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Ivorian cashew (Anacardium occidentale L.) orchards are essentially comprised of unselected trees of diverse origins and characterized by a very low yield per hectare. In these orchards, potentially high-yielding trees have been identified. Vegetative propagation remains the most appropriate technique for the regeneration of these trees. Air layering is the regeneration technique used for a number of wood species that are difficult to root through clonal propagation. The objective of this study was to set up a regeneration protocol using the layering technique. Specifically, we evaluated the effect of the substrates, diameter class, and indole butyric acid concentration on the rooting percentage and survival of hardened plants. For this purpose, two diameter classes 5-8 mm and 8-12 mm, four substrates (sawdust, rice chip, coco peat, and coffee integument), two concentrations of indole butyric acid (2.5 and 5 mg/L) and one control (no indole butyric acid solution). were tested. Rooting percentages of 88.09, 79.36, and 61.90 were obtained with sawdust, rice chip, and coco peat respectively. No roots were observed on the coffee integument. Diameter class 8-12 mm promoted the most significant percentage of survival (89.41%) and rooting (85.18%). The concentration of 5 mg/L favored the induction of the greatest number of roots (30.79). The specific percentage of possible survival in the field of the weaned layer was above 80%. Branches with 8-12 mm diameter treated with indole butyric acid 5 mg/L in sawdust induced was the optimum treatment combination for cashew nut layering propagation in Cote d'Ivoire. [ABSTRACT FROM AUTHOR]

The evaluation of guava genotypes (Psidium guajava L.) for air layering under sub-humid conditions in the southern plains of Rajasthan was conducted from 5th to 15th July 2015-16. The genotypes were used: L-49, Allahabad Safeda, Lalit, Red Fleshed, Pant Prabhat, Safed Jam, Arka Amulya, Arka Mridula, MPUAT S-l, MPUAT S-2, Shweta, Burfkhan, Sarbati, RCGH-1, and One-Kg. Among genotypes, Lalit exhibited highest early root initiation, percentage of rooted air layers, survival percentage, and vigor index. The number of secondary roots was highest in L-49, and root-to-shoot ratio was highest in Shweta. One-Kg showed a poor response to rooting. [ABSTRACT FROM AUTHOR]

Ximenia americana, Vitex doniana and Lophira lanceolata are species prized by the populations of the Guinean savannah highlands of Cameroon. They are unfortunately still in the wild where they are subjected to various pressures. From the perspective of the conservation and enhancement of local biodiversity, their domestication appears necessary. The objective of the work is to study the vegetative propagation by air layering of these fruit trees. The experimental device used is a split-split-plot with three repetitions. Species represents the main treatment; the substrates constitute the secondary treatment while the covering of the layers wit h aluminum foil represents the tertiary treatment. The experimental unit was 30 layers. The rooting rate of layers varies significantly (0.000<0.001) from 48.88±1.89% in Ximenia americana to 81.38±2.08% in Lophira lanceolata. Sphagnum was the best substrate with 69.63±1.38% against 61.66±1.54% for the black soil-sawdust mixture. The analysis of variance reveals a significant difference for the substrates (0.0025<0.01). Covering the layers with aluminum foil presented a rate of 69.44±2.15% while the uncovered layers presented 61.85±1.54%, the analysis of variance shows a significant difference (0,0031<0.01). Lophira lanceolata exhibited the best air layering ability; the rooted layers were weaned and acclimatized for two months before being transferred to the field. During this process 19% and 52% respectively of the layers of Vitex doniana and Ximenia americana flowered. This inexpensive technique is an essential step in the process of their domestication. [ABSTRACT FROM AUTHOR]

The glasshouse renovation works being undertaken at the Royal Botanic Garden Edinburgh (RBGE) as part of the Edinburgh Biomes Project (2020–2027) pose a number of challenges to the horticulturists managing the plant collections. The grandeur of many of the larger specimens and the limit of available space are the most prominent of these. Air layering is a propagation method that until recently has not been used widely at RBGE. It has however proven to be a successful technique to maintain the genetic diversity of the collection while reducing both the need for space in propagation glasshouses and the level of aftercare required once propagation is complete. This Short Note explains the method used and highlights several successful propagations, illustrated with images, along with suggestions for implementing the method in the future.

Abstract The objective of this work was to evaluate air layering, cutting, and grafting, with different indolebutyric acid (IBA) rates, for the vegetative propagation of Eugenia involucrata. Air layering was carried out for two consecutive years with five different IBA rates. Cutting was tested for woody and herbaceous cuttings, using four IBA rates, in three seasons. The grafting methods – cleft graft and splice graft – were tested in two seasons. For the air layering, cutting, and grafting trials the experimental designs were randomized complete blocks, completely randomized in a 3x4 factorial arrangement, and completely randomized, respectively. Plants were evaluated for rooting, survival percentage, and shoot development. In air layering, low rooting rates of 0 to 50% were observed, the use of IBA showed no consistent results, and no resulting propagules survived after being transplanted. The cutting technique showed low survival, rooting, and leaf retention rates, with no consistent effect of IBA rates. Grafting showed 35 to 50% graft fixation, with no significant difference between the splice and cleft grafting techniques. The air layering and cutting techniques are not efficient for the propagation of E. involucrata, as they do not favor the survival and rooting of seedlings. Grafting, by both techniques, is the most efficient method for E. involucrata propagation.

Copyright of Revista Chapingo Serie Ciencias Forestales is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Elaeocarpus ganitrus Roxb. commonly identified as 'rudraksha', belonging to Elaeocarpaceae possess a great religious, spiritual and materialistic significance which is placed under the threatened category in the tropical wet evergreen forests of North East India. Because of its over-exploitation, poor germination, low viability rate and hard seed coat, an attempt has been done for mass production of planting materials through cuttings and air layering's. Cuttings trials were conducted during three different periods, mid - March, mid - July and mid - November by using Indol butyric acid and Napthalene acetic acid of 1000, 2000, 4000, 6000 ppm where air layering's were done during mid - May by treating IBA and NAA solution of 500, 1000 and 2000 ppm in combination with para-hydroxybenzoic acid of 2000 ppm as synergist. Application of IBA and NAA of different concentration did not encourage the growth in the cuttings in all three periods. Air layering's treated with NAA 1000 ppm+2000ppm para-hydroxy benzoic acid and IBA 500 ppm +2000ppm parahydroxy benzoic acid resulted the highest and same value of callusing and rooting percent (70 and 66.67%), respectively while minimum callusing and rooting percentage (56.67 and 51.67%) was recorded in control. The present study focused on the mass production of planting materials in shorter duration with a reasonable cost for enhancing production as well as socio-economic conditions. [ABSTRACT FROM AUTHOR]

Elaeocarpus ganitrus Roxb. commonly identified as ‘rudraksha’, belonging to Elaeocarpaceae possess a great religious, spiritual and materialistic significance which is placed under the threatened category in the tropical wet evergreen forests of North East India. Because of its over-exploitation, poor germination, low viability rate and hard seed coat, an attempt has been done for mass production of planting materials through cuttings and air layering’s. Cuttings trials were conducted during three different periods, mid - March, mid – July and mid – November by using Indol butyric acid and Napthalene acetic acid of 1000, 2000, 4000, 6000 ppm where air layering’s were done during mid - May by treating IBA and NAA solution of 500, 1000 and 2000 ppm in combination with para-hydroxybenzoic acid of 2000 ppm as synergist. Application of IBA and NAA of different concentration did not encourage the growth in the cuttings in all three periods. Air layering’s treated with NAA 1000 ppm+2000ppm para- hydroxy benzoic acid and IBA 500 ppm +2000ppm para- hydroxy benzoic acid resulted the highest and same value of callusing and rooting percent (70 and 66.67%), respectively while minimum callusing and rooting percentage (56.67 and 51.67%) was recorded in control. The present study focused on the mass production of planting materials in shorter duration with a reasonable cost for enhancing production as well as socio-economic conditions.

Mulberry (Moraceae) is the type of seed plant grown in the deciduous trees and cultivated in numerous temperate regions. Air layering is the technique of plant propagation through cutting; wounding and layering are often performed. This study was conducted with the investigation of air layering survival growth of roots and other plant growth parameters in mulberry plant by using three different types of composts. Vermicompost is a nutritious natural fertilizer with plant obtainable form of macro and micronutrients, beneficial to soil microbes, nitrogen-fixing and plant growth regulators. Therefore, present experiment was undertaken in the Department of Zoology, Kongunadu Arts and Science, (Coimbatore) during the year 2019-2020. The healthy mulberry plants were chosen for practices of air layering by using three different types of vermicomposts i.e. Elephant Dung (100% ED), Cow Dung (100% CD), Elephant Dung + Cow Dung (50% ED + 50% CD) and soil were used as control in triplicates. Best results were achieved with elephant dung vermicompost recorded significantly higher values for rooted air layer length, number of primary roots and secondary roots, root shoot ratio, number of fruits and number of leaves. Hence the shoot length and Shoot weight greater in vermicompost of cow dung, but growth of the plants were recorded significantly higher in plants which treated with all vermicompost, when compared to that of control. [ABSTRACT FROM AUTHOR]

The population of Andaman padauk (Pterocarpus dalbergioides Roxb.), an endemic ornamental timber species, is fast depleting in the Andaman Islands. Afforestation through seedlings is hindered by low germination and high mortality rates. This study attempts to assess the efficacy of clonal propagation methods to hasten mass multiplication by trying out different combinations of growth hormones, concentration, and dipping duration in semi-hardwood stem cuttings and different combinations of growth hormone concentration and substrate in air layering. Dipping the cuttings in indole-3-butyric acid (IBA) 1,500 ppm for 24 hours and spraying the modified stem-cut layers with IBA 2,000 ppm and binding with top soil and decomposed coir dust turned out to be the best treatment combination for cutting and air layering, respectively. Among the considered factors, the concentration of growth hormone is crucial for cutting, as the performance is enhanced with concentration under a given growth hormone and dipping duration. Similarly, the substrate is crucial for air layering, as modified stem-cut air layers bound with top soil and decomposed coir dust not only achieve the best performance, but also catalyze IBA for further improvement when other substrates remain unresponsive. Successful outcome of both clonal propagation techniques gives hope for disseminating the species across the tropics at global level. [ABSTRACT FROM AUTHOR]

Brosimum alicastrum is a tree species in Mexico with wide potential for animal and human food, which is distributed naturally with no silvicultural management, so there is little information on the propagation methods of the species. The objective of this work was to analyze the scientific research published on B. alicastrum, through literature review to know the techniques that exist on its propagation. In addition, the quality of the seedling obtained by sexual propagation and asexual methods (cuttings, layers and grafts) was evaluated in the nursery, by means of experimental designs. 550 scientific articles on B. alicastrum were found, the disciplines where they were published were: Ecology (44.18%), Botany (13.27%), Forest Sciences (11.27%, of which 2.54% worked propagation in the nursery), Zoology (11.09%), Agriculture (9.64%), Anthropology (5.45%) and others (5.10%). Regarding the seed propagation method, the best seedling quality was associated with low porosity substrates (bush soil) and containers with large diameters (36 cm). In the case of asexual propagation, with the layering method when peat was used as the substrate 90% survival was obtained, and by lateral grafting technique 75% yield was found. Due to the little research that exists on the propagation of the species, it is recommended that the selection of the propagation technique is based on the purpose of the seedling; if it is required to shorten the seed production cycles of B. alicastrum the asexual techniques grafting and layering can be more efficient. [ABSTRACT FROM AUTHOR]

Tree peony (Paeonia suffruticosa Andr.), a unique traditional flower in China, is famous for its ornamental value, medical use, and edible oil production. Traditional propagation methods, such as sowing, dividing, and grafting do not allow the large-scale production of selected peony varieties. Therefore, the objective of our study is to evaluate an air-layering technique on the rooting success of three tree peony cultivars (‘Baoqing Hong’, ‘Quehao’, and ‘Xishi’). The experiments were established through consideration of the influence of the time of the year the rooting was performed (mid-May, mid-June, or mid-July) and the growth regulators (1-naphthaleneacetic acid-NAA and indole-3-butyric acid-IBA) applied at different concentrations (1000 mg/L, 1500 mg/L, 2000 mg/L). The results showed that the rooting rate was the highest when the air-layering time occurred in mid-June, and the rooting rate of ‘Quehao’ was found to be the most significant, reaching 100%. The rooting percentages of 82.86% and 77.14% were obtained for ‘Baoqing Hong’ and ‘Xishi’, respectively. The growth regulators affected the rooting performance of the three cultivars differently. The rooting parameters of ‘Quehao’ were negatively correlated with the concentration of NAA but positively correlated with IBA, whereas the ‘Baoqing Hong’ and ‘Xishi’ cultivars showed no dose dependence for the supplied growth regulators. Root number, root tip number, and maximum root length in ‘Quehao’ were higher than those of the other two cultivars. The conclusion of our study is that the air-layering technique is a suitable method for achieving satisfactory propagation of selected tree peony cultivars.

Long‐range aerosol transport is an important physical mechanism for ecological, biological, and hydrological elements of the earth system. Regarding the latter, regional climate models have no way of assimilating future aerosol concentrations, so dust aerosol emissions must be parameterized using local landscape and meteorological conditions. The purpose of this study is to evaluate the accuracy of different dust emission settings within the Weather Research and Forecasting model coupled with chemistry (WRF‐Chem) to facilitate future dynamical downscaling work. This study performs nine WRF‐Chem hindcasts, each utilizing a different dust emission configuration, from 1 March to 31 May 2015, coinciding with a Saharan air layer (SAL) dust outbreak during the 2015 Caribbean drought. WRF‐Chem aerosol optical depth (AOD) and Gálvez‐Davison Index (GDI), a convective forecasting parameter, are validated against analogous MODIS, AERONET, and ERA5 products. In aggregate, the GOCART dust emission scheme with Air Force Weather Agency modifications (GOCART‐AFWA) achieved the best balance between AOD and GDI accuracy when employing the default tuning constant (1.00). As the schemes emitted dust more aggressively, WRF‐Chem produced warming at 500 hPa, reducing GDI over the central and eastern Atlantic near the modeled dust trajectory. Though AOD was generally too low over the southwest Atlantic, the eastern Caribbean occupies a transition zone between negative and positive AOD biases where this field was hindcast with relative accuracy. Meanwhile, areas with positive AOD biases were associated with negative GDI biases (and vice versa) indicating the covariability between SAL dust loadings and thermodynamic conditions in the tropical north Atlantic. Plain Language Summary: Hot, dry, and dusty air from the Sahara can be blown across the Atlantic, impacting locations far to the west. Recently, these intrusions of Saharan dust have been associated with drought in the Caribbean. A dust‐enabled weather model is used to identify effective physical parameterizations for reproducing a well‐documented Saharan dust event in April‐May 2015. The simulations showed that the weather model can capture the magnitude and cadence, though not necessarily the timing, of the dust pulses. Additionally, areas where the model struggled to accurately represent dust concentrations also experienced higher biases of temperature‐ and moisture‐related variables, further illustrating the link between Saharan dust and precipitation processes. Key Points: Dust concentration biases within a regional weather model are associated with thermodynamic biasesDust concentrations are over‐represented in the eastern tropical north Atlantic and under‐represented in the CaribbeanAreas with high (low) dust bias also under‐ (over‐) represented convective thermodynamic potential [ABSTRACT FROM AUTHOR]

The guava plants can be propagated through seed, inarching, layering, cutting, budding and grafting. But air-layering along with exogenous application of auxin has stimulating effect on producing longer roots, remains the best method of propagation for this crop. Growth regulator like IBA has been used to stimulate plant growth and specially root formation with better vigour in layering. The effects of auxins however are significantly influenced by environmental conditions, time and rooting media used. Therefore, this research was mainly conducted to find out the effects of various IBA concentration, time and rooting media on response and performance of rooting in air layering of Guava. In general, growth regulators viz., IBA alone and in combination with rooting media viz., Moss grass, Coco peat, and Moss grass + Coco peat is used in different time of layering viz., June, July favoured rooting in air-layers. It is being revealed that High percentage of rooting and root characters of air layers of guava can be successfully achieved by exogenous application of IBA in June and July. [ABSTRACT FROM AUTHOR]

Due to over exploitation, the population of Eusideroxylon zwageri is decreasing drastically. One simple technique to conserve the last remaining genetic resources of E. zwageri is by air layering. The experiment was divided into two. The experiment was conducted from July 2018 to February 2019. The first experiment was conducted using branches that grew from coppices while the second experiment using twigs that grew from normal adult trees. Randomized Block Design was applied with three replicates. The treatments were consisted of nine concentration of auxin namely 0 ppm of auxin; 1, 000 ppm; 1,500 ppm; 2,000 ppm and 2,500 ppm of IAA and 1,000 ppm; 2,000 ppm; 3,000 ppm and 4,000 ppm of IBA. The result of experiment shows that the IBA growth regulator seems to be more effective in regulating growth and rooting of E. zwageri air layering compared to IAA. Results for air layering which was taken from coppices revealed that 1,000 ppm of IBA obtained the best results. Air layering of branches taken from coppice is possible even without any additional growth regulator. While, air layering of twigs which was taken from normal trees revealed that the best treatment is 3,000 ppm of IBA.

Copyright of Brazilian Journal of Applied Technology for Agricultural Science / Revista Brasileira de Tecnologia Aplicada nas Ciências Agrárias is the property of Brazilian Journal of Applied Technology for Agricultural Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This research was conducted in the College of Agricultural Sciences Engineering, University of Sulaimani, Kurdistan region/Iraq, to study the possibility of propagation of pistachio Pistacia vera cv. Batoury by air layering through treating the girdling wounds with IBA, and spray of layered shoots with IBA and GA3. The experiment was laid out by RCBD design with three replications on six trees. 20000 ppm IBA applied to the girdling wounds of layered shoots gave values of rooting percentage (63%), root number (4.6), root length (5.7 cm) and survival percentage (80%), while control gave no rooting. The rooting percentage of (33.4%) was achieved from layered shoots without spray and from those sprayed by 25 and 50 ppm IBA. A survival percentage of (50%) was achieved from layered shoots sprayed by 25, 50 ppm IBA and 30 ppm GA3. Interaction of 20000 ppm IBA treatment of girdling wound with 25 and 50 ppm IBA spray of layered shoots and without spray gave (70%) rooting percentage. 20000 ppm IBA treatment of girdling wound with spray of layered shoots by 25, 50 ppm IBA and 30 ppm GA3 showed the highest (100%) survival percentage. [ABSTRACT FROM AUTHOR]

Nutmeg is an important perennial spice crop, which is dioecious in nature. Vegetative propagation is the norm in commercial propagation of the tree. The existing practice of propagation is grafting and budding which needs good skill and expertise for reasonable success. As an alternative to these two methods, air layering was attempted in matured trees for the first time in the country. Air layering was successful in plagiotropic and orthotropic shoots with 100 per cent survival. This method is cost effective and is easy for adoption. [ABSTRACT FROM AUTHOR]

Abstract The different propagation systems for litchis are reviewed. After examining the main morphological and developmental characteristics of the plant and the description of the structures and materials, including types of substrate required for the propagation of this species, the different methods for its propagation are discussed. Propagation by seeds is only used for breeding or research purposes or for raising rootstock for grafting. Although propagation by cuttings is done in many countries and stooling has been reported as highly successful in India, air layering is the most common commercial way of propagation for this species. Despite that the cambium activity varies from place to place around the stem with only 30% of the cambium being active at any one time grafting is of current use in China.

The current experiment was conducted to study the response of Ficus elastica var. decora air-layers to seven treatments of IBA (control, 50 and 100 ppm in rooting substrate, 1500 and 3000 ppm by painting girdled zone, and 1500 and 3000 ppm in talc paste) in the presence of root promoting microorganisms including Bacillus subtilis and arbuscular mycorrhizal fungi (AMF). The obtained results indicated that 3000 ppm IBA applied by painting girdled zone gave a significant increase in rooting percentage and the best root and growth characteristics (number of days for root appearance, number, length, fresh and dry weights of roots per rooted air-layer, survival percentage, plant height and number of leaves and shoots) as well as total content of carbohydrates and phenolics, and showed the shortest period required for root appearance in comparison with the other treatments. Air-layers treated with B. subtilis were superior to those treated with AMF. The best results concerning rooting percentage, root characteristics, total contents of carbohydrates and phenolics, survival percentage, increment in growth of air-layers after six months from detachment were observed in airlayers treated with 3000 ppm IBA by painting girdled zone in combination with B. subtilis followed by the same IBA treatment combined with AMF. [ABSTRACT FROM AUTHOR]

This study was conducted to define the best auxin application method with or without the inoculation with beneficial microorganism (Bacillus subtilis and arbuscular mycorrhizal fungi "AMF") to improve rooting characteristics of F. benjamina air-layers. The treatments were arranged in a split-plot design. Seven combined treatments of auxin concentrations and application methods (control, 50 and 100 ppm IBA in rooting substrate, 1500 and 3000 ppm IBA by painting girdled zone, 1500 and 3000 ppm IBA in talc paste) were assigned to the main plots. The sub-plots comprehended the application of B. subtilis and arbuscular mycorrhizal fungi in addition to the control. Data recorded on air-layers performance exhibited significant variation among different application methods and concentrations of IBA compared with the control with clear superiority of applying IBA at 3000 ppm by painting girdled zone in enhancing rooting%, number, length, fresh and dry weights of roots per rooted air-layer, as well as total contents of both carbohydrates and phenolics, and showed the shortest period required for root appearance. Similar trend was noticed regarding survival percentage, increment in plant height and number of leaves and shoots after detaching air-layers from mother plants. All root and growth characteristics showed significant increment when air-layers were treated with B. subtilis or AMF compared to the control with clear superiority of B. subtilis. The combined treatment of IBA at 3000 ppm by painting girdled zone and B. subtilis recorded the highest rooting (100%) and survival percentages (100%) and the best root and growth characteristics. This treatment could be recommended for propagation of Ficus benjamina by air layering. [ABSTRACT FROM AUTHOR]

In the boreal forest of eastern North America, the distribution of eastern white cedar (Thuja occidentalis) is characterized by a latitudinal fragmentation gradient from south to north. Marginal populations could be outposts allowing cedar to expand its presence in the north in response to climate change. This study aimed to characterize the spatio-temporal regeneration dynamics of 20 marginal cedar stands in order to evaluate their expansion capacity into adjacent black spruce stands. Cedar recruitment within marginal cedar stands was mainly by layering, which allowed the species to maintain for a long time in the landscape. However, the rate of expansion of marginal stands into adjacent black spruce stands through seed dispersal was very low (0.28 m.year−1) and it was negatively influenced by distance to seed trees. Substrate had no significant effect. Global warming could lead to increased seed production by cedar, which could favour the species' expansion at its northern distribution limit. However, global warming could also increase the frequency and severity of wildfires, which would have a negative effect on cedar expansion capacity. [ABSTRACT FROM AUTHOR]

The Saharan Air Layer (SAL) in the summertime eastern Atlantic is typically well mixed and 3–4 km deep, overlying the marine boundary layer (MBL). In this paper, we show experimental evidence that at times a very different structure can be observed. During the AERosol properties – Dust (AER-D) airborne campaign in August 2015, the typical structure described above was observed most of the time, and was associated with a moderate dust content yielding an aerosol optical depth (AOD) of 0.3–0.4 at 355 nm. In an intense event, however, an unprecedented vertical structure was observed close to the eastern boundary of the basin, displaying an uneven vertical distribution and a very large AOD (1.5–2), with most of the dust in a much lower level than usual (0.3–2 km). Estimated dust concentrations and column loadings for all flights during the campaign spanned 300–5500 and 0.8–7.5 g m -2 , respectively. The shortwave direct radiative impact of the intense dust event has been evaluated to be as large as -260±30 and -120±15 W m -2 at the surface and top of atmosphere (TOA), respectively. We also report the correlation of this event with anomalous lightning activity in the Canary Islands. In all cases, our measurements detected a broad distribution of aerosol sizes, ranging from ∼0.1 to ∼80 µ m (diameter), thus highlighting the presence of giant particles. Giant dust particles were also found in the MBL. We note that most aerosol models may miss the giant particles due to the fact that they use size bins up to 10–25 µ m. The unusual vertical structure and the giant particles may have implications for dust transport over the Atlantic during intense events and may affect the estimate of dust deposited to the ocean. We believe that future campaigns could focus more on events with high aerosol load and that instrumentation capable of detecting giant particles will be key to dust observations in this part of the world. [ABSTRACT FROM AUTHOR]

We report an experimental investigation of the wake of free falling super-hydrophobic spheres. The mutual interaction between the air layer (plastron) encapsulating the super-hydrophobic spheres and the flow is emphasised by studying the performance. It is found that the air plastron adapts its shape to the flow-induced stresses which compete with the surface tension. This competition is characterised by introducing the Weber number We, whilst the plastron deformation is estimated via the aspect ratio χ. While noticeable distortions are locally observed, the plastron becomes more and more spherical on average (i.e.χ → 1) as far as We increases. The study of the falling motion reveals that the plastron compliance has a sizeable influence on the wake development. Investigating the lift force experienced by the super-hydrophobic spheres, the onset of wake instabilities is found to be triggered earlier than for smooth spheres used as reference. Surprisingly, it is also observed that the early promotion of the wake instabilities is even more pronounced beyond a critical Weber number, Wec, which corresponds to a critical aspect ratio χc. Furthermore, the magnitude of the hydrodynamic loads is found to be dependent on the average deformation of the gas/liquid interface. Indeed, in comparison to the reference spheres, the high deformation achieved for χ > χc (oblate shape) leads to lift and drag increase, whereas the low deformation obtained for χ < χc(spherical shape) yields lift and drag mitigation. Accordingly, taking into account the plastron deformation provides an attractive way to explain the somehow discordant results reported in other studies at comparable Reynolds numbers. These results suggest that the amount of vorticity produced at the body surface and then released in the wake is strongly impacted by the plastron compliance. If confirmed by additional studies and extrapolated to other flow configurations, our findings would imply that plastron compliance and its feedback on the flow, which are currently neglected in most theoretical works and numerical simulations, must be accounted for to design super-hydrophobic surfaces and/or predict their performance. [ABSTRACT FROM AUTHOR]

A hierarchy of models is formulated for the deflection of a thin two-dimensional liquid jet as it passes over a thin air-cushioning layer above a rigid flat impermeable substrate. We perform a systematic derivation of the leading-order equations of motion for the jet in the distinguished limit in which the air pressure jump, surface tension and gravity affect the displacement of the centreline of the jet, but not its thickness or velocity. We identify thereby the axial length scales for centreline deflection in regimes in which the air layer is dominated by viscous or inertial effects. The derived length scales and reduced equations aim to expand the suite of tools available for future analyses of the evolution of lamellae and ejecta in impact problems. Assuming that the jet is sufficiently long that tip and entry effects can be neglected, we demonstrate that the centreline of a constant-thickness jet moving with constant axial speed is destabilised by the air layer for sufficiently small surface tension. Expressions for the fastest-growing modes are obtained in both the viscous-dominated air and inertiadominated air regimes. For a finite-length jet emanating from a nozzle, we show that, in one particular asymptotic limit, the evolution of the jet centreline is akin to the flapping of an unfurling flag above a thin air layer. We discuss the distinguished limit in which tip retraction can be neglected and perform numerical investigations into the resulting model. We show that the cushioning layer causes the jet centreline to bend, leading to rupture of the air layer. We discuss how our toolbox of models can be adapted and utilised in the context of recent experimental and numerical studies of splash dynamics. [ABSTRACT FROM AUTHOR]

During the 2012 deployment of the NASA Hurricane and Severe Storm Sentinel (HS3) field campaign, several flights were dedicated to investigating Hurricane Nadine. Hurricane Nadine developed in close proximity to the dust-laden Saharan air layer and is the fourth-longest-lived Atlantic hurricane on record, experiencing two strengthening and weakening periods during its 22-day total life cycle as a tropical cyclone. In this study, the NASA GEOS-5 atmospheric general circulation model and data assimilation system was used to simulate the impacts of dust during the first intensification and weakening phases of Hurricane Nadine using a series of GEOS-5 forecasts initialized during Nadine's intensification phase (12 September 2012). The forecasts explore a hierarchy of aerosol interactions within the model: no aerosol interaction, aerosol--radiation interactions, and aerosol--radiation and aerosol--cloud interactions simultaneously, as well as variations in assumed dust optical properties. When only aerosol--radiation interactions are included, Nadine's track exhibits sensitivity to dust shortwave absorption, as a more absorbing dust introduces a shortwave temperature perturbation that impacts Nadine's structure and steering flow, leading to a northward track divergence after 5 days of simulation time. When aerosol--cloud interactions are added, the track exhibits little sensitivity to dust optical properties. This result is attributed to enhanced longwave atmospheric cooling from clouds that counters shortwave atmospheric warming by dust surrounding Nadine, suggesting that aerosol--cloud interactions are a more significant influence on Nadine's track than aerosol--radiation interactions. These findings demonstrate that tropical systems, specifically their track, can be impacted by dust interaction with the atmosphere. [ABSTRACT FROM AUTHOR]

The effect of timing intervals on the rooting response and performance of olive cultivars through Air-Layerage was determined at Olive Model Farm, Sangbhatti Mardan-Pakistan during the year 2014. The experiment was laid out according to Randomized Complete Block Design with two factors factorial arrangement. Air layerings were practiced on July 1, 16, 31; August 15, 30 and September 14 in plants of olive cultivars Frontoio, Manzanilla, Ottobratica, Pendolino and Picual. Significant variations were recorded among olive cultivars regarding asexual propagation through air-layerage. The daughter saplings of cultivar Manzanilla took less number of days (47.94) to root appearance, produced more rooting percentage (38.89%), number of roots (4.31), root length (4.61 cm) and root weight (1.77g) with more number of re-sprouts (3.18) and shoot length (5.28 cm). The time intervals of air layering also significantly influenced the rooting and growth attributes of olive cultivars. Mid August, proved to be the most favorable time for air-layering in terms of rooting percentage (42.40%), number of root (4.37), root length (4.35 cm), weight (1.68 g), number of re-sprout (3.67) and shoot length (5.61 cm) while late (September 14) and early (July 1) layering responded poorly to all the studied attributes. The response of individual cultivar was dissimilar to different times of layering. Cultivars: Frontoio, Manzanilla and Pendolino took minimum days to root appearance, attained high rooting percentage, produced maximum number of roots, root length and root weight with more number of lengthy re-sprouts, when air-layered during mid August while Ottobratica and Picual, layered during mid and late July respectively, responded well to all these attributed. [ABSTRACT FROM AUTHOR]

The needs to reduce the frictional component of the resistance of a ship leads researchers to find new solutions. The air cavity solution seems to be one of the most promising one. Usually, it is very difficult with the experimental tests to understand the air distribution under the hull and the streamlines during the injection of air. The principal objective of this paper is evaluating the potentiality of the CFD approach in the study of Air Cavity Ships (ACS) for a planing yacht. The first part of paper describes the CFD evaluation of the resistance curves without air-injection. The second part deals with the injection of the air under the hull. In this case the boundary conditions are the results of the first campaign of simulations. A comparison between the experimental and CFD results is shown. An assessment of the streamlines and air distribution is proposed and an evaluation of the wetted and ventilated areas is conducted in order to understand the relation between the flow rate, the velocity of the hull and the air distribution. The results can be used for modifying the hull geometry in order to better accommodate the air layer. [ABSTRACT FROM AUTHOR]

The present investigation was undertaken to study the effect of different concentrations of Indole 3-butyric acid (0, 2000, 4000, 8000 and 10000 ppm), different types of rooting media (i.e. sphagnum moss, coco peat, vermicompost, sphagnum moss + coco peat and sphagnum moss + coco peat + vermicompost) and the interaction of these in different combinations on rooting and growth characteristic of guava, cv. L-49. The results revealed that the exogenous application of Indole 3-butyric acid (IBA) 8000 ppm with media combination of sphagnum moss + coco peat + vermicompost (I3M5) significantly increased the root characters i.e. success percent of air-layers (83.3%), callus formation (23.7), number of primary roots (24.21) and secondary roots (32.57); and growth characters i.e. number of leaves (48.17), branches (7.92) and sprouts (8.48) and survival percentages (83.18) over the other treatments and control. Among the rooting media, the combination of sphagnum moss + coco peat + vermicompost (M5) produced the highest rooting percentage (71.27), root characters and growth characters during months of July and August. [ABSTRACT FROM AUTHOR]

This paper aims to make clear the effects of two important parameters, namely thickness of soil layer and leaf area index of plant layer, on green roof energy and thermal performance. Based on a coupled hygrothermal transfer model validated by field experiments in Shanghai area, energy balance of plant and soil layer is analyzed. Then 18 cases are simulated for different combinations of soil thickness and leaf area index, the results show that soil thickness has a significant effect on long term thermal performance of green roof in both summer and winter, while the effect of leaf area index is only great in summer. Compared with the hypothetical case without evaporation and transpiration, it is found that evaporation of soil layer makes a greater contribution in summer but a less one in winter compared with insulation effect of soil layer. For plant layer, shading is the main cooling way of roof deck while transpiration plays a minor role. Finally, based on the simulation results of long-term thermal performance, two new indexes are proposed to evaluate the relative thermal characteristic of green roof. And the influences of soil thickness, leaf area index and evapotranspiration on the two indexes are analyzed respectively. [ABSTRACT FROM AUTHOR]

Double-skin facade (DSF) has been widely used in different kinds of architecture as new building envelopes. The position of the shading louver and opening size of the air layer is the key point to thermal performance of DSF. A temperature test, which is in a DSF building in Wuhan, has been conducted in this paper. The ANSYS software has also been used to simulate the velocity and temperature field in the DSF with different opening size. The results show that the test data keeps well accordance with the simulation. Significant differences exist in the velocity and temperature field in DSF with different shading louver position and opening size. The computing results in summer day indicate that as the opening size varies from 0.1m to 0.6m, temperature and velocity of the air in the layer decrease first, then remain the same. Temperature and velocity distribution becomes more regularly with the louver shading in the middle of the layer or near the outside glass than the region close to the inside glass. The testing data in sunny day keeps well accordance with the simulation result, which means the simulation results have certain reliability. [ABSTRACT FROM AUTHOR]

The composition of polycyclic aromatic hydrocarbons (PAHs) in Lake Baikal water and adjacent air layer and PAH emission composition profiles of possible sources were investigated. Analysis of emission composition data showed that the source profiles could not be grouped by fuel type or pyrogenic/petrogenic origin. Because of the similarity of source PAH profiles, the drawing of 3D mixing diagrams was the only way to check whether some of the potential PAH sources were the true sources. The mixing diagrams showed that the sources of air pollution were paper mills and wood burning and that the sources of water pollution were coal-fired and oil-fired boilers. The common source for both air and water was only oil and petroleum products. To determine the locations of PAH sources, their contributions to air and water pollution were calculated and mapped. Based on the results, air and water were polluted from both local and regional sources. The location of the zone influenced by a particular source was conditioned by physical properties of source emission, direction of air/water flows that transfer PAHs and temperature differences between mixing air/water flows. [ABSTRACT FROM AUTHOR]

In hot climates tiled pitched roofs significantly reduce the heat transfer across the roof structure, due to the ventilated air layer between tiles and roofing underlay formed by the arrangement of battens and counter-battens supporting the tiles. This so-called Above Sheathing Ventilation (ASV) depends on the air entering and leaving at the eaves, ridge and the gaps between the tiles. With a view towards higher energy savings in space cooling, the natural and forced convection occurring in ASV could be enhanced by increasing the roof air permeability by means of novel tile shapes, as here analysed in two stages. The first stage of designing the new tile shapes was to measure the air permeability for a type of existing tile (Marseillaise style) using an experimental test rig, by monitoring the volumetric flow rate through the tiles over a range of pressure differences across the tiles. Then, a three-dimensional CFD model was implemented to replicate the full test rig geometry, and this was calibrated against the experimental data. In the next stage, the calibration was used to support the design of novel Marseillaise tile shapes, and to compare their performance against existing tiles. Finally, in order to analyse the variation in air flow under typical wind conditions for a pitched roof, a parametric study was undertaken, consisting of 72 scenarios varying wind speed, direction and angle of incidence. An increase in volumetric flow rate through the tiles was found to be related not only to an increase in the open area between tiles, but also to the design of the tile locks. By redesigning the geometry of these locks, whilst still giving consideration to their primary purpose of preventing the ingress of driving rain, it was possible to yield an improvement in air permeability of up to 100% in comparison with the original designs. Additionally, these novel designs were shown to increase the air flow rate as the wind angle moved from being directly up the roof slope around to the side, in contrast to the decrease seen with existing tile shapes. [ABSTRACT FROM AUTHOR]

'Guabijuzeiro' and 'cerejeira da mata' are plant species from the Myrtaceae family, with many difficulties in asexual multiplication. Thus, the aim of this study was to evaluate 'cerejeira da mata' (Eugenia involucrata DC.) tree and 'guabijuzeiro' [Myrcianthes pungens (Berg) Legrand] tree propagation by air layering, using different IBA concentrations (0, 1000, 2000 and 3000 mg L-1) and materials to wrap the substrate (transparent plastic, black plastic and transparent plastic + aluminum foil). The experimental design for both experiments was a randomized blocks, in a 3 x 4 factorial (wrapping material x IBA concentration), with three repetitions of five air layering each. After 180 days, the percentage of rooting, length and number of roots were evaluated. Sixty days after rooting the percentage of survival plants were evaluated. The air layering technique was not efficient in the 'guabijuzeiro' propagation. This technique could be used in 'cerejeira da mata' plants without the IBA application and using transparent plastic, but with low performance. [ABSTRACT FROM AUTHOR]

Artifact caching, soil layering, and other intentional depositional practices-archaeologically defined 'ritual deposits' of the past-are especially prevalent during the Mississippian period. Employing a perspective of relational ontology, however, we interrogate the validity of a past partitioned into religious, political, and daily spheres. Rather, this perspective emphasizes the multi-experiential and multi-dimensional aspects of social life. Meaning, intentional depositional acts can no longer be usefully described as simply 'sacred' or 'ritual' practices. Rather, these deposits should be explored as experiences tied to multiple layers of social life, investigating the relationships constructed through such deposits between humans, nonhuman agents, and the landscape. [ABSTRACT FROM AUTHOR]

Although Brazil is the largest fig (Ficus carica L.) producer in the Southern Hemisphere, it mainly uses only one cultivar, ‘Roxo de Valinhos’. In addition, propagation is almost entirely through hardwood cuttings. Therefore, the aim of this study was to establish a propagation method that provides more successful rooting of stem segments of fig cultivars for the purpose of expanding the genetic base of the fig tree. The cultivars used were ‘Brunswick’, ‘Calabacita’, ‘Negro de Bursa’, ‘Mini Figo’, ‘Lampa Preta’, ‘Lemon’, ‘Troiano’,’ Nazaré’, ‘Três num Prato’, ‘Princesa’, ‘Colo de Dama’, ‘Montes’, ‘Bêbera Branca’, ‘Pingo de Mel’, and ‘Roxo de Valinhos’. The propagation methods used were layering, hardwood cuttings, nodal segments, herbaceous cuttings originating from the removal of sprouts, and herbaceous cuttings obtained during growth. We found that the propagation method influences the rooting of stem segments, and cultivars differ in their rooting potential.

The variability of air-earth electric currents in the lower 3-m air layer is analyzed in a complex with measurement data on the physical parameters that affect charge transfer in the atmosphere. Three types of air-earth current density profiles have been revealed during experimental observations in summer in Rostov region: (1) the current density decreases with an increase in the distance from the Earth's surface and then stabilizes (nighttime conditions); (2) the current density increases with altitude up to 1 m and then decreases as altitude increases (day hours); (3) transient between types 1 and 2 that are observed in the morning and evening hours. The intensity of charge transfer in the surface air layer under the action of mechanical forces under different stratifications is estimated on the basis of data on altitude variations in the air-earth current density in view of the stationarity of electric processes and the constancy in the altitude of the total air-earth current density. Thermodynamic conditions are estimated with the use of wind velocity measurements and calculations of the turbulence factor and vertical component of the air temperature gradient. [ABSTRACT FROM AUTHOR]

Due to the advanced lightweight characteristic of sandwich structures, ambient air can significantly affect their natural frequency. In order to clarify the importance and magnitude of this effect, the natural frequency of a sandwich panel surrounded by air layers using experiment and numerical simulation was investigated in this study. The experiment setup based on modal testing was proposed with the feature of simulating air layers around the sandwich panel. The numerical simulation was formulated on the basis of fluid–structure interaction analysis. The experimental and numerical simulation results correspondingly demonstrated that the fundamental natural frequency of sandwich panel tends to decrease to be less than 25% of the frequency neglecting the air effect when the air layer thickness becomes thinner than 3 mm. [ABSTRACT FROM AUTHOR]