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Influence of temperature and steam environment on set recovery of compressive deformation of wood 总被引:3,自引:2,他引:1
Low-density hybrid poplar wood (Populus deltoides?×?Populus trichocarpa) was densified by mechanical compression under saturated steam, superheated steam, and transient conditions at temperature levels of 150, 160, and 170°C. Furthermore, compression of wood under saturated steam conditions at 170°C, followed by post-heat-treatment at 200°C for 1, 2, and 3?min, was performed. To determine the influence of compression treatment on the set recovery, specimens were subjected to five cycles of water soaking and drying. Modulus of rupture (MOR) and modulus of elasticity (MOE) of specimens compressed under saturated steam conditions at 170°C and post-heat-treated at 200°C were determined in the dry condition and after five soak/dry cycles. Higher temperature of the compression treatment resulted in lower equilibrium moisture content, while the steam conditions during the treatment and the post-heat-treatment did not have significant effect. Furthermore, the highest degree of densification was obtained in specimens compressed under saturated steam conditions at 170°C and post-heat-treated at 200°C. The steam condition and temperature influenced the set recovery of compressive deformation. Reduced hygroscopicity does not necessarily imply reduced set recovery. The results established that considerable fixation of compressive deformation can be obtained by compressing the wood in a saturated steam environment and by post-heat-treatment at 200°C. The short heat-treatment had no influence on MOR or MOE, but soaking/drying treatments caused a decrease in the MOR and MOE. 相似文献
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The effects of diet supplemented with Lactobacillus rhamnosus on tissue parameters of rainbow trout,Oncorhynchus mykiss (Walbaum) 下载免费PDF全文
Natalija Topic Popovic Ivancica Strunjak‐Perovic Roberta Sauerborn‐Klobucar Josip Barisic Margita Jadan Snjezana Kazazic Inga Kesner‐Koren Andreja Prevendar Crnic Jelena Suran Blanka Beer Ljubic Vesna Matijatko Rozelindra Coz‐Rakovac 《Aquaculture Research》2017,48(5):2388-2401
This study was carried out to establish the effects of a 6 week treatment with the diet supplemented with L. rhamnosus in concentrations of 107 CFU g?1 (G1 group) and 108 CFU g?1 (G2 group) on the condition expressed by condition factors (Fulton's, Clark's and B), intestinal microbiology, haematological, histological and selected antioxidative parameters of rainbow trout. A significantly higher condition factors were found in G1 group indicating that higher concentration of probiotic (108 CFU g?1) did not result in the better condition. Cholesterol and urea levels were significantly higher in both G1 and G2 groups, albumin in G1 and creatinine in G2 group with respect to control. A significantly higher liver TBARS level was observed in G2 group. The feeding with supplemented probiont apparently changed the resident microbiota. Three weeks after withdrawal of the supplemented feed, the microflora mostly reverted to the control composition, although L. rhamnosus in faecal matter of fish remained inherent. The epithelial structure of the proximal and distal intestine revealed the increased absorptive area in both treated groups, as well as the increase in the mucin‐secreting goblet cells. The L. rhamnosus‐treated groups demonstrated the capacity for the augmentation of the innate host defence. 相似文献
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Matthew Schwarzkopf Michael Burnard Guillermo Martínez Pastur Lucas Monelos Andreja Kutnar 《Wood material science & engineering》2018,13(5):305-315
Nothofagus pumilio and N. antarctica forests of Southern Patagonia, Argentina are currently being managed for production of saw logs with fast growing conditions. The result of these management strategies is faster growing forests, but also an increase in the percentage of low-density wood. The motivation for this study was to find a way to valorise this low-density wood. Surface and bulk densification treatments were applied these wood species and were then applied as face layers in three-layer composites. The mechanical properties of three-layer composites were studied. The modulus of elasticity, modulus of rupture, and modulus of hardness were improved compared to many types of structural composite lumber. This increase in mechanical properties of N. pumilio and N. antarctica wood opens the possibility for its use in structural composites and added value to these otherwise underutilised and undervalued species. 相似文献
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Dragutin Perina Marina Korolija Marijana Popovi? Had?ija Ivana Grbe?a Robert Belu?i? Mirna Ime?ek Christine Morrow Melanija Posavec Marjanovi? Tatjana Bakran-Petricioli Andreja Miko? Helena ?etkovi? 《Marine drugs》2015,13(7):4179-4196
Finkel-Biskis-Reilly murine sarcoma virus (FBR-MuSV) ubiquitously expressed (FAU) gene is down-regulated in human prostate, breast and ovarian cancers. Moreover, its dysregulation is associated with poor prognosis in breast cancer. Sponges (Porifera) are animals without tissues which branched off first from the common ancestor of all metazoans. A large majority of genes implicated in human cancers have their homologues in the sponge genome. Our study suggests that FAU gene from the sponge Suberites domuncula reflects characteristics of the FAU gene from the metazoan ancestor, which have changed only slightly during the course of animal evolution. We found pro-apoptotic activity of sponge FAU protein. The same as its human homologue, sponge FAU increases apoptosis in human HEK293T cells. This indicates that the biological functions of FAU, usually associated with “higher” metazoans, particularly in cancer etiology, possess a biochemical background established early in metazoan evolution. The ancestor of all animals possibly possessed FAU protein with the structure and function similar to evolutionarily more recent versions of the protein, even before the appearance of true tissues and the origin of tumors and metastasis. It provides an opportunity to use pre-bilaterian animals as a simpler model for studying complex interactions in human cancerogenesis. 相似文献
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Marek's disease vaccination, with turkey herpesvirus, and enrofloxacin modulate the activities of hepatic microsomal enzymes in broiler chickens 总被引:1,自引:0,他引:1
Sakar D Prukner-Radovcić E Prevendar Crnić A Pompe-Gotal J Ragland WL Mazija H 《Acta veterinaria Hungarica》2004,52(2):211-217
Chickens were vaccinated against Marek's disease intramuscularly at one day of age. Enrofloxacin was given ad libitum in the drinking water at concentrations of 50, 100 and 250 mg/L from 8 days to 13 days of age when the animals were killed and the activities of cytochrome P-450 enzymes in the liver were measured. Vaccinated non-treated chickens served as a positive control. A negative control group was neither vaccinated nor treated. Vaccination decreased the activity of aniline hydroxylase and ethylmorphine N-demethylase in the positive control group. Subsequent application of enrofloxacin in the lowest concentration (50 mg/L) decreased, while that given at the highest level (250 mg/L) significantly increased the activity of the same microsomal enzymes. Relative liver weights and concentrations of proteins in 9000 x g supernatant were not affected by vaccination or treatment. 相似文献
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The viscoelastic thermal compression (VTC) of low-density hybrid poplar (Populus deltoides × Populus trichocarpa) from fast growing trees was performed in order to produce specimens with three different degrees of densification (63, 98, and 132%). The morphology and density profile of the VTC specimens were studied. Three different methods for the preparation of specimens for microscopy were used in order to find a technique that makes it possible to examine the VTC wood microscopically in the completely deformed state. It was found that the abrasive surface preparation of oil-embedded blocks was the most promising technique. Microscopic observation revealed that the deformations in the VTC wood were mostly the result of the viscous buckling of cell walls without fracture. The volume of the void areas in the specimens decreased with the degree of densification. The results showed that the density profile of the VTC wood varied with the degree of densification as a consequence of different temperature and moisture gradients formed before and during wood compression. The density profile is also visible on the cross-section of the VTC specimens. 相似文献
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Moze S Polak T Gasperlin L Koron D Vanzo A Poklar Ulrih N Abram V 《Journal of agricultural and food chemistry》2011,59(13):6998-7004
Phenolics from bilberries ( Vaccinium myrtillus L.) sampled from seven different locations and highbush blueberries ( Vaccinium corymbosum L.) from one location in Slovenia were analyzed. In samples of both species 15 anthocyanins were identified by LC-MS/MS. Their contents were expressed as cyanidin 3-glucoside equivalents (C3GE); bilberries contained 1210.3 ± 111.5 mg C3GE/100 g fw and blueberries 212.4 ± 14.1 mg C3GE/100 g fw. Glycosides of delphinidin and cyanidin were predominant (488.5 vs 363.6 mg C3GE/100 g fw) in the bilberries and glycosides of malvidin (108.0 vs 100.8 mg C3GE/100 g fw) in the blueberries, whereas the contents of peonidin were lowest (74.5 vs 4.8 mg C3GE/100 g fw) in both berries. The contents of flavanols, flavonols, phenolic acids, and stilbenes were determined by LC-MS. For the first time, rutin was identified (bilberries, 0.2 ± 0.0 mg/100 g fw; blueberries, 3.1 ± 0.1 mg/100 g fw). Chlorogenic acid (as 3-caffeoylquinic acid) was the most abundant among the phenolic acids (23.1 ± 1.0 mg/100 g fw in bilberries and 70.0 ± 3.4 mg/100 g fw in blueberries). Statistical analysis shows that the content of 27 individual flavonoids, phenolic acids, and stilbenes can be used to identify the picking region of these Slovenian bilberries. 相似文献