Oven-dried Samples Research Articles

Diagnostic Value of Energy Dispersive Hand-Held X-ray Fluorescence Spectrometry in Determining Trace Element Concentrations in Ovine Liver

There are no data available on the use of hand-held X-ray fluorescence (XRF) spectrometry to determine trace element concentrations in veterinary diagnostics. The hand-held XRF spectrometer is easy to use and does not require extensive training for the operator. In Sub-Saharan Africa with few centralised analytical laboratories equipped with expensive apparatus or mass spectrometry capabilities, trace element analysis using the hand-held XRF spectrometer provides an alternative. The objective of this study was to compare ovine hepatic copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), selenium (Se) and zinc (Zn) concentrations as obtained with the hand-held XRF spectrometer to those of a reference laboratory using inductively coupled plasma mass spectrometry (ICP-MS). Thirty ovine livers were obtained from an abattoir; prepared as wet blended and oven-dried samples and analysed. Bayesian correlation was used to assess the correspondence between results from the XRF and ICP-MS analyses. The oven-dried preparation procedure for XRF provided the best correlation with the ICP-MS data. The correlations for Cu and Zn were strong and the XRF method may represent a suitable substitute for ICP-MS analysis. For Mn and Fe the correlations were moderately strong and the XRF method may be suitable. For Mo, the correlation was weak and XRF cannot be recommended. Selenium could not be detected in samples prepared by either method. Hand-held XRF spectrometry was a practical method to determine liver concentrations of specific trace elements under African conditions and may significantly reduce the turn-around time of analysis, but unfortunately the apparatus is expensive.

Combined different dehydration pretreatments and torrefaction to upgrade fuel properties of hybrid pennisetum (Pennisetum americanum ×P. purpureum)

Different dehydrating methods combined with torrefaction were investigated to find the underlying mechanism that how dehydration process influence the degree of hornification. Hybrid pennisetum was selected as the experiment material. Oven-dried sample (ODS), crushed dried sample (CDS), and sun-cured dried sample (SDS) were torrefied under the temperature of 275 °C and 300 °C with the duration time of 60 min. The results showed that, changes in elevated carbon content and higher heating value (HHV) and reduced oxygen content of SDS were the most obvious under identical torrefaction conditions. Fuel ratio of SDS was enhanced most under 300 °C. It also had the highest devolatilization index (Di). The combination of sun-cured dried with torrefaction under 300 °C caused lowest degree of irreversible hornification happened during dehydrating process, and different hornification degrees caused by different dehydrating methods effect the enhancement of fuel properties of lignocellulosic biomass material.

Mineral nitrogen in soils of Lithuania’s agricultural land: comparison of oven-dried and field-moist samples

Mineral nitrogen in soils of Lithuania’s agricultural land: comparison of oven-dried and field-moist samples

The Influence of Water Saturation on the Short- and Long-Term Mechanical Behavior of Red Sandstone

The presence of water greatly influences time-dependent rock deformation. An understanding of how water can affect the time-dependent mechanical behavior of rock is important when assessing the long-term stability of geotechnical projects. While the previous studies have performed brittle creep experiments on oven-dry or fully-saturated rocks, we report here on a study designed to better understand brittle creep at different levels of saturation. We performed brittle creep experiments on oven-dry samples of red sandstone (Hunan province, China) and samples of the sandstone pre-immersed in water for different durations (from 2 to 8 days). These samples were deformed at a constant stress in one of either two conditions: dry or submerged in water. Before performing creep experiments, we first performed a series of water absorption and constant stress rate experiments to guide the stresses required for our creep tests and to assist with their interpretation. Our creep experiments show that immersion in water greatly increased the minimum creep strain rate and greatly shortened the time-to-failure when compared to the dry state. In detail, the minimum creep strain rate and time-to-failure increased and decreased, respectively, as pre-immersion duration increased from 4 to 6 days, but did not change as the duration was further increased to 8 days. We attribute this to the saturation of microcracks between 4 and 6 days (i.e., water imbibition was complete, or close to completion, following 6 days). We also show that oven-dry samples deformed at a constant stress underwater fail at stresses much lower than oven-dry samples deformed under dry conditions, due to the imbibition of water during deformation. Samples pre-immersed in water, but deformed in the dry condition were characterized by lower strain rates and longer time-to-failure than those pre-immersed in water and deformed underwater. Our explanation for this is that, due to the availability of water, crack tips can remain hydrated when the sample is deformed underwater, thus increasing the efficacy of stress corrosion cracking. The relationships and data provided herein inform on the long-term stability of engineering structures.

Modelling the Effects of Debranching and Microwave Irradiation Treatments on the Properties of High Amylose Corn Starch by Using Response Surface Methodology

Response surface methodology was applied to determine the effects of pullulanase debranching, microwave irradiation time (2–4 min) and power (20–100%) on resistant starch (RS) formation and in-vitro glycemic index (GI) values in high amylose corn starch, Hylon VII. Starch:water (1:10) suspensions were cooked and autoclaved, debranched with pullulanase (1000 PUN/g; 1500 U/kg starch) at 60 °C and then different microwave-storing cycles and drying (oven or freeze drying) processes were applied. In order to describe the relationship between the dependent and independent variables (microwave power and irradiation time), the response values were fitted by first order polynomial regression models. Significance analysis showed that microwave irradiation time had significant effect on RS content and GI value of the samples treated with one cycle of microwave-storing prior to freeze-drying. Microwave power had significant factor on the GI value of the samples that were oven-dried after one cycle of microwave-storing. Solubility and water binding capacity values of all heat treated samples were higher than those of native starch. On the other hand, RVA viscosity values were lower than native starch for oven-dried samples. Water binding capacity, solubility and final viscosity values of the freeze-dried samples were higher than those of oven-dried ones.

Determination of physical and chemical properties and degradation of archeological Japanese cypress wood from the Tohyamago area using near-infrared spectroscopy

Here, we evaluated the application of near-infrared (NIR) spectroscopy for estimating the degradation level of archeological wood samples from the Tohyamago area, the dendrochronological ages of which were also determined. The wood samples were radially cut from three logs obtained from the Tohyamago area. NIR reflectance spectra were measured from the tangential faces of air- and oven-dried wood samples using a Fourier transform NIR spectrophotometer. The second derivative spectra within the wavenumber range of 6400–5200 cm−1, in which the effect of moisture content in wood is suspected to be insignificant, showed a characteristic behavior with age. By comparing the second derivative spectral change in our wood samples with that in wood degraded by aging, thermal treatment, fungal attack, and lightning reported in the literature, we found that the second derivative spectra of wood samples from one log was similar to those of wood degraded by hygro-thermal treatment, whereas those of wood samples from another log was similar to those of wood degraded by brown-rot fungi. The physical and chemical properties of archeological wood were well predicted using a combination of partial least square regression analysis and NIR spectroscopy.

Using digital image analysis to improve a simple colorimetric kit for COD and to estimate the content of available nitrogen in paddy soils from the measurement of COD in the water extracts of oven-dried soil samples

Using digital image analysis to improve a simple colorimetric kit for COD and to estimate the content of available nitrogen in paddy soils from the measurement of COD in the water extracts of oven-dried soil samples

Influence of drying of chara cellulose on length/length distribution of microfibrils after acid hydrolysis

Chara is a genus of freshwater alga that is evolutionarily observed at the aquatic-terrestrial boundary, whose cellulose microfibrils are similar to those of terrestrial plants regarding the crystallinity and biosynthesis of cellulose. Oven-dried and never-dried celluloses samples were prepared from chara. Terrestrial plant cellulose samples were used as references. The lengths and length distributions of oven-dried and never-dried chara cellulose microfibrils after acid hydrolysis with or without pretreatment by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation, which was used for efficient fibrillation of acid-hydrolyzed products, were observed by transmission electron microscopy. All terrestrial plant celluloses and oven-dried chara cellulose had short nanocrystal-like morphologies of 100–300 nm in length after acid hydrolysis. In contrast, the never-dried chara cellulose had much longer microfibrils of ∼970 nm in length after acid hydrolysis. These results indicated that disordered regions present periodically along the cellulose microfibrils, which cause the formation of cellulose nanocrystals after acid hydrolysis, are not present in inherent chara cellulose microfibrils in water, but are formed artificially under drying or dehydration conditions.

Young herbaceous legumes – a natural reserve of bioactive compounds and antioxidants for healthy food and supplements

Young plants of clover (Trifolium pratense L. and T. medium L.), medick (Medicago sativa L. and M. lupulina L.), sainfoin (Onobrychis viciifolia Scop.) and milkvetch (Astragalus glycyphyllos L. and A. cicer L.), were investigated for total contents of phenolics, flavonoids, isoflavones, condensed tannins and triterpene saponins as well as their extracts for antiradical and ferrous ion chelating activity. The impact of two sample drying methods on the aforementioned characters was compared. The phytochemical concentrations were higher in the freeze-dried legumes; however, antioxidant activities were generally higher of oven-dried samples. Both the composition of health promoting phytochemicals and antioxidant properties were strongly species-dependent. Among the species tested, Trifolium spp. were most abundant in isoflavones, Medicago spp. – in saponins and O. viciifolia – in tannins. Plants of T. medium and O. viciifolia were rich in TPC. The extracts of T. pratense, O. viciifolia and A. cicer possessed significant antiradical activity; the extracts from Astragalus spp. proved to be promising chelators of ferrous ion. We concluded that young perennial legumes could be considered as potential candidates for the development of nutraceuticals and functional food ingredients to accommodate the need for a particular bioactive component or property.

Mobilization of phenolic antioxidants from grape, apple and pitahaya residues via solid state fungal fermentation and carbohydrase treatment

This paper reports two strategies to mobilize phenolic antioxidants from lyophilized and oven-dried black grape (Vitis vinifera x (Vitis labrusca x Vitis riparia)) pomace, and apple (Malus domestica cv. Jonagold) and yellow pitahaya (Hylocereus megalanthus) peel, core, peduncle and seed mixtures: a solid-state Rhizomucor miehei NRRL 5282 fermentation-based process and a carbohydrate-cleaving enzyme treatment using R. miehei NRRL 5282 cellulase and Aspergillus niger pectinase cocktails. Both methods proved to be suitable to increase the extractable phenolic content and improve the antioxidant properties of the phenolics as determined by 1,1-diphenyl-2-picrylhydrazyl radical inhibition or ferric reducing antioxidant power analyses. During solid-state fermentation, maximal phenolic yields obtained in lyophilized grape, apple and pitahaya residues were 1956 ± 31, 477 ± 37 and 495 ± 27 mg gallic acid equivalents (GAE)/100 g dry matter (DM), respectively, while they were 1385 ± 71, 362 ± 27 and 615 ± 26 mg GAE/100 g DM in oven-dried samples, respectively. The major individual phenolics produced enzymatically from the substrates were identified by HPLC as gallic acid, 4-hydroxybenzoic acid, vanillic acid, (+)-catechin and (−)-epicatechin, with yields ranging from 0.58 ± 0.06 to 215.81 ± 17.17 mg/100 g DM depending on the substrate and the pretreatment. The obtained phenolic-enriched extracts could potentially be applicable as sources of natural antioxidants.

Estimating the Energy Content of Wastewater Using Combustion Calorimetry and Different Drying Processes

The energy content of wastewater is routinely assessed by chemical oxygen demand (COD) measurements that only provide an incomplete picture and the data fundament of other energy parameters remains scarce. The heat of combustion (∆CH) of raw wastewater from a municipal wastewater treatment plant (WWTP) was assessed using oven drying method (∆CH = −6.8±4.3 kJ L−1, n = 20) and freeze drying method (∆CH = −20.2±9.7 kJ L−1, n = 6) illustrating the substantial loss during the oven drying approach. Normalizing ∆CH to COD of raw wastewater yielded −6.2±3.5 kJ gCOD−1 for oven-dried samples (n = 14) and −13.0±1.6 kJ gCOD−1 for freeze-dried samples (n = 3). A subsequent correlation analysis with further chemical wastewater parameters revealed a dependency of ∆CHvol on COD, TOC, C:N ratio and total sulfur content. To verify these correlations, wastewater of a second WWTP was sampled and analyzed. Only COD and TOC were in accordance with the data set from the first WWTP representing potential predictors for the chemical energy stored in wastewater for comparable WWTPs. Unfortunately, during the most practical method (oven drying), a certain loss of volatile compounds is inevitable so that the derived ∆CHvol systematically underestimates the total energetic potential of wastewater. Nevertheless, this work expands the, so far, little data fundament on the energy resource wastewater and implies the requirement for further long-term studies on different sites and different wastewater types with a highly standardized sample treatment protocol.

Impact of volatile composition on the sensorial attributes of dried paprikas

Here we characterised the aroma of smoked, oven-dried, and sun-dried paprikas by sensorial evaluation and analysis of their volatile profiles. The sensorial panel defined smoked paprikas as having an intense, persistent, smoked odour and flavour and the highest acceptability. The oven-dried paprikas had a fruity odour and flavour related with aroma notes to fresh peppers. The sun-dried paprikas were associated with straw aromas and the worse valued. The chemical classes of volatile compounds also defined the paprika types. The smoked paprikas were richer in alcohols, phenols, pyrroles, and pyranones, whereas the oven-dried samples were characterised by their aldehydes and terpenes. The sun-dried paprikas had significantly lower amounts of odorant substances than the smoked and oven-dried paprikas. The intensity, persistence and smokiness descriptors (associated with smoked paprika) were positively associated with phenols and alcohols. Aldehydes were positively correlated with a fruity descriptor, which defined oven-dried paprikas, and negatively correlated with intensity, persistence, smokiness, toasted, and dried pepper descriptors. The descriptor straw, which defined sun-dried paprikas, was negatively correlated with alcohols, phenols, furans, and pyrroles.

Microwave testing of moist and oven-dry wood to evaluate grain angle, density, moisture content and the dielectric constant of spruce from 8\xa0GHz to 12\xa0GHz

The scope of this work is to discuss the challenges and demonstrate the potential of microwave testing for applications in the wood processing industry. Microwave technology benefits from the anisotropic dielectric properties of wood to simultaneously identify grain angle, density, and moisture content of wood. Therefore, the theory of free space transmission measurement is thoroughly discussed with emphasis on the characteristics of (and how to deal with) reflections occurring in real measurements. A more sophisticated calculation method for the derivation of the desired physical wood properties is presented. The advantages of a modern laboratory style setup are shown and its possible transition in an industrial-style application is discussed. Moist (moisture content 7.6–14%) and oven-dry spruce samples are tested. The detection of grain angle for moist and oven-dry wood yields an RMSE (root-mean-squared-error) of 0.14° and 0.4°, respectively. Moisture content is evaluated with density- and thickness-independent methods. Adapted regression models are proposed yielding an RMSE for moisture content of 0.45% for a single frequency measurement. The promising advantages of wood moisture estimation with frequency sweeps instead of fixed frequency signals are discussed and demonstrated for all samples (RMSE 0.39%). The dielectric constant of moist and oven dry spruce in the range from 8 to 12 GHz is evaluated in respect to density, moisture content and temperature. The respective constants ε′, ε′′, and tan(δ) are formulated in a general form via a non-linear regression and compared to existing data in literature.

Structural and functional properties of pectin extracted from jackfruit (Artocarpus heterophyllus) waste: Effects of drying

ABSTRACTPectin extracted from jackfruit waste was dried using different drying techniques, and the chemical composition and structure, flowability, appearance, solubility, and flow behaviour of the dried materials were determined. Yield, galacturonic acid content, and the degree of esterification were found within the ranges of 7–11, 62–68, and 59–66%, respectively, for freeze-dried, spray-dried, vacuum oven-dried, and oven-dried pectin samples from jackfruit waste. Fourier transform infrared spectral analysis showed no major structural differences in the pectin samples produced by the various drying techniques, and their surface structures were comparable to those of analytical and food pectin. The drying methods did not significantly affect the chemical composition (p > 0.05) but did significantly affect the physical appearance, viscosity, and solubility of jackfruit waste pectin (p < 0.05).

Determining the relationship of thermal conductivity and compressional wave velocity of common rock types as a basis for reservoir characterization

A comprehensive dataset detailing thermal conductivity and acoustic (compressional) wave velocity of 1430 oven-dry rock samples from clastic sedimentary (sandstone, arkose, greywacke), carbonatic (limestone, marl, dolomite, marble, coquina), plutonic (gabbro, gabbrodiorite, diorite, granodiorite, granite) and volcanic (basalt, andesite, rhyolite) rock types is presented. Correlation of thermal conductivity, compressional wave velocity and porosity are discussed in detail for each tested rock type. The study confirms that thermal conductivity of dry rocks can be predicted from acoustic velocity for porous rock types such as volcanites and sandstones, while non- and low-porous rocks show no to minor trends. With a prediction accuracy ±0.5Wm−1K−1 and a confidence of >80% for sediments and mafic volcanites the calculated data is far more comprehensive than data collected from literature, and is likely accurate enough for most first exploration approaches or geoscientific models before detailed site-scale investigation or modelling is conducted.To investigate the effect of water saturation on thermal conductivity and compressional wave velocity 118 sedimentary samples (arkose and fine-, medium- and coarse sandstones) were saturated in de-aired water and the heat conduction and acoustic velocity were remeasured. The obtained data shows that both thermal conductivity and compressional wave velocity of saturated samples markedly increase in contrast to dry samples. The extent of the thermal conductivity and compressional wave velocity gain is mainly controlled by porosity. Thermal conductivity of saturated samples increases twice as much for higher porous samples than for low porous fine and medium sandstones. In contrast, the gain of compressional wave velocity of saturated sandstones decreases with increasing porosity.

Improving the Concentrations of the Active Components in the Herbal Tea Ingredient, Uraria crinita: The Effect of Post-harvest Oven-drying Processing

Uraria crinita is widely used as a popular folk drink; however, little is known about how the post-harvest operations affect the chemical composition and bioactivity of UC. We assessed three drying methods (Oven-drying, Air-drying, Sun-drying), as well as the Oven-drying temperature using metabolomics approaches and bioactivity assays. The samples processed at 40 degree show a greater effect on the levels of estrogen receptor-alpha activity and nuclear factor erythroid 2–related factor 2 activity, anti-oxidative activity, and cyclooxygenase-2 inhibition compared with the other samples. A multivariate analysis showed a clear separation between the 40 degree Oven-dried samples and the other samples, which is consistent with the results of bioactivity assay. These results are ascribed to at least two-fold increase in the concentrations of flavonoids, spatholosineside A and triterpenoids in the oven-dried samples compared with the other groups. The proposed Oven-drying method at 40 degree results in an improved quality of UC.

In vitro nematicidal activity of plant species possessing alkaloids and tannins

This study determined the most effective of three doses per plant extract on L3 nematode larvae. Seven plant species: Crinum macowanii, Gunnera perpensa, Nicotiana tabacum, Sarcostema viminale, Vernonia amygdalina, Zingiber officinale and Zizyphus mucronata, had alkaloids and tannins as bioactive principle. Oven-dried leaf samples (40 g; 20 g; 10 g) of each species were extracted in 70% ethanol, and concentrated to 100 ml; constituting 4×, 2× and 1× crude extract concentration. Rectal faecal materials were collected from 10 Merino sheep and 25 Nguni goats, pooled within species and hand-mixed. Dung samples (5 g) were weighed and cultured for 12 days at 27°C. On day 13, four plates were watered, and others (4) treated with 70% ethanol to correct solvent effect on mortality. The trial had 2 (animal species) × 7 (plant species) × 3 (extract concentrations) factorial design. In each run, three plates were treated with each crude extract concentrations. L3 larvae were isolated on day 14, larval counts done, and mortality became indices of dosed anthelmintic efficacy. The study was re-run three times. Animal species (p = 0.0107) and concentration (p = 0.0005) affected efficacy; a change in crude extract concentration resulted to efficacy of 71.2 ± 2.62%, 88.0 ± 1.88% and 97.9 ± 0.91% for goats and 93.8 ± 2.62%, 96.0 ± 1.88% and 98.0 ± 0.91% for sheep. Interaction of crude extract concentration and animal species affected efficacy (p = 0.0127). Condensed tannin and alkaloid content was high, but within close range. Differences in specific anthelmintic activity exist among plants possessing the two principle(s); suggesting that combined activity of any two species extract may have enhanced activity.

Influence of Different Processing Methods on Aflatoxin Level in &amp;lt;i&amp;gt;Ogi&amp;lt;/i&amp;gt; Slurry Produced from Millet (&amp;lt;i&amp;gt;Pennisetum typhoideum&amp;lt;/i&amp;gt;)

The global shortage of cereal foods arising from improper processing and preservation methods adopted in some of our industries could be the sources of contamination of various food products which could lead to devastating health disorder. From this study, millet grains were subjected to different processing methods such as fermentation, alkaline boiling, oven drying and sun drying. The microorganisms associated with the processed samples were isolated and identified using standard microbiological and biochemical methods. The extraction, detection and quantification of aflatoxin from ogi slurry were quantified using thin layer chromatography. The sample fermented with ethanol and water showed higher fungal count 37.33cfu/ml while the sample fermented in sodium hypochloride shown no growth of Aspergillus flavus with fermentation time at initial inoculation. The milled fermented oven dry sample showed higher colony counts 14.50 cfu/g when compared to milled sun-dry and alkaline boiling fermented samples. The aflatoxin level of the ogi slurry ranged from 0.00ppb to 0.02ppb. Samples fermented with water and ethanol showed high effect in removal of aflatoxin B and G produced by toxigenic Aspergillus flavus while the alkaline boiling showed less effect on aflatoxin B1 and B2. Aflatoxin G1 and G2 were completely removed/destroyed from the sample fermented with ordinary water with aflatoxin level 0.00ppb. The sample subjected to oven dry and sun-dry showed complete removal/reduction in aflatoxin B1 and G1. The reduction in aflatoxin level of ogi slurry produced from millet using different processing methods showed its permissible level below the standard as recommended by National Agency for Food Drug Administration and Control (NAFDAC) and European Union which could be promising prior to this methods in controlling the level of contaminant in our food products for human use.

Performance of concrete blended with pozzolanic materials in marine environment

Reinforced concretes structures located at or near the coast line needs to be repaired more frequently when compared to structures located elsewhere. This study is continuation of previous studies carried out at the Department of Civil Engineering, NED University of Engineering and Technology, Karachi, Pakistan to study the performance of concrete made up of cements blended by pozzolonic materials. Different pozzolanic materials (blast furnace slag, fly ash and silica fume) were used in the study. Tests conducted during the study to compare the performance of samples cast from concrete of different mix designs were Compressive Strength Test (ASTM C 39), Flexural Strength Test (ASTM C 293), Rapid Migration Test (NT Build 492), Absorptivity of the oven-dried samples (ASTM C 642) and Half Cell Potential (ASTM C 876). Use of cements blended with pozzolanic materials, used during the study, proved to be effective in enhancing the performance of the concrete exposed to marine environment. Use of pozzolans in concrete not only provides a sustainable and feasible solution to the durability problems in coastal areas, it also helps in conservation of natural resources and reduction of pollution and energy leading to a green environment.

Determination of T2 cut-off for shale reservoirs: a case study from the Carynginia formation, Perth Basin, Western Australia

Over recent decades, the low-field Nuclear Magnetic Resonance (NMR) method has been consistently used in the petroleum industry for the petrophysical characterisation of conventional reservoirs. Through this non-invasive technique, the porosity, pore size distribution and fluid properties can be determined from the signal emitted by fluids present in the porous media. Transverse relaxation (T2) data, in particular, are one of the most valuable sources of information in an NMR measurement, as the resulting signal decay can be inverted to obtain the T2 distribution of the rock, which can in turn be correlated with porosity and pore size distribution. The complex pore network of shales, which can have a large portion of pore sizes in the nanopore and mesopore range, restricts the techniques that can be used to investigate their pore structure and porosity. The ability of the NMR technique to detect signals from a wide range of pores has therefore prompted the quest for more standardised interpretation methods suitable for shales. Using low-field NMR, T2 experiments were performed on shale samples from the Carynginia formation, Perth Basin, at different saturation levels. The shale samples were initially saturated with brine and the T2 spectrum for each sample was obtained. Then, they were placed in a vacuum oven and their weight monitored until a constant value was reached. T2 curves were subsequently obtained for each of the oven-dried samples and a cut-off value for clay-bound water was calculated.