Adsorption of Polyvinyl Acetate (PVAc) Adhesive Emulsion from Aqueous Solution by Lignin-Phenol Based Cationic Surfactant Modified Organic Kieselguhr

The kieselguhr was modified by the lignin-based cationic surfactant which obtained from the Mannich reaction. Modified organic kieselguhr exhibited favorable adsorption to adhesive and fine colloidal substance. Dissolved and colloidal substances (DCS) appeared in the secondary fibre reuse process interfered the pulping and papermaking seriously. The organic clay could remove the stickies substances through adsorption approach technically. In this paper, PVAc was chosen as the simulacrum of stickies because of its wide application as the adhesives in wood, textile, paint, paper processing and other industries. The organic kieselguhr was characterized by scanning electron microscope (SEM) and infrared spectrum (IR), etc. Then the adsorption experiment of PVAc emulsion from aqueous solution was carried out. 78.61% of the adhesive was absorbed by the organic kieselguhr, while the untreated clay only removed 53.41%. Common cationic surfactant, such as dodecyl trimethyl ammonium bromide (DTAB) and cetyl trimethyl ammonium bromide (CTAB), the modified clays were taken as the reference substance. The results indicated that the modified organic kieselguhr had well absorption efficacy to the stickies simulacrum, which provided a novel approach for the stickies controlling.

ANATOMY AND LIGNIN DISTRIBUTION OF “COMPRESSION-WOOD-LIKE REACTION WOOD” IN GARDENIA JASMINOIDES

Anatomical characteristics and lignin distribution of ‘compression-wood-like reaction wood’ in Gardenia jasminoides Ellis were investigated. Two coppiced stems of a tree were artificially inclined to form reaction wood (RW). One stem of the same tree was fixed straight as a control, and referred to as normal wood (NW). Excessive positive values of surface-released strain were measured on the underside of RW stems. Anatomical characteristics of xylem formed on the underside of RW and in NW stems were also observed. The xylem formed on the underside exhibited a lack of S3 layer in the secondary fibre walls, an increase of pit aperture angle in the S2 layer, and an increase in lignin content. Some of the anatomical characteristics observed in the underside xylem resembled compression wood in gymnosperms. These results suggest that the increase of microfibril angle in the secondary wall and an increase in lignin content in angiosperms might be common phenomena resembling compression wood of gymnosperms.

Relationships between blood hormonal concentrations and secondary fibre shedding in young cashmere-bearing goats at their first moult

The aim of this study was to evaluate secondary fibre shedding in relation to seasonal hormonal changes in young cashmere-bearing goats reared in southern Italy. We used 14 cashmere-bearing kids, seven males and seven females, of a Scottish breed-population of goats specialized in cashmere production. Monthly, a hair patch of 4 cm2was clipped from both left and right mid sides alternately and cashmere length and its yield were determined. Blood samples were taken every 2 weeks and plasma was assayed for prolactin (PRL), growth hormone (GH), tri-iodothyronine (T3), thyroxine (T4), progesterone and testosterone. With the same frequency, animals were monitored for onset of moult. Our data indicate that in young cashmere goats at their first moult, secondary fibre shedding is a seasonal event that is strictly related to changes in photoperiod and that PRL has a pivotal rôle in regulating this phenomenon. This corresponds with findings in adults. The observation that both thyroid hormones and sex steroids varied seasonally suggests that they are involved in the regulation of the moult cycle, but their precise rôle remains to be elucidated. Our data also indicate that GH seems to be implicated in the control of the moult cycle. The finding that maximal fibre shedding occurred earlier in males than females could be ascribed to differences in GH levels and to the earlier increase in plasma concentration of PRL observed in males.

The effects of bovine somatotropin on hair follicle activity and cashmere fibre growth in goats

The aim of this study was to determine the role of circulating growth hormone (GH) profiles in the cessation of secondary hair follicle activity and secondary fibre growth in goats during autumn/winter and to determine whether it is possible to extend the period of growth of this fibre by artificially increasing circulating concentrations of this hormone. Nine cashmere goats were each injected, weekly, with 50 mg of bovine somatotropin (bST; treated) in carrier oil, for a period of 5 months between late August and late January. Goats of a second group of 9 animals were injected with sesame oil and served as controls. Treated goats had significantly higher circulating concentrations of growth hormone (P< 0.001), insulin (P< 0.01), thyroxine (P< 0.001), and insulin-like growth factor-I (IGF-I; P< 0.001). Secondary fibre growth rate and liveweight gains were significantly (P< 0.05) higher in treated than control goats. The proportion of active secondary follicles was positively associated with circulating IGF- I concentrations in treated but not control goats. Follicle activity was not related to the profiles of any of the other hormones measured. The mean date of cessation of secondary fibre growth was not affected by treatment. It is concluded that treatment with bST stimulated the rate of secondary fibre growth but did not delay the time of cessation of this growth or the decline in follicle activity. It is further concluded that circulating hormone profiles do not directly control follicle activity and secondary fibre growth and moult and that their effects probably involve changes within the skin and/or hair follicle, possibly in hormone receptor populations, deiodinase enzyme activity, or growth factor synthesis.

Effects of methylthiouracil treatment on the growth and moult of cashmere fibre in goats

The effect of long-term treatment of goats with methylthiouracil on the timing, amount and quality of secondary fibre (cashmere) growth and timing of cashmere moult in goats was investigated. From early June, groups of 10 Icelandic × Scottish feral goats were dosed orally each day, for a 15-month period, with 5 mg methylthiouracil per kg live weight in 30 ml water (treated; T) or with water only (control; C). Treatment with methylthiouracil resulted in a significant reduction (P < 0·05) in the proportion of active secondary hair follicles present during March. This was associated with a delayed onset of moult of cashmere in T compared with C goats at both the head (11 March v. 23 February; s.e. 3·33 days; P< 0·05) and mid side (27 March v. 26 February; s.e. 3·58 days; P < 0·001). There was no effect on the time of onset (C, 19 July; T, 19 July; s.e. 5·84 days) or cessation of cashmere fibre growth (C, 9 December; T, 8 December; s.e. 1·69 days) or the mean growth rate (C, 0·473 mm/day; T, 0·451 mm/day; s.e. 0·025) and fibre diameter (C, 16·9 μm; T, 15·4 jim; s.e. 0·266). Wlien present in the fleece, the mean weight and proportion of cashmere was higher in C than in T goats (P < 0·05). It is concluded that methylthiouracil treatment altered secondary follicle activity and the time of onset of the moult of cashmere and that these changes may be a result of reduced triiodothyronine production from thyroxine and associated secondary changes in profiles of insulin and IGF-1.