Mesh Cover Research Articles

Superhydrophobic coating with super-high adhesive strength to substrate

Porous and hydrophilic concrete coating on the insulation layers of dam suffered from adhesion of cold water and subsequent icing in a freezing environment, which might result in severe ice pullout phenomenon. Although a lot of superhydrophobic concrete (SC) coatings have been developed, the coatings generally had poor adhesive strength with the insulation layers, which restricted their application in protecting the insulation layers. Herein, we first developed a novel superhydrophobic polymer concrete (SPC) coating by polyacrylate emulsion (PAE) and stone protector addition, and nylon mesh cover. The SPC coating exhibited good superhydrophobicity with a contact angle of ∼156° and a sliding angle of ∼10°. And the adhesive strength between SPC coating and insulation layer was 96 % larger than that of SC coating, indicating much better performance in the insulation layer protection. In addition, the SPC coating possessed excellent surface robustness, anti-icing capacity, and self-cleaning property, and was expected to be a promising candidate for protecting the insulation layers.

Drivers of zooplankton dispersal in a pond metacommunity

Dispersal success is crucial for the survival of species in metacommunities. Zooplankton species engage in dispersal through time (i.e., egg bank) and space (i.e., vectors) by means of resting eggs. However, dispersal to patches does not equate to successful colonization, as there is a clear distinction between dispersal rates and successful colonization. We performed a field mesocosm experiment assessing dispersal and colonization success of zooplankton from resting eggs or transport via directional wind/airborne and biotic vectors in the vicinity of three ponds. By using active vs. sterile pond sediments and mesh-covered vs. open mesocosms, we disentangled the two mechanisms of dispersal, i.e., from the egg bank vs. space. We found that for both rotifers and cladocerans, sediment type, mesh cover and duration of the experiment influenced species richness and species composition. The relative contribution of resting stages to dispersal and colonization success was substantial for both rotifers and cladocerans. However, wind/airborne dispersal was relatively weak for cladocerans when compared to rotifers, whereas biotic vectors contributed to dispersal success especially for cladocerans. Our study demonstrates that dispersal and colonization success of zooplankton species strongly depends on the dispersal mode and that different dispersal vectors can generate distinct community composition.

ЭКСПЕРИМЕНТАЛЬНОГО ИССЛЕДОВАНИЯ ПРОТОТИПА ИОННОГО ДВИГАТЕЛЯ ВРЕМЯПРОЛЕТНЫМ МЕТОДОМ

The article presents the results of experimental studies of the resonator ion thruster by the timeof-flight method in order to determine the accelerating structural elements. Four assembly variants were investigated: the outflow of ions from a magnetic cell; the outflow of ions from a magnetic cell with an installed core; the outflow of ions from a magnetic cell with an installed core and the side wall of the resonator; the outflow of ions from a magnetic cell with an installed core and the side wall of the resonator with a mesh cover. The energy consumption of the magnetic cell was 5.6 W, and the ion beam velocity at 11 Pa was no more than 7 m/s. In the assembly according to the second variant, the power consumption was 6.6 W at a pressure of 11 Pa and a speed of no more than 30 m/s. The power consumption for the third and fourth assembly variants was 6 watts, and the ion beam velocity at 11 Pa was no more than 48 m/s.

Mitigate the reverse effects of frost by cultivate tomato plants under different types of mesh cover for low tunnels

Tomato plants are highly sensitive to chilling stress so this experiment was conducted during successive winter seasons of 2020/2021 and 2021/2022 to investigate the possibility of sustaining production and quality of tomato yield under cold conditions by using different types of mesh cover for low tunnels. Two commercial cultivars, i.e., Super gold F1 and Super streen F1 were used. Seedlings were transplanted under different types of mesh cover for low tunnels. Three types of mesh cover (63%, 65%, 73%) had done to cover the plants of all tested seasons compared to open field condition (control "Without cover"). Results show that significant differences were observed among the two hybrid varieties of tomato studied, in terms of their vegetative growth characteristics (plant height, number of branches, number of leaves, fresh weight, dry weight and leaves area) as well as yield and fruit quality characteristics (Fruit set, total yield, firmness, T.S.S and Vit. C. ‘Super gold’ exhibited significantly higher values for these characteristics, compared to ‘Super strain B’. Chilling reduced the growth parameters (plant height, number of leaves, number of branches, plant fresh weight, plant dry weight) for control plants (without cover) compared to the coverage treatments (63%, 65%, 73%). Significant highest results in the growth, chemical composition of tomato leaves as well as yield and fruit quality parameters were obtained with covering tomato plants by white mesh cover 63% flowed by 65% of treatments which were best than the chilled plants. Concerning the interaction between hybrid varieties and covering treatments, it can be noticed that Cv. Super gold F1 which grown under white mesh cover 63% recorded a highly significant increases in plant height, number of branches, number of leaves, fresh weight, dry weight, leaves area, N, P, K, total chlorophyll, total proline, total sugers contents, fruit set, total yield, firmness, T.S.S and Vit. C. when compared to Cv. Super streen B F1 which grown in open field (without coverage).

Growing cabbage (Brassica oleraceae var. capitata) under low cover Agronets prevents pest infestation and increases yields in Kenya

Cabbage (Brassica oleracea var. capitata) is an important vegetable crop in Kenya both in production and income provision to smallholder farmers. Pests are serious hindrance to its production and most farmers rely on synthetic insecticides. Such reliance has negative effects on non-target organisms, environment, animal and human health. This study was carried out from May to October 2011 to determine impact of low cover nets of different mesh size and cover duration on reducing cabbage pest infestation and yields. The study was conducted at Kenya Agricultural Research Institute Kabete and Practical Training Centre Thika based on a randomized complete block design with five replicates. Treatments included Agronets of fine (0.4mm) and large (0.9mm) mesh covered over the crop permanently (season-long) or temporarily (opened three times a week from 9am to 3pm) and control where no Agronet was used. The results show that the number and damage by diamondback moth (DBM) was significantly lower on cabbages grown under the Agronets compared with control. Infestation by thrips was lower on cabbages grown under permanent cover compared with those under temporal cover and without cover. However, there was no significant difference of aphids infestation. The marketable yield was significantly higher on cabbages grown under the Agronets, recording about 17% yield loss compared with control that recorded about 90% yield loss. The study concludes that Agronets provide an important component of integrated pest management strategy for cabbage production in Kenya with high crop yields benefit and highly recommended for application by growers. Key words: Agronet, Aphids, Cabbage, Diamondback moth, Thrips

Durability performance of geopolymer ferrocement panels prepared by different alkaline activators

Ferrocement is a composite material consisting of a steel mesh bonded mortar used to form thin sections in numerous applications. Corrosion of ferrocement is more critical than the conventional reinforced concrete because of the small diameter of wire mesh and small concrete cover. This study aims to investigate the durability of fly ash-based geopolymer ferrocement composites. The accelerated corrosion test was conducted on ferrocement panel specimens with various affecting parameters. Series of ferrocement panel specimens were cast. The studied parameters included; type of steel wire mesh (welded, woven and expanded), thickness of panel specimens (20, 25 and 30 mm), number of mesh layers (1, 2 and 3 layers) and type of mortar mixtures. Four geopolymer (GP) mortar mixes were prepared with four different alkaline solutions. The alkaline solutions were a mixture of sodium silicate (NS), sodium hydroxide (NH), potassium silicate (KS) and potassium hydroxide (KH) as NS + NH, NS + KH, KS + NH and KS + KH. Parallel with the investigated GP mixture, a Portland cement mix was prepared. All mortar mixes were exposed to different aggressive environments including 5% sulphuric acid (H2SO4) and sodium sulphate for 24 weeks as well as water absorption test was conducted. Test results indicated that using a thicker steel mesh such as woven mesh, a thicker mortar cover and more than one layer in ferrocement panel specimens provides more resistance against reinforcement corrosion. The investigated GP mortar mixes provide a good passivation protection than cement mortar. Moreover, the fly ash-based GP mortar activated by NS showed passivation protection of steel wire mesh greater than the fly ash-based GP mortar activated by KS and showed a higher resistance to sodium sulphate and sulphuric acid exposure.

Fertilizers in the yield of chile habanero (Capsicum chínense) in Úrsulo Galván, Veracruz

Mexico is the country in the world with the greatest genetic variety of Capsicum: its richness is largely due to the diversity of climates and soils, which is why the commonly called “habanero” pepper is found throughout the peninsula. The objective of this project is to evaluate their adaptation to edaphoclimatic conditions different from those prevailing in their area of origin. As well as different mineral and organic fertilizers, which meet the nutritional needs in the cultivation of habanero pepper to obtain better yields and better profits for the producer. The experiment was carried out at the Tecnológico Nacional de Mexico Campus Úrsulo Galván. The experiment was carried out in a shade mesh cover, the experimental design was completely randomized with 5 treatments and 7 repetitions with a total of 35 experimental units. Therefore, it is expected that fertilizers and fertilizers have a greater significant response in the increase of the habanero pepper (Capsicum chínense Jacq) in Úrsulo Galván, Ver.

Use of direct seeding and seedling planting to restore Korean pine (Pinus koraiensis Sieb. Et Zucc.) in secondary forests of Northeast China

The poor natural regeneration of Korean pine represents a substantial hurdle limiting the restoration of secondary forests to mixed broad-leaved Korean pine forests (MBKPFs). Active restoration based on direct seeding or planting seedlings is accordingly considered to be a prerequisite for promoting Korean pine recruitment in secondary forests. To evaluate the most effective practices for restoring Korean pine in secondary forests, we studied the effects of microsites associated with gaps of different sizes and within-gap locations on direct seeding (rodent access/exclusion and soil/litter cover) and seedling planting (1-, 2-, and 3-year-old seedlings). We found that an average of 82.4% of sown seeds were eaten by rodents, with only 9.9% germinating and surviving after two growing seasons. Among the germinated seedlings, 37.6% were subsequently excised by rodents, whereas 6% died due to other natural causes. Furthermore, compared with the control sites (forest understorey), we detected no significant differences among the different microsites with respect to an effective reduction in rodent damage or promotion of seed germination, whereas rodent exclusion was more effective in protecting seeds from predation than the effect of microsite. With regards to planted seedlings, we found that the proportion of survival and relative root collar diameter growth were highest in the center (64.1%) and edge (60.0%) sites of large gaps, and that the survival of planted seedlings (43.7%) was considerably higher than that of seedlings derived from directly sown seeds (9.9%). Collectively, our findings indicate that, owing to seed predation and seedling excision by rodents, direct seeding with either mesh or soil cover would not represent an effective strategy for promoting Korean pine recruitment in secondary forests. Accordingly, for the purposes of restoring secondary forests to MBKPFs, we recommend planting 3-year-old Korean pine seedlings in large gaps within secondary forests.

Root growth and presence of Rhizophagus irregularis distinctly alter substrate hydraulic properties in a model system with Medicago truncatula

AimWe investigated how substrate hydraulic properties respond to the presence of arbuscular mycorrhizal fungi (AMF) in root-containing and root-free substrate zones in a Medicago truncatula-Rhizophagus irregularis model system.MethodsBefore planting, two compartments constructed from standard soil sampling cores (250 cm3) were implanted into non-mycorrhizal and mycorrhizal pots containing a sand-zeolite-soil mix. One compartment allowed root penetration (1 mm mesh cover) and the other only hyphal ingrowth (42 μm mesh cover). After eight weeks of growth under maintenance of moist conditions, the cores were subjected to water retention measurements. Additionally, we measured water retention of bare substrates before and after drying events to check for successful maintenance of moist conditions in pots.ResultsDrying of bare substrates decreased water retention, but planting at least sustained it. The parameters of water retention models responded linearly to root morphological traits across mycorrhizal and non-mycorrhizal substrates. Hyphae-only colonization comparatively affected the course of water retention in ways that suggest increased pore space heterogeneity while maintaining water storage capacity of substrates.ConclusionsHence, water contents corresponded to different substrate matric potentials in non-mycorrhizal and mycorrhizal pots. We conclude that changes to water retention in AMF colonized substrates can contribute to a widely observed phenomenon, i.e. that mycorrhizal plants differ in their moisture stress response from non-mycorrhizal plants.

Options for shorebird-exclusion devices for pitfall traps on sandy shores

Abstract ContextPitfall trapping is a standard technique for indexing surface active invertebrates on beaches, and underpins the study of sandy shore ecology. However, pitfall traps may pose a risk to the flightless young of beach-nesting birds, which may fall into such traps and potentially die. AimThe aim of the present study was to compare the invertebrates captured in standard pitfall traps with those captured in pitfall traps fitted with one of three potential shorebird exclusion devices. Ideally, the traps with exclusion devices would perform similarly to the standard traps (to enable inter-study comparability) and would detect ecological gradients, such as those evident in invertebrate assemblages between the beach and foredune. MethodsA systematic array was deployed, using 64 pitfall traps of four types: three types with bird-exclusion devices (a mesh cover, a fence around the rim and a low roof); and a standard pitfall trap with no exclusion device. Pitfall traps were stratified across two habitat types (upper beach and foredune) and were simultaneously deployed to control for environmental and other variables. ResultsEach trap type was broadly comparable in terms of the assemblage of invertebrates recorded, with two exceptions: (1) there was a slightly lower species diversity in mesh than in roofed traps; and (2) the assemblage captured differed between roofed and fenced traps, with the former trapping more isopods and amphipods. No trap type differed from control traps, and all differentiated an ecological gradient between beach and foredune. Thus, any trap design option we tested met our criteria. Conclusions and implicationsThe present study shows that bird-exclusion devices for pitfall traps need not compromise trap performance, comparability or utility.

New Approach for Codend Selectivity: a Case Study of Coastal Beach Seine for Big-Scale Sand Smelt (Atherina boyeri) Fishery in İznik Lake

Sand smelt (Atherina boyeri Risso, 1810), which is an exotic species with invasive character, is the third most caught species in the small-scale fisheries among the inland fisheries in Turkey. The fact that it has become an important source of income for the fishermen with low income due to its export potential has led to the maintenance of its stock recently. In this study, the selectivity of coastal beach seine used in the fishing of the species was investigated. A specially designed coastal beach seine with 10 m codend consisting of 4 different compartments was used in the study. Among the compartments of the codend, which was surrounded by a 6 mm mesh cover, in the codend panels mesh with 9, 12 and 14 mm were used. Field studies were carried out on a monthly basis in 4 different stations of İznik Lake in 2014. Selectivity data were collected by the covered codend method and analyzed by means of a logistic equation with the maximum likelihood method. A totally 3053 individuals were caught length ranged from 2.6-11.2 cm and weight ranged from 0.11-11.02 g. The mean L50 values of 14, 12- and 9-mm panels were determined as 6.71, 5.62 and 4.51 cm total length, respectively. It is concluded that 12 mm mesh size panel is suitable for sustainable A. boyeri fishery by beach seine net when considered given by length at first maturity size.

Experimental and Statistical Validation of Data on Mesh-Coupled Annular Distributor Design for Swirling Fluidized Beds

In this study, velocimetry and statistical analyses were conducted on a swirling fluidized bed. A bed of spherical particles (4 mm) was fluidized by using an annular distributor covered with mesh. The angles of rectangular blades in the distributor were set at 30°, 45°, 60°, 75° and 90°, and the cell size of the mesh cover was 2.5 × 2.5 mm2. The weight was varied from 500 to 1250 g and the effect of each variable on bed velocity response was quantified through velocimetry and statistical analysis. The statistical analysis was conducted using NCSS statistical software. The blade angle, bed weight and superficial velocity for 4 mm particles were statistically optimized at 750 g, 58.26° and 1.45 m/s, respectively. On the experimental side, these parameters have been optimized at 750 g, 60° and 1.41 m/s, respectively. A small difference of 1.74° was noticed in experimental and statistical predictions for the blade angle. The bed weights and superficial velocities were found to be same in both cases. The confidence interval (95%) for bed velocity was proposed in the range of 0.513 to 0.519 m/s. The experimentally optimized bed velocity remained within the proposed range. The well-agreeing results indicate good practical value of distributor design and high precision of the experimental measurements.

Effect of modified bandaging method on facial rejuvenation with small incision

Objective To observe the clinical effect of the modified bandaging method for facial rejuvenation with small incision and to explore its applicable scope. Methods From March to October 2019, 12 people in the outpatient department underwent small incision facial rejuvenation surgery and the improved bandaging method was used. Results After the small incision facial rejuvenation operation, the relaxation and drooping of the facial tissue in 12 patients were significantly improved without complications, and no cotton pad, bandage and elastic mesh cover were used for fixation. Conclusions This improved bandaging method does not affect daily work and life, and meets the needs of patients with this requirement, and plays a very good role in promoting the small incision facial rejuvenation surgery. Key words: Small incision; Facial rejuvenation surgery; Improvement; Bandage; Effect

Yield and quality of hybrid tomato grafted and cultivated under shade mesh and greenhouse

The objective was to determine the yield, fruit quality and root development of four grafted tomato hybrids grown under anti-aphid mesh cover and greenhouse. The grafted hybrids were grown under shade mesh and greenhouse from april to november 2014. Variables evaluated were: fruit weight per plant, number of clusters per plant, number of fruits per plant, polar and equatorial fruit diameter, vitamin C and lycopene contents, and root fresh and dry weight. Hybrids grafted and cultivated under anti-aphid mesh had higher quality than the production obtained under greenhouse. However, lycopene and vitamin C contents and accumulated root system dry matter are greater under greenhouse.

Management of Intersegmental Plane on Pulmonary Segmentectomy Concerning Postoperative Complications

For primary lung cancer, anatomic pulmonary segmentectomy may have a functional advantage over lobectomy; however, persistent air leak or delayed pneumothorax after segmentectomy is prevalent and increases surgical morbidity. To prevent pulmonary complications after pulmonary segmentectomy, we used 2 methods for the involved intersegmental plane: coverage using polyglycolic acid mesh and fibrin glue (mesh cover) or closing it by suturing the pleural edge (pleural suture). We aimed to compare postoperative pulmonary function and complications between the 2 groups. A total of 133 patients who underwent pulmonary segmentectomy for stage IA non-small cell lung cancer were analyzed retrospectively. A pulmonary function test, including vital capacity and forced expiratory volume in 1 second, was performed preoperatively and at 1 and 6 months postoperatively. Propensity score analysis generated 2 matched pairs of 46 patients in the pleural suture and mesh cover groups. In each group, there was no significant difference in the recovery rate of vital capacity and forced expiratory volume in 1 second at 1 and 6 months postoperatively. Compared with the pleural suture group, the mesh cover group had higher incidence of prolonged air leak (8.7% versus 0%; p= 0.042), delayed pneumothorax (10.9% versus 2.2%; p= 0.051). On logistic regression analysis, management of intersegmental plane by either mesh cover or pleural suture was the only independent factor related to pulmonary complications (prolonged air leak or delayed pneumothorax) after pulmonary segmentectomy (odds ratio: 5.26, p= 0.047; odds ratio: 13.39, p= 0.018, respectively). Pleural suturing of the involved intersegmental plane during pulmonary segmentectomy appeared to be an acceptable method to reduce postoperative pulmonary complications.

Analysis of body size selectivity of by-catch using the cover net method for a shrimp beam trawl

Selectivity and by-catch are the main features used to define fish catch for fisheries management or to determine fishing gear efficiency. A fish girth distribution analysis was carried out to determine the retention rate of juveniles discarded and to establish common selectivity for a multispecies catch. Total body length, body weight, and girth of juvenile fish retained in the cod-end and cover net separately were collected using an 18-mm mesh cover net during 12 fishing trials with a 41-mm cod-end beam trawl. The by-catch weight ratio in the cod-end was twice that of the by-catch ratio in number. The 50% selectivity of body length and 50% girth of redfin velvet fish were not significantly different between the cod-end and cover net, whereas those of other fish species were significantly different between the cod-end and cover net. The difference in 50% selectivity girth of other fish between the cod-end and cover net was similar between cod-end mesh size and cover net mesh size. Furthermore, the difference in 50% body length selectivity of other fish between the cod-end and cover net was almost double the difference in girth. Girth selectivity in a multispecies catch using towed fishing gear was effectively used to determine fish and net mesh size.

Simultaneous multiselective spectroelectrochemical fiber-optic sensor: demonstration of the concept using methylene blue and ferrocyanide.

Herein, we present a novel spectroelectrochemical fiber-optic sensor that combines electrochemistry, spectroscopy, and electrostatic adsorption in three modes of selectivity. The proposed sensor is simple and consists of a gold mesh cover on a multimode fiber optic that uses attenuated total reflection as the optical detection mode. The sensing is based on changes in the attenuation of the light that passes through the fiber-optic core accompanying the electrochemical oxidation-reduction of an analyte at the electrode. Methylene blue and ferrocyanide were used as model analytes to evaluate the performance of the proposed sensor. The optical transmission changes generated by electrochemical manipulation showed a good linear relationship with the concentration and the limits of detection (3σ) for methylene blue and ferrocyanide at 2.0 × 10(-7) and 1.6 × 10(-3) M, respectively. The sensor responses were successfully enhanced with an additional level of selectivity via an electrostatically adsorbed, self-assembled monolayer (SAM), which consisted of a silane coupling layer, a polyanion, and a polycation. The improvement observed in the sensitivity of a SAM-modified fiber-optic sensor was rather encouraging. The optimized sensor had detection limits (3σ) of 8.3 × 10(-9) M for methylene blue and 7.1 × 10(-4) M for ferrocyanide. The developed sensor was successfully applied to the detection of ferrocyanide in simulated nuclear waste.

Математическая модель расчета геометрических параметров деревянных сетчатых сводов с ортогональной сеткой

Mesh cover design, a multi-element design, which ensures the correct geometrical arrangement of the elements, is a very important task. The purpose of the given article is the development of a mathematical model for selecting the geometric parameters of wooden arches with mesh orthogonal grid with different input data. In this article three variants of design were observed. The main differences between them are in the relative position of longitudinal and transverse components. When performing static calculations of such designs in order to achieve their subsequent correct assembly, the following location conditions were observed: all the items must strictly match with each other without a gap and without overlap. However, these conditions must be met for any ratio of height to the arch span, the number of longitudinal members and the thickness of longitudinal members. Inverse problems also take place. In this case, the geometric calculation is not possible to vary the cross-section elements, and the stress-strain state of the cover is provided by varying the pitch of the transverse arches of the elements, on which the geometric calculation has no influence. All this determines the need for universal mathematical models describing any geometrical parameter of the designs needed for their geometrical calculation. The basic approach for the development of such models is the use of the known trigonometric formulas, giving a complete description of the desired geometry of the arch. Finally three transcendental equations were obtained, the solution algorithm of which using Newton’s method is presented in the MathCAD. The complexity of solving such equations using the proposed algorithm in the MathCAD is reduced to a minimum.

Increase of cutting tool wear resistance by mesh cover coating

The article proposes the technology to increase the tool life by applying ecological technological environment. The results of studies show the effect of green technological environment on wear resistance of the cutting tool.

Increase of cutting tool wear resistance by diffusion mesh cover coating

This article discusses the influence of physical and mechanical properties during processing on the surface layer of the part. The study shows wear resistance of the cutting tool with diffusion mesh coating.