Addition Of Diatomaceous Earth Research Articles

Effect of different compatibilizers on environmentally friendly composites from poly(lactic acid) and diatomaceous earth

AbstractEnvironmentally friendly composites from poly(lactic acid) (PLA) and diatomaceous earth (DE) were successfully manufactured by extrusion, followed by injection moulding. DE was used as a filler; several compatibilizer/coupling agents, namely (3‐glycidyloxypropyl)trimethoxysilane, epoxy styrene acrylic oligomer and maleinized linseed oil, were used to improve polymer–filler interactions. Mechanical characterization was carried out by standard tensile, impact and hardness tests while morphological characterization of the fractured surfaces was conducted by field emission scanning electron microscopy. The effect of DE was evaluated by differential scanning calorimetry and dynamic mechanical thermal behaviour. The results show that the addition of DE provides an improved tensile modulus and induces more brittle composites due to stress concentration phenomena. The addition of compatibilizers in PLA‐DE positively contributes to improve ductile properties, thus leading to high environmental efficiency materials with balanced mechanical properties. Specifically, the compatibility improvement between the PLA and DE was good with maleinized linseed oil and contributed to improving the impact strength, which is a key factor in PLA‐based composites due to the intrinsic brittleness of neat PLA. © 2019 Society of Chemical Industry

Effect of biofertilizers and diatomaceous earth on life and movement of subterranean termites under laboratory conditions

AbstractThe presence of biofertilizers can affect the life and movement of subterranean organisms in the soil. In the current study, the effect of three biofertilizers (Unigrow, Rhizogold and Rhizogold Plus) alone and in combination with diatomaceous earth (DE) and insecticides on mortality and movement of subterranean termites, Coptotermes heimi (Wasmann), was investigated under laboratory conditions. The mortality of termites in soil mixed with biofertilizers was low as compared to the control treatment, which led to significant mortality. Length of galleries formed by termites with the addition of Unigrow in the soil was significantly higher as compared to the other two biofertilizers and control treatments. Mortality increased in the presence of insecticides and DE in the soil substrate. Unigrow mixed soil having chlorfenapyr had maximum mortality and minimum gallery length followed by Rhizogold and Rhizogold Plus. The addition of DE and insecticide further enhances mortality, and we recommend that some toxic elements should be incorporated in biofertilizers to control subterranean termites.

Properties of Modified Lime-Based Plasters for Renewal of Historical Buildings Exposed to Accelerated Carbonation Test

This paper deals with determination of basic physical, mechanical, thermal and water transport properties of lime–based plasters whose composition was modified by the addition of diatomaceous earth. To eliminate possible deterioration of original lime plaster by natural weathering, the hydrophobic admixtures on the stearate and oleate basis were added into the plaster mixtures and boiled linseed oil as a painting was applied. All studied material parameters were tested after 28 days of wet curing and after exposition to accelerated carbonation. The results of examined properties of developed plasters gave promising outcomes for the use of hydrophobised materials in renewal of historical buildings. Based on the obtained data, plaster made of lime hydrate, diatomite, and combination of water repellent agents can be recommended for renovation purposes.

Light-trapping in polymer solar cells by processing with nanostructured diatomaceous earth

Abstract We demonstrate the use of fossilized diatoms (diatomaceous earth) as light traps in regioregular poly(3-hexylthiophene) (P3HT) and fullerene derivative [6,6]-phenyl-C60-butyric acid methyl ester (PCBM) solar cells. Diatoms, the most common type of phytoplankton found in nature, are optimized for light absorption through millions of years of adaptive evolution. They are also an earth-abundant source of silica that can be incorporated into polymer solar cells without the need for complicated processing. Here we establish protocols dispersing the diatomaceous earth throughout the P3HT:PCBM active layer with characterization by optical and current-voltage measurements. We show that through the addition of diatomaceous earth, we can achieve the same power conversion efficiencies as standard thickness cells while using 36% thinner active layers. We find that adding the diatomaceous earth acts as a scattering center and textures the silver back contact, contributing to increases in the optical path length within devices. Results from this study open up pathways for incorporating hierarchical materials from nature into energy conversion devices.

Sugar beet wireworm Limonius californicus damage to wheat and barley: evaluations of plant damage with respect to soil media, seeding depth, and diatomaceous earth application

Wireworms, the larval stage of click beetles (Coleoptera: Elateridae), continue to be one of the major concerns of cereal producers, primarily due to the lack of effective pesticides and species-specific management options. To have a better understanding of species-specific interactions of one of the most damaging wireworms in the Pacific Northwest and intermountain regions of the USA, a greenhouse study was set to evaluate the damage from the sugar beet wireworm Limonius californicus to wheat and barley planted at different depths and in soil media with varying levels of organic content and texture. Overall, the evaluated wheat appeared to be more susceptible than the barley, showing greater reductions in emergence success and foliar biomass. The greatest loss of foliar biomass was observed in peatmoss-dominated medium, as indicated by a significant host plant-by-soil media interaction. Percentage of plants fed upon by L. californicus was significantly higher in the sand-dominated medium than peatmoss-dominated and 1:1 mix media. Moreover, manipulation of soil media by the addition of diatomaceous earth showed no consistent effect in protecting the planted wheat. Our findings indicated that in addition to quantifying wireworm species-specific interactions, host plant interactions with the environment in the presence of wireworm infestation should also be further studied. These relationships could influence the outcome of integrated management approaches and future risk assessment models and recovery plans.

Simultaneous Use of Entomopathogenic Fungus <i>Beauveria bassiana</i> and Diatomaceous Earth against the Larvae of Indian Meal Moth, <i>Plodia interpunctella</i>

The suppressive ability of entomopathogenic fungus Beauveria bassiana alone and in combination with diatomaceous earth (DE) was studied against the larvae of Indian meal moth, Plodia interpunctella (Hubner) (Lep., Pyralidae). This study clearly showed that simultaneous use of B. bassiana and DE against larvae of P. interpunctella, not only could reduce the required concentration of fungal conidia or DE, but also could shorten the time need for showing insecticidal effects. The LC50 value of fungus at 7 d after treatment was 9.8 × 105 conidia mg-1 diet. Larvae showed a dose response to B. bassiana, and the addition of diatomaceous earth at 500 and 2000 ppm resulted in a significant increase in mortality. Larval mortality reached to the maximum of 28.3% and 71.7% after 7 d exposure to 500 and 2000 ppm DE concentrations, respectively. The LC50 value for B. bassiana in the presence of DE 500 ppm was 4.6 × 104 con. mg-1 diet and of DE 2000 ppm was 1.65 × 103 con. mg-1 diet. According to our results, B. bassiana and DE can be considered as two suitable candidates for integration into IPM strategy.

Burning characteristics of ammonium perchlorate-based composite propellant supplemented with diatomaceous earth

For composite propellants, solid-phase thermal conduction is one of the dominant processes of propellant combustion and influences their burning characteristics. In this study, diatomaceous earth (DE) was used as a low-thermal-conductivity material, and the influence of DE on the burning characteristics of an ammonium perchlorate (AP)-based composite propellant was investigated.The ignitability of the propellant was improved by the addition of DE. DE showed both positive and negative effects on the burning rate of the propellant. The negative effect was attributable to the reduction of energy by the addition of DE. The enhancement in the burning characteristics was attributable to the particle shape and size of DE, the catalytic effect of Fe2O3, and the physical effect of SiO2; Fe2O3 and SiO2 are constituents of DE. The mechanism of the physical effect of SiO2 is as follows. The heat conduction in the solid phase is obstructed by SiO2 particles in the propellant matrix, and the temperature in the vicinity of these particles becomes higher. Consequently, a hot spot is formed on the burning surface side of the SiO2 particles, and the burning rate is then increased. Further, the hot spot effect was dependent on the AP interparticle distance in propellant matrix and the specific surface area of AP.

Aiming for the management of the small hive beetle, Aethina tumida, using relative humidity and diatomaceous earth

Small hive beetles (SHBs) are a global pest of European honeybee colonies. In the laboratory, the survival of adult SHBs was evaluated in relation to relative humidity (RH = 56, 64, 73, 82 and 96 %) and treatment with diatomaceous earth (DE) across 4 days. Low RH reduced survival. The application of DE reduced survival in addition to RH. Adults treated with corn flour (control) showed no difference in survival from untreated beetles. Scanning electron microscopy images showed no scarification of adult beetle cuticle after exposure to DE; therefore, water loss is likely facilitated through non-abrasive means such as the adsorption of cuticular lipids. The data agree with the hypothesis that DE causes mortality through water loss from treated insects. Egress, ingress, mortality and the egg-laying behaviours of beetles were observed in relation to a popular in-hive trench trap with and without the addition of DE. Traps filled with DE resulted in 100 % mortality of beetles compared with 8.6 % mortality when no DE was present. A simple method for visually determining beetle sex was used and documented.

Development of pilot-scale fermentation and stabilisation processes for the production of microsclerotia of the entomopathogenic fungus Metarhizium brunneum strain F52

Using 100 L stirred-tank bioreactors, we evaluated the effect of fermentation parameters and drying protocols on the production and stabilisation of microsclerotia (MS) of the entomopathogenic fungus Metarhizium brunneum (formerly M. anisopliae F52). Results showed that stirred-tank bioreactors can be used to mass produce stable MS of Metarhizium and that culturing and drying protocols significantly affected MS yield and stability. Length of fermentation (4–7 days) for Metarhizium cultures had no significant impact on biomass accumulation, MS formation or the storage stability of the air-dried MS granules. Although cultures of Metarhizium grown on media with a carbon-to-nitrogen (C:N) ratio of 30:1 produced significantly more biomass when compared to cultures grown in media with a C:N ratio of 50:1, MS formation and desiccation tolerance following drying were similar. After storage for 1 year at 4°C, conidia production by air-dried MS granules from 50:1 media was significantly higher compared to MS granules from 30:1 media. The addition of diatomaceous earth (DE) to cultures of Metarhizium prior to drying at rates of 0–60 g L−1 had no significant effect on MS desiccation tolerance but did impact conidia production. Air-dried MS granules without DE produced significantly more conidia g−1 during the first 4 months of storage, but after 1 year, conidia production was similar regardless of DE content of the MS granule. Microsclerotial granules with higher moisture levels (2.6–5.0% w/w) produced significantly more conidia immediately after drying and MS granules with low moisture (0–2.5% w/w) produced more conidia after 12 months storage.

Transformation and attachment of Beauveria bassiana conidia on the cuticle of Tribolium confusum and Sitophilus oryzae in conjunction with diatomaceous earth

Agrobacterium tumefaciens-mediated transformation (AMT) was used in order to create fluorescent conidia of Beauveria bassiana (Balsamo) Vuillemin (Ascomycota: Hypocreales). From the fungal transformants, one Enhanced Green Fluorescent Protein B. bassiana strain indicated stability (maintained the GFP characteristics) in fluorescent signal, while its pathogenicity did not differ significantly from the wild B. bassiana type. After exposure on wheat treated with the transformed conidia, fluorescence was evident on all body parts but especially on metasternon of adults of Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae) and on elytra in of Sitophilus oryzae (L.) (Coleoptera: Curculionidae). No significant differences were noted in fluorescence levels in the case of T. confusum between the transformed and the wild strain. However, the addition of diatomaceous earth (DE) increased attachment, especially at increased intervals after exposure. For S. oryzae, fluorescence of the transformed strain was decreased with the increased post-exposure time, but the simultaneous presence of DE increased fluorescence. The results of this study demonstrate that fluorescent conidia of B. bassiana can be utilized as a tool for the evaluation of parameters that affect the attachment of entomopathogenic fungi in insects’ cuticle.

Analysis of marble statues from the San Bruno Church (Serra San Bruno, Southern Italy): provenance and degradation

This paper illustrates the results of a multidisciplinary study on two white marble statues placed in the San Bruno Church (Calabria—Southern Italy): the ‘Madonna con Bambino’ and ‘San Bruno’ statues. The study, performed by combining different analytical techniques (LA-ICP-MS, CL, SEM-EDS, OM, FT-IR, isotopic ratios of 18O/16O and 13C/12C by mass spectrometry), aims to give information on the provenance of the marble, the kinds and causes of decay forms that affect the surface of the statues, and the materials used during some undated renovation works. As regards the “San Bruno” statue, three past undocumented restoration samples were analysed. Two of these samples were made with a mixture of gypsum and white pigments, while the other one is a mixture of lime mortar and white pigments, with the addition of diatomaceous earth. A comparison of the obtained data with bibliographic studies concerning pigments allowed the formulation of some hypotheses about the renovation works: they were probably carried out after the early 800s. For both statues several analyses were carried out to characterise some yellow–brown patinas present on their bases. Wax and calcium oxalate are the main components of the patinas on the statues: the former attributable to the use of wax candles, the latter, probably due to the alteration of organic matter, which may have been used during previous restoration phases. The Mn content, the maximum grain size (MGS) of calcite crystals and the isotopic analyses (δ13C, δ18O) confirmed that Carrara white marble was used to sculpt the two statues and their bases.

Short communication: Evaluation of supercritical fluid extraction aids for optimum extraction of nonpolar lipids from buttermilk powder

The milk fat globule membrane, present in buttermilk, contains complex lipids such as phospholipids. Microfiltration coupled with supercritical fluid extraction (SFE) may provide a method of enriching these nutritionally valuable lipids into a novel ingredient. Therefore, SFE as a method for phospholipid enrichment needs to be optimized for lipid removal effectiveness. The role of matrix additions to the buttermilk powder for extraction efficiency was evaluated. Diatomaceous earth (biosilicates), Teflon beads, and physical vibration were tested and shown to reduce total lipid by 86, 78, and 70%, respectively. Four consecutive treatments were shown to exhaust the system; however, similar extraction efficiencies were noted for 1 treatment with biosilicate addition, 2 treatments with physical vibration, or 3 treatments with added Teflon beads. The extracted lipid material consisted of the nonpolar fraction, and protein concentration was observed to increase slightly compared with the control. Although higher lipid extraction was achieved from the powder with addition of diatomaceous earth, a removable aid is ideal for an edible product.

Diatomaceous Earth Increases the Efficacy of Beauveria bassiana Against Tribolium castaneum Larvae and Increases Conidia Attachment

This research tested the suppressive ability of Beauveria bassiana (Balsamo) Vuillemin alone and in combination with diatomaceous earth against the red flour beetle, Tribolium castaneum (Herbst). Adults did not show a dose response to B. bassiana, and the addition of diatomaceous earth (DE) did not result in a significant increase in mortality. Against larvae, however, DE at 190 mg/kg grain enhanced the efficacy of B. bassiana at all concentrations ranging from 33 to 2,700 mg of conidia per kilogram of grain. The presence of DE resulted in 17- and 16-fold decreases in the median lethal concentration of B. bassiana at 56 and 75% RH, respectively. No significant differences in larval mortality in response to B. bassiana and diatomaceous earth alone or in combination were found between 56 and 75% RH. Conidial attachment to larvae was significantly greater with 190 mg/kg DE than without it. The partial analysis of lipids taken up by DE from the larvae revealed the removal of phospholipids and long-chain fatty acids. These results support the hypothesis that diatomaceous earth enhances the efficacy of B. bassiana against larval T. castaneum, at least in part by damaging the insect cuticle, thus increasing conidial attachment and making nutrients more available to conidia for their germination.

Diatomaceous earth increases the efficacy of Beauveria bassiana against Tribolium castaneum larvae and increases conidia attachment.

This research tested the suppressive ability of Beauveria bassiana (Balsamo) Vuillemin alone and in combination with diatomaceous earth against the red flour beetle, Tribolium castaneum (Herbst). Adults did not show a dose response to B. bassiana, and the addition of diatomaceous earth (DE) did not result in a significant increase in mortality. Against larvae, however, DE at 190 mg/kg grain enhanced the efficacy of B. bassiana at all concentrations ranging from 33 to 2,700 mg of conidia per kilogram of grain. The presence of DE resulted in 17- and 16-fold decreases in the median lethal concentration of B. bassiana at 56 and 75% RH, respectively. No significant differences in larval mortality in response to B. bassiana and diatomaceous earth alone or in combination were found between 56 and 75% RH. Conidial attachment to larvae was significantly greater with 190 mg/kg DE than without it. The partial analysis of lipids taken up by DE from the larvae revealed the removal of phospholipids and long-chain fatty acids. These results support the hypothesis that diatomaceous earth enhances the efficacy of B. bassiana against larval T. castaneum, at least in part by damaging the insect cuticle, thus increasing conidial attachment and making nutrients more available to conidia for their germination.

DIATOMACEOUS EARTH TO CONTROL CRYPTOLESTES FERRUGINEUS (COLEOPTERA: CUCUJIDAE) IN STORED BARLEY IN FARM GRANARIES

AbstractGranary trials to determine the efficacy of an enhanced diatomaceous earth (DE) formulation (Protect-It™) at 0.15 kg DE/t grain to control grain-feeding beetles in barley, Hordeum vulgare L. (Poaceae), were conducted at Glenlea, Manitoba. During the test, the grain moisture content ranged from 11 to 13%, and grain temperature ranged from 27 to 2 °C. The bulk density of barley was reduced 10–20 kg/m3 by the addition of diatomaceous earth. Adults of the rusty grain beetle, Cryptolestes ferrugineus (Stephens), were released onto the top surface of the grain of each granary, producing an average density of approximately 4 insects/kg grain. Using Berlese funnels to extract insects from grain samples there was a 95% reduction in adults and an 80% reduction in larvae found in treated grain compared with untreated grain, 1 month after releasing insects into the grain. There was a 95% or greater decrease in the total number of insects caught with probe pitfall traps in the treated barley compared with the untreated barley for all sampling dates. For the confined populations, 200 adult C. ferrugineus or Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) (red flour beetle) were held in screened jars in the grain until the end of October, and there was over a 99% reduction in both insect species, compared with insects held on untreated grain. These results indicate that this diatomaceous earth formulation can control C. ferrugineus in barley in granaries at 0.15 kg DE/t grain.

鉄酸化細菌の塩素イオン阻害に及ぼす珪藻土の効果

This paper describes an inhibition of oxidation and growth of Thiobacillus ferrooxidans by chloride ion and the effect of diatomaceous earth against its inhibition. Ferrous ion oxidation experiment in the absence of nutrient salts was carried out with various amount of chloride ion. The assay solution of this experiment contained only ferrous sulfate and magnesium sulfate (pH 1.5), and no bacteria grew in this condition. The oxidation of ferrous ion was inhibited by the chloride ion, and was subjected to the competitive inhibition from the Lineweaver-Burg plot. The addition of the diatomaceous earth in assay solution had no effect on the bacterial oxidation. The growth of T. ferrooxidans in 9 K medium was also inhibited by the chloride ion. The growth kinetics of this bacterium in the presence of chloride ion were described with the modified Monod type equation including the term of inhibitor concentration. The growth inhibition reduced by the addition of diatomaceous earth in the medium. The oxidation rate in the presence of diatomaceous earth was much faster than that in the absence of it in high concentration of chloride ion. The growth inhibition constant of adsorbed bacteria was about 60 % larger than that of free bacteria, which was the reason the oxidation of ferrous ion in the presence of diatomaceous earth was faster. The adsorption amount of T. ferrooxidans onto the diatomaceous earth was almost constant in this experimental range of the chloride ion.

Inactivation of bacteria by solids coated with magnesium peroxide

Abstract Heating diatomaceous earth or sand that has been soaked with a solution of magnesium chloride results in coating of the materials with magnesium oxide. The addition of hydrogen peroxide converts this coating to magnesium peroxide. The magnesium peroxide coating on sand or diatomaceous earth is relatively stable during storage. Greater than 50% of the oxidizing power remained after 6 months storage at room temperature. The addition of diatomaceous earth or sand coated with magnesium peroxide to aqueous solutions led to release of hydrogen peroxide into the solution, reduced the number of bacteria, and prevented bacterial growth as compared with controls. Filters made with modified and untreated diatomaceous earth removed bacteria from water equally well. However, bacteria survived or grew on filters made with untreated materials, but were greatly reduced in numbers on filters made with modified diatomaceous earth.