Spray Time Research Articles

Cellulose nanofibrils/nanoclay hybrid composite as a paper coating: Effects of spray time, nanoclay content and corona discharge on barrier and mechanical properties of the coated papers

Abstract The objective of this paper was evaluate the effects of spray time, nanoclay content and corona discharge on oxygen transmission rate (OTR), water vapor transmission rate (WVTR), basis weight, thickness and tensile strength of the coated papers. An aqueous slurry base, a mixture of cellulose nanofibrils (CNF) and nanoclay particles, was sprayed on a kraft writing & printing paper surface as base substrate. Upon drying, the suspension on the paper surface formed a hybrid nanocomposite layer with CNF (matrix) and nanoclay (mineral filler). Paper substrate was coated by a laboratory-assembled spray coater. Corona discharge enhanced the wetting of paper surfaces, improving adherence between paper and hybrid composite. Increased spray time improved tensile strength and barrier properties i.e. OTR and WVTR. Higher nanoclay content in coated paper enhanced its barrier properties but reduced its tensile strength. Tensile strength and morphological properties demonstrated effective adhesion between base substrate and hybrid composite.

Implication of Fungicide Application Regimes and Post Spray Irrigation on Late Leaf Spot and its Residual Impact on Stem Rot of Groundnut

A field experiment was conducted during rabi season of 2015-16 and 2016-17 to study the efficacy of different protectant and systemic fungicides in different application regimes on late leaf spot disease of groundnut and to assess the impact of post spray irrigation timing on the severity of late leaf spot and as well as management of stem rot disease through deposition of foliar applied fungicides. Three sprays of chlorothalonil @ 2g/l (1th, 3rd, 5th) alternated with three sprays of pyraclostrobin @ 1g/l at 2nd, 4th and 6th spray (T8) reduced the highest disease severity (40.74%) as compared to seven spraying of chlorothalonil (T2) at 10 days interval (60.00%). The AUDPC values were significantly different among various treatments. Highest yield (28.89 q/ha) was also recorded in T8. The number of late leaf spot lesion decreased with the increase in gap between spraying and irrigation time. Irrigation after 96 h of fungicide spray caused only 2.02 leaf spot lesion per leaflet and highest pod colonization of 43.63% due to stem rot. Negative correlation was found between pod colonization and number of leaf spot lesion.

Electrospray deposit structure of nanoparticle suspensions

Electrospray atomization has unique capabilities for deploying colloidal suspensions to create nanoparticle films and coatings. This technique can deliver precise quantities of particles in a dry state to a target substrate and overcomes many limitations of other printing and coating technologies. Since the structure of a nanoparticle layer governs its functionalities, it is essential to understand the relationship between the key operating parameters and the macro- and microstructure of an electrospray deposit. We investigated the role of three key parameters on the deposit structure: electrospray time, the target substrate electrical properties, and the polydispersity of the colloidal suspension. The macrostructure of the nanoparticle deposits was similar for all spray times and substrates. In particular, the deposited particles segregate to the center and edge of a deposit, leaving a depletion region in between. We speculate that the mutual Coulombic forces due to the space charge inside the plume play a key role in governing the trajectory of the nanoparticles and the ensuing deposit morphology. Since particles emitted by electrospray are highly charged, the microstructure of a deposit was strongly influenced by the electrical conductivity of the target substrate. By maintaining a net charge, particles deposited on to a dielectric substrate could influence the deposition of subsequent in-flight particles, which opens new routes for exerting control over the deposit structure.

PENGARUH APLIKASI INSEKTISIDA BERBAHAN AKTIF ASETAMIPRID TERHADAP ULAT PENGGULUNG PUCUK (Cydia leucostoma) PADA TANAMAN TEH

Tea Shoot roller (Cydia leucostoma Meyrick) is one potential pests that attack tea shoot, mainly on the new tea shoot after prunning, it caused plant growth becomes stunted. One of control that can be done is by application of insecticides. To determine the effectiveness of insecticide Acetamiprid, the trial has been conducted at Block A7, Gambung field trial, Kabupaten Bandung, during ± 3 months, from October up to December 2016. The trial was designed in Randomized Complete Block Design (RCBD) with five treatments and four replications. The treatment tested covered insecticide Asetamiprid 30% at 1; 0.75; 0.50; 0.25 l/ha and control. The insecticide was sprayed six times using knapsack sprayer one day after plucking, with one week interval. Tea shoot roller attack intensity was observed weekly at the time of plucking. Shoot production, phytotoxicity, as well as rainfall were also observed as a supporting data. The results showed that after three times of spraying, insecticide Asetamiprid 30% at all formulation doses tested could effectively suppress the attack intensity of tea shoot roller. The last observation result, after six times spraying, revealed that the average efficacy level relatively high, i.e. 73,24%. Therefore, for controlling tea shoot roller on tea it could be recommended the use of insecticide Asetamiprid 30%.

Paparan pestisida terhadap kejadian penyakit paru obstruktif kronis pada petani

PurposeThis study aims to analyze and describe the risk of exposure to pesticides (age, sex, education, smoking habits, length of service, time of spraying, number of pesticides and personal protective equipment) related to the incidence of COPD to farmers in Barus Jahe, Karo District.Methods This case control study with a total sample of 90 people, consisting of 45 cases and 45 controls. Samples were taken by simple random sampling. Data analysis was performed using univariable tests, bivariable with Chi-square tests and multivariable with logistic regression.Results There was a significant correlation between age, gender, education, employment, personal protective equipment to the incidence of COPD, while there was no significant association between the time of spraying, the amount of pesticides and smoking status with the incidence of COPD. The most influential factors on the incidence of COPD is the working period and personal protective equipment.Conclusion Farmers should always use personal protective equipment and appropriate dosage of pesticide as stated on the packaging label. Public health office also can reduce COPD infections with early detection to farmers who exposed to pesticides every day.

Experimental study of the suppression of flaming combustion and thermal decomposition of model ground and crown forest fires

This paper presents an experimental study of heat and mass transfer and phase transformations in the suppression of flaming combustion and thermal decomposition of model ground, crown, and mixed forest fires due to local exposure to water. The experiments were carried out with typical combustible forest materials (mixture of leaves, needles, and twigs) and models of trunks and branches of trees. The conditions and characteristics of suppression of the flaming combustion and thermal decomposition of combustible forest materials were determined. It is shown that in the case of crown and mixed fires, local short-term (a few seconds) action of a liquid projectile does not suppress the thermal decomposition of the material (but can only lead to localization of flaming combustion). In the case of ground forest fires, this approach can be efficient with an appropriate choice of the water-irrigated area of the combustion zone and the rate and time of water spraying.

Study of hydrogen risk in a PWR-W containment during a SBO scenario; Tau parameter definition and application on venting strategy analysis

Hydrogen management is still one of the main nuclear safety topics because of its violent reaction with oxygen. During a severe accident, hydrogen can be generated and it can be released into the containment atmosphere. To deal with this threat, the severe accident management guidelines must be used. These guidelines include several actions to coup with the hydrogen challenge, including the venting strategy. However, these guidelines do not normally help the operators in deciding when the optimal moment to vent is.In this study, a PWR-W GOTHIC 3D containment model is used to simulate a station blackout scenario. The venting and spraying strategy and their impact on hydrogen risk are evaluated in a sensitivity analysis. For this goal, more than 60 sequences with different timing of venting and spraying have been performed and analyzed.To compare all simulations between each other, a quantitative approach to hydrogen risk was needed. Therefore, hydrogen risk is estimated and quantified using a new parameter named Tau. This parameter proposal takes into account three variables for each cell that account for likelihood and consequences of a hydrogen burn: the time a hydrogen cloud spends within the flammability limits, the mass of hydrogen that is within the flammability limits, and the combustion regime reached. With this parameter, a single value can be obtained to quantify the hydrogen risk in a full transient.Finally, reviewing the sensitivity analysis, it is observed that hydrogen risk is highly dependent on the venting strategy used, increasing it if performed prior to the hydrogen release, or decreasing it if performed during or after the hydrogen release peak. To conclude, optimal time windows for venting are proposed in order to reduce the hydrogen risk during the transient.

Short‐term efficacy and nontarget effects of aerial glyphosate applications for controlling Lonicera maackii (Amur honeysuckle) in oak‐hickory forests of Eastern Missouri, U.S.A.

Lonicera maackii (Amur honeysuckle) is a non‐native species that has invaded forest stands throughout the eastern United States. This research examined using aerially applied glyphosate in autumn 2013 to control L. maackii in oak‐hickory forest stands in Missouri, U.S.A. We targeted the spraying time period when L. maackii was still green and most native plants were dormant. Across treatment units, the mean difference in L. maackii stem density significantly declined (p = 0.004) by 5.4 stems per plot from spring 2013 to summer 2014 when compared to control units which increased by 1.8 stems per plot. Treated units with a high initial infestation level of L. maackii (>50% cover) had a significant (p = 0.004) decline in the mean difference in L. maackii cover of −50.0% per plot between spring 2013 and summer 2014 compared to an average increase of 9.2% in the controls. Similar results were found for treated units with a low initial infestation level of L. maackii (10–50% cover). Mortality of native overstory and understory trees post‐treatment was negligible. In the ground layer of forest stands with a low initial L. maackii infestation level, native non‐spray‐sensitive forb cover per plot significantly increased (p = 0.023) relative to controls between summer 2013 and summer 2014 while native spray‐sensitive species cover significantly decreased (p = 0.021) during the same period. These results suggest that an aerial application of glyphosate can provide an L. maackii control option, but with trade‐offs in compositional shifts in the native ground‐layer vegetation.

Control Recommendations for Black Medic (Medicago lupulina) Based on Growth and Development in Competition with Strawberry

Strawberries are an important horticultural crop in Florida. Black medic is among the most problematic weeds within the production system. To better coordinate control measures, black medic growth and development while in competition with strawberry was studied. Twelve plants were randomly selected at each of four field sites in Hillsborough County, FL, in 2014. Plants were repeatedly measured over the growing season for stem length and number of primary branches, flower buds, flowers, and seed clusters. Growing degree days (GDD) were calculated (Tbase=0 C) starting from the hole-punch application of the plastic mulch (October 8, 2014, to October 10, 2014) from weather station data generated from the Florida Automated Weather Network. Strawberry height and width increased consistently across all sites, but black medic growth and development varied considerably. Strawberry suppressed black medic growth up to 1,805 cumulative GDD at three of four sites where black medic remained beneath the strawberry canopy. After 1,805 GDD, the black medic stems still remained below but experienced exponential growth for total stem length and, in turn, flower buds, inflorescence, and immature seed clusters. Ideal clopyralid spray timing based on susceptible plant size was 890 to 1,152 GDD. Optimal hand-weeding time frames would likely occur as the plant stems expand beyond the strawberry canopy (to improve visibility) and before flower production to prevent seed return to the seedbank. First seed production was observed at 1,200 GDD at the earliest site and between 1,966 to 2,365 GDD across all the other sites. Overall, consistent trends were observed across sites, but between-site variability was observed that could not be accounted for by differences in temperature.

A Study on the Effect of Nitrogen Spray at Different Times on Color and Yield Parameters of Grape cv. Pykany

In order to study the effect of nitrogen spray at different times on color and yield parameters of grape cv. Pykany, an experiment was carried out in factorial based on randomized complete block design with four replications in Khalil Abad County in 2015. The treatments included three concentrations of nitrogen (0, 5 and 10 ppm) and three spray times (Late April, before bloom stage, and after pollination and fruit set stage). Color parameters such as brightness rate (L), redness (a) and yellowness (b), chroma, hue angle and browning index were evaluated in this experiment. The results of variance analysis and means comparison showed that the effect of treatment containing spray at concentration of 10 ppm on yield was significant at 1%. There were not significant differences among treatments of urea concentrations and spray times on L and b but different concentrations of urea had significant effect on a* at the level of 1%, so that the highest amount of significant difference was due to the treatment of urea spray at the concentration of 10 ppm and the lowest amount was due to the control treatment. Furthermore, the interaction effect of concentration and different times of nitrogen application on color intensity index was significant at the level of 5%. Based on the results, the effect of different concentrations of urea spray on hue angle was significant at 1% so that the highest level of significant difference was due to the concentration of 10 ppm and the lowest was related to control treatment.

Structure of Electrospray Printed Deposits for Short Spray Times

In electrospray printing, a plume of highly charged droplets is created from a conductive ink. Printing occurs by positioning a target substrate (TS) in the path of the emitted material. Here, the ink used is a colloidal dispersion consisting of nanoparticles suspended in a volatile solvent. The selection of a volatile solvent allows for rapid evaporation of the droplets in-flight to produce dry nanoparticles. A net electric charge is imparted on the emitted particles during electrospray. The interaction of this charge with the global electric field and with other charged particles/droplets governs the particles' trajectory and determines the microstructure of the printed deposit. In this study, we characterized the structure of nanoparticle deposits printed using electrospray for deposits with low particle count. During printing, the TS was: (i) held stationary and (ii) translated with various short spray times and substrate velocities, respectively. Examination of both a static and translating TS provided fundamental insights into the printing process. Electrospray printing is capable of exerting much finer control over microstructure compared to other printing techniques. This has significant implications for the manufacturing of thin-films.

Qualitative and quantitative factors affecting the relationship between Canola leaf spot epidemic and stem base canker (Leptosphaeria maculans) in Argentina

Stem base canker caused by Leptosphaeria maculans (SBC) has been reported to affect canola production worldwide. Ascospores infections produce leaf spots (LS) in early vegetative stages. From these initial spots, the fungus grows towards the stem crown and may cause SBC, lodging and premature ripening at maturity. Growth stage at LS presence, cultivar resistance and environment conditions are factors associated with SBC severity. Since there are no studies that associate the LS epidemic with SBC for the Argentine cropping conditions we performed two experiments to address this essential knowledge for SBC management. In 2010, plants of four cultivars (varying in their level of resistance to LS and SBC) ranging from cotyledon stage up to 9 developed leaves were transplanted to a field where artificial inoculation was carried out by spreading infected canola stubble from the previous year. The probability of SBC occurrence depended on the interaction between cultivar resistance level and the number of developed leaves at the moment of LS detection. Based on these results, in 2011 plots of the most susceptible cultivar (Nexera 8450) received different fungicide protection treatments (azoxystrobin or propiconazole and timing of spraying) and were exposed to natural L. maculans infections. We observed that the maximum incidence of LS up to 8th developed leaf best correlated with SBC severity at maturity and a linear regression was fitted to model the relationship between these two variables.

Effect of solvent concentration on performance of polysulfone membrane for filtration and separation

This study was conducted to investigate the effect of solvent concentration on the performance of polysulfone membrane via airbrush spray method. The solvent concentration was varied from 73% to 80% in dope solution. The study also investigated airbrush processing parameter such as spray time and distance at different solvent concentration. The prepared membrane was characterized in respect to its morphology and the performance of the membrane were evaluated via gas permeability performance. This study found that the membrane fiber size was reduced as solvent concentration increases. When time increased the diameter of fiber also increased. The distance also affected the fiber size, when the distance increased the diameter of fiber became smaller. 80% of solvent concentration has better filtration and separation ability compared to other solvent due to its porosity and morphology. From the gas permeability cell testing it shows that the permeability is increasing as the solvent concentration decrease.

Study of the influence of coating methods on lipid spheres manufactured on rotor fluidized bed process

Different previous works have shown that various kinds of spheres can be manufactured by rotor granulation in a ‘single-pot process’ using a lipid base: hydrogenated castor oil. This single-pot technology is based on wet granulation where all components are placed in the powder form in the rotor bowl; then, they are continuously suspended in a fluidized air, with a tangentially sprayed liquid solution. This process allows the granulation and manufacturing of sphere during the same time. Previous experiments have studied the influence of the formulation and the manufacturing process parameters on spheres in terms of feasibility and dissolution properties. Both the spraying time and the weight of liquid sprayed were found to be the most relevant parameters that govern the final quality of the sphere. Now, in a second part of the work, a first comparison is made with two different fluid bed methods: the tangential rotor spray and the Wurster bottom spray for coating the lipid spheres previously manufactured with the rotor tangential spray. The external aspect of the coated spheres manufactured has been evaluated with an electronic microscopy analysis and a study of dissolution properties of the active ingredient has been done by USP in vitro dissolution tests.

Risk factors for kiwifruit bacterial canker disease development in ‘Hayward’ kiwifruit blocks

In November 2010 Pseudomonas syringae pv. actinidiae biovar 3, the cause of a severe disease, kiwifruit bacterial canker, was first recorded in New Zealand. This study examined risk factors relating to disease management, vine management and orchard layout that were associated with disease symptoms observed by orchardists in Actinidia chinensis var. deliciosa ‘Hayward’ orchards. A cross-sectional study using data collected via a questionnaire investigated orchard blocks that were symptom-free in March 2012. The outcome we modelled was detection of disease in the block during the study period from March 2012 to February 2013, and multivariable logistic regression was used to identify potential risk factors. Data from 194 growers were included and comprised 53 orchard blocks which remained disease free and 141 which became diseased. This cross-sectional study identified four factors that were associated with Psa symptom development. The associated factors identified in this study are not necessarily causal, but our results can be used by the kiwifruit industry to help prioritise research needs to identify processes involved in the development of kiwifruit bacterial canker in kiwifruit orchards. Priority for further research is the relationship between the timing of copper sprays, callus tissue formation and Psa mobilisation. A second priority is to determine the biological mechanism for the association between girdling and a reduction in disease risk. Use of a cross-sectional study provided a new way to investigate plant disease risk factors and this type of study could be more extensively used, especially during incursions of unwanted organisms.

Preparation of Titania on Stainless Steel by the Spray-ILGAR Technique as Active Photocatalyst under UV Light Irradiation for the Decomposition of Acetaldehyde

One of the methods used to produce buffer layers for thin film solar cells is the Spray ion layer gas reaction (SPRAY-ILGAR). This method has exhibited astonishing efficiencies in the fabrication of homogenous compact metal chalcogenide films. The same approach can be applied in the preparation of photocatalyst on a substrate, in order to acquire a homogeneous and durable layer. In this work, the Spray-ILGAR technique has been utilized in the preparation of titania photocatalysts on stainless steel, which was carried out at Helmholtz-Zentrum Berlin for Materials and Energy, in Berlin, Germany. The characterizations and photocatalytic testing of the synthesized materials were then done at the Institute of Catalysis, Hokkaido University. The scanning electron microscopy (SEM) analysis showed that the titania was dispersed uniformly on top of the stainless steel, with a very durable and strong attachment. It was also found that the concentration of the titania on stainless steel can be easily varied by changing the concentration of the titania-precursor solution. Higher concentrations will result in a more compact and dense layer, while lowering the concentration of the precursor solution produces a less dense layer of TiO2. Apart from that, different temperatures did not change the distribution of the samples much. The photocatalytic activity of the synthesized materials was determined in terms of the photocatalytic decomposition of acetaldehyde under ultra violet (UV) light irradiation. The photocatalytic testing results proved that the samples can completely degrade acetaldehyde under UV irradiation. The heating temperature played a crucial role, as the sample prepared by with heating temperature of 550 °C, concentration of titania-precursor of 6.83 mM and a spraying time of 12 min showed the best results, requiring only 35 min to fully degrade 500 ppm of acetaldehyde.

Microstructure and Salt Fog Corrosion Behavior of AA2219 Friction-Stir-Welded Aluminum Alloy

Plates (8.1-mm-thick) from aluminum alloy AA2219-T87 are studied after friction stir welding. The plates are subjected to salt fog corrosion tests according to ASTM B117 at different pH values and different spraying times. The regions affected by corrosion are studied in different zones of welded joints by the methods of optical and transmission electron microscopy. The corrosion resistance is determined in acid, basic and neutral solutions. The resistances of the base metal and of the zones of welded joints are compared.

CO<sub>2</sub> and Er,Cr:YSGG Laser Applications in Debonding Ceramic Materials: An in Vitro Study

Introduction: The aim of this study is to measure the strength needed to debond ceramic cylinders by using CO2 and Er,Cr:YSGG lasers. Materials and methods: The in vitro experiment consists of 60 human teeth divided in 3 groups: Group 1 control, Group 2 with 3 seconds application of CO2 laser, and Group 3 with 5 seconds application of Er,Cr:YSGG laser. The 3mmx3mm cylinders are made with E-max Press pressed ceramic and are cemented to the teeth with Relyx ®. After the laser application on the samples, a Shear Bond Tester device was used to measure the shear strength. Results: Significant differences are found between the Group 1 control and the two treated with laser (p<0.001). Conclusion: The use of CO2 and Er,Cr:YSGG lasers can be considered as a valid and safe method of ceramic restoration debonding. Further studies are necessary to evaluate different currents, the use water spray and different debonding times.

Influence of substrate temperature on structural, morphological, optical and electrical properties of Bi-doped MnInS4 thin films prepared by nebuliser spray pyrolysis technique

Bismuth (Bi)-doped manganese indium sulphide (MnInS4) thin films were deposited on heated glass substrates using an aqueous solution of MnCl2, InCl3, (NH2)2CS and BiCl3 by the common nebuliser spray pyrolysis technique. The thin films were grown at various substrate temperatures ranging from 250 to 400 °C with a constant spray time (5 min). The present work aims to study the effect of substrate temperature on the structural, optical, photoluminescence and electrical properties of the grown thin films using various techniques like X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive spectrum (EDS), UV–Vis absorption spectroscopy, photoluminescence spectra (PL) and four probe methods. The XRD pattern reveals that the Bi-doped MnInS4 thin films were polycrystalline in nature with a cubic spinel structure whose particle size varies between 8.2 and 23.5 nm. From the FE-SEM micrographs, due to the change in the substrate temperature, shapes such as spherical, needle-shaped and T-shaped grains were observed throughout the surface of the films. The energy dispersive analysis spectrum (EDS) shows the presence of Mn, In, S and Bi in the film grown at 250 °C. It is interesting to note that the structural homogeneity and crystallinity of the film is improved due to the decrease in the absorption coefficient (α) and extinction coefficient (K) with an increase in substrate temperature. Also, with an increase in the substrate temperature, the calculated band gap energy was found to decrease from 1.87 to 1.59 eV. From the PL spectra, several intense peaks corresponding to blue, green, yellow, orange and red band emissions were observed in the wavelength region of 350–650 nm. Moreover as the intensity of the peak increases with increase in the substrate temperature, the crystallinity of the material of the film greatly improves concomitant with minimum strain and defect states. From the electrical studies, the electrical conductivity increases with increase in substrate temperature and a maximum electrical conductivity of 3.73 × 10−3 Ω−1m−1 were obtained for the film prepared at 400 °C. The thickness of the films was also measured and the values ranged between 743 nm (250 °C) to 629 nm (400 °C). The high absorption coefficient (1.85 × 104 cm−1) and high transmittance of the films make them an efficient window layer for solar cell applications. Incorporation of Bismuth (Bi) into MnInS4 matrix leads to improve the optical transmittance (85%) and electrical conductivity (3.11 × 10−3 Ω−1 m−1) of the film grown at 400 °C. Other important parameters like dislocation density (δ), strain (ε), the number of crystallites per unit area (N) and lattice distortion (LD), which are commonly used to describe the structural analysis were also presented. Bi-doped MnInS4 thin films were grown by a variety of deposition methods. Among them, spray pyrolysis is an eco-friendly method because of its low cost, mass production capacity, large area coatings and minimum wastage of the source materials.

Effect of the annealing and the spraying time on the properties of CZTS thin films prepared by the “Spray sandwich” technique

We have investigated synthesis conditions and some properties of sprayed Cu2ZnSnS4 (CZTS) thin films to determine the best preparation conditions for the realization of CZTS-based photovoltaic solar cells. The thin films are made by means of spraying sandwich. To optimize the preparation conditions of the CZTS films, two series of experiments are performed. In the first series, the sprayed duration was changed from 20 to 60 min. In each series, effect annealing was investigated. The X-ray diffraction shows, on one hand, that the best crystalline was obtained after annealing for 60 min as sprayed duration. On the other hand, these CZTS films exhibit the Kesterite structure with preferential orientation along the [112] direction. Raman spectrum indicated the presence of principal Stannite peak 336 cm−1. SEM showed that the surface of CZTS was uniform. After the annealing treatment, we estimated the optical band-gap energy of the CZTS thin film exhibiting the best crystalline as 1.5 eV which is quite close to the optimum value for a solar cell.