Spray Duration Research Articles

Pengaruh Lama Penyemprotan terhadap Kadar Enzim Cholinesterase pada Petani Pengguna Pestisida Organofosfat

Pesticides can increase productivity in agriculture. Excessive and uncontrolled use of pesticides can pose a risk of poisoning farmers. Decreased levels of cholinesterase enzymes characterize poisoning. The duration of spraying is an indicator that can affect the levels of the cholinesterase enzyme. This study aimed to determine how long spraying affects cholinesterase enzyme levels in farmers who use organophosphate pesticides. Examination of cholinesterase using the enzymatic cholinesterase test method. The most commonly used sample is a sample of serum rather than red blood cells. The study's results stated that there was a relationship between the duration of spraying and the levels of the cholinesterase enzyme. The duration of spraying in a day gives an idea of ​​the intensity of pesticide exposure. The longer the spraying time, the higher the pesticide exposure and the decreased levels of the cholinesterase enzyme in the blood.

Heat and mass transfer characteristics during spray drying of Na2Fe0.6Mn0.4PO4F/C cathode material for Na-ion batteries

The paper presents a detailed experimental investigation on heat and mass transfer characteristics during the synthesis of Na2Fe0.6Mn0.4PO4F/C using intermittent spray drying. The drying process is carried out in a custom-made spray dryer. The novelty of the work is the study of the effect of intermittency on the spray drying process heat and mass transfer characteristics using a volumetric approach. The nozzle orifice diameter, spray duration, and spray pressure are operating parameters of the process that are varied between 0.2 and 0.4 mm at 10 and 40 sand 4 and 7 bar. An increase in nozzle orifice diameter and pumping pressure improves the heat transfer significantly; however, an increase in spray time diminishes the heat transfer. Under considered operating conditions, the volumetric heat transfer coefficient varied between 1.5 and 3.5 kW/m3K. The volumetric mass transfer coefficient ranges between 2.5 and 5.0 s−1. Based on the study, correlations for heat and mass transfer coefficients have been developed that relate the thermophysical properties of both the carrier gas and the precursor fluid in terms of Ohnesorge number and Reynolds number.

PENGGUNAAN PESTISIDA DAN KADAR CHOLINESTRASE PADA PETANI PENYEMPROT

Using pesticides can decrease the population of organisms in plants. A pesticide which the work of cholinesterase enzyme in the body is oregano phosphate; it also has a side effect on the decrease in cholinesterase content. The research used a cross-sectional design which was aimed to find out the influence of using pesticides on the decrease in blood cholinesterase content in farmers who spray their plants with pesticides at Desa Cikaok, Kecamatan Sitellu Talli Urang Julu, Kabupaten Pakpak Bharat. The samples were farmers who sprayed their plants with pesticides. Chi Square statistic test was used to find out the variables which probably decrease in cholinesterase content at p,0,05. It was found that 26,7% of the respondents underwent a normal decrease in cholinesterase content, and 73,3% of the respondents underwent an abnormal decrease. Statistically, there was a significant correlation between the length of spraying pesticides with the decrease in cholinesterase content in the blood of farmers who sprayed their plants with pesticides at Desa Cikaok at p-value = 0,678. It is recommended that the farmers lessen the duration of spraying in order to reduce the risk of exposure to pesticides and use personal protective devices such as gloves, hats masks, glasses, uniforms, and shoes. The regional government should provide protection, counseling, and training about the procedure of using pesticides in order to forestall the incidence of illness in the farmers who sprayed their plants with pesticides.

Insight of Salt Spray Corrosion on Mechanical Properties of TA1-Al5052 Self-Piercing Riveted Joint

Self-piercing riveted (SPR) joints in automobiles inevitably suffer from corrosion damage and performance reduction. In this work, the influence of salt spray corrosion on the mechanical properties of TA1-Al5052 alloy SPR joints was studied. The TA1-5052 SPR joints were prepared and salt spray tests were carried out for different durations. The static and fatigue strengths of the joints after salt spray corrosion were tested to analyze the effect of salt spray duration on the performance of the joints. The results show that the joints' static strength and fatigue strength decrease with prolonged salt spray time. The salt spray duration affects the joint's tensile failure mode. The tensile failure without corrosion and with a short salt spray time is the fracture failure of the lower aluminum sheet, and the tensile failure of the joints after a long time of salt spray corrosion is the failure of the rivets. The fatigue failure form of the SPR joint is the formation of fatigue cracks in the lower aluminum sheet, and salt spray time has little effect on the fatigue failure form. Salt spray corrosion can promote the initiation and propagation of fatigue cracks. The fatigue crack initiation area is located at the boundary between the lower aluminum sheet and the rivet leg. The initiation of cracks originates from the wear zones among the sheet metal, rivets, and salt spray particles.

Verification of GOTHIC Multivolume Containment Model during NPP Krško DBA LOCA

New containment multivolume model of NPP Krsko for GOTHIC code is developed. It is based on plant drawings and other available data. It is supported by developed SketchUp 3D containment model. The model is subdivided in volumes following physical boundaries and clearly defined flow paths. All important concrete heat structures are taken into account. Metal heat structures are based on plant’s SAR Chapter 6 licensing model. RCFC (Reactor Containment Fan Cooler) units are explicitly modelled as well as all main ventilation ducts. The model includes two trains of containment spray system. PARs (Passive Autocatalytic Recombiner) and PCFV (Passive Containment Filter Venting) filters added during plant safety upgrade project are part of the model too. It was intention to use model for both DBA (Design Basis Accident) and for DEC (Design Extended Conditions) and BDBA (Beyond Design Basis Accident) calculations. Based on the same discretization and data, and on experience acquired during GOTHIC model development and use, containment models for MELCOR and MAAP integral codes are developed too. As part of initial verification of the GOTHIC model containment DBA LOCA calculation is performed using SAR MER (Mass and Energy Release) data. The influence of different break positions on peak containment atmosphere pressure and temperature was studied. The results were compared against results obtained in single volume containment licensing model. Beside local effects due to different containment subdivision similar results are obtained when comparing containment dome from multivolume and the single volume in licensing model. Special attention was paid to distribution of water in lower part of the containment during recirculation phase. In this case much more valuable information are obtained in multivolume model with explicit volumes for main sump, recirculation sump and sump pit. Another point of interest was influence of containment spray duration on long term pressure and temperature behaviour. The intention was to study consistency of assumed different spray operation times used in safety analyses, EQ analyses and SAMGs and related consequences for plant operation during DBA LOCA.

Bacterial Disinfection Using Ozone Gas to Extent Spinach’s Shelf Life: The Effect of Dosage, Duration, and Spraying Frequency

Spinach (Amaranthus tricolor) is one type of leafy vegetable famous as a nutrition source in Indonesia. However, it has short shelf life due to bacterial activity, which requires an alternative preservation solution besides drying. Ozone can be used as a disinfectant that is not harmful to humans and has been applied in food and agricultural product preservation. Ozone gas spraying reduces bacterial growth so that quality degradation due to decay can be slowed. In this research, spinach is preserved by spraying ozone gas to the extent of its shelf life. Spinach is ozonated with ozone gas at various dosages of 30.72 mg/hr, 48.60 mg/hr, and 80.16 mg/hr, with the spraying frequency of once, twice, and 3 times for 15 minutes. Ozone gas spraying duration is also variated: 2 minutes, 3 minutes, and 6 minutes. Then, the sample is stored for 7 days to see the change of its characteristic. The best quality during storage is shown by spinach treated with ozonation at a dosage of 48.60 mg/hr; 6 minutes; and the frequency of 3 times. In addition to variations in duration, dosage, and frequency, the same ozone exposure with different combination of duration-frequency and duration-dosage were also observed to evaluate the optimum ozone treatment for preserving spinach, and it was found that longest duration-least frequency and moderate duration-moderate dosage are preferred in maintaining the quality of spinach during storage.

Design and Performance Test of Autonomous Precision Spraying Robot for Cabbage Cultivation

Pest control in cabbage cultivation generally using pesticides by spraying all areas of cabbage plantation by using a backpack sprayer (knapsack sprayer, semi-automatic sprayer, or electric sprayer). This type of sprayer has difficult to set a consistent spraying duration on each cabbage which affects the accuracy of its application dosage, inconsistence spray pressure affects the droplets produced, and also backpack sprayers can cause injury and harm the health of farmers. This research was conducted to design and analyze an autonomous robot that can precisely spray pesticide on cabbage with appropriate spraying position, droplets diameter, and application dosage. The robot can run straight along the cabbage beds using a wall-follower method and successfully detect and spray pesticide solution on each cabbage by using machine vision with an accuracy of 88% and 80% accuracy of spraying position. The application dosage (L/ha) produced by the robot can approach the reference value compared with the farmer.

Spray characteristics from nasal spray atomization

In addition to topical delivery, nasal sprays offer an alternative drug administration route to the systemic circulation, therefore avoiding the need for painful, invasive delivery techniques. Studies on the efficacy of nasal drug delivery to date have been conflicting despite its potential. In particular computational studies, e.g. Computational Fluid Dynamics (CFD), of nasal spray deposition require realistic initial spray conditions, which are lacking in the literature. This study aims to provide benchmark experimental data for CFD inputs by characterizing four different types of commercially available nasal sprays used in an ENT (Ear Nose Throat) clinic. Spray characteristics were obtained via high-speed videography, while droplet size distribution (DSD) measurements were obtained with laser diffraction. Three actuation forces were evaluated, representing the use-case of an average adult, average child and the maximum force applied to the spray device. The results demonstrated that actuation force influenced spray velocity, spray duration, DSD, and breakup length. Quantitative data of Rosin–Rammler diameter distributions, spray cone angles, dispersion angles and breakup lengths were found, assisting computational models with realistic values, thereby improving future CFD studies of nasal spray drug delivery in the nasal cavity.

Risk Factors Related To Pesticide Exposure In Banjar Horticultural Farmers

Agriculture in Indonesia is the driving force for the country's economy. Farmers in an effort to improve the quality and productivity of agricultural products use pesticides. The use of pesticides to control pests is growing rapidly. Banjar farmers from the Dasong Department are active pesticide users, so there is a potential for pesticide exposure. This study aims to determine the relationship between risk factors and complaints on horticultural farmers in Banjar Dinas Dasong, Pancasari Village, Sukasada District, Buleleng Regency. This study is an analytical observational study with a cross-sectional approach using 46 respondents. Data were analyzed by SPSS using chi-square test and logistic regression. The results of the Chi-Square test showed that there was no significant relationship between age, pesticide dose, duration of spraying, time of spraying, and frequency of spraying with complaints from farmers (p>0.05). While there is a significant relationship between the use of PPE with complaints to farmers (p <0.05). The results of the logistic regression test showed that the duration of spraying, spraying time, frequency of spraying, and use of PPE with complaints to farmers was not significant (p>0.05). This is due to other external factors. This research can be concluded that there is no correlation between the duration of spraying, spraying time, frequency of spraying, and the use of PPE with the complaints of farmers in Banjar Dinas Dasong, Pancasari Village, Sukasada District, Buleleng Regency.

Risk Factors Related To Pesticide Exposure In Banjar Horticultural Farmers

Agriculture in Indonesia is the driving force for the country's economy. Farmers in an effort to improve the quality and productivity of agricultural products use pesticides. The use of pesticides to control pests is growing rapidly. Banjar farmers from the Dasong Department are active pesticide users, so there is a potential for pesticide exposure. This study aims to determine the relationship between risk factors and complaints on horticultural farmers in Banjar Dinas Dasong, Pancasari Village, Sukasada District, Buleleng Regency. This study is an analytical observational study with a cross-sectional approach using 46 respondents. Data were analyzed by SPSS using chi-square test and logistic regression. The results of the Chi-Square test showed that there was no significant relationship between age, pesticide dose, duration of spraying, time of spraying, and frequency of spraying with complaints from farmers (p>0.05). While there is a significant relationship between the use of PPE with complaints to farmers (p <0.05). The results of the logistic regression test showed that the duration of spraying, spraying time, frequency of spraying, and use of PPE with complaints to farmers was not significant (p>0.05). This is due to other external factors. This research can be concluded that there is no correlation between the duration of spraying, spraying time, frequency of spraying, and the use of PPE with the complaints of farmers in Banjar Dinas Dasong, Pancasari Village, Sukasada District, Buleleng Regency.

The leaching of antimony and arsenic by simulated acid rain in three soil types from the world's largest antimony mine area.

A simulated acid rain (SAR) experiment on leaching of antimony (Sb) and arsenic (As) in three soil types including paddy soils (PS), vegetable soils (VS) and slag based soils (SS) from Xikuangshan (XKS) Sb mine area was conducted. The SAR at pH 2.5, 3.5, 4.5 and 5.6 were sprayed to soil columns with intermittent pattern in a period of 50days. Through the spraying duration, leaching Sb in PS, VS and SS showed decreasing trends regardless of pH values in SAR and were in the ranges of 0.026-0.064mg L-1, 0.19-2.18mg L-1 and 11.8-32.4mg L-1, respectively. By contrast, leaching As in these three soil types continuously increased at the initial five spraying times and then deeply decreased afterward, with ranges being 0-0.007mg L-1, 0.001-0.071mg L-1 and 0.17-1.07mg L-1, respectively. The leaching Sb in all the three soil types were extremely higher than the reference value in grade IV (0.01mg L-1) for groundwater quality of China (GB/T 14,848-2017). For leaching As, peck values in VS and all the values in SS were also greater than the corresponding reference value (0.05mg L-1). This indicated that leaching Sb and As could pollute the groundwater in XKS Sb mine area, especially those in slag based soils. The total leaching losses of Sb and As were affected by pH ambiguously, such as SAR at pH 2.5, 5.6 and 2.5 induced the greatest losses of Sb in PS, VS and SS, and pH 3.5, 5.6 and 2.5 resulted in the greatest leaching losses of As in these soils. After SAR treatment, the specific sorbed and Fe/Mn oxide-associated Sb and As significantly decreased. It demonstrated that these two fractions of both Sb and As were involved in leaching losses. The present study also found that the SAR treatment resulted in soil acidification in all the three soil types. In addition, available N, P and K in all the SAR treatments decreased regardless of pH values, except for available N and P in PS.

Изучение и анализ параметров распыления назальных спреев на основе фрамицетина

Objective. To compare spraying characteristics of two nasal sprays containing framycetin – Isofra and Tramicent Materials and methods. We used a silicone model of the nasal cavity (Koken Co. Ltd., Tokyo, Japan) to assess dose distribution of the drug inside the nose. Shadow photography was applied to analyze dynamic characteristics of spraying and the dispersed composition of spray particles. Results. Using a silicone model, we evaluated the dose distribution of the spray inside the nasal cavity. We compared dose distribution of two nasal sprays containing framycetin (Isofra and Tramicent) with full and half-full bottles. Shadow photography was applied to evaluate dynamic characteristics of these sprays, including total duration of spraying, duration of its individual phases, spraying angle, as well as dispersion characteristics, such as average particle size and particle size distributions. Conclusion. The experiments with a silicone nose model demonstrated that Isofra ensured a larger distribution area inside the nasal cavity compared to Terramycin, which suggests a better coverage of the nasal mucosa with Isofra. Comparison of dynamic spraying characteristics (including duration of spraying phases, spraying angle, and shape of the cone) between Isofra and Tramicent using shadow photography showed that Isofra ensured a more homogenous spraying coverage with fine particles. Comparison of the dispersion composition of the two sprays showed that most of the Isofra dose was sprayed with smaller drops than Tramicent, which indicates a better dispersion of Isofra. Our findings suggest that Isofra ensured high quality spraying and effective delivery of the medicine into the nasal cavity. Key words: framycetin, spray, silicone nose model, shadow photography, spray characteristics

Prevalence and Exposure to Ergonomic Risk Factors among Crop Farmers in Nigeria

This study examined the prevalence and exposure to ergonomic risks factors among crop farmers in selected states in Nigeria. We used cross-sectional data to provide this evidence. Data were collected with the aid of a standardized questionnaire administered to farmers. A total of 480 smallholder cassava farmers selected across 24 farming communities in Kogi and Kwara states, Nigeria, were engaged in the study. Descriptive statistics and binary regression were used for analysis. About 96% of the respondents reported shoulder pain, 85% reported lower back pain, 82% reported upper back pain, 64% reported neck pain, and 53% reported elbow pain during farming operations. We found that the age of farmers (OR = 2.01) and daily duration of daily chemical spray (OR = 1.17) were risk factors, while previous training on the safe use and application of farm chemicals was found to be a protective factor (α = 0.05). The study identified affordability of farm safety measures and poor access to relevant safety information as top constraints to farmers’ adoption of safe farm practices. We concluded there is a high prevalence of ergonomic risks during cassava operations among respondents. A crop-specific co-designed ergonomic intervention targeted at Nigerian farmers to reduce exposure to ergonomic risks is recommended.

O-NE005. Electroneuromyography as a predictor of peripheral neuropathy symptoms after two years follow-up in farmers exposed to pesticide: A cohort study

Introduction . Farmer is one of the most common occupation in Indonesia. To increase crop production, they tend to use organophosphate or carbamate pesticides. These extensive pesticide uses could cause low cholinesterase levels in blood, and cause injury in peripheral nerve and neuropathy symptoms. With electroneuromyography (ENMG), subclinical neuropathy preceding its symptom could be found. The purpose of this study is to find association between any abnormality measurement in ENMG with neuropathic symptoms after two years. Methods . This was cohort prospective study. Farmers with history of pesticide exposure, without neuropathic symptoms in 2017, had low blood cholinesterase levels, and gave consent to have ENMG examination were recruited. Motor and sensory aspect of nerve was examined. For motor, we examined distal latency (DL), nerve conduction velocity (NCV), proximal amplitude (PA) and distal amplitude (DA) of median, ulnar, and tibial nerves. For sensory, we examined DL and PA of median, ulnar, and sural nerves. Neuropathic symptoms in 2 years follow up were determined from Total Neuropathic Symptoms Scale, with score > 0 diagnosed as having neuropathic symptoms. Results . There were 26 farmers included in this study. After statistical analyses, there were association between neuropathic symptoms after 2 years with motor NCV, motor PA and sensory DL of median nerve; motor NCV and motor PA of ulnar nerve (p-value > 0.05). After age, gender, working hour, pesticide spray duration adjustment, ENMG markers which had significant and independent association with neuropathy symptoms after two years were ulnar motor DL (p-value: 0.032), median motor NCV (p-value: 0.035), median motor PA (p-value: 0.043), and ulnar sensory DL (p-value: 0.010). Conclusion . From this study, we concluded that ENMG can be used as predictor for neuropathic symptoms in 2 years for asymptomatic farmers exposed to pesticide with low blood cholinesterase levels.

Flow Structure and Particle Deposition Analyses for Optimization of a Pressurized Metered Dose Inhaler (pMDI) in a Model of Tracheobronchial Airway

Inhalation therapy plays an important role in management or treatment of respiratory diseases such asthma and chronic obstructive pulmonary diseases (COPDs). For decades, pressurized metered dose inhalers (pMDIs) have been the most popular and prescribed drug delivery devices for inhalation therapy. The main objectives of the present computational work are to study flow structure inside a pMDI, as well as transport and deposition of micron-sized particles in a model of human tracheobronchial airways and their dependence on inhalation air flow rate and characteristic pMDI parameters. The upper airway geometry, which includes the extrathoracic region, trachea, and bronchial airways up to the fourth generation in some branches, was constructed based on computed tomography (CT) images of an adult healthy female. Computational fluid dynamics (CFD) simulation was employed using the k−ω model with low-Reynolds number (LRN) corrections to accomplish the objectives. The deposition results of the present study were verified with the in vitro deposition data of our previous investigation on pulmonary drug delivery using a hollow replica of the same airway geometry as used for CFD modeling. It was found that the flow structure inside the pMDI and extrathoracic region strongly depends on inhalation flow rate and geometry of the inhaler. In addition, regional aerosol deposition patterns were investigated at four inhalation flow rates between 30 and 120 L/min and for 60 L/min yielding highest deposition fractions of 24.4% and 3.1% for the extrathoracic region (EX) and the trachea, respectively. It was also revealed that particle deposition was larger in the right branches of the bronchial airways (right lung) than the left branches (left lung) for all of the considered cases. Also, optimization of spray characteristics showed that the optimum values for initial spray velocity, spray cone angle and spray duration were 100 m/s, 10° and 0.1 sec, respectively. Moreover, spray cone angle, more than any other of the investigated pMDI parameters can change the deposition pattern of inhaled particles in the airway model. In conclusion, the present investigation provides a validated CFD model for particle deposition and new insights into the relevance of flow structure for deposition of pMDI-emitted pharmaceutical aerosols in the upper respiratory tract.

Neurobehavioral performance of Indonesian farmers and its association with pesticide exposure: A cross-sectional study

BackgroundAcute and chronic pesticide exposure affect human health. The study aimed to assess the neurobehavioral performance and its association with pesticide exposure factors among Indonesian farmers. MethodsA cross-sectional study was conducted among farmers living in Jember, Indonesia. Basic individual characteristics and pesticide exposure factors were documented using questionnaire-based interviews. The neurobehavioral performance was assessed by the German Q18 questionnaire and the WHO Neurobehavioral Core Test Battery (NCTB) consists of the Digit Span, Digit Symbol, Pursuit Aiming, and Trail making instruments. Data were presented descriptively and analyzed statistically using the chi-square test. ResultsAs many as 90 farmers were recruited. Most farmers were 45–55 years old and had a normal nutritional status and moderate smokers. The neurobehavioral performance of the farmers was 62.22% normal and 37.78% abnormal. The most common neurobehavioral deficits were short memory, concentration difficulties, excessive fatigue, frequent headache, and tremor. The chi-square test showed that the spraying frequency (p = 0.006), the spraying duration (p = 0.002), the working years (p = 0.013), and the PPE usage (p = 0.022) associated with neurobehavioral performance, but the pesticide types (p = 0.289) and spraying time (p = 0.627) did not associated with neurobehavioral performance. ConclusionAlthough most farmers showed a normal neurobehavioral performance, some pesticide exposure factors demonstrated an association with neurobehavioral performance among Indonesian farmers. Multiple approaches including implementation of the regulation, choosing alternative biopesticides, and regular counseling on all aspects of pesticides, their impact on health are recommended to minimize pesticides' negative effects.

Experimental investigation into the use of emergency spray on suppression of battery thermal runaway

The thermal safety of lithium-ion batteries limits the development of electric vehicles. When the battery heat generation rate exceeds the critical cooling rate of the battery thermal management system, thermal runaway will occur. This article uses spray as an emergency cooling method to suppress battery thermal runaway, which can inhibit the battery heating process when the thermal management system cannot meet the heat dissipation requirements, and ensure thermal safety across the entire temperature range. In this paper, spray is applied to the cooling of battery thermal runaway, and a series of experiments are carried out to study the inhibitory effect of spray cooling on the battery. This experiment explored the influence of spray trigger temperature (Te) and spray duration (ts) on the suppression effect of thermal runaway. In order to achieve a lightweight and economical spray system, whilst ensuring an efficient cooling performance, we tried to analyze the relationship between Te and ts, hoping to quantitatively control spray flow and use the smallest spray flow to achieve suppression.This research provides meaningful results for the application of spray cooling in suppressing battery thermal runaway.

Wear resistance of HVOF sprayed NiSiCrFeB, WC-Co/NiSiCrFeB, WC-Co, and WC-Cr3C2-Ni rice harvesting blades

Abstract In this work, NiSiCrFeB, WC-Co/NiSiCrFeB, WC-Co, and WC-Cr3C2-Ni coatings were sprayed on rice harvesting blade surfaces using a high velocity oxygen fuel (HVOF) process. Each of the rice harvesting blades was sprayed with one of four coating materials using different spraying durations. The effects of coating materials and spraying durations on the average values of coated blade volume loss, hardness and surface roughness (Ra) were studied through real rice-harvesting field tests. Analysis of variance (ANOVA) and a multiple comparison approach with Tukey’s test were used in order to conduct a comparative performance analysis of the coating materials of rice harvesting blades. The experimental results indicated that the NiSiCrFeB coating exhibited the highest volume loss compared with all others. In addition, the WC-Co-coated blade had significantly greater hardness than those coated with NiSiCrFeB, WC-Co/NiSiCrFeB, or WC-Cr3C2-Ni. The rice harvesting blade coated with either WC-Co/NiSiCrFeB, WC-Co, or WC-Cr3C2-Ni using the shortest spraying duration was recommended for installation in rice harvesting machines.

A Theoretical Model for Ship–Wave Impact Generated Sea Spray

AbstractSpray generated by ships traveling in cold oceans often leads to topside icing, which can be dangerous to vessels. Estimation of the spray flux is a first step in predicting icing accumulation. The amount of spray water, the duration of exposure to the spray, and the frequency at which the spray is generated are all important parameters in estimating the spray flux. Most existing spray flux formulae are based on field observations from small fishing vessels. They consider meteorological and oceanographic parameters but neglect the vessel behavior. Ship heave and pitch motions, together with ship speed, determine the frequency of spray events. Thus, the existing formulae are not generally applicable to different sizes and types of vessels. This paper develops simple methods to quantify spray properties in terms that can be applied to vessels of any size or type. Formulae to estimate water content and spray duration are derived based on principles of energy conservation and dimensional analysis. To estimate spray frequency considering ship motions, a theoretical model is proposed. The model inputs are restricted to ship’s principal particulars, operating conditions, and environmental conditions. Wave-induced motions are estimated using semi-empirical analytical expressions. A novel spray threshold is developed to separate deck wetness frequency from spray frequency. Spray flux estimates are validated against full-scale field measurements available in the open literature with reasonable agreement.

Simultaneous Optimization of Water Usage Efficiency and Yield of Cucumber Planted in a Columnar Aeroponic System

The development of aeroponic cultivation technology has led to more efficient use of water and plant nutrients for producing high quality agricultural commodities. In this research, cucumbers were grown in columnar aeroponic systems for nine weeks and the effect of spraying rate and spraying duration on the cucumber average yield and water usage efficiency were investigated. The experiments were performed using factorial experiment based on completely randomized designs. The spraying rate had three levels of 125, 250 and 375 mL/min, and the spraying durations were 10, 15 and 20 min. During the experiment, the spraying pumps were turned off for 15 min between each spraying time. Then, the two factors were simultaneously optimized using response surface methodology to maximize fruit yield and water usage efficiency. The ANOVA results showed that both responses were significantly affected by the main effects of the factors (α = 0.01) and by their interaction effects (α = 0.05). The comparison of first and second-order models to show the average yield and water usage efficiency as functions of sparing rate and sparing time indicated that the second-order models fitted with higher accuracies (R2> 80%) to the experimental data than the first-order model. Simultaneous optimization showed that the most suitable spraying rate was 233.37 mL/min and for the spraying duration, it was 16.06 min. At the optimum conditions, the average yield per plant yield was 2.96 kg and the water usage efficiency was 110.37 kg/m3.