Additives Incorporated in Cellulose Acetate Membranes to Improve Its Performance as a Barrier in Periodontal Treatment

In this study, we prepared cellulose acetate membranes, by means of casting mold, incorporated with two additives, sodium carboxymethyl lignin and calcium glycerophosphate, in order to improve properties for periodontal applications. The membranes were characterized from the morphological, structural, thermal and mechanical point of view, as well as by physiological pH tests. The results showed that membranes with additives improve the physical-chemical and mechanical properties, especially when the two additives are present in the same membrane, which can be attributed to the important synergy between them. The most significant effects occur in increasing the thickness and decreasing the density, which reflects in the porosity of the membranes, although the added amounts do not exceed 1.4%. A 1% increase in lignin concentration does not change the thickness and density of the membrane, but that amount of lignin plus 0.4% calcium glycerophosphate increases the thickness of the membrane by 42% and decreases the density by about 6%. Although there is a decrease in mechanical properties, as observed in Young's modulus and crystallinity, the significant and intermittent increase in sample weight loss with both additives in physiological solution indicates that, in the long run, it can be used as a degradable barrier.

Influence of jeringau (Acorus calamus Linn.) rhizome extract against dry-wood termites (Cryptotermes cynocephalus Light.)

Rubberwood (Hevea brasiliensis Muell Arg.) is classified as a hardwood, yet it is vulnerable to dry-wood termites attack, namely Cryptotermes cynocephalus Light. Hence, a preservative is necessary for prevention. The purpose of this research was to examine the effect of jeringau rhizome extract on dry-wood termites C. cynocephalus attack. The experimental design was a completely randomized factorial design with two factors include 2 levels of solvent (water and ethanol) and 4 levels of extract ratio (1:4, 1:6, 1:8, and 1:10). Parameters observed were actual retention, termites mortality, sample weight loss, and attack degree. Rubberwood was sized in 5 cm x 3 cm x 3 cm. The method used was immersing the samples in a container that contains jeringau rhizome extract in various treatments for 72 hours. The immersed samples were then fed to healthy and active C. cynocephalus for 12 weeks. The results showed that the type of solvents and extract ratio had a significant effect on termites mortality and samples weight loss, while actual retention was influenced by the extract ratio. In conclusion, the most effective formula to prevent dry-wood termites attack was jeringau rhizome extract with a weight ratio of jeringau powder and ethanol 1:6.

Anti-termite activities of Indonesia’s essential oils against invasive drywood termite for wood product protection

The Indo-Malayan drywood termite, Cryptotermes cynocephalus (Light) (Kalotermitidae), is considered one of the most invasive drywood termites in the Southeast Asian region. Once infesting a timber, the colony of a drywood termite is very difficult to be controlled. Thus, the best way to mitigate a new infestation of a drywood termite is by applying chemical protection on wood. In recent years, particular attention has been given by researchers to develop and use organic termiticides, such as essential oils extracted from plants as active ingredients. The objective of the present study is to evaluate the repellency performance of several economically important essential oils from Indonesia, such as Clove (Eugenia caryophyllata), Cubeb Pepper (Piper cubeba L), and Lemon Grass (Cymbopogon winterianus Jowitt) against a drywood termite, C. cynocephalus. The test was performed by subjecting various concentrations of essential oil toward C. cynocephalus in the force-feeding test method. Sample weight-loss was evaluated after two weeks test. The results suggested that Clove oil has the highest repellence performance against C. cynocephalus, followed by Lemon Grass and Cubeb Pepper oils. The Termite mortality rate was also recorded to understand the toxicity performance of those essential oils.

Corrosion Behavior of Al7Cu0.2Si0.2Zn0.2Mg0.1 Complex Concentrated Alloy, in 3wt% and 5wt% Na Cl Solution

Complex concentrated alloys (CCAs) are new types of materials, where the equimolar rule proposed by high entropy alloys (HEAs) is modified in relation to the potential of the obtained structures. CCAs expend the compositional space of the conventional alloys, revealing new pathways for material design. The Al7Cu0.2Si0.2Zn0.2Mg0.1 alloy was prepared in an induction furnace, in controlled atmosphere and was cast in a copper ingot mold. The resulting samples of Al7Cu0.2Si0.2Zn0.2Mg0.1 were analysed by chemical, structural, and corrosion resistance. Furthermore, the alloy has been subjected to mechanical tests of hardness, elongation and tensile strength. The corrosion immersion tests were performed in 3wt% and 5wt% NaClsolution, and corrosion indices were measured periodically. The obtained corrosion film was analized by SEM-EDS to determine the composition and structural behaviour. Depending on the adhesion level, the corrosion film remained stable or partially broken and separated in the solution. The sample weight loss presented large variations between the various experimental conditions, but the general tendency was the decrease in the weight of the samples during the corrosion tests. The formation of oxide and chloride layers, during the corrosion process, determined only the dealloying in Al. Other elements remained in initial concentrations. Overall, the resistance of the alloy in saline environment seems to be promising, with significant improvement over the comparable compositions of 2000 and 7000 series aluminium alloys.

Activity of Mikania micrantha leaf extract against subterranian termite and wood decay

Mikania micrantha is a wild weed that thrives in tropical areas, grows rapidly in areas with high humidity and light intensity as well as in fertile soil. Meanwhile, Indonesia s tropical climate is also a suitable habitat for the breeding of termites and wood decay fungi. This study aims to determine the bioactivity of M. micrantha leaf extract against subterranean termite, Coptotermes curvignathus (Holmgren) and wood decaying fungus, Schizopyllum commune and its optimal extract concentration to prevent termite attack and inhibit fungal growth. The extracts were obtained by drying and mashing of M. micrantha leaves. The leaf powder was sieved with a 40-60 mesh filter and macerated with methanol for 3x24 h. The maceration results were filtered and the filtrate was concentrated using a rotary evaporator. Furthermore, identification of the secondary metabolites of the extract was carried out by phytochemistry. The bioactivity test included anti-subterranean termite and wood decay fungus using Potatos Dextrose Agar (PDA) medium. The results showed that M. micrantha leaf extract affected sample weight loss, termite mortality rates and the growth of wood decay fungi. Furthermore, the concentration of M. micrantha extract was inversely proportional to the sample weight loss and directly proportional to the termite mortality rate. In addition, the concentration of M. micrantha leaf extract had a negative correlation with the growth of the decaying fungus of S. commune therefore, the concentration of the extract was directly proportional to the growth inhibition of fungus. Meanwhile, the 4 percent extract concentration led to the increase in termite mortality rate above 80 percent and inhibited fungal growth by 100 percent. The results suggest that the bio-efficacy data from this study may be used to develop wood protecting systems based on wild weeds which are found in tropical areas.

Research into the Effect of Grain and the Content of Alundum on Tribological Properties and Selected Mechanical Properties of Polymer Composites

The subject of the research is a polymer composite with a matrix base of epoxy resin L285 cured with H285 hardener, and a physical modifier of friction in the form of alundum. The article presents an analysis of findings of tribological examinations. The authors evaluated the influence of the modifier properties in the form of alundum, i.e., mass share and grain size, on the abrasive wear of a composite, defined as loss of weight as well as on roughness parameters and selected mechanical properties. The tribological examinations have been extended by measurements of hardness and density of the prepared composites. The obtained results of tribological examinations showed an increase in the average value of weight loss in relation to the loss of sample weight loss between the cycles. The influence of both the grain size and the mass percentage share of alundum upon the increase in the longitudinal modulus of elasticity was also observed. On the basis of the obtained results, it was found that alundum of grain sizes equal to F220 and F240 exerted the best influence on the reduction of abrasive wear of the tested samples. In the case of F220, it was 14.04% of the average value of the weight loss between the cycles for all percentage shares of the used grains.

Methodology for Assessing Progeny Production and Grain Damage on Commodities Treated with Insecticides

In evaluating insecticides, progeny production on grain commodities can be evaluated by either exposing adults on a commodity for a given time period, then removing them and assessing mortality and progeny production, or by leaving the adults on the commodity continuously, and then assessing progeny production. Little research directly compares these methodologies. Thus, our aims were to: (1) determine residual efficacy of Diacon IGR+ (methoprene+deltamethrin) and Gravista (methoprene+deltamethrin+piperonyl butoxide) on wheat, corn, and brown rice over the course of a year, using bioassays with select stored product insects at different time intervals, and (2) directly compare the two different methods of parental adult exposure on progeny production. Adults were either exposed for 7 d, then removed and assessed for survival, and the commodities were held for 6–7 weeks to assess progeny production, or adults were continuously exposed on the commodities for 6–7 weeks. Commodities were aged and sampled every 3 months for 12 months. Afterwards, samples were examined for progeny, sample weight loss, and insect feeding damage. Each insecticide killed exposed adults and prevented progeny of Rhyzopertha dominica on wheat and brown rice, and Tribolium castaneum on corn. There was extensive survival of Sitophilus spp. on all commodities, though Gravista did initially suppress S. oryzae on wheat and S. zeamais on corn compared to Diacon IGR+. Progeny, weight loss, and insect feeding damage were positively correlated in the 7 d exposure compared with continuous parental exposure. Both insecticides will control R. dominica and externally-feeding insects, but may exhibit reduced effectiveness for Sitophilus spp., especially S. oryzae. Food managers can utilize these data to more effectively plan management programs.

BRUCITE-BASED MAGNESIUM PHOSPHATE BONDING AGENT, ITS ANALYSIS AND APPLICATION FOR PERICLASE SINTERING

Some results on magnesium phosphate binder obtained from natural brucite (mainly Mg(OH)2) and H3PO4 were discussed. Hereafter, it was named brucite phosphate (BPB). This binder then was used to the sintering of MgO (periclase). MgO is one of the most high-refractory materials and chemically stable to various aggressive mediums, so the aim was presented as actual. To determine the phase composition data on sample weight loss in different temperature intervals were compared. All weight losses were related to the multistage water moving away. Up to 140 °С it was the removal of crystalline hydrate water. Then monosubstituted magnesium hydrophosphate transformed into MgH2P2O7 and Mg2P4O12, that in principle was in accordance with literature data. Dehydration was accompanied with appropriate endothermal effects. There was a slight exothermal effect which could relate to a structure rearrangement (cyclization) of primary magnesium metaphosphates and/or some crystallization of anhydrous cyclophosphates from primarily obtained amorphous phase non-connected with a weight loss in the interval of 450-575 °С. At 500–1000 °С the phase composition remained constant that was in a good accordance with data obtained by other methods. By means of IR-spectroscopy, it was confirmed the formation of structure cycles composed from oxygen-phosphor tetrahedrons. To determine kinetics parameters of periclase sintering with BPB it was used a model being proposed that took the role of a physical consolidation and a chemical binding in the presence of binder into account under heating. The obtained parameters analysis showed that the forming conglomerate strength was provided with the sintering properly as well as with binder action; an estimated chemical factor contribution was maximal at low temperatures (1100-1200 °C). The activation energy value was practically identical to the activation energy of oxygen diffusion in MgO.

Efficacy of Combinations of Methoprene and Deltamethrin as Long-Term Commodity Protectants

Wheat, corn, and brown rice were treated with different combinations of a deltamethrin suspension concentrate (SC) formulation and a new emulsifiable concentrate (EC) formulation, at rates of either 0.5 or 1.0 ppm alone or in combination with 1.25 and 2.5 ppm methoprene (10 treatments in all, including an untreated control). Treated commodities were stored at ambient conditions on the floor of an empty grain bin in Manhattan, KS, USA, in 5-kg lots for individual replicates. The commodities were sampled and bio-assayed every three months for 15 months by exposing 10 mixed-sex parental adults of selected adult stored product insects on 70–80 g of the commodity. For all treatments, there was no regression of declining efficacy with respect to the month. Therefore, the data were combined for analysis. On wheat and brown rice, there was no reproduction of Rhyzopertha dominica (Fabricius) in any of the treatments, and there was no weight loss in either commodity that was caused by feeding of the parental adults or developing progeny. There was reproduction of Sitophilus oryzae (L.) on wheat but, for several combinations, the EC formulation gave better suppression of progeny compared to the standard SC. However, on brown rice, only the combination of 1.0 ppm deltamethrin EC and 2.5 ppm methoprene was different than other treatments with respect to progeny development, sample weight loss caused by feeding, and weight of the feeding damage itself. Progeny production was correlated with grain damage. No progeny of Tribolium castaneum (Herbst) developed on the treated corn, but there was some variation in insect damage, with less damage in those treatments involving the EC formulation. Progeny production of Sitophilus zeamais (Motschulsky) was at the lowest in the combination of 1.0 ppm deltamethrin EC and 2.5 ppm methoprene. The resulting insect damage was the lowest in this combination as well. Results of this study were used by the registrant (Central Life Sciences) in the United States (US) to modify the commercial formulation to replace the deltamethrin SC with the EC, at label rates of either 0.5 ppm EC+ 1.25 ppm methoprene, or 1.0 ppm EC + 2.5 ppm methoprene, on wheat, corn, and rice.

SYNTHESIS AND INVESTIGATION OF THERMOSTATABILITIVE ACTION ON POLYSTYRENE OF NEW METHACRYLIC MONOMERS BASED ON AURONE

In this work, 6-hydroxy- and 4'-hydroxyaurones were synthesized by condensation reaction of 6-hydroxybenzofuran-3-one with benzaldehyde and benzofuran-3-one with 4-hydroxybenzaldehyde. Methacrylic monomers – (2Z)-6-methacryloxy-2-(4-R-benzylidene)-1-benzofuran-3-(2H)-one and a new 4-[(Z)-(3-oxo-1-benzofuran-2-(3H)ilidene)methyl]phenyl-2-methyl acrylate were obtained by acylation with the methacryloyl chloride in the presence of triethylamine as HCl acceptor at the temperature 0–5°C. These monomers were synthesized to create special purpose polymers. New methacrylic derivatives are not deeply painted and stable in air crystalline monomers. The structure of the synthesized compounds was confirmed by spectral methods. 1H NMR (400 MHz) spectra were recorded on a Mercury (Varian) 400 spectrometer with tetramethylsilane as internal standard in DMSO-d6. The intrachain thermostabilizing effect of these monomers on the polystyrene destruction processes was studied. Polystyrene and its modified samples were obtained by radical thermoinitiated polymerization (initiator – azo-bis-isobutyronitrile – 1 mass percent) in ethyl acetate at the temperature 78°C during 16 hours. In a case modified samples, 3 mol percent of aurone containing monomers were added. Destruction of modified polystyrene was studied by using dynamic thermogravimetric analysis. Destruction of modified polystyrene was carried out in a Simultaneous Differential Thermogravimetric Analyzer which combines a heat-flux type DTA with a TGA (Shimadzu, DTG-60, Japan). Simultaneous TG, DTG and DTA curves were obtained and sample weight loss as functions of time and temperature were recorded continuously under dynamic conditions. Sintered a-alumina was used as the reference material. Sample with mass of 4 mg was inserted directly into platin crucible and temperature was ramped from 20 to 600°C. The heating rates were controlled at 10°C/min. Experiments were performed under an air atmosphere. It was established, that the investigated additives covalently attached to the polystyrene are inhibited the polystyrene destruction processes. Moreover, the additive with the methacrylic group in 6-position of the aurone is significantly more efficient than with the methacrylic group in 4’- position. It has been shown that samples of modified polystyrene by the applications of 4'-methacryloxy aurone and 6-methacryloxy aurone are more thermostable than the industrial sample of polystyrene of brand STYRON (Switzerland). It was shown that the temperature of 10% of the mass loss of modified samples is higher on 14–34 degrees than for the sample of polystyrene of brand STYRON. Thus, the new additives could be proposed for thermostabilizing of polystyrene production.