CT Contents Research Articles

Influence of Sintering Temperature on Physical and Mechanical Properties of Hydroxyapatite-Calcium Titanate Composite

This research is concerned with the effect of sintering temperature on physical and mechanical properties. This Hydroxyapatite-calcium titanate (HA-CT) composites were synthesized using conventional route technique. The HA-CT composites were sintered between 1200 up to 1300 °C. The effect of sintering temperature on the physical and mechanical properties of HA-CT composites was discussed. The physical properties were studied in term of densification and apparent porosity. As well as, the mechanical properties were determined in term of Vickers microhardness. The increasing of the sintering temperature increased both of the bulk density and the Vickers microhardness properties. However, the apparent porosity was decreased with increasing sintering temperature. The highest bulk density was found at 0.15 mol.% of CT in HA-CT composites which was sintered at 1300 °C for 3 h. Moreover, the mechanical properties as a function of the sintering temperature and the CT contents were also discussed and compared with other related work.

Phase, mechanical and bioactivity properties of hydroxyapatite-calcium titanate composite

This research synthesizes hydroxyapatite-calcium titanate composites (HA-CT) using conventional route technique. The synthesis procedure involves two steps: (i) synthesis nanoparticle of HA and the fine powder of CT and (ii) synthesis the HA-CT composites ceramic, respectively. The nanoparticle of HA was synthesized through the co-precipitation method with control pH at 8. The fine powder of CT was prepared by molten salt synthesis. The densification, phase formation, microstructure, and mechanical properties of the HA-CT composite samples were investigated. The decreasing decomposition of HA in HA-CT composites at high temperature sintering is related to the increase of CT content. The HA-CT composites showed improvement properties of densification, Vickers hardness, Knoop hardness and Young’s modulus with the maximum value as 91.20 GPa for CT 0.15 mol% in HA-CT samples. The fracture toughness resulted in data shown that the fracture toughness behavior of the HA-CT composites was controlled by the CT contents as well as grain size and porosity. The information of microstructures by SEM analysis indicated that the CT content produced a notable decrease in grain size of the HA-CT composites.

The Changes of Energy and Carbon in Top Soil and above-Ground Part ofDryopteris filix-masSpecies along the Succession of Beech Forest

The objective of research was to verify, whether succesion of nudal beech forests affects energy, ash and Ct contents of top layers of cambisols and aboveground part of dominant herb species Dryopteris filix-mas. The forest stands, from the juvenile stemwood to the stand of primeval forest character, were located in Slovenské stredohorie Mts (Western Carpathians). It has been found out that the successional stages of beech stands significantly affected soil characteristics of the ecotope, in the case of Dryopteris filix-mas species significant difference was observed only for the energy content. Approximately 7.5% less energy was accumulated in humus subhorizons Oof of mature beech stands (110, 200 years) compared with the juvenile stemwoods. On the other hand, in Aoq horizons markedly more energy (by 35–66%) was accumulated in the soils of mature beech phytocoenoses. The influence of stand succession differentiated ash content in Aoq horizons too. Significant difference (7.6%) was found between 85 and 200-year-old beech stand. Within studied parameters only accumulation of Ct in top soil layers was not significantly affected by stand succession. The relation between energy and ash accumulation in top soil layers of studied beech stands showed significant correlations between the variables (P <0.01). Approximately 62% of energy variability in humus subhorizons Ool of the studied stands was affected by the ash content (lower was the ash content — higher was the energy content). In Aoq soil horizons this dependence was 50% (higher was the ash content — lower was the energy content).

Effects of CaTiO3 on crystal structures and dielectric properties of Ba(Zn1/3Nb2/3)O3 ceramics via X-ray diffraction and Raman spectroscopy

Ba(Zn1/3Nb2/3)O3–CaTiO3 (BZN–CT) ceramics were synthesized at 1,395 °C for 4 h using a conventional solid-state sintering technique, with CT contents of 0, 30, 60, 75, and 90 wt%. Crystal structures were analyzed by X-ray diffraction, and vibrational modes were obtained by Raman spectroscopy to evaluate the correlation between crystal structures, dielectric properties, and phonon modes of these ceramics. Increasing CT content can remarkably affect the crystal structures and dielectric properties of BZN–CT ceramics. Crystal symmetries decrease with CT concentration from cubic to hexagonal structure. The lattice constant and the degree of order also change accordingly. The ordered phases transform from 1:1 to 1:2 ordered structure with changing crystal structures. The relationship between the Raman shifts, the FWHM values, and the dielectric properties were obtained by Raman spectral analyses.

TANNINS IN SOME AGRO FORESTRY SPECIES OF LOCAL INTEREST

Total and condensed tannin contents were determined in six agro forestry species usedby local farmers to feed ruminants. Total and condensed tannins were determined byFolin-Ciocalteu and Butanol-Hcl methods respectively. Total tannin (1T) contentranged from 5.41% for Calliandra calothyrsus to 0.15% for Erythrina indica.Condensed tannins (CT) contents ranged from 6.92% in Acacia auricu/iformis to 0.78%in G/iricidia sepium. The percentages of CT were 6.40%, 4.60%, and 1.58% respectivelyfor Artocarpus heterophy//us, C. ca/othyrsus, and Leucaena le ucoceph ala. Among thesix species tested, E. indica, was free of CT while having traces of IT. On the basis oftheir respective CT contents G. sepium was classified as containing traces of CT «1 %),while L. /eucocepha/a classified as containing low level of CT (1-3%). C. calothyrsuswas classified as containing medium level of CT (4-6%) while A. auriculiformis and A.heterophyl/us classified as containing high level of CT (&gt;6%).In a further study, it was found that tender leaves and stems (0-30 cm from the tip) of C.calothyrsus, and A. auriculiformis contained higher levels of IT and CT as comparedwith mature leaves and stems (30-60 em from the tip) of the same species. In contrasttender leaves and stems of A heterophyllus contained low levels IT as compared withmature leaves and stems.The results suggest that IT and CT contents of tested six species are different due totheir inherent characteristics. It was also evident that tannins are present not only inleguminous species but also in non-leguminous species such as A. heterophyllus. Theincrease in TT and CT contents in tender parts of C. callothyrsus and A. auriculiformismay be associated with the chemical defence mechanisms found in younger plant parts.Further investigations are necessary to verify the effects of tannins on their nutritivevalue of above forages

일 지역 종합병원 영상의학과 MDCT선량에 대한 연구

Abstract The difference of radiation dose of MDCT due to different proto cols between hospitals was analyzed by CTDI, DLP, the number of Slice and the number of DLP/Slice in 3 0 cases of the head, the abdomen and the chest that have 10 cases each from MDCT examination of the depa rtment of diagnostic imaging of three general hospitals in Gyeongsangbuk-do. The difference of image quality, CTDI, DLP, radiation dose in the eye and radiation dose in thyroid was analyzed after both helical s can and normal scan for head CT were performed because a protocol of head CT is relatively simple and head CT is the most frequent case.Head CT was significantly higher in two-thirds of hospitals com pared to A hospital that does not exceed a CTDI diagnostic reference level (IAEA 50mGy, Korea 60mGy) (p<0. 001). DLP was higher in one-third of hospitals than a diagnostic reference level of IAEA 1,050mGy.cm and Korea 1,000mGy.cm and two-thirds exceeded the recommendation of Korea and those were significant ly higher than A hospital that does not exceed a diagnostic reference level (p<0.001).Abdomen CT showed 119mGy that was higher than a diagnostic refe rence level of IAEA 25mGy and Korea 20mGy in one-third. DLP in all hospitals was higher that Korea recommendation of 700mGy.cm. Among target hospitals, C hospital showed high radiation dose in all tests b ecause MPR and 3D were of great importance due to low pitch and high Tube Curren.To analyze the difference of radiation dose by scan methods, no rmal scan and helical scan for head CT of the same patient were performed. In the result, CTDI and DLP of helical CT were higher 63.4% and 93.7% than normal scan (p<0.05, p<0.01). However, normal scan of radi ation dose in thyroid was higher 87.26% (p<0.01). Beam of helical CT looked like a bell in the deep par t and the marginal part so thyroid was exposed with low radiation dose deviated from central beam. In addition , helical scan used Gantry angle perpendicularly and normal scan used it parallel to the orbitomeatal line. Ther efore, radiation dose in thyroid decreased in helical scan. However, a protocol in this study showed higher r adiation dose than diagnostic reference level of KFDA. To obey the recommendation of KFDA, low Tube Curren and h igh pitch were demanded. In this study, the difference of image quality between normal scan and helical scan was not significant. Therefore, a standardized protocol of normal scan was generally used and pro tective gear for thyroid was needed except a special case.

Farklı Meşe Türlerinden Elde Edilen Palamutlarının Potansiyel Besleme Değeri ve Kondense Tanen İçerikleri

Summary The potential nutritive values of acorns of Quercus suber, Quercus branti, Quercus coccifera, Quercus cerris and Quercus infectoria were estimated by chemical composition and in vitro gas production technique. Acorns collected at least 10 different trees in three experimental plots. There were significant (P 0.5) differences in the potential gas production of acorn among oak species when incubated in the absence of PEG, there is significant (P<0.001) differences in the potential gas production of acorn among oak species when incubated in the presence of PEG. Although the estimated organic matter (OMD) and metabolisable (ME) contents of acorn for Q. suber and Q. infectoria were significantly (P<0.001) higher than those for Q. branti, Q. coccifera and Q. cerris when incubated in the absence of PEG, the estimated OMD and ME contents of acorn for Quercus cerris and Q. infectoria were significantly lower than those for Q. suber, Q. branti and Q. coccifera when incubated in the presence of PEG. The improvement in gas production, OMD and ME in the presence of PEG emphasizes the negative effect of tannins on digestibility. As a conclusion, oak acorns have potential nutritive values for ruminant animals such as sheep and goat since acorns have high starch, OMD and ME but low level of CT contents. However these results obtained in the current study should be supported by in vivo feeding experiments.

Chemical Composition and Nutritive Value of Oak (Quercus robur) Nut and Leaves

Kilic, U., Boga, M. and Guven, I. 2010. Chemical composition and nutritive value of oak (Quercus robur) nut and leaves. J. Appl. Anim. Res., 38: 101–104. To determine the potential nutritive value of different parts of Quercus robur chemical composition and in vitro gas production technique were used. Crude protein, dry matter contents and gas production of kernel were higher (P<0.01) than the other parts of oak, whereas, CT, NDF and ADF contents were lower. The NDF and ADF contents of cup and hull were significantly higher compared to those of the other parts of oak. Oak nut and leaves have potential nutritive value for ruminant animals.

Optimum extraction process of polyphenols from Bridelia grandis stem bark using experimental design

Euphorbiaceae barks are known to contain an appreciable amount of polyphenolic compounds responsible for several biological activities. Preliminary extraction from Bridelia grandis stem bark afforded high content of polyphenols, determined by spectrophotometric methods such as Folin-Ciocalteu (for total phenols, TP) and n-butanol-HCl (for condensed tannins, CT). A preliminary Plackett-Burman screening design was used to identify the key factors that influence the TP and CT extraction. Between all the variables known to influence the extraction from vegetable matrixes, six were selected; maceration was chosen as traditional extraction methodology. To investigate the effect of solvents and extraction method, methanol, acetone 70% (v/v in water), centrifugation and ultrasound were chosen. A full factorial design 2(3) was applied to optimize the extraction procedure. The responses were obtained analyzing the extracts for their TP and CT contents determined by the above-mentioned spectrophotometric methods. The results confirm that, within the explored domain, the optimum solvent is methanol and the optimum method is one-cycle centrifugation. Finally, it was also compared with the effect of maceration on the considered responses. It has never given results better than centrifugation, whereas in the case of CT it represents an advantage to employ a three-cycle centrifugation instead of one.

Auditing the Semantic Completeness of SNOMED CT Using Formal Concept Analysis

ObjectiveThis study sought to develop and evaluate an approach for auditing the semantic completeness of the SNOMED CT contents using a formal concept analysis (FCA)–based model. DesignWe developed a model for formalizing the normal forms of SNOMED CT expressions using FCA. Anonymous nodes, identified through the analyses, were retrieved from the model for evaluation. Two quasi-Poisson regression models were developed to test whether anonymous nodes can evaluate the semantic completeness of SNOMED CT contents (Model 1), and for testing whether such completeness differs between 2 clinical domains (Model 2). The data were randomly sampled from all the contexts that could be formed in the 2 largest domains: Procedure and Clinical Finding. Case studies (n = 4) were performed on randomly selected anonymous node samples for validation. MeasurementsIn Model 1, the outcome variable is the number of fully defined concepts within a context, while the explanatory variables are the number of lattice nodes and the number of anonymous nodes. In Model 2, the outcome variable is the number of anonymous nodes and the explanatory variables are the number of lattice nodes and a binary category for domain (Procedure/Clinical Finding). ResultsA total of 5,450 contexts from the 2 domains were collected for analyses. Our findings revealed that the number of anonymous nodes had a significant negative correlation with the number of fully defined concepts within a context (p < 0.001). Further, the Clinical Finding domain had fewer anonymous nodes than the Procedure domain (p < 0.001). Case studies demonstrated that the anonymous nodes are an effective index for auditing SNOMED CT. ConclusionThe anonymous nodes retrieved from FCA-based analyses are a candidate proxy for the semantic completeness of the SNOMED CT contents. Our novel FCA-based approach can be useful for auditing the semantic completeness of SNOMED CT contents, or any large ontology, within or across domains.

Impact of season of harvest on in vitro gas production and dry matter degradability of Acacia saligna leaves with inoculum from three ruminant species

In vitro gas production (IVGP) and dry matter degradability (IVDMD) of Acacia saligna leaves (ASL) from four seasons were studied under arid Egyptian conditions as a 4 × 3 factorial experiment (4 seasons × 3 ruminant species). Incubations were completed using rumen liquid collected immediately after slaughter from sheep, cattle and buffalo, in order to investigate differences among ruminants in their ASL fermentation capacity. Samples of ASL were collected during the last 2 months of each season, being autumn, winter, spring and summer (between the 5th and 12th week of each season). Dried samples of ASL were incubated for 24 h in each of the three buffered rumen liquors, using a syringe technique, to determine IVGP and IVDMD. The crude protein content of ASL was lower ( P<0.01) in summer (143 g/kg DM) than autumn (171 g/kg DM), winter (177 g/kg DM) and spring (182 g/kg DM). In winter, ASL had lower neutral detergent fibre, acid detergent fibre, acid detergent lignin and cellulose than in other seasons ( P<0.05), but there were no differences among seasons in ash and hemicellulose contents. Condensed tannin (CT, as quebracho tannin equivalent) contents of ASL were higher ( P<0.001) in summer (113 g/kg DM) versus the other seasons, with the lowest value during winter (63 g/kg DM). Gas production after 24 h was higher ( P<0.05) with buffalo rumen fluid, versus cattle or sheep, in all seasons except winter. IVGP with buffalo rumen fluid was not affected by season but, with cattle and sheep, IVGP was higher ( P<0.01) in winter. IVDMD was higher in winter and spring, and lower in summer and autumn, within all species, and higher ( P<0.001) values were general with buffalo versus other species. IVGP was positively ( P<0.05) correlated with IVDMD, but there was no consistent relationship between IVGP or IVDMD and chemical composition of ASL. Rumen fluid from buffalo, cattle and sheep have different capacities to ferment A. saligna leaves, and differences among species were smallest in winter, when the fibre and CT contents of ASL were lower.

Phosphorus status of soil and leaching losses: results from operating and dismantled lysimeters after 15 experimental years

The objectives of the present study were: (1) to evaluate the predicting value of the most important European soil P tests for P leaching losses; and (2) to investigate how these soil P tests reflect the development of P depth profiles in original homogeneous soils of lysimeters. The study included more than 100 lysimeters, located at the Lysimeter Station Falkenberg/Saxony-Anhalt, UFZ-Centre for Environmental Research Leipzig-Halle GmbH, Germany. Soil textures were sand, sandy loam, loam and silt. The management forms were arable land, grassland and fallow with various variation in fertilisation, crop rotation and irrigation. Samples were collected from the A-horizons and from the whole profiles of eight set-aside and dismantled lysimeters at 10-cm sections. The concentrations of total P were determined monthly in the leachates and evaluated for a three-year period. The concentrations of P extracted by ammonium acetate lactate (AL-P), double lactate (DL-P), sodium bicarbonate (Olsen-P) and ammonium oxalate (OX-P) as well as Pt were significantly correlated with each other (P 0.954, P<0.001) predicted by the OX-P concentrations of arable topsoils in lysimeters filled with sand. For sandy loam under grass the agronomic soil P tests (AL-P, DL-P and Olsen-P) enabled reasonable predictions of P in leachate. Under arable use, factors such as fertilisation, management intensity, depth of tillage and irrigation resulted in weak correlations between soil P concentrations and P in leachate. It was shown for the first time that all P extractants reflected P enrichments in topsoils and subsoils and the development of distinct depth profiles. Influence of soil use on the depth distribution of P was more pronounced in the 0–20 cm layer than in the subsoils. Here, the original homogeneous substrate had oscillating P concentrations at 10-cm increments under all soil uses. These could not be explained by Alox and Feox but were significantly correlated with the Ct contents and bulk density. This indicates that vertical movement of P containing organic matter along with differences in porosity contributed to the heterogeneous P distribution in the lysimeter subsoils. This new evidence must be considered if data sets from long-term lysimeter experiments are used to calibrate and validate P leaching models.

Nuclear magnetic resonance study on isomorphous behaviour in random copolyesters: poly(ethylene terephthalate- co-1,4-cyclohexenedimethylene terephthalate)

Isomorphism of copolymers of ethylene terephthalate (ET) and 1,4-cyclohexenedimethylene terephthalate (CT) was analysed by high-resolution solid-state 13C nuclear magnetic resonance (n.m.r.) spectroscopy. The ET/CT copolymer system was confirmed to have random comonomer sequence distribution. The trans/cis isomer compositions of the cyclohexene group in the CT unit were almost constant for all samples, giving a ratio of 67/33. The CT contents in the crystalline phases were determined by high-resolution solid-state 13C n.m.r. spectroscopy. The crystalline phases consisted of only ET components in the composition range of 80–100 mol% ET, whereas those in the composition range of 66–100% CT adopted the incorporation of the comonomer units in the PCT crystal.

Correlation between CT and DNA contents in peripheral lung cancers

The DNA contents of 30 lung cancers were correlated with preoperative chest CT findings. Tumors with diameters less than 4 cm had lower DNA contents than larger ones, and tumors with spiculated margins had lower DNA than those with lobulated or smooth margins. As DNA contents are correlated with prognosis, the border configuration of peripheral lung cancers may be enough to predict prognosis.