High recovery of stilbene glucosides by acetone extraction of fresh inner bark of Norway spruce

Abstract Stilbenes are plant polyphenols that have shown beneficial pharmacological activities in a variety of diseases. The considerable amount of stilbene glucosides in spruce inner bark encouraged us to develop a straightforward and simple method of extraction with high recovery and yield. Stilbene glucosides from fresh inner bark of Norway spruce were extracted in one simple step with acetone at 20 °C. After three weeks of soaking in acetone, the extracts were dried and the composition was determined by GC-FID using a short and a long column (HP-5) and GC-MS (HP-1). The amount of the extracted compounds was also compared with a similar extract from air dried inner bark samples. The extracts from the fresh sample contained 30–50% of stilbene glucosides and the average yield [0.185 g extract/g bark] was as good as or slightly better than in previously reported works. However, no drying, milling, or sequential extractions with different solvents in elevated temperatures were needed. Moreover, this study revealed that the drying process can decrease the amount of extractable stilbenes significantly. Therefore, this method can be considered as an alternative for preparative isolation of stilbene glucosides, especially isorhapontin and astringin from inner bark of Norway spruce.

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Fish bone-derived interconnected carbon nanofibers for efficient and lightweight microwave absorption

SN Applied Sciences ◽

10.1007/s42452-021-04204-4 ◽

2021 ◽

Vol 3 (2) ◽

Author(s):

Yangyang Gu ◽

Peng Dai ◽

Wen Zhang ◽

Zhanwen Su

Keyword(s):

Microwave Absorption ◽

Carbon Nanofibers ◽

Three Dimensional ◽

Fish Bone ◽

Absorption Properties ◽

Simple Method ◽

Microwave Absorption Properties ◽

Absorption Performance ◽

Microwave Absorption Performance ◽

Better Than

AbstractIn this work, we demonstrated a simple method for preparing three-dimensional interconnected carbon nanofibers (ICNF) derived from fish bone as an efficient and lightweight microwave absorber. The as-obtained ICNF exhibits excellent microwave absorption performance with a maximum reflection loss of –59.2 dB at the filler content of 15 wt%. In addition, the effective absorption bandwidth can reach 4.96 GHz at the thickness of 2 mm. The outstanding microwave absorption properties can be mainly ascribed to its well-defined interconnected nanofibers architecture and the doping of nitrogen atoms, which are also better than most of the reported carbon-based absorbents. This work paves an attractive way for the design and fabrication of highly efficient and lightweight electromagnetic wave absorbers.

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Newly Developed Heat Resistant Magnesium Alloy by Thixomolding®

Materials Science Forum ◽

10.4028/www.scientific.net/msf.488-489.287 ◽

2005 ◽

Vol 488-489 ◽

pp. 287-290 ◽

Cited By ~ 1

Author(s):

Tadayoshi Tsukeda ◽

Ken Saito ◽

Mayumi Suzuki ◽

Junichi Koike ◽

Kouichi Maruyama

Keyword(s):

Aluminum Alloy ◽

Magnesium Alloy ◽

Magnesium Alloys ◽

Room Temperature ◽

Elevated Temperatures ◽

Die Casting ◽

The Other ◽

Heat Resistant ◽

Higher Temperature ◽

Better Than

We compared the newly developed heat resistant magnesium alloy with conventional ones by Thixomolding® and aluminum alloy by die casting. Tensile properties at elevated temperatures of AXEJ6310 were equal to those of ADC12. In particular, elongation tendency of AXEJ6310 at higher temperature was better than those of the other alloys. Creep resistance of AXEJ6310 was larger than that of AE42 by almost 3 orders and smaller than that of ADC12 by almost 2 orders of magnitude. Fatigue limits at room temperature and 423K of AXEJ6310 was superior among conventional magnesium alloys.

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Simple Method for Estimating the Contribution of Neighbouring n-beam Interactions to Two-beam Structure Factors

Australian Journal of Physics ◽

10.1071/ph880469 ◽

1988 ◽

Vol 41 (3) ◽

pp. 469

Author(s):

HJ Juretschke ◽

HK Wagenfeld

Keyword(s):

Experimental Determination ◽

Structure Factor ◽

Beam Structure ◽

Simple Method ◽

Experimental Configuration ◽

Structure Factors ◽

Special Cases ◽

Better Than

Unless special precautions are taken, the experimental determination of two-beam structure factors to better than 1 % may include contributions from neighbouring n-beam interactions. In any particular experimental configuration, corrections for such contributions are easily carried out using the modified two-beam structure factor formalism developed recently (Juretschke 1984), once the full indexing of the pertinent n-beam interactions is known. The method is illustrated for both weak and strong primary reflections and its applicability in special cases, as well as for less than perfect crystals, is discussed.

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Comparison of Conventional and Microwave Synthesis of Phenyl-1H-pyrazoles and Phenyl-1H-pyrazoles-4-carboxylic Acid Derivatives

Current Organic Synthesis ◽

10.2174/1570179418666210618162518 ◽

2021 ◽

Vol 18 ◽

Author(s):

Antônio S. Machado ◽

Flávio S. de Carvalho ◽

Rayssa B.P. Mouraa ◽

Lorrayne S. Chaves ◽

Luciano M. Lião ◽

...

Keyword(s):

Reaction Time ◽

Carboxylic Acid ◽

Pyrazole Ring ◽

Conventional Heating ◽

Pharmacological Activities ◽

1H And 13C Nmr ◽

Microwave Assisted ◽

Attractive Option ◽

Work Up ◽

Better Than

Background: Molecules containing the pyrazole subunit considered that privileged scaffolds are of high importance due to their broad spectrum of pharmacological activities. For this reason, a method that is more efficient needs to be developed for the preparation of pyrazole derivatives. Objective: The purpose of this study was the optimisation of the conventional synthesis of the pyrazole ring and the oxidation of phenyl-1H-pyrazole-4-carbaldehyde to phenyl-1H-pyrazole-4-carboxylic acid through Microwave-Assisted Organic Synthesis (MAOS). Method: We performed a comparison between conventional synthesis and conventional synthesis with microwave heating using the synthesis of pyrazole ring described by Finar and Godfrey and, for the oxidation of phenyl-1H-pyrazole-4-carbaldehyde, the method described by Shriner and Kleiderer was used. Results: MAOS reduces the reaction time to obtain all compounds compared to conventional heating. At a temperature of 60°C, 5 minutes of reaction time, and power of 50W, the yield of phenyl-1H-pyrazoles (3a-m) compounds was in the range of 91 - 98% using MAOS, which is better than conventional heating (73 - 90%, 75ºC, 2 hours). An improvement in the yield for the oxidation reaction was also achieved with MAOS. The compounds (5a-m) were obtained with yields ranging from 62 - 92% (80ºC, 2 minutes, 150W), while the yields with conventional heating were in the range of 48 - 85% (80ºC, 1 hour). The 26 compounds were achieved through an easy work-up procedure with no chromatographic separation. The pure products were characterised by the spectral data obtained from IR, MS, 1H and 13C NMR or HSQC/HMBC techniques. Conclusion: The advantages of MAOS include short reaction time and increased yield, due to which it is an attractive option for the synthesis of pyrazole compounds.

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Fate of Antioxidative Compounds within Bark during Storage: A Case of Norway Spruce Logs

Molecules ◽

10.3390/molecules25184228 ◽

2020 ◽

Vol 25 (18) ◽

pp. 4228

Author(s):

Tuula Jyske ◽

Hanna Brännström ◽

Tytti Sarjala ◽

Jarkko Hellström ◽

Eelis Halmemies ◽

...

Keyword(s):

Norway Spruce ◽

Condensed Tannins ◽

Antioxidative Activity ◽

Value Added ◽

Hot Water ◽

Raw Material ◽

Outer Bark ◽

Production Chain ◽

Inner Bark ◽

Storage Treatment

Softwood bark is an important by-product of forest industry. Currently, bark is under-utilized and mainly directed for energy production, although it can be extracted with hot water to obtain compounds for value-added use. In Norway spruce (Picea abies [L.] Karst.) bark, condensed tannins and stilbene glycosides are among the compounds that comprise majority of the antioxidative extractives. For developing feasible production chain for softwood bark extractives, knowledge on raw material quality is critical. This study examined the fate of spruce bark tannins and stilbenes during storage treatment with two seasonal replications (i.e., during winter and summer). In the experiment, mature logs were harvested and stored outside. During six-month-storage periods, samples were periodically collected for chemical analysis from both inner and outer bark layers. Additionally, bark extractives were analyzed for antioxidative activities by FRAP, ORAC, and H2O2 scavenging assays. According to the results, stilbenes rapidly degraded during storage, whereas tannins were more stable: only 5–7% of the original stilbene amount and ca. 30–50% of the original amount of condensed tannins were found after 24-week-storage. Summer conditions led to the faster modification of bark chemistry than winter conditions. Changes in antioxidative activity were less pronounced than those of analyzed chemical compounds, indicating that the derivatives of the compounds contribute to the antioxidative activity. The results of the assays showed that, on average, ca. 27% of the original antioxidative capacity remained 24 weeks after the onset of the storage treatment, while a large variation (2–95% of the original capacity remaining) was found between assays, seasons, and bark layers. Inner bark preserved its activities longer than outer bark, and intact bark attached to timber is expected to maintain its activities longer than a debarked one. Thus, to ensure prolonged quality, no debarking before storage is suggested: outer bark protects the inner bark, and debarking enhances the degradation.

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THE SORPTION OF VAPORS BY ACTIVE SILICA

Canadian Journal of Research ◽

10.1139/cjr35-004 ◽

1935 ◽

Vol 12 (1) ◽

pp. 41-56 ◽

Cited By ~ 3

Author(s):

L. M. Pidgeon

Keyword(s):

Water Vapor ◽

Silica Gel ◽

Dynamic Method ◽

Activated Alumina ◽

Simple Method ◽

Commercial Alumina ◽

Method Of Production ◽

Effective Sorbent ◽

Better Than

The sorptive properties of a new active silica have been examined. This sorbent is prepared by the action of acids on the mineral serpentine. The quartz spiral sorption balance has been employed to obtain isotherms for water, benzene and alcohol. Relative rates of sorption have been measured and compared with those for silica gel.Efficiency measurements have also been made, using the dynamic method, with water vapor as the sorbate. Comparative measurements have been carried out on commercial silica gel, and data are cited from the literature for activated alumina. A comparison of the data indicates that active silica is inferior to silica gel but somewhat better than commercial alumina. Its simple method of production combined with reasonably good sorptive properties should result in a cheap and effective sorbent for technical purposes.The type of isotherm exhibited by active silica is similar to that associated with the "chalky" gels described by Holmes. Certain theoretical aspects of sorption by "chalky" and "vitreous" gels are discussed.

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Turbulent Heat Transfer in a Backward-Facing Step Flow Using a Non-Linear k-ε Model

Heat Transfer, Volume 6 ◽

10.1115/imece2002-33925 ◽

2002 ◽

Author(s):

Marcelo Assato ◽

Marcelo J. S. de Lemos

Keyword(s):

Heat Transfer ◽

Turbulent Heat Transfer ◽

Turbulent Heat ◽

Backward Facing Step ◽

Simple Method ◽

Wall Functions ◽

Non Linear ◽

Standard Linear ◽

Experimental Values ◽

Better Than

This work presents numerical results for heat transfer in turbulent flow past a backward-facing step. It is shown that nonlinear k-ε models perform better than their linear counterparts when simulations are compared with experimental values. Wall functions are used for simplicity of the simulations. The finite-volume technique is employed for discretizing the transport equation set on a non-orthogonal grid system. The SIMPLE method is used for correcting the pressure field. Results for the reattachment length using the non-linear model are closer to the experimental values when compared with similar calculations using the standard linear closure.

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Coverage Evaluation on Probabilistically Linked Data

Journal of Official Statistics ◽

10.1515/jos-2015-0025 ◽

2015 ◽

Vol 31 (3) ◽

pp. 415-429 ◽

Cited By ~ 2

Author(s):

Loredana Di Consiglio ◽

Tiziana Tuoto

Keyword(s):

Administrative Data ◽

Simulation Study ◽

Record Linkage ◽

Linked Data ◽

Data Sources ◽

Simple Method ◽

Population Total ◽

Linkage Error ◽

Capture Recapture ◽

Better Than

Abstract The Capture-recapture method is a well-known solution for evaluating the unknown size of a population. Administrative data represent sources of independent counts of a population and can be jointly exploited for applying the capture-recapture method. Of course, administrative sources are affected by over- or undercoverage when considered separately. The standard Petersen approach is based on strong assumptions, including perfect record linkage between lists. In reality, record linkage results can be affected by errors. A simple method for achieving linkage error-unbiased population total estimates is proposed in Ding and Fienberg (1994). In this article, an extension of the Ding and Fienberg model by relaxing their conditions is proposed. The procedures are illustrated for estimating the total number of road casualties, on the basis of a probabilistic record linkage between two administrative data sources. Moreover, a simulation study is developed, providing evidence that the adjusted estimator always performs better than the Petersen estimator.

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