Cyclopentadiene: The Impact of Storage Conditions on Thermal Stability

2007 ◽  
Vol 11 (6) ◽  
pp. 1141-1146 ◽  
Author(s):  
David J. am Ende ◽  
David C. Whritenour ◽  
Jotham W. Coe
2013 ◽  
Author(s):  
Jr Morris ◽  
Shardo Robert W. ◽  
Higgins James ◽  
Cook Kim ◽  
Tanner Rhonda ◽  
...  

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 545
Author(s):  
Grzegorz P. Łysiak ◽  
Krzysztof Rutkowski ◽  
Dorota Walkowiak-Tomczak

Late pear cultivars, such as ‘Conference’, can be stored for a long period if kept in good storage conditions. A three-year study (2011–2013) compared the impact of six-month storage using four technologies—normal atmosphere, normal atmosphere + 1-methylcyclopropene (1-MCP), controlled atmosphere, and controlled atmosphere + 1-MCP—on the quality parameters of ‘Conference’ pears, such as mass loss, firmness, total soluble solids, acidity, antioxidant capacity, and the incidence of diseases and disorders. Additionally, the study analysed different storage conditions in terms of profitability, based on the market prices for pears in the seasons during which the pears were stored. The storage conditions had a very strong influence on the fruit quality parameters, and were found to affect most visibly the mass loss and the incidence of postharvest diseases and disorders. The storage of ‘Conference’ pears for 180 days in normal atmosphere is not economically viable, even if the fruit is subjected to 1-MCP treatment; at the same time, it is profitable to store ‘Conference’ pears in controlled atmosphere for the same period, no matter whether 1-MCP was applied or not.


Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 968
Author(s):  
David A. Vargas ◽  
Markus F. Miller ◽  
Dale R. Woerner ◽  
Alejandro Echeverry

The use of antimicrobials in the pork industry is critical in order to ensure food safety and, at the same time, extend shelf life. The objective of the study was to determine the impact of antimicrobials on indicator bacteria on pork loins under long, dark, refrigerated storage conditions. Fresh boneless pork loins (n = 36) were split in five sections and treated with antimicrobials: Water (WAT), Bovibrom 225 ppm (BB225), Bovibrom 500 ppm (BB500), Fit Fresh 3 ppm (FF3), or Washing Solution 750 ppm (WS750). Sections were stored for 1, 14, 28, and 42 days at 2–4 °C. Mesophilic and psychrotrophic aerobic bacteria (APC-M, APC-P), lactic acid bacteria (LAB-M), coliforms, and Escherichia coli were enumerated before intervention, after intervention, and at each storage time. All bacterial enumeration data were converted into log10 for statistical analysis, and the Kruskal–Wallis test was used to find statistical differences (p < 0.05). Initial counts did not differ between treatments, while, after treatment interventions, treatment WS750 did not effectively reduce counts for APC-M, APC-P, and coliforms (p < 0.01). BB500, FF3, and WS750 performed better at inhibiting the growth of indicator bacteria when compared with water until 14 days of dark storage.


2020 ◽  
Vol 1 ◽  
Author(s):  
Waylon J. Hastings ◽  
Dan T.A. Eisenberg ◽  
Idan Shalev

Abstract Technical challenges associated with telomere length (TL) measurements have prompted concerns regarding their utility as a biomarker of aging. Several factors influence TL assessment via qPCR, the most common measurement method in epidemiological studies, including storage conditions and DNA extraction method. Here, we tested the impact of power supply during the qPCR assay. Momentary fluctuations in power can affect the functioning of high-performance electronics, including real-time thermocyclers. We investigated if mitigating these fluctuations by using an uninterruptible power supply (UPS) influenced TL assessment via qPCR. Samples run with a UPS had significantly lower standard deviation (p < 0.001) and coefficient of variation (p < 0.001) across technical replicates than those run without a UPS. UPS usage also improved exponential amplification efficiency at the replicate, sample, and plate levels. Together these improvements translated to increased performance across metrics of external validity including correlation with age, within-person correlation across tissues, and correlation between parents and offspring.


2021 ◽  
Author(s):  
Dawn Friesen ◽  
Brian Seymour ◽  
Aaron Sanders

Abstract Viscoelastic surfactant (VES)-based fracturing fluids can reduce the risk of formation damage when compared with conventional polymer-based fracturing systems. However, many VES systems lose viscoelasticity rapidly under high-temperature conditions, leading to high fluid leakoff and problems in proppant placement. A gemini cationic VES-based system offering thermal stability above 250°F and its efficiency in friction reduction is presented in this paper. Rheology measurements were conducted on viscoelastic cationic gemini surfactant fluids as a function of temperature (70 – 300°F) and surfactant concentration. The length of surfactant alkyl chain was varied to investigate the impact of surfactant chain length on VES fluid viscosity at elevated temperatures. The effect of flow rate on friction reduction capability of the surfactant fluid was measured on a friction flow loop. Foam rheology measurements were conducted to evaluate the VES fluid's ability to maintain high temperature viscosity with reduced surfactant concentration. A gemini cationic surfactant was used to prepare a viscoelastic surfactant system that could maintain viscosity over 50 cP at a shear rate of 100 s−1up to at least 250°F. With this system, viscoelastic gel viscosity was maintained without degradation for over 18 hours at 250°F, and the fluid showed rapid shear recovery throughout. Decreasing the average alkyl chain length on the surfactant reduced the maximum working temperature of the resulting viscoelastic gel and showed the critical influence of surfactant structure on the resulting fluid performance. The presence of elongated, worm-like micelles in the fluid provided polymer-like friction reduction even at low surfactant concentrations, with friction reduction of over 70% observed during pumping (relative to fresh water) up to a critical Reynolds number. Energized fluids could also be formulated with the gemini surfactant to give foam fluids suitable for hydraulic fracturing or wellbore cleanouts. The resulting viscoelastic surfactant foams had viscosities over 50 cP up to at least 300°F with both nitrogen and carbon dioxide as the gas phase. The information presented in this paper is important for various field applications where thermal stability of the treatment fluid is essential. This will hopefully expand the use of VES-based systems as an alternative to conventional polymer systems in oilfield applications where a less damaging viscosified fluid system is required.


2017 ◽  
Vol 12 (9) ◽  
pp. 566-569 ◽  
Author(s):  
Anastasia Mantziari ◽  
Juhani Aakko ◽  
Himanshu Kumar ◽  
Satu Tölkkö ◽  
Elloise du Toit ◽  
...  

2018 ◽  
Vol 39 (4) ◽  
pp. 434-438 ◽  
Author(s):  
Donna M. Schora ◽  
Lance R. Peterson ◽  
Elena A. Usacheva

OBJECTIVEThe impact of storage on stability and detection ofClostridium difficiletoxins in feces is poorly understood. The objective of this study was to investigate the immunological stability ofC. difficiletoxins in clinical stool specimens under different storage conditions by evaluating this stability using toxin detection by enzyme immunoassay (EIA).METHODSStool specimens positive forC. difficileinfection (CDI) by quantitative polymerase chain reaction (qPCR) were used for EIA testing with theC. difficileTox A/B II kit. The EIA-positive specimens were stored aerobically under refrigerated (4–10°C) and frozen (−30°C and −80°C) conditions. Measurement of toxin quantity was conducting using optical density (OD) on days 0, 14, 30, 60, 90, and 120 of storage.RESULTSClostridium difficiletoxins demonstrated good detection in undiluted stool specimens by EIA up to 120 days of storage. Good detection of the toxins was observed in diluted samples at refrigerated and −80°C temperatures. Dilution detrimentally affected toxin detection at −30°C.CONCLUSIONStorage of undiluted clinical stool specimens at refrigerated, −30°C, and −80°C temperatures for up to 120 days has no discernible effect on the immunological stability ofC. difficilecytotoxins. However, storage at −30°C has a detrimental effect onC. difficiletoxin stability in diluted specimens.Infect Control Hosp Epidemiol2018;39:434–438


Diagnostics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 51
Author(s):  
Lilla Pawlik-Sobecka ◽  
Katarzyna Sołkiewicz ◽  
Izabela Kokot ◽  
Aleksandra Kiraga ◽  
Sylwia Płaczkowska ◽  
...  

The present work aims at accessing the stability of biological material stored for diagnostic and scientific purposes. The influence of the temperature, storage time, and cyclic thawing on concentration stability of selected oxidative stress parameters in human serum was investigated. The study group consisted of 20 serum samples collected from healthy volunteers aged 18–52. The parameters whose reference ranges were not determined and to which validated determination methods did not correspond were examined by manual methods (FRAP and AOPP). Automatic methods were used to determine routine laboratory tests (albumin, total protein, bilirubin, uric acid) using the Konelab 20i® analyzer. The samples were stored at various temperatures (room temperature, 4 °C, −20 °C, −80 °C) for max 6 months and were subjected to cyclic thawing at 1 month intervals. In order to check whether any differences between the concentrations of the studied parameters existed when the samples were stored in various conditions, the paired Student t-test or Wilcoxon test and comparison to desirable bias were applied. Based on the obtained results, it was found that the temperature and time of serum sample storage significantly affected the stability of the analyzed parameters and determined different shelf lives of serum samples for oxidative stress examination. Therefore, continuing the investigation concerning the impact of storage conditions on various serum parameters seems justified due to the discrepancy between the individual results obtained by different researchers and the inconsistencies between the results of scientific research and the applicable recommendations.


2008 ◽  
Vol 4 (1) ◽  
pp. 61-75 ◽  
Author(s):  
Tímea Kaszab ◽  
Ferenc Firtha ◽  
András Fekete

The objective of the work reported here was to determine changes in the moisture content, firmness characteristics, color attributes and NIR absorbance of two carrot cultivars during storage. There was a definite loss in the moisture content that caused changes in the firmness. This result shows that carrot firmness is very sensitive to the moisture content. The firmness — especially the cutting force — is a good characteristic for predicting changes in carrot moisture content during storage. The color characteristics — a* and b* — showed a slight change in the function of the moisture content. However, these color characteristics are suitable for distinguishing the phloem and xylem parts of carrot cultivars. There were not found definite changes in the NIR absorbance as the function of the moisture content. Consequently, the specific cutting force and the impact stiffness coefficient are good characteristics of the carrot moisture content and the mass reduction during storage under non-ideal conditions.


Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4188
Author(s):  
Ce Cheng ◽  
Yi Gao ◽  
Zhihua Wu ◽  
Jinyu Miao ◽  
Hongxia Gao ◽  
...  

β-carotene is a promising natural active ingredient for optimum human health. However, the insolubility in water, low oral bioavailability, and instability in oxygen, heat, and light are key factors to limit its application as incorporation into functional foods. Therefore, gliadin nanoparticles (GNPs) Pickering emulgels were chosen as food-grade β-carotene delivery systems. The objectives of the present study were to investigate the influence of GNPs concentration on the rheological properties, stability, and simulated gastrointestinal fate of β-carotene of Pickering emulgels. The formulations of Pickering emulgels at low GNPs concentration had better fluidity, whereas at high GNPs concentration, they had stronger gel structures. Furthermore, the thermal stability of β-carotene loaded in Pickering emulgels after two pasteurization treatments was significantly improved with the increase of GNPs concentration. The Pickering emulgels stabilized with higher GNPs concentration could improve the protection and bioaccessibility of β-carotene after different storage conditions. This study demonstrated the tremendous potential of GNPs Pickering emulgels to carry β-carotene.


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