We observed that the Cs adsorption efficiencies of cobalt and nickel ferrocyanides decreased as their aging period increased, while the Cs adsorption efficiencies of copper and zinc ferrocyanides did not decrease. The tendencies of these ferrocyanides were accelerated by exposure of the solids at a higher temperature for a longer time. Our comprehensive analyses demonstrated that only the oxidizable metals in the MFCs can be oxidized by aging time and increasing temperature; also, this affects the Cs removal efficiency by decreasing the exchangeable sites in the solids. The chemical stability of MFCs is very important for the optimization of the synthesis and storage conditions.

Measurement of Flavor Absorption from Soft Drinks into PET Bottle by Headspace Solid Phase Microextraction-Gas Chromatography

2011 ◽  
Vol 7 (4) ◽  
Author(s):  
Mehdi Farhoodi ◽  
Maryam Salami ◽  
Zahra Emam-Djomeh ◽  
SM Mohammad Mousavi ◽  
Karamatollah Rezaei
Keyword(s):  
Gas Chromatography ◽  
Solid Phase Microextraction ◽  
Storage Temperature ◽  
Solid Phase ◽  
Media Type ◽  
Pet Bottles ◽  
The Media ◽  
Increasing Temperature ◽  
And Storage ◽  
Absorption Level

Absorption of flavors into packaging is of great importance in the food industry because of the final quality needs of the product. In the present study one-sided exposure of D-limone, ?-Pinene and myrcene from three types of carbonated drinks into PET bottles was studied at different test temperatures (4, 25 and 40°C). Headspace solid-phase microexraction was used as a technique for extracting the absorbed flavors from PET and the analysis performed by gas chromatography coupled with FID detector. The results showed that the absorption level of flavors is dependent on the structure and initial concentration of the flavors, media type and storage temperature. The flavors stored at 4°C showed higher consistency in the media, but the absorption rate of flavors enhanced with increasing temperature.

scholarly journals Volatile Changes during Storage of Shelf Stable Apple Juice: Integrating GC-MS Fingerprinting and Chemometrics

Foods ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 165 ◽  
Author(s):  
Biniam Kebede ◽  
Vivien Ting ◽  
Graham Eyres ◽  
Indrawati Oey
Keyword(s):  
Shelf Life ◽  
Solid Phase Microextraction ◽  
Apple Juice ◽  
Solid Phase ◽  
Storage Conditions ◽  
Gas Chromatography Mass Spectrometry ◽  
Dimethyl Sulphide ◽  
Processing And Storage ◽  
Shelf Stable ◽  
And Storage

This is the first study to reveal potential markers for volatile changes during ambient and accelerated shelf life of pasteurized apple juice. The volatile changes were monitored at 20, 30 and 40 °C using a headspace solid-phase microextraction-gas chromatography-mass spectrometry fingerprinting method. Using modern chemometrics and feature selection, hexanal, trans-2-hexenal, dimethyl sulphide, furfural, ethyl acetate and 1-pentanol were chosen as potential shelf life markers. Volatiles associated with the green, grassy and fresh apple aroma, such as hexanal and trans-2-hexenal, decreased during storage, whereas thermal load and browning associated compounds, like dimethyl sulphide and furfural, increased during storage. Hexanal and trans-2-hexenal can be markers to monitor the change in green-apple like character. Furfural and dimethyl sulphide can be markers of temperature abuse during juice processing and storage. Furfural can also be an indicator for juice browning. The present work effectively identified potential markers to monitor and predict volatile aroma changes of shelf stable apple juice in different storage conditions. Sensory analysis can be conducted in the future to confirm the aroma relevance of selected markers.

scholarly journals Thermal Decomposition of HMX: Low Temperature Reaction Kinetics and their Use for Assessing Response in Abnormal Thermal Environments and Implications for Long-Term Aging

1995 ◽  
Vol 418 ◽  
Author(s):  
Richard Behrens ◽  
Suryanarayana Bulusu
Keyword(s):  
Thermal Decomposition ◽  
Solid Phase ◽  
Test Sample ◽  
Storage Conditions ◽  
Kcal Mole ◽  
Decomposition Products ◽  
Gaseous Products ◽  
Thermal Environments ◽  
Higher Temperature

AbstractThe thermal decomposition of HMX between 175°C and 200°C has been studied using the simultaneous thermogravimetric modulated beam mass spectrometer (STMBMS) apparatus with a focus on the initial stages of the decomposition. The identity of thermal decomposition products is the same as that measured in previous higher temperature experiments. The initial stages of the decomposition are characterized by an induction period followed by two acceleratory periods. The Arrhenius parameters for the induction and two acceleratory periods are (Log(A)= 18.2 ± 0.8, Ea = 48.2 ± 1.8 kcal/mole), (Log (A) = 17.15 ± 1.5 and Ea = 48.9 ± 3.2 kcal/mole), (Log (A) = 19.1 ± 3.0 and Ea = 52.1 ± 6.3 kcal/mole), respectively. The data can be used to calculate the time and temperature required to decompose a desired fraction of a test sample that is being prepared to test the effect of thermal degradation on its sensitivity or burn rates. It can also be used to estimate the extent of decomposition that may be expected under normal storage conditions for munitions containing HMX. The data, along with previous mechanistic studies conducted at higher temperatures, suggest that the process that controls the early stages of decomposition of HMX in the solid phase is scission of the N-NO2 bond, reaction of the NO2 within a “lattice cage” to form the mononitroso analogue of HMX and decomposition of the mononitroso HMX within the HMX lattice to form gaseous products that are retained in bubbles or diffuse into the surrounding lattice.

Barley seed storage under controlled conditions

2019 ◽  
pp. 140-150 ◽  
Author(s):  
O. A. Zadorozhna ◽  
T. P. Shyianova ◽  
M.Yu. Skorokhodov
Keyword(s):  
Hordeum Vulgare ◽  
Moisture Content ◽  
Spring Barley ◽  
Seed Storage ◽  
Growing Season ◽  
Storage Conditions ◽  
Meteorological Conditions ◽  
Hordeum Vulgare L ◽  
The Relationship ◽  
And Storage

Seed longevity of 76 spring barley gene pool samples (Hordeum vulgare L. subsp. distichon, convar. distichon: 56 nutans Schubl., two deficience (Steud.) Koern., two erectum Rode ex Shuebl., two medicum Koern.; convar. nudum (L.) A.Trof.: one nudum L. та subsp. vulgare: convar. vulgare: nine pallidum Ser., three rikotense Regel.; convar. coeleste (L.) A.Trof.: one coeleste (L.) A.Trof.) from 26 countries, 11 years and four places of reproduction was analyzed. Seeds with 5–8% moisture content were stored in chamber with unregulated and 4oC temperature. The possibility of seed storage under these conditions for at least 10 years without significant changes in germination has been established. The importance of meteorological conditions in the formation and ripening of seeds for their longevity is confirmed. The relationship between the decrease of barley seeds longevity and storage conditions, amount of rainfall, temperature regime during the growing season of plants is discussed.

Comparison of Procedures for Isolation of Monoterpene Hydrocarbons from Fresh Needles of Picea abies and Picea omorica

2000 ◽  
Vol 65 (7) ◽  
pp. 1073-1081 ◽  
Author(s):  
Valerie Holubová ◽  
Iva Chvílíčková ◽  
Vlastimil Kubáň
Keyword(s):  
Picea Abies ◽  
Liquid Nitrogen ◽  
Steam Distillation ◽  
Extraction Efficiency ◽  
Total Content ◽  
Storage Conditions ◽  
Fresh Weight ◽  
Hexane Extraction ◽  
Monoterpene Hydrocarbons ◽  
And Storage

Extraction procedures (steam distillation, supercritical fluid extraction and solvent extraction) for isolation of monoterpene hydrocarbons from fresh needles of Picea abies and Picea omorica were optimised. The procedures were compared with the aim of minimizing consumption of needles and improving the extraction efficiency and repeatability. An influence of homogenisation procedures and storage conditions (liquid nitrogen, -18 and 4 °C) on the total content and composition of essential oils was studied. Cryogenic grinding (liquid nitrogen) combined with the extraction with cold hexane (extraction time 2 h) and subsequent GC-MS determination in freshly homogenised needles gives the best results (1.5-4 times better extraction efficiency, RSD < 10% for P. abies and < 25% for P. omorica). Limits of detections (3 S/N) for individual monoterpene hydrocarbons from units to tens of ng/g and recoveries 97.2-101.4% were found in fresh needles (calculated to fresh weight). While cooling to 4 °C is unacceptable, freezing at -18 °C for the period of 18 days in the dark gives also good results.

scholarly journals Evaluation of the Possibility of Using 1.4462 and 1.4501 Steel as a Construction Material for Apparatus Operating at an Increased Temperature and with Corrosive Factors

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4014
Author(s):  
Karol Prałat ◽  
Andżelika Krupińska ◽  
Marek Ochowiak ◽  
Sylwia Włodarczak ◽  
Magdalena Matuszak ◽  
...  
Keyword(s):  
Construction Material ◽  
Construction Materials ◽  
Optical Microscope ◽  
Passive Layer ◽  
Initial State ◽  
Time Intervals ◽  
Significant Deterioration ◽  
Higher Temperature ◽  
Increasing Temperature ◽  
Steel Heat

The objective of this study was to determine the requirements for steels used as construction materials for chemical apparatus operating at an elevated temperature and to correlate them with the properties of the tested steels. The experimental part examined the influence of the annealing process on the structure and properties of X2CrNiMoN22-5-3 (1.4462) and X2CrNiMoCuWN25-7-4 (1.4501) steel. Heat treatment was carried out on the tested samples at a temperature of 600 °C and 800 °C. Changes were observed after the indicated time intervals of 250 and 500 h. In order to determine the differences between the initial state and after individual annealing stages, metallographic specimens were performed, the structure was analyzed using an optical microscope and the micro-hardness was measured using the Vickers method. Potentiostatic tests of the samples were carried out to assess the influence of thermal process parameters on the electrochemical properties of the passive layer. An increase in the hardness of the samples was observed with increasing temperature and annealing time, the disappearance of magnetic properties for both samples after annealing at the temperature of 800 °C, as well as a significant deterioration in corrosion resistance in the case of treatment at a higher temperature.

scholarly journals Changes of Physicochemical Properties of Starch Syrups Recommended for Winter Feeding of Honeybees during Storage

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 374
Author(s):  
Teresa Szczęsna ◽  
Ewa Waś ◽  
Piotr Semkiw ◽  
Piotr Skubida ◽  
Katarzyna Jaśkiewicz ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Physicochemical Properties ◽  
Physicochemical Parameters ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Different Temperatures ◽  
And Storage ◽  
Bee Colonies ◽  
Temperature Time ◽  
Winter Feeding

The aim of this study was to determine the influence of storage temperature and time on physicochemical parameters of starch syrups recommended for the winter feeding of bee colonies. The studies included commercially available three starch syrups and an inverted saccharose syrup that were stored at different temperatures: ca. 20 °C, 10–14 °C, and ca. 4 °C. Physicochemical parameters of fresh syrups (immediately after purchase) and syrups after 3, 6, 9, 12, 15, 18, 21, and 24 months of storage at the abovementioned temperatures were measured. It was observed that the rate of unfavorable changes in chemical composition of starch syrups and the inverted saccharose syrup, mainly the changes in the 5-hydroxymethylfurfural (HMF) content, depended on the type of a syrup and storage conditions (temperature, time). Properties of tested starch syrups intended for winter feeding of bees stored at ca. 20 °C maintained unchanged for up to 6 months, whereas the same syrups stored at lower temperatures (10–14 °C) maintained unchanged physicochemical parameters for about 12 months. In higher temperatures, the HMF content increased. To date, the influence of this compound on bees has not been thoroughly investigated.

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