Rockwool is an inorganic fiber with interesting properties obtained from basaltic rocks. It can possibly be used in rubber technical products which work under critical conditions in several ...industries. This study aims to investigate properties of three short rockwool fibers/nitrile rubber composites. Ten formulations were prepared with 10, 25 and 40 phr of rockwool fibers with different length and modification. The composites were assessed on its morphological aspects, thermal, rheological, and mechanical behaviors. The results remarked that the rockwool fiber with chemical modification had better interfacial interaction with the polymer enhancing modulus at 100% of deformation, Shore A hardness, tear strength, Payne effect and stress relaxation under a compressive regime. An outstanding result was observed for the composite with 10 phr of fiber with chemical modification that had less stress relaxation when compared with the unfilled NBR indicating an excellent possibility of use of this fiber in materials that work under compressive forces. The difference in length of the rockwool fibers (125 μm–300 μm) did not interfere significantly on most of the results.
•All fibers studied did not interfere on vulcanization times of NBR.•Payne effect reduced considerably on composites with modified fiber.•SEM micrographs showed the stronger rubber/fiber adhesion in composites with modified fiber.•Composite R2-10 had lower stress relaxation under a compressive regime when compared to the NBR.•Tensile strength results and SEM micrographs suggested that the fibers did not assume a preferential orientation on the polymeric matrixes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The Rockwool – RWP is a man-made inorganic fiber produced mainly from basalt (igneous) rock, mainly destined for industrial landfills, generating negative environmental impacts. The aim of this ...research was to find the pozzolanic potential of Rockwool waste to its valorization as a pozzolanic material. The greatest innovation of this work was to analyze the possibility and the effect of replacing Portland cement with Rockwool waste in mortars, with the aim of making the method viable and sustainable. The results of the tests carried out show that the waste of Rockwool is classified as class II A - non-inert (not dangerous), it has a characteristic of amorphous solid and showed a potential development of pozzolanicity at an advanced age. The granulometric distribution curves exhibited a multimodal character and the presence of a fine fraction for the two milling times around 3 μm, in addition to a very fine fraction around 0.2 μm for a 2-h grinding.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Summary
For a screening test to discover nematicide candidates to control Meloidogyne incognita, a potted plant-based assay to observe gall formation on the root is realistic because it can cover the ...nematode life-cycle period and a broad range of mode of actions of tested compounds. However, both time and labour are needed for its operation. The objective of this study was to develop a plant-based screening method enabling easy periodical observation of the progress of root gall formation under almost no soil adsorption conditions of tested compounds. As an alternative material for soil, rockwool substrate for growing vegetable seedlings was used with a nutrient solution. Observation of gall formation on the same substrates was possible for 3-4 weeks. With this method, standard nematicides, e.g., fosthiazate and fluopyram, provided clear inhibitory effect on gall formation. Their ED50 values at 21 days after inoculation of 300 second-stage juveniles (substrate)−1 were 0.0034 mg (substrate)−1 and 0.0035 mg (substrate)−1, respectively. Furthermore, conventional fungicides and insecticides were screened with the method. Activities were observed in some products like polyoxins, which showed 100% control at 25 mg (substrate)−1, a considerably higher dose than that in standard nematicides. This study developed a simple test method for evaluating inhibitory effect on gall formation by M. incognita and proved its usefulness by applying it to nematicide screening.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Abstract
Airborne fibers, when sufficiently biopersistent, can cause chronic pleural diseases, as well as excess pulmonary fibrosis and lung cancers. Mesothelioma and pleural plaques are caused by ...biopersistent fibers thinner than ∼0.1 μm and longer than ∼5 μm. Excess lung cancer and pulmonary fibrosis are caused by biopersistent fibers that are longer than ∼20 μm. While biopersistence varies with fiber type, all amphibole and erionite fibers are sufficiently biopersistent to cause pathogenic effects, while the greater in vivo solubility of chrysotile fibers makes them somewhat less causal for the lung diseases, and much less causal for the pleural diseases. Most synthetic vitreous fibers are more soluble in vivo than chrysotile, and pose little, if any, health pulmonary or pleural health risk, but some specialty SVFs were sufficiently biopersistent to cause pathogenic effects in animal studies. My conclusions are based on the following: 1) epidemiologic studies that specified the origin of the fibers by type, and especially those that identified their fiber length and diameter distributions; 2) laboratory-based toxicologic studies involving fiber size characterization and/or dissolution rates and long-term observation of biological responses; and 3) the largely coherent findings of the epidemiology and the toxicology. The strong dependence of effects on fiber diameter, length, and biopersistence makes reliable routine quantitative exposure and risk assessment impractical in some cases, since it would require transmission electronic microscopic examination, of representative membrane filter samples, for determining statistically sufficient numbers of fibers longer than 5 and 20 μm, and those thinner than 0.1 μm, based on the fiber types.
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DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
•Most of the growth parameters were greater in vermiculite than in rockwool.•Dissolved oxygen concentration decreased sharply in rockwool but slightly in vermiculite.•The growth of wasabi plantlets ...is depressed at low dissolved oxygen concentrations.•A hydroponic system incorporates a 50% or 100% nutrient concentration and vermiculite.•The above-hydroponic system allows high-quality wasabi plantlets.
The growth of wasabi (Wasabia japonica Matsumura) plantlets was compared in four concentrations of standard Enshi nutrient solution (25%, 50%, 100%, and 150%) and two kinds of supporting materials (rockwool and vermiculite) using an in vitro hydroponic culture system for photoautotrophic micropropagation. After 28 days of culture, most of the growth parameters such as fresh weight and dry weight, shoot/root dry weight ratio, and leaf area ratio were highest in wasabi plantlets grown in 50% or 100% nutrient solution, and this enhancement was greater in vermiculite than in rockwool. Dissolved oxygen concentration decreased sharply in rockwool but only slightly in vermiculite during the course of the experiment, resulting in a dissolved oxygen concentration of 8 mg L−1 in the vermiculite and 6 mg L−1 in the rockwool. The highest root nitrogen concentration was observed at a nutrient concentration of 100% in vermiculite and rockwool. The highest net photosynthetic rates were observed on day 28 in vermiculite at nutrient concentrations of 50% and 100%. The growth of wasabi plantlets is depressed through a decrease in root water and nutrient uptake caused by low dissolved oxygen concentrations. These findings clearly demonstrate that a hydroponic system that incorporates a 50% or 100% nutrient solution concentration and vermiculite will allow high-quality wasabi plantlets to be propagated rapidly under photoautotrophic conditions.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract
Two experiments evaluated rooting of blueberry in substrates for use in soilless production systems. Apical and basal semi-hardwood stem cuttings of Vaccinium corymbosum x angustifolium ...‘Northland' were rooted in rockwool cubes, shredded rockwool, or 3 perlite:1 sphagnum peat moss (v/v). Cuttings were treated with 0.1% indolebutyric acid (IBA) in 1:1 95% ethyl alcohol: water, 0.1% potassium salt of indolebutyric acid (K-IBA), 1:1 95% ethyl alcohol: water, or water. In Expt. 2, basal stem cuttings of ‘Northland' and V. angustifolium ‘Brunswick' were rooted in the same substrates with the addition of coco coir, treated with 1,000 ppm K-IBA, then fertilized weekly (after rooting began) with water, 75 ppm N from 16-4-17 fertilizer or 4-18-38 and Ca(NO3)2 plus MgSO4 fertilizer, all adjusted to pH 4.0. Rooting percentages were calculated, and rooting quality was assessed using a 6-point visual scale. ‘Northland' roots well (>80%) in peat:perlite and coco coir substrates and acceptably in two rockwool substrates (∼50%). ‘Brunswick' rooted acceptably in peat:perlite and coco coir (27% and 41%, respectively), and very poorly in two rockwool substrates (<2%). Rooting of ‘Northland' was not improved with application of 0.1% auxin. Apical cuttings of ‘Northland' had a higher rooting success than basal stem cuttings. Weekly fertilization did not improve root ratings, and had minimal effect on rooting success.
Index words: adventitious rooting, auxin, coco coir, hydroponics, indolebutyric acid, rockwool, Vaccinium.
Species used: ‘Northland' half-highbush blueberry, Vaccinium corymbosum L. X angustifolium Aiton, ‘Brunswick' low-bush blueberry, V. angustifolium Aiton.
Chemicals used: auxin, potassium salt indolebutyric acid, K-IBA; Sigma-Aldrich, St. Louis, MO, USA, auxin, indolebutyric acid, IBA; Sigma-Aldrich, St. Louis, MO, USA, Oasis® 16-4-17 fertilizer, OASIS® Grower Solutions, Kent, OH, USA, ChemGro 4-18-38 fertilizer, ChemGro Hydro-Gardens, Colorado Springs, CO, USA, Ca(NO3)2, Yara North America, Tampa, FL, USA, and MgSO4, PQ Corp., Valley Forge, PA, USA.
Butterfly pea ( Clitoria ternatea ) is a unique perennial and leguminous plant that produces brightly colored flowers that can be used as a pH-dependent natural food colorant in culinary and cosmetic ...preparations. Butterfly pea is commonly propagated from seed. Because of the increased interest in its commercial applications, effective production techniques are necessary to ensure consistent and successful commercial production. The objective of this research was to determine the influence of the substrate type and temperature on butterfly pea germination. Two substrate types (rockwool and commercial soilless substrate mix) and three temperatures (70, 80, and 90 °F) were evaluated to determine their effects on germination of butterfly pea seed. Collected and calculated germination data included germination capacity (G), mean germination time (MT), coefficient of variation of the germination time ( cv t ), mean germination rate (MR), uncertainty of the germination process (U), and synchrony of the germination process (Z). Differences were observed among substrate temperatures for the MT, cv t , and MR values, with germination greater at both 70 and 80 °F than at 90 °F. Similarly, significant differences among substrate types were observed for the G, MT, cv t , and MR values, with germination of seeds in rockwool outperforming seeds in soilless substrate mix. Because of the high priority for successful and uniform germination in commercial plant production operations, the results suggest that commercial germination of butterfly pea would be best in rockwool at 70 °F. Results of this study can be used for the commercial production of butterfly pea, for which propagation from seed is the primary means of plant production.
According to the rapid population growth, the challenging issue of production of economic and suitable food sources has led to greater attention to soilless culture greenhouse production systems. ...Components of growth media in horticulture are usually selected based on physical and chemical properties and their abilities in providing enough water and oxygen for roots. This study was conducted to investigate the feasibility of using some agricultural wastes (i.e., sawdust and wheat straw) and three rockwool types (i.e., raw, ground, ground, and sieved) as substitutes for commercial greenhouse growing media such as cocopeat and perlite. Several hydraulic, aeration, and chemical properties including easily available water (EAW), air after irrigation (AIR), water holding capacity (WHC), water buffering capacity (WBC), saturated water content (θs), bulk density (BD), total porosity (TP), water drop penetration time (WDPT), pH, and electrical conductivity (EC) were measured and scored in the growth media. Raw rockwool had larger particles compared to ground rockwool, which resulted in its faster water release. Processing of the rockwool decreased the saturated water content and saturated hydraulic conductivity due to the decrease in particle size. Four growth media were scored as very good and one was scored as good. The highest and lowest scores belonged to sawdust (34) and ground rockwool (30), respectively. The studied growth media with high TP, EAW, and WHC and low BD, EC, and WDPT can be used individually or combined with other commercial substrates for greenhouse growth media.
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