Spray Time 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.

INNOVATIVE TECHNOLOGIES FOR THE APPLICATION IN VINEYARDS AND ORCHARDS OF SPRAYING TREATMENTS WITH REDUCED IMPACT ON THE ENVIRONMENT. PRESENT AND PERSPECTIVES

The paper presents an analysis of the innovative technologies that are currently implementing spraying treatments with the reduction of specific consumption of pesticides, fuel, labour and especially the reduction of environmental pollution. They are presented for the administration of insecticides-fungicides and liquid fertilizers with machines for spraying vines and orchards of the carried type with a tank of 300-600 litres and of the trailed type with a tank of 600-2000 litres, which have standard fans or a tower with controlled spraying, 600-800 mm propellers with adjustable pitch, hot-dip galvanized metal parts, bronze nozzle holder, cardan shaft, etc. The work concludes with the recommendation of using an innovative spraying machine that allows significant savings of active substance, depending on the vegetative phase of the plantation at the time of spraying compared to conventional treatment.

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.

Visualized study of wetting enhancement and thermal performance of fiber-coated indirect evaporative cooler

Poor wetting is a serious problem facing the traditional aluminum and polymer indirect evaporative cooler, which largely deteriorates its cooling performance. Therefore, a fiber coating (70% rayon + 30% polyester textile) is proposed to be attached to the plate heat exchanger walls to improve the wetting condition by its good moisture diffusion. Firstly, the characteristics of the fiber are evaluated by a laser microscope, wicking height and diffusivity tests. Then, its application on an indirect evaporative cooler is investigated. On one hand, to quantitatively evaluate the wetting enhancement by the fiber, comparative visualized experiments are carried out between fiber-coated and non-coated cooler to investigate the water distribution, wetting ratio and water retention at three typical core positions under different spraying time (5 s–180 s), water flow rate (2 L/min–6 L/min) and nozzle height (50 mm to 250 mm). The visualized experiment innovatively combines fluorescence display and digital image processing methods. On the other hand, the thermal conductivity of the fiber-coated plate is tested and used as input for the heat and mass transfer model of indirect evaporative cooler to predict the outlet air temperature. The results show that the non-coated plate suffers from uneven water distribution and low wetting ratio, but the fiber coating can significantly improve the wetting conditions by providing 100% wetting ratio in only 30 s under 150 mm nozzle height and 5 L/min flow rate. The influence of thermal resistance of wetted fiber on outlet air temperature is negligible, but the dry fiber will increase the supply air temperature by 0.3 °C.

Efficacy of bear spray as a deterrent against polar bears

AbstractAlthough there have been few attempts to systematically analyze information on the use of deterrents on polar bears (Ursus maritimus), understanding their effectiveness in mitigating human‐polar bear conflicts is critical to ensuring both human safety and polar bear conservation. To fill this knowledge gap, we analyzed 19 incidents involving the use of bear spray on free‐ranging polar bears from 1986 to 2019 in Canada, Russia, and the United States to evaluate the effectiveness of bear spray as a polar bear deterrent. We found that bear spray was an effective deterrent in close‐range encounters with polar bears, stopping undesirable behavior in 18 of 19 incidents. Bear spray effectively deterred both curious and aggressive polar bears, including polar bears attempting to attack people. The mean distance between user and bear at the time of spraying was 2 m (min–max = 0.2–10.0 m, mode = 1 m), though bears were usually first seen at greater distances. Bear spray was successfully deployed against polar bears in all 4 seasons. Wind affected spray performance in 1 of 19 of incidents. In 8 of 14 bear spray incidents, other deterrents were used without success before bear spray was used effectively to deter polar bears. No humans or polar bears were killed or injured in any of the incidents in which bear spray was used. We also analyzed 54 polar bear attacks and attempted attacks on humans where bear spray was not carried. The data suggest that in 93% of those incidents, the use of bear spray might have saved the lives of both the people and bears involved if it had been available and used. Our analysis improves our understanding of the effectiveness of bear spray for polar bear conflict mitigation.

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.

Effect of Shot Peen Forming on Corrosion-Resistant of 2024 Aluminum Alloy in Salt Spray Environment

The effect of shot peen forming on the corrosion-resistant of 2024 aluminum alloy in a salt spray environment was studied with an electrochemical workstation. The surface morphology and cross sectional morphology of the original and shot peen-formed sample were studied by a scanning electron microscope. After shot peen forming, the salt spray corrosion resistance of 2024 aluminum alloy was worsened (the corrosion rates of the original alloy and the shot peen-formed alloy were 0.10467 mg/(cm2·h) and 0.27333 mg/(cm2·h), respectively, when the salt spray corrosion time was 5 h). The radius of capacitive reactance arc of the sample subjected to shot peen forming was smaller than that of the original sample. When the salt spray corrosion time was 5 h, the doping density (NA) of the original alloy was 2.5128 × 10-13/cm3. After shot peen forming, the NA of the alloy increased to 15 × 10-13/cm3. For the shot peen-formed sample, pitting corrosion first occurred in the crater lap zone and became severe with salt spray time. The cross sectional morphology of both original and the shot peen-formed samples shows that severe intergranular corrosion occurred in the salt spray environment. However, for the original sample, the intergranular corrosion distribution was lamellar. For shot peen-formed sample, the intergranular corrosion distribution was network.

Compatibility of biological control and pesticides mediated by arthropod movement behavior and field spatial scale

Integrated pest management programs frequently rely on a combination of pesticide use with cultural controls such as diversifying agroecosystems to control pest populations. Selective pesticides can impose both lethal and sublethal effects on natural enemies. However, understanding the compatibility of pesticide use with biological control strategies is critical for pest management success. The population dynamics of natural enemies subjected to the effects of pesticides, especially those that experience sublethal effects, is critical to this understanding. Although lethal effects of pesticides on natural enemies are well-studied, sublethal effects of pesticide exposure such as the impact on natural enemy movement is less well understood – especially across different habitat spatial scales. We present a simulation model using coupled partial differential equations to explore the sublethal effects of pesticide use, via reduced predator movement, on pest suppression across a gradient of farm spatial scales. Using a beetle-aphid model system, we find that in small fields, increased abundance of natural enemies can reduce the need for pesticide sprays. However, in mid-sized fields, we find that impaired predator mobility caused by pesticide sprays has a negative impact on biological control by the natural predator community. We also demonstrate how timing of predator introduction to a field can complement timing of pesticide sprays. We discuss the implications of these results for biological control planning and implementation.

The Climbing Swamp Fern, Stenochlaena palustris (Burm. F.) Bedd. (Blechnaceae) - A Noxious Weed in Oil Palm Estates and Its Management

The climbing swamp fern or Stenochlaena palustris, is a fern that has a creeping stem/rhizome which often grows into a vigorous sheet colony over large areas and climbs robustly on palm trunks as an epiphyte. The young shoots or new fronds of this fern are consumed as vegetables by humans. The fern has other usages in local medicine, basket making and a beneficial role in pest management. In a field with thick tall sheet growth of S. palustris, the harvesting, evacuation of fresh fruit bunch (FFB), loose fruit collection and many field operations will be difficult to be carried out efficiently. The luxurious epiphytic growth on palm trunk up into the canopy prevents the sighting and cutting of FFB during harvesting and thus many ripe FFB are left unharvested, which subsequently become over-ripe/ rotten. In both situations, oil palm yield in severely infested fields is badly impacted. In line with the integrated weed management approach, prevention of the establishment of S. palustris is important by early control of isolated colonies or small patches of this noxious weed in the replanting fields, drain sides and on trunk chips. In the control of this serious noxious weed, various measures applied singly or in combination are necessary in line with integrated weed management approach. Over the years, chemical control has been widely practiced in rubber and oil palm plantations. The herbicides including 2,4,5-T, paraquat, DSMA (disodium methyl arsonate), MSMA (monosodium methanearsonate), diuron, sodium chlorate, 2,4-D sodium, 2,4-D amine, imazapyr, glyphosate, glufosinate-ammonium, metsulfuron-methyl, saflufenacil and sulfentrazone (and mixtures) are briefly discussed and reviewed. To mitigate the removal of paraquat, several alternatives have been identified and reported by several researchers. The writer’s recommendations to control S. palustris for mature plantings are: i) sodium chlorate + metsulfuron-methyl at 5.5 kg + 75 g per hectare (or 220 g + 3 g per 18 L water), ii) glyphosate + metsulfuron-methyl at 1.5 L + 75 g per hectare (or 60 ml + 3 g per 18 L water), iii) glufosinate-ammonium at 3.3 L per hectare (or 132 ml per 18 L water). For control of S. palustris in inter-row areas of immature plantings, treatments i) and iii) are recommended. This is to avoid unacceptable phytotoxicity to spear and new fronds of immature palms due to spray drift of glyphosate. For long-term control of S. palustris in pure stand and in inter-row areas, spraying of metsulfuron-methyl at 150 g product per hectare (or 20% product in 6 g per 18 L water) is recommended. For spraying of epiphytic S. palustris and other mixed species of epiphytes, glyphosate + metsulfuron-methyl at 1.5 L + 75 g per hectare (or 60 ml + 3 g per 18 L water) is recommended and the optimum spraying time is after frond pruning operation. Keywords: Stenochlaena palustris, noxious weed, climbing epiphytic weed, oil palm plantations, management, herbicides.

Dynamics of a class of nonlinear pest–natural enemy discrete model

The inappropriate use of insecticides may lead to disastrous pest outbreaks. Aiming at avoiding the outbreak of pests by optimizing the control strategies, we propose a novel mathematical model based on the idea of pulse in this study, namely, a discrete‐time model of pest–natural enemies, which considers the implementation of spraying insecticides within the time interval between two generations of pests. We first investigate the existence and stability of fixed points, and then using the central manifold theory, we proved that the system can exist period‐doubling bifurcation. The main theoretical results are verified by numerical simulations. The experiments show that if the insecticidal time is within a certain range, the lower insecticidal rate stimulates the growth of pests and natural enemies, while the larger insecticidal rate can inhibit the growth of pests and natural enemies. In addition, the effects of pest growth rate, timing of pesticide spraying, and pesticide intensity on the system are comprehensively discussed. The main research provides good reference significance to choose an appropriate time to prevent pest outbreaks.

Quantification of methoprene aerosol deposition using reversed-phase high-performance liquid chromatography

Methoprene is an insect growth regulator (IGR), which acts on the juvenile stages of insects and is used as pest control method in food processing facilities. A chemical reference method was developed to quantitate aerosol deposition of methoprene using High-Performance Liquid Chromatography, HPLC. The method starts with placing 2.5 g (∼1 level tsp) flour in the opened Petri-dish (150 mm × 15 mm) as an absorber and placing the Petri dish on the floor and in the facility treated with pesticide aerosol. After treatment, the dishes were collected and analyzed with HPLC. The flour from each dish was emptied into a 50 mL centrifuge tube along with 40 mL of methanol and mixed. The samples were then centrifuged and loaded on the HPLC. The HPLC method could detect methoprene concentrations down to 0.2 μg/mL. In validation test, unknown samples matched the real spray times with a SE from 0.1 to 0.8. Historic methods used 120 min mixing time and 48 h holding time. It was found that a mixing time of 30 min and 0 holding time was sufficient to obtain greater than 90% recovery. The objective of this study was to develop a standard chemical methodology to quantify the amount of methoprene insecticide deposited on floors and surfaces when applied from compressed cylinders as an aerosol insecticide. The HPLC method developed explored the impact of flour, mixing, holding, and processing times on methoprene recovery. The HPLC method developed in this study will provide pesticide applicators a method to accurately determine product deposition and to evaluate pesticide distributions throughout facilities and determine areas which may require additional treatment.

Time and rate of acetate foliar spray can ameliorate adverse effect of NaCl stress on strawberry

• Acetic acid as an intermediated substance can be used to improve the salt tolerance in strawberry. • Timing of use acetic acid is very important. • the best time of using acetic acid under saline condition is one week before salinity stress. • The acetic acid in 1 mM concentration produces the best an avoidance strategy and can be helpful for plant tolerance and increase in yield in salinity stress conditions. Acetyl-CoA is a central metabolic intermediate. It is widely used in macromolecule biosynthesis and energy production to support plant cellular growth. Acetate is a precursor of acetyl - CoA which is used by plant cells. Strawberry plants were subjected to 0 and 40 mM NaCl, and foliar acetic acid at the rate of (0, 1, and 2 mM) at three different times (one week before, simultaneously, and one week after starting of salinity stress application). Salinity stress reduced the strawberry leaf area (67%), plant biomass (27%), total chlorophyll content (44%), and fruit diameter (13%). However acetic acid application ameliorated the adverse effect of NaCl on strawberry plants. Salinity alone reduced plant biomass, whereas the acetate treatment (1 mM) increased it by 6% when used simultaneously with salinity and by 26% when used one week after salinity. This treatment increased proline content and soluble carbohydrate while improving antioxidant defense in fruit tissue, e.g., ascorbic acid, phenol content, and anthocyanin. These data support the idea that adjustment acetic acid application to plant can enhance salinity tolerance. The best concentration of acetic acid was 1 mM which could be optimally used either one week before or simultaneously with salinity stress.

Experimental investigations on thermal performance of spray cooling double skin façade in hot humid climate region

Thermal performance of the spray cooling double skin façade in hot and humid climate region are experimentally investigated in this study. Two identical double skin facades are constructed for the comparative analysis. Thermal performance of the spray cooling double skin façade is evaluated by the indicators of cavity air temperature, glass surface temperature, the U-value, and solar heat gain coefficient. The influences of the ventilation mode (open conditions of the top and bottom vents in the double skin façade system), operation time (spray and interval time of the spray system), and spray direction on the cooling effect of the spray cooling double skin façade are experimentally compared and analyzed, and the operation mode of the spray cooling double skin façade with the best thermal performance is obtained. The results demonstrate that the appropriate operation mode of the spray cooling double skin façade is that the top and bottom vents are opened, and the spray direction is from up to down with the operation time of 10/15 min (spray/interval time). The average temperature of the cavity and inner glass decreased by 8.1 °C and 3.7 °C, respectively. The mean U-value and SHGC of the spray cooling double skin façade are 2.13 W/(m2·K) and 0.25, respectively, which are smaller than the most stringent limit values of the current national standard. The spray cooling double skin façade has good thermal performance in hot humid climate region in China.

Study on Damage Behavior of NiCoCrAlY/MSZ Plasma-Sprayed Coating in Neutral Salt Spray Environment

In order to explore the corrosion damage behavior of plasma-sprayed NiCoCrAlY/magnesia-stabilized zirconia (18~22 wt.% MgO-ZrO2, MSZ) thermal barrier and anti-ablation coatings in a salt spray environment, a series of neutral salt spray (NSS) tests for 96 h (N-2), 192 h (N-4) and 288 h (N-6) were carried out on the coatings. The microstructures, composition distributions, potentiodynamic polarization curves, bonding strengths and anti-ablation properties of the coatings before and after the NSS tests were characterized. The results show that, with the increase in salt spray time, the expansion and overflow of corrosion products (FexOy) led to more defects forming inside the coating; the porosity of the top coat (TC) of N-6 increased to 15.2% in comparison to that of the blank control sample (N-0), which was 8.5%. According to the potentiodynamic polarization curves, accelerated corrosion occurred in the coating samples after the salt spray time reached 192 h, and the corrosion current density rapidly surged from 2.2 × 10−8 A·cm−2 (N-4) to 2.2 × 10−5 A·cm−2 (N-6). Similar degradation tends could be found in the bonding strengths and mass ablation rates of the coatings due to the accumulation of loose corrosion products on the substrate, which affected the bonding states of the coatings and promoted their spalling under an oxyacetylene flame (OAF). As a result, the maximum service life of the NiCoCrAlY/MSZ coatings in the neutral salt spray environment was about 192 h. This work is instructive for studying the environmental adaptability of metal/ceramic double-layer coatings.

Pengaruh Interval Waktu Aplikasi Beauveria bassiana dalam Mengendalikan Hama Spodoptera frugiperda pada Tanaman Jagung

Spodoptera frugiperda is a harmful pest on maize. These larvae damage shoots, young leaves or plant growth points. B. bassiana is a biological agent that has been shown to be able to effectively control S. frugiperda. This research was carried out in two stages, namely the first stage of research carried out at the Plant Protection Laboratory and the second stage at the Jember State Polytechnic Land. The purpose of the first stage is to determine the reference concentration in the field based on mortality and insecticide efficacy tests. The second stage aims to observe the intensity of S. frugiperda attack on corn plants with spraying time intervals of once in 2 days in block 1 and every 5 days in block 2 and observe the weight of cobs and dry shells per sample. The first stage of data analysis used a completely randomized design with 5 treatments and repeated 6 times. Further test using the smallest Significant Difference (BNT) 5%. The second stage of data analysis was the intensity of attack at 2 and 5 days application time interval and the weight of wet and dry shelled cobs using the Mann Whitney non-parametric analysis test. Based on the results of further tests, the efficacy of the insecticide B. bassiana to control the 3rd instar armyworm was 15ml/L and became the reference concentration in the field. With the application of once every 2 days the intensity of S. frugiperda attacks before the application of B. bassiana is 7% and after the application is 3%. Then with the application of B. bassiana once every 5 days the intensity of S. frugiperda attacks before the application is 3% and after the application is 1%. The average weight of wet cobs per sample for blocks 1 and 2 were 248 and 237 grams, respectively. The average dry shell weight per sample in block 1 and block 2 was 150.62 and 167 grams, respectively.

Effectiveness of various insecticides and predatory bug, Orius laevigatus (Fieber, 1860) (Hemiptera: Anthocoridae) releases on Thrips hawaiiensis (Morgan, 1913) (Thysanoptera: Thripidae) in lemon, Citrus limon (L.) (Rutales: Rutaceae), orchard in Mersin (Türkiye)

The important invasive thrips species Hawaiian flower thrips, Thrips hawaiiensis (Morgan, 1913) (Thysanoptera: Thripidae) was first reported in Türkiye in 2015. Since then, it has been causing damage in lemon orchards. This study was conducted to reveal the most effective insecticides, the most effective spraying time and the efficacy of biological control. For this purpose, the effectiveness of five insecticides (480 g/l spinosad, 25% spinetoram, 100 g/l spirotetramat, 50% flonicamid, 240 g/l tau-fluvalinate), effect of three spray programs and effectiveness of predatory bug Orius laevigatus (Fieber, 1860) (Hemiptera: Anthocoridae) were tested in a lemon orchard [Citrus limon (L.) (Rutales: Rutaceae)] in Erdemli district of Mersin province in 2018 and 2019. In order to determine the most effective spraying time, three spray programs were tested. In Program 1, two sprays during the flowering period were applied. In Program 2, two sprays were applied, one at petal fall and the other at the small fruiting stage. In Program 3, one spray at petal fall and two sprays in the fruiting stages were applied. According to the results, 240 g/l tau-fluvalinate and 50% flonicamid showed the lowest efficacy of the insecticides in the three programs. Spinetoram was found the most effective of the others. Insecticide applications to control T. hawaiiensis during the flowering period (Program 1) had low efficacy. Program 3 was found to be the most effective. Predatory bug O. laevigatus, as a biological control agent was found to have a potential efficacy for suppressing T. hawaiiensis populations.

KNOWLEDGE OF STUDENTS’ INFECTION CONTROL WHEN PARTICIPATING IN COVID-19 TEST SAMPLING IN THE COMMUNITY

Background: Coronavirus Disease 2019 (COVID-19) pandemic got extremely complicated in 2021, appeared many new strains of viruses with high infectivity. So, knowledge and manipulation were important for protecting students against infection in COVID-19 sampling. Objectives: The study surveyed knowledge of students’ infection control when participating in COVID-19 test sampling in the community. Materials and methods: A cross-sectional descriptive study was conducted on 195 volunteer students of Can Tho University of Medicine and Pharmacy (CTUMP). A series of 11 questions were also used to interview the participants. Results: The proportion of female volunteers who participated in the research was 52.8%, higher than male volunteers (47.2%). Students in the 45th cohort participated in research with the highest quantity (43.6%) and the lowest in the 42nd cohort (0.5%). The research had the largest number of general medical students participating (69.2%). The results showed that the knowledge of regular hand washing, removing gloves, removing N95 masks, and the time of disinfection spray with median points equal to the maximum point. The median overall knowledge score for the principle of removing Personal Protective Equipment (PPE) was 50%, compared to the maximum point of 100%. Only 24.6% of students got maximum scores in the knowledge of minimum safe distance, whereas 98.5% achieved maximum scores in the knowledge of COVID-19 sample collection skills. Conclusions: Students who took part in COVID-19 community sampling had a good understanding of most research topics. However, the principle of removing PPE was not well-understood.

Anti-Ovipositor Power of Jayanti Plant (Sesbania sesban) for Integrated Control of Cabbage Pest (Plutella xylostella)

Cabbage harvest failure is often caused by failure to control cabbage pests. Cabbage pest control by eradicating Plutella xylostella larvae is considered less effective because the cabbage plant has been damaged due to infection with P. xylostella eggs and larvae. Thus, the control target needs to be shifted to prevent P. xylostella amago from laying eggs (ova-positioning) on cabbage plants. This study aims to determine the anti-ovipositor power of Sesbania sesban leaf extract against P. xylostella. The leaves of S. sesban were air-dried and then ground. The dry powder (simplicia) of S. sesban leaves was extracted with water as the sole solvent. The water-extract of S. sesban leaves was tested for anti-ovipositor against P. xylostella in situ on cabbage plants according to a completely randomized block design. Experimental groups were made according to variations in extract concentration. Complete randomization was carried out on experimental units in each group according to the variation in the length of exposure to the extract before access to the ovipositor was opened (Cages were opened after 1,2,3,4,5 and 6 days from the time of extract spraying). Each experimental unit consisted of 4 cabbage plants as replicates. The treatment was given by spraying a solution of S. sesban leaf extract with a concentration according to the group evenly on the entire leaf surface of each cabbage plant. The observed research variable was the number of P. xylostella eggs per cabbage plant after the cage of cabbage plant unit was opened. The results showed that the leaf extract of S. sesban could inhibit P. xylostella as an ovipositor to lay its eggs on cabbage plants effectively for up to three days. With concentrations of 1.83 to 2.14 ppm, the aqueous extract of S. sesban leaves did not inhibit P. xylostella egg laying, but with concentrations of 478.63 to 1283.88 ppm it could inhibit 50 to 100%.

Characteristics of urine spraying and scraping the ground with hind paws as scent-marking of captive cheetahs (Acinonyx jubatus)

Olfactory communication is common in felids. We observed two scent-markings, urine spraying and scraping the ground with hind paws during excretion, of 25 captive cheetahs. We analyzed the association of sniffing with the timing of urine spraying and scraping, and differences in these behaviors based on sex, age, and captive environment to understand the olfactory communication among cheetahs. Both scent-markings were strongly associated with sniffing, especially scraping, and the presence or absence of scent was thought to be a trigger. Both behaviors were observed only in adults; scraping was observed only in males. To our knowledge, this study was first to confirm the discharge of secretions from the anal glands during scraping. The frequencies of both behaviors were significantly higher in males kept in shared enclosures containing other individuals than in males kept in monopolized enclosures, while there was no difference in the frequencies among females. Female cheetahs are solitary and have non-exclusive home range, whereas male cheetahs are either solitary or live in coalition groups and there are territorial and non-territorial males. Our results could be attributed to the differences in sociality between the sexes and effect of the living environment.

Convection heat transfer coefficient of building glasses under salt deposition conditions

Glass buildings in coastal regions and islands exposed to the hydrothermal marine environment, in addition to salt deposition and erosion, lead to a change in the surface convective heat transfer coefficient (CHTC) and gradual degradation of the building energy and thermal performance. However, limited research has been conducted on the influence of salt deposition on the CHTC of building glasses. Hence, in this study, the salt deposition characteristics of the glasses were obtained by conducting an accelerated salt spray test. In addition, the influence of salt deposition on the CHTC and heat transmission coefficient (HTC) was investigated. The results indicate that the sizes of the salt spots on the glass surface increased significantly and unevenly. The salt deposition per unit area (p) exhibited a logarithmic growth trend between 14.4 and 40.0 mg/m2, considering the spray time. Under the 10% saline condition, p was larger than that under the 5% saline condition, ranging between 15.6 and 44.3 mg/m2, with an average increase rate of 11.6%. The CHTC exhibited a monotonic increase in terms of the deposition amount on the glass. Compared with the salt-free scenario, the maximum increase in CHTC was 178.7%, which exhibited a linear relationship with p. When p increased to 40.0 mg/m2, the HTC increase rate of the single clear glass and hollow Low-E glass reached 20.1% and 5.2%, respectively. The findings of this study provide insights into the influence of salt deposition on the CHTC of building glasses and can serve as a basis for energy consumption studies in coastal regions.