Technical Grade Materials Research Articles

BASELINE SUSCEPTABILITY AND FIRST OBSERVATION OF KNOCKDOWN RESISTANCE IN AEDES TAENIORHYNCHUS POPULATION OF ST. JOHNS COUNTY, FLORIDA.

The black saltmarsh mosquito, Aedes taeniorhynchus, is a prominent nuisance mosquito within St. Johns County, Florida. Due to their characteristically large outbreaks, and the elevated amount of insecticide application correlated with the outbreaks, local populations of Ae. taeniorhynchus are at an increased risk of developing insecticide resistance. This study was established to form a baseline susceptibility of Ae. taeniorhynchus against two technical grade materials, permethrin, and chlorpyrifos. Centers for Disease Control and Prevention bottle bioassays were conducted with technical-grade materials during two outbreaks in the fall of 2023. Results indicated a baseline susceptibility against the materials tested, but most notably, the phenotypic expression of knockdown resistance (kdr) was observed. Results highlight the need for continued monitoring and investigation into the resistance status and resistance level of this common Florida species.

Application of technical grade reagent in soybean-crude urease calcite precipitation (SCU-CP) method for soil improvement technique

Soybean crude urease-calcite precipitation (SCU-CP) is a potential method as a sustainable and economical soil improvement technique. This method begins with developing the bio-cementation method that has successfully increased soil strength. The use of laboratory-grade material is high-cost for large-scale. The applicability of original soybean material combined with technical grade reagent in SCU-CP was discussed, considering its relevance for a larger scale treatment. The hydrolysis rate, test-tube experiment, and X-Ray Diffraction (XRD) test were conducted to evaluate the entire material's potential for the calcite precipitation method considered for precipitation materials. This study shows that low-cost soybean material and technical-grade reagents have a good level of effectiveness for calcite production. The low-cost material of soybean 20 g/L produced the highest hydrolysis rate of 331.701 u/g. Technical-grade reagent with a concentration of 1 mol/L was proven effective compared to laboratory-grade with a precipitation ratio of 114.44%. XRD results showed that the highest calcite formation was in technical-grade samples using soybean Gasol with a crystallinity of 40.25%. Unconfined compressive strength (UCS) results showed that the original soybean has a higher value than other solutions, which is 66.18 kPa in 14 days. Therefore, technical-grade materials are more economical with 100% cheaper than laboratory-grade. The result of this study elucidated that SCU-CP has a high potential to be an economical, sustainable and effective soil improvement technique.

Simplified Procedures for Managing Insecticidal Waste: A Case Report of KCMUCo-PAMVERC Vector Control Product Testing Facility in North-Eastern Tanzania

Insecticide testing facilities that evaluate a variety of vector control products may generate a large number of hazardous wastes from routine operations. These wastes originate from degraded technical grade materials, sprayed substrates with Indoor Residual Spraying (IRS), and redundant stock or working insecticidal solutions. The washing of Long-Lasting Insecticidal Nets (LLINs) during preparation for laboratory and experimental hut trials also contribute to wastewater with insecticide content. Human and environmental exposure to insecticidal waste can occur during transport, categorization, storage, and disposal, resulting in environmental pollution and potential health effects. Various national and international guidelines have been devised for safe disposal and should be strictly followed to avoid adverse effects on humans or environment. To facilitate proper insecticidal waste management, this paper outlines simple but safe practices derived from international and national guidelines that can be adopted by other similar facilities. National and international policies related to chemical management were reviewed and translated into Standard Operating Procedures (SOPs), training pathways, and manuals. National Environmental Management Council (NEMC) assessed the test facility and recommended disposal procedures. NEMC recommendations were followed to construct the soak pits for liquid waste disposal while chemical transporters and incinerators were contracted for solid waste disposal. An environmental expert was contracted for environmental audit and annual monitoring. Studies and activities at the facility were evaluated for their waste generation index. Safety manual and SOPs on risk assessment, waste management and disposal, handling hazardous materials, health and safety procedures, and chemical usage were written. At KCMUCo-PAMVERC, an annual average of 0.02 and 24.9 cubic meters of liquid waste, which mainly includes a mixture of water, insecticides, and solvents, were generated from laboratory experiments (phase I) and semi-field LLIN experiments (phase II), respectively, while the IRS semi-field experiments generated an annual average of 88 L of liquid waste and 6.3 tons of solid waste. An annual average of 0.18 cubic meters of liquid waste results from other sources, including expired laboratory reagents. Well-translated national and international policies/regulations may be adopted by insecticide test facilities for proper and effective waste disposal.

The Influence of Sintering Temperature and Mn-Ti Doped BaFe<sub>12</sub>O<sub>19</sub> on the Microwave Absorbing Properties

The effect of sintering temperature and Mn-Ti (x = 0.1 and 0.5 % mol) doped in Barium hexaferrite (BaFe12O19) on the microwave absorption properties have been investigated. The BaFe(12-2x)MnxTixO19samples were prepared by using a solid state reaction method from technical grade materials of BaCO3, Fe2O3, MnO2, and TiO2. The permagraph and vector network analyzer (VNA) measurement with frequency of 4 – 10 GHz were used to determine the magnetic properties and microwave absorbing properties, respectively. The magnetic induction and magnetizing force (B-H) curve analysis of BaFe(12-2x)MnxTixO19revealed that by increasing the Mn-Ti dopant concentrations, the remanence (Br) and BH(max) increases, meanwhile, the HCBvalue decreases for both 1100 and 1150oC. The frequency dependence of reflection loss (RL) measurement given anoptimum value of-26.15 dB at frequency of 9.18 GHz which obtained by x = 0.1% mol Mn-Ti (1100oC). The maximum absorption peak was achieved for 0.5 % mol Mn-Ti sample with ~98.3 % at 9.18 GHz. By controlling the sintering temperature and Mn-Ti dopant concentration, the RL and absorption behavior can be modified to desirable values and also indicates that higher Mn-Ti dopant concentration (0.5% mol) possess better absorbing characteristics. Furthermore, it was found that complex permitivitty and permeability values of BaFe12O19can be modified by controlling the Mn-Ti dopant concentration.

Synthesis and Characterization of High Aluminum Zeolite X from Technical Grade Materials

Zeolites are widely used as ion exchangers, adsorbents, separation materials and catalyst due to their well-tailored and highly-reproducible structures; therefore, the synthesis of zeolite from low grade resources can be interested. In the present work, high aluminum zeolite X was prepared from mixing technical grade sodium aluminate and sodium silicate solutions at temperatures between 70°C and 100°C. The synthesized zeolite X was characterized by SEM and X-ray methods according to ASTM standard procedures. The results showed that aging of the synthesis medium at the room temperature considerably increased the selectivity of zeolite X formation. On the other hand, high temperature of reaction mixture during crystallization formed zeolite A in the product; therefore, it decreased the purity of zeolite X. In addition, it was found that increasing H2O/Na2O and decreasing Na2O/SiO2 molar ratios in the reaction mixture resulted product with higher purity. © 2013 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)

Heterogeneous oxidation of the insecticide cypermethrin as thin film and airborne particles by hydroxyl radicals and ozone

Evaluation of pesticides' fate in the atmosphere is important in terms of environmental effects on non-target areas and risk assessments analysis. This evaluation is usually done in the laboratory using analytical grade materials and is then extrapolated to more realistic conditions. To assess the effect of the pesticide purity level (i.e. analytical vs. technical) and state (i.e. sorbed film vs. airborne particles), we have investigated the oxidation rates and products of technical grade cypermethrin as thin film and in its airborne form, and compared it with our former results for analytical grade material. Technical grade thin film kinetics for both ozone and OH radicals revealed reaction rates similar to the analytical material, implying that for these processes, the analytical grade can be used as a good proxy. Oxidation products, however, were slightly different with two additional condensed phase products: formanilide, N-phenyl and 2-biphenyl carboxylic acid, which were seen with the technical grade material only. OH experiments revealed spectral changes that suggest the immediate formation of surface products containing OH functionalities. For the ozonolysis studies of airborne material, a novel set-up was used, which included a long-path FTIR cell in conjugation with a Scanning Mobility Particle Sizer (SMPS) system. This set-up allowed monitoring of real-time reaction kinetics and product formation (gas and condensed phases) together with aerosol size distribution measurements. Similar condensed phase products were observed for airborne and thin film technical grade cypermethrin after ozonolysis. Additionally, CO, CO(2) and possibly acetaldehyde were identified as gaseous oxidation products in the aerosols experiments only. A kinetic model fitted to our experimental system enabled the identification of both primary and secondary products as well as extraction of a formation rate constant. Kinetic calculations (based on gaseous products formation rate) have revealed values similar to that of the thin film experiments. Interestingly, heterogeneous oxidation of cypermethrin was also found to generate ultra fine secondary organic aerosols. Again, no significant difference was observed between analytical and technical grade materials. However, particle size distribution was much broader when films were exposed to OH and ozone than to ozone alone.

Susceptibility to Insecticides Used for Control of <I>Piezodorus guildinii</I> (Heteroptera: Pentatomidae) in the United States and Brazil

Limited information exists on the insecticide susceptibility of redbanded stink bug, Piezodorus guildinii (Westwood) (Heteroptera: Pentatomidae), despite its impact on soybean, Glycine max (L.) Merr., production in Brazil and the United States. Therefore, this study set out to 1) determine baseline levels of susceptibility to currently recommended pesticides using topical and vial bioassays, 2) determine the levels of esterase activity in populations in the United States and Brazil, and 3) compare control among products in field trials. In topical bioassays conducted in the United States using technical grade materials, the LC50 values of lambda-cyhalothrin, acephate, and methamidophos were 4-25, 141-295, and 40-151 ng per insect, respectively. The LC50 values of imidacloprid and thiamethoxam were 11 and 27 ng per insect, respectively. In vial bioassays conducted in the United States using technical grade materials, the LC50 values of cypermethrin, acephate, and methamidophos were 0.4-0.9, 3.8, and 1.6 microg per vial, respectively. In topical bioassays conducted in Brazil by using commercially formulated products, the LC50 values of acephate, methamidophos, endosulfan, and imidacloprid were 0.90-1.9, 0.4-0.6, 1.5-6.6, and 0.2-0.3 microg per insect, respectively. In vial bioassays conducted in Brazil using commercially formulated products, the LC50 values of endosulfan, methamidophos, and lambda-cyhalothrin were 4-32 and 2-24 microg/cm2 for thiamethoxam and imidacloprid. Esterase activity in Louisiana (United States) populations ranged from 251 to 658 nmol alpha-naphthol formed/min/mg protein. Esterase activity levels in Londrina (Brazil) populations averaged 163 nmol/min/mg. In field tests, P. guildinii in Louisiana were controlled by organophosphates thiamethoxam and imidacloprid and in Brazil, with combinations of neonicotinoids and pyrethroids.

Tetradecane and hexadecane binary mixtures as phase change materials (PCMs) for cool storage in district cooling systems

As the demand for refrigeration and air-conditioning has increased during the last decade, district cooling systems have been introduced in some major European cities. In a district cooling system, the combination of central cooling facilities and cool storage systems provides economic advantages over older conventional cooling plants. A cool storage system can meet the same total cooling load as a non-storage system over a given period of time with a smaller chiller. Cool storage systems using Phase Change Materials (PCMs) have a low temperature range and high energy density in the melting solidification of PCMs compared to sensible heat storage. Thus they are advantageous in reducing the storage volume, heat loss, and size of the chilling equipment. In this paper we describe some paraffin waxes and their binary mixtures. We discuss the thermal properties of laboratory-grade tetradecane, hexadecane and their binary mixtures, and we demonstrate their potential for use as PCMs for cool storage. The thermal properties include freezing point, the heat of fusion, thermal stability and volume expansion during the phase change process. In the study, a Differential Scanning Calorimeter (DSC) was used to determine the heat of fusion of these materials and to generate thermal data for study and analysis. The results show that these materials are attractive candidates as potential PCMs for cool storage in district cooling systems. However, because of the high cost of laboratory-grade materials, technical-grade materials must be used for cool storage.

Identification and Determination of the Isomeric Bromo- and/or Chloro-Substituted l,3-Dihalo-5,5- Dimethylhydantoins Used in Disinfectants and Molluscicides

Abstract Proton nuclear magnetic resonance spectrometry (1H NMR) was used to identify and quantitate the 4 isomeric bromo- and/or chloro-substituted 1,3-dihalo-5,5-dimethylhydantoins in technical-grade materials used to prepare commercial disinfectants and molluscicides. We found that the technical grades of bromo/chloro-substituted 1,3-dihalo-5,5-dimethylhydantoins are mixtures of the 4 possible isomers, that interconversion among isomers occurs in solution and can be detected by 1H NMR, and that isomer interconversion occurs over times greater than those of the NMR timescale.

Liquid Chromatographic Method for Determination of Dithianon in Technical Products and Formulations: Collaborative Study

Abstract A liquid chromatographic method for determination of dithianon in technical products and formulations was evaluated by 22 laboratories participating in a collaborative study. Data received from 19 laboratories were used in the statistical analysis. The study included 3 technical grade materials, 1 suspension concentrate, and 1 wettable powder. Dithianon is determined by reversed-phase liquid chromatography on a C18 column with a mobile phase of acetonitrile and water. Detection at 254 nm with peak area measurements is used with an external standard for quantitation of dithianon. The liquid chromatographic method for determination of dithianon in technical products and formulations has been adopted first action by AOAC INTERNATIONAL.

Mutagenicity studies in a tyre plant: in vitro activity of workers' urinary concentrates and raw materials.

The possible contribution to urinary mutagenicity of occupational exposures in the rubber industry was studied by assaying the urine concentrates of 72 workmen (44 smokers) employed in a tyre plant. Twenty three clerks (16 smokers) engaged in the administrative department of the same factory served as presumptive unexposed controls. XAD-2 resin concentrates of urine samples were assayed in the plate incorporation test and in the microtitre fluctuation assay with Salmonella typhimurium strains TA1535, TA98, and TA100. Furthermore, the in vitro mutagenicity of the major raw materials in use at the plant was determined in the plate incorporation assay with S typhimurium strains TA1535, TA1537, TA98, and TA100. The results obtained from the urinary mutagenicity study show that smoking habits, but not occupation, were statistically significantly related to the appearance of a urinary mutagenicity that was detectable with strain TA98. A possible synergistic effect of occupation with smoking was observed among tyre builders who were also smokers. The study of the raw materials showed that three technical grade materials were weakly active as mutagens in strain TA98 in the absence (poly-p-dinitrosobenzene) or in the presence of metabolic activation (mixed diaryl-p-phenylendiamines and tetramethyltiuram disulphide). The latter chemical was also weakly active in strain TA100.

Laboratory Screening of Materials to Control the Vector of Bluet0Ngue Disease, 1980-81

Abstract Adulticides were evaluated as technical grade materials dissolved in acetone, and were applied to caged colonized insects by injection into the airstream of a wind tunnel. There were 3 replications of 4 doses and a control treatment. Mortality counts were made at 24 h after exposure (or treatment). Larvicides (except Bactimos) were evaluated as technical grade materials initially dissolved in acetone with emulsifier and then added to deionized water to give the selected doses. There were 3 reDlications of 4 doses and a control treatment. Mortality counts were made at 24 h. All data were subjected to probit analyses.

Velvetbean Caterpillar Ld*Jq Studies, 1973

Abstract Twelve insecticides were tested against the velvetbean caterpillar. Four to six treatment rates plus a solvent-treated check were included for each insecticide tested. A 50% acetone-water mixture was used to dissolve and dilute technical grade carbaryl and acephate to the desired concentrations. Solutions of other chemicals were prepared by dissolving and diluting technical grade materials with pure acetone. All treatments were administered with a rmcroapplicator (Isco, Model M). Test insects from an established laboratory culture of velvetbean caterpillar were used. Larbae were supplied with fresh soybean leaves daily. Last-Instar velvetbean caterpillar larvae were apportioned randomly into groups of 10. Groups were weighed collectively, and the mean weight of larvae of each group was used to determine dosages of insecticides. Individuals were topically treated with 1 u! of solution applied to the thoracic dorsum. After treatment, larvae were placed in 236 ml screen-topped cardboard cups with fresh soybean leaves. These cups were then returned to the rearing room with 25�C, 50% RH, 12/12 h light/dark phoroperiod. Mortality counts were made 24 h after treatment. The method of Litchfield and Wilcoxon (1949) was used to calculate dosage-mortality curves and LD5Q values (expressed as ug of roxicant/g of insect).

An incongruent heat-of-fusion system—CaCl 2·6H 2O—Made congruent through modification of the chemical composition of the system

Incongruent melting with phase separation is a frequent cause of failure of heat-of-fusion systems. In devices based on CaCl 2·6H 2O, formation of a tetrahydrate poses such problems. This paper describes means of making the incongruent system congruent, i.e. ensuring that the tetrahydrate never is the stable species, through chemically modifying the system. Thus, addition of SrCl 2·6H 2O to a CaCl 2H 2O system causes the solubility of CaCl 2·6H 2O to decrease and CaCl 2·4H 2O to increase. The reasons for the different effects on the hexahydrate and the tetrahydrate are related to decreased activities in the solid state through formation of a solid solution in the former case and to the decreased activities in the liquid state in the latter case (i.e. the phenomenon of freezing point depression). If the addition of SrCl 2·6H 2O is sufficiently large (about 2 wt per cent), the melting point maximum for CaCl 2·6H 2O coincides with the peritectic point for equilibrium between the hexahydrate, the tetrahydrate, and the solution. With technical grade materials, tetrahydrate formation is a more severe problem as they contain impurities (KCl and NaCl) which have an opposite influence on the solubilities of the CaCl 2 hydrates as described above for SrCl 2·6H 2O. Addition of Ca(OH) 2 is shown to be an effective tool in suppressing tetrahydrate formation in these cases. It acts through neutralizing the excess of chloride and through formation of the phase CaCl 2·CaO·2H 2O.

Topical Toxicity of Insecticides to Strawberry Sap Beetle Adults, Ohio, 1978

Abstract Strawberry sap beetle adults were laboratory-reared and maintained on autoclaves prunes at 23 ± 2°C and 70% RH under a 16-hr photoperiod. Stock solutions (0.01%) of each insecticide tested were prepared from technical grade materials and diluted with technical grade acetone. Two replicates of 20beetles each (mixed sex and age) were anesthetized by placing them in a 9.0-cm plastic petri dish and placing the dish on a cold surface (ca. 1.0° C). Topical applications (1 μl/beetle) were applied to the venter of the abdomen with a 0.25-cc glass syringe using a microapplicator. After treatment, beetles were placed in inverted 9.0-cm plastic petri dishes lined with filter paper discs. A 10% honey solution was added to the filter paper via a plastic squeeze bottle. The honey solution provided a carbohydrate source as well as water. Controls consisted of 2 replicates which were treated with the solvent and 2 replicates which were not treated. All beetles were placed in an insect-rearing room maintained under the above conditions. Mortality was assessed 24 hr after treatment.

Contact Toxicity of Seven Insecticides To Rose Chafer Adults, 1976

Abstract Adults of the rose chafer were collected from grape blossom buds in a sandy area near North Kingsville, Ohio, just prior to bloom. These insects were brought to O.A.R.D.C. to test their susceptibility to a broad range of insecticides. They were held 24 hr at the holding conditions indicated below, prior to being treated. Methoxychlor had given poor results in the area of collection. Stock solutions (1%) of all materials tested were prepared from technical grade materials using a mixture of acetone and olive o i l , 19:1 (vol/vol), as the solvent. Two replicates of 10 beetles each, selected at random, were anesthetized with ether and placed on filter paper in 9-cm glass petri dishes. Each replicate was sprayed with 5 ml of the insecticides at one of the concentrations in a Potter spray tower. Checks consisted of 2 sets of 10 beetles each sprayed with the solvent. Treated beetles were removed from petri dishes and placed in paper cups with a moist wick of 5% honey-water and covered with a glass petri dish and held at 24° t 1,5°C and 6 0% RH. Treatments were made on June 17 and mortality readings were made 24 hours later.

Contact Toxicity of Seven Insecticides To Strawberry Sap Beetle Adults, 1976

Abstract Adults of the strawberry sap beetle were collected on overripe strawberries in a commercial strawberry field near Akron, Ohio. These beetles were brought to O.A.R.D.C. to test their susceptibility to several classes of insecticides. They were held 24 hr at the holding conditions indicated below, prior to being treated. Stock solutions (1 %) of each material tested were prepared from technical grade materials using a mixture of acetone and olive o i l , 19:1 (vol/vol), as the solvent. Two replicates of 10 beetles each, selected at random, were anesthetized with ether and placed on filter paper in 9-cm glass petri dishes. Each replicate was sprayed with 5 ml of the insecticides at one of the concentrations in a Potter spray tower. Checks consisted of 2 sets of 10 beetles each sprayed with the solvent. Treated beetles were removed from petri dishes and placed in paper cups with a moist wick of 5% honey-water and covered with a glass petri dish and held at 24° ± 1.5°C and 60% RH. Treatments were made on July 27, July 29 or September 13. Mortality readings were made 24 hr after treatment.

Control of Forest Insects by Ultra‐low Volume Spraying

AbstractUltra‐low volume spraying calls for special insecticide formulations. Technical grade material is sprayed, at rates of only 500–1,500 c.c./ha., by mistblower, fixedwing aircraft, or helicopter, using special nozzles or the rotary atomizer system. There are a number of advantages in the use of technical grade materials, particularly in forestry: the need for solvents and carriers is eliminated, mixing is unnecessary, storage and transport costs are greatly reduced and aircraft payloads provide for greater coverage.Trials carried out in the period 1967–69 against 11 forest insect pests, including sucking species, beetles, and larvae, gave good results with ULV concentrates of malathion, dimethoate, and bromophos‐ethyl. Motorized knapsack sprayers were used for the work, but a trial helicopter spraying with 1,500 c.c. malathion against larvae of Coleophora laricella (Hb.) was also made in August 1968, producing the result required: protection of trees from significant defoliation.

Preparation of Boron from Boron Carbide

A process to prepare elemental boron from boron carbide is presented. Included is evidence that the process is one of anodic transfer. Boron of at least 99.8% purity can be made directly from technical grade materials. Purity is a function of electrolysis voltages and boron carbide purity. Current efficiencies in excess of 95% are obtained and preferred electrolysis conditions are stated.

Determination of Parathion and p-Nitrophenol in Technical Grade Materials and in Dust Preparations

Determination of Parathion and p-Nitrophenol in Technical Grade Materials and in Dust Preparations