Tapping System Research Articles

Custo de implantação, produção e rentabilidade do cultivo da seringueira no estado de São Paulo, 2016.

This article presents cost estimates for the establishment, development and maintenance of rubber plantations, as well as net revenue and profitability. The data are presented for the D4 tapping system, the most commonly used in the State of São Paulo. The total operating cost (TOC) for the formation of one hectare in 6 years is estimated to be 8.01 USD. To maintain the full productivity of the plantation the TOC is 0.96 USD per kg of coagulated rubber. The labor force percentage participation and the expenses associated with its use reach 61.2% of the TOC. The results of the profitability analysis show that a good management of the tapping system is determinant to reduce the production cost per unit and increase the attractiveness of the rubber culture.

NEAT: A Platform- and Protocol-Independent Internet Transport API

The sockets API has become the standard way that applications access the transport services offered by the IP stack. This article presents NEAT, a user space library that can provide an alternate transport API. NEAT allows applications to request the service they need using a new design that is agnostic to the specific choice of transport protocol underneath. This not only allows applications to take advantage of common protocol machinery, but also eases introduction of new network mechanisms and transport protocols. The article describes the components of the NEAT library and illustrates the important benefits that can be gained from this new approach. NEAT is a software platform for developing advanced network applications that was designed in accordance with the standardization efforts on transport services in the IETF, but its features exceed the envisioned functionality of a TAPS system.

Considerations for Scale-Up of Ferronickel Electric Smelting Furnaces

In ferronickel smelting, the selective carbothermic reduction of calcined nickel laterite ores in large electric furnaces yields a crude ferronickel product. The optimal process for nickel laterite smelting requires a fine balance between the metallurgical requirements of the process (feed composition, nickel recovery, energy consumption, product quality) and the capabilities of the feeding, tapping and off-gas systems, and especially of the furnace crucible and electrical system. The scale-up of nickel laterite smelting operations over the last 50 years has seen a tenfold increase in furnace power input. Furnace operations within the industry are examined to identify common trends and some new metrics are proposed which incorporate the combination of electrode power densities and the impact of alloy nickel grade on gas generation rates, and hence local electrode gas fluxes, which may impact on future scale-up of ferronickel furnaces.

Modifying the existing water tap system to create a no touch, cost effective solution

Modifying the existing water tap system to create a no touch, cost effective solution

Training of selective attention in work-active stroke patients.

The aim was to examine the effects of computer-based cognitive rehabilitation of attention in work-active patients after stroke. The study included 11 patients treated as inpatients at the University Rehabilitation Institute, Republic of Slovenia, who were included in intensive selective attention training four times a week for 3 months. Each patient was assessed at the initial and the final rehabilitation stage with the TAP system (Test of Attentional Performance), alertness, and divided attention tasks. The results indicate a moderate to strong increase in performance on the divided attention test and a mild effect on the alertness test. Early cognitive rehabilitation of the attentional system can contribute toward recovery of divided attention in work-active patients after stroke.

Application of Vertical Electrical Soundings (VES) for Delineating Sub Surface Lithology for Foundations. (CVG Link Canal A Case Study)

In today’s world, field investigation is a necessity to get a detailed overview of any area for civil engineering construction purpose. Precise determination of engineering geological properties is essential to plan for a proper design and successful construction for any civil engineering structure. The traditionally practiced conventional methods for the same are invasive, costly and time consuming. Electrical Resistivity Survey is an attractive tool for delineating subsurface geology without soil disturbance. Reliable correlation between electrical resistivity values and other field geological parameters can help in successful interpretation of the engineering properties and behavior of soil in evaluation of difficult terrains e.g. for obtaining hard rock position, obtaining continuity of rock strata and for knowing the position of various sub – stratifications. This has led to develop and put in practice the geophysical method of subsurface investigation for a more precise, economical and fast assessment of large areas like the present study area of Cauvery-Vaigai link canal project. The present paper presents the results of the use of Vertical Electrical Sounding coupled with Hydrogeological studies of the Cauvery-Vaigai-Gundar (CVG) link canal area. On the basis of generalized Vertical Electrical Soundings (VES) log it is seen that the aquifers in tertiary rocks are deep – seated, the depth varying from 80 to 300 m from the ground level. It was observed that the open wells are tapping unconfined aquifer system is highly weathered rock, moderately weathered/ fractured hard rock and highly fractured hard rock. The bore wells are tapping the confined aquifer system 40 m Below Ground Level (BGL) in highly fractured hard rock. The aquifers in the bore wells were reported to be in between 40 to 120 m BGL. Most of the bore wells are dry at present due to depletion of aquifer owing to very little precipitation and over exploitation. From resistivity survey it is inferred that where ever highly fractured hard rock are expected along the link, abundant quantity of ground water may be present there in that fractured zones. The result of resistivity values of different rock types of the area show resistivity of less than 20 ohm-m in the weathered soil, while highly fractured rocks show its range between 100 to 250 ohm-m, moderately fractured rocks shows range between 250 and 500 ohm-m and the massive crystalline rocks exhibit the range of more than 500 ohm-m. The water table shows periodical variations. During the excavation of the canal, the study of water table condition will give an idea about the chances of striking ground water to cut and cross drainage portions as ground water poses a serious hazard during the excavation works.

Efeito da frequência da sangria em diferentes clones na produtividade de seringueira

The study evaluated the effect of tapping frequency on the productivity of rubber tree clones (PB235, IAN873, GT1 e RRIM600) planted in 1990 at Indianapolis-PR in a 8 x 4 m spacing. Treatments included tapping system in a half spiral every 3, 4 and 5 days. Data (g per tree per month) was collected from November, December and January of 2009/2010 and of 2010/2011 harvest seasons with ten repetitions. Results indicated that clone productivity was independent of tapping frequency.

Transcriptome sequencing and comparative analysis reveal long-term flowing mechanisms in Hevea brasiliensis latex

BackgroundThe rubber tree, Hevea brasiliensis, is a major commercial source of natural rubber. Increasing the rubber yield of rubber trees is a very serious problem since the demands for high quality rubber materials are great. Establishment of a tapping system is based on an estimate of tapping intensity from the rubber tree. Latex flowing time is one of the most critical factors that determine the rubber yield. Long-term flow is a type of phenomenon of the rubber tree latex with longer flowing time than normal latex flow, and is always caused by intensive tapping. Thus, transcriptome and expression profiling data for long-term flowing latex (LFL) are needed as an important resource to identify genes and to better understand the biological mechanisms of latex flow in rubber trees. ResultsThe transcripts were sequenced using the Illumina sequencing platform. After cleaning, quality checks and sequencing, 98,697 transcripts and 38,584 unigenes were assembled with the mean size of 1437.31bp and 923.86bp, respectively. In BLAST searches of our database against public databases, 65.17% (25,147) of the unigenes were annotated with gene descriptions, conserved protein domains, or gene ontology terms. Functional categorization further revealed 853 individual unigenes related to long-term flow. According to KEGG classification, the clusters for “cysteine and methionine metabolism”, “energy”, “oxidative phosphorylation”, “terpenoid backbone biosynthesis”, “plant hormone signal transduction” and “copper, potassium transporter” were significantly enriched metabolic pathways. ConclusionsWe conducted high-resolution transcriptome profiling related to LFL in H. brasiliensis. The research facilitates further studies on gene discovery and on the molecular mechanisms related to the estimation of tapping intensity and prolonging latex flowing time. We concluded that it was necessary to improve energy supplies for intensive tapping and the copper ion content of rubber tree latex could be considered as a standard to estimate tapping intensity.

Variation of phloem turgor pressure in Hevea brasiliensis: An implication for latex yield and tapping system optimization

Phloem turgor pressure (PTP) is the initial driving force for latex flow after a rubber tree is tapped and therefore plays an important role in rubber tree latex production. Variation in PTP with rubber tree clone, age, yield potential and commonly used Ethrel (an ethylene releaser) stimulation have, however, not been comprehensively studied to date. The aim of this study was to investigate these relations and examine whether PTP can be used as an index for rubber tree clone assessment and tapping system optimization. The results showed that: (1) the daily change of PTP in the foliation season suggests that a high PTP can ensure a high latex yield and tapping could be moved forward to midnight or earlier in the night; (2) the decrease of PTP from the basal to distal stem indicates the benefit of a controlled upward tapping system; (3) the logarithmic increase in PTP with rubber tree planting age and age-based mean girth suggests that the preferred age for the commencement of rubber tree tapping is eight years; (4) the change of PTP with regenerated bark age suggests that the regenerated bark could be exploited again after the second year; (5) PTP is positively related to the yield potential of rubber tree clones; (6) although Ethrel stimulation could not significantly increase the initial PTP of a rubber tree, it delays the recovery of PTP after tapping. Therefore, PTP is an indicator of rubber tree latex yield and can be used for tapping system optimization.

Biomechanical Analysis of Cement Augmentation Techniques on Pedicle Screw Fixation in Osteopenic Bone: A Cadaveric Study

Study DesignThree techniques for cement injection into osteopenic pedicles for screw augmentation were compared in a cadaver model. ObjectivesTo compare the safety and efficacy of 3 techniques for cement augmentation of pedicle screws in a cadaver model. BackgroundCement augmentation of pedicle screws improves fixation in osteopenic spines. Some investigators have used kyphoplasty osteo introducers to inject viscous cement into the pedicle. In addition, a novel fenestrated tapping system was studied that leaves a threaded cement tract for final pedicle screw insertion. MethodsThis 3-phase biomechanical study compared cement augmentation effects on the cephalocaudal toggle of pedicle screws within 34 fresh osteopenic human cadaveric vertebrae. Phase 1 compared injection through a fenestrated tap to a direct injection. Phase 2 evaluated the fenestrated tap versus injection of more viscous cement using a kyphoplasty osteo inducer. Phase 3 compared kyphoplasty and direct injection techniques. Each vertebral body was prepared with each of the 2 techniques. The pedicle screws were subjected to 10,000 cycles of cephalocaudal toggling, and total vertical displacement of each screw head was measured. ResultsIn a combined analysis, overall displacement was 2.26 ± 0.57 mm for the direct injection, 2.88 ± 0.56 mm for the kyphoplasty technique, and 3.74 ± 0.59 mm for the fenestrated tap (p < .01). In Phase 1, extravasation of cement occurred in 5% of the fenestrated tap, 86% of the direct injection. Phase 2 results showed that extravasation occurred in 0% for the fenestrated tap group and 18% for the kyphoplasty group. In Phase 3, extravasation of cement was 54% of the direct injection, compared with 31% of the kyphoplasty group. ConclusionsThe novel fenestrated tap system provided less resistance to toggle than either of the other 2 techniques but provided a lower incidence of cement extravasation. More viscous cement injected using kyphoplasty technique provides a combination of safety and efficacy.

A Comparative Analysis of Smallholders Tapping Practices in Four Rubber Producing Regions of Thailand

Rubber has been grown for long in the South and East of Thailand. Since 2005, rubber plantations have largely spread to new regions, in the North and above all in the Northeast. Tapping is one of the most important practices to optimize the yield of rubber plantations and farmers income [. If tapping practices are well documented in the traditional growing areas [2, , we lack information for the new rubber producing regions. And so far, no study has been done at the level of the country. Therefore, a survey was conducted with 219 rubber farmers from 10 provinces in four rubber producing regions to describe farmers tapping practices. The objective was to compare farmers practices in the different regions and try to identify some standardization or differentiation factors. Results show that tapping systems used by the farmers vary with the region but everywhere, even in the South and Centre east, the real tapping practices are not really intensive. Tapping practices seem to be linked to farmers rubber experience, the size of mature plantation, the rainfall and the length of the leaf-fall period. So finally, tapping days are irregularly distributed throughout the year which probably affects latex physiology and so, the potential yield of rubber plantations.

Alternative Tapping Systems for RRIC 100 Clone from Opening

Alternative Tapping Systems for RRIC 100 Clone from Opening

Modelling and Optimization of Stability Constants of Cadmium or Zinc with Biological Buffers (DIPSO or TAPS) in Aqueous Solutions by Electrochemical Techniques

The complexation behavior of four systems involving cadmium(II) or zinc(II) in aqueous solutions with the biological buffers 3-[N,N-bis(2-hydroxyethyl)amino]-2-hydroxypropanesulfonic acid (DIPSO), and [(2-hydroxy-1,1-bis(hydroxymethyl)ethyl)amino]-1-propanesulfonic acid (TAPS) was studied by direct current polarography (DCP) and glass electrode potentiometry (GEP), at 25.0 ± 0.1 °C and ionic strength 0.1 mol·dm−3 KNO3. Except for the Cd–TAPS system, for which full characterization of the system was possible either by DCP or GEP, full characterization of the other metal-buffer systems (Zn–DIPSO, Zn–TAPS and Cd–DIPSO) was only possible using DCP. For Zn-buffers systems, ZnL+ and $$ {\text{ZnL(OH)}}_{2}^{ - } $$ (where L stands for buffer) were identified. For the Zn–DIPSO system, the overall stability constant values (as log10 β) are 2.1 ± 0.2 and 13.4 ± 0.2, respectively. For the Zn–TAPS system, the overall stability constants values (as log10 β) are 2.4 ± 0.1 and 12.9 ± 0.3, respectively. For the Cd–DIPSO system, the overall stability constants values (as log10 β) of CdL+ and CdL(OH) are 2.9 ± 0.1 and 6.9 ± 0.3, respectively. For the Cd–TAPS system, only the species CdL+ was identified with log10 β = 2.5 ± 0.1.

Impact of tapping and soil water status on fine root dynamics in a rubber tree plantation in Thailand.

Fine roots (FR) play a major role in the water and nutrient uptake of plants and contribute significantly to the carbon and nutrient cycles of ecosystems through their annual production and turnover. FR growth dynamics were studied to understand the endogenous and exogenous factors driving these processes in a 14-year-old plantation of rubber trees located in eastern Thailand. FR dynamics were observed using field rhizotrons from October 2007 to October 2009. This period covered two complete dry seasons (November to March) and two complete rainy seasons (April to October), allowing us to study the effect of rainfall seasonality on FR dynamics. Rainfall and its distribution during the two successive years showed strong differences with 1500 and 950 mm in 2008 and 2009, respectively. FR production (FRP) completely stopped during the dry seasons and resumed quickly after the first rains. During the rainy seasons, FRP and the daily root elongation rate (RER) were highly variable and exhibited strong annual variations with a total FRP of 139.8 and 40.4 mm-2 and an average RER of 0.16 and 0.12 cm day-1 in 2008 and 2009, respectively. The significant positive correlations found between FRP, RER, the appearance of new roots, and rainfall at monthly intervals revealed the impact of rainfall seasonality on FR dynamics. However, the rainfall patterns failed to explain the weekly variations of FR dynamics observed particularly during the rainy seasons. At this time step, FRP, RER, and the appearance of new FR were negatively correlated to the average soil matric potential measured at a depth of between 30 and 60 cm. In addition, our study revealed a significant negative correlation between FR dynamics and the monthly production of dry rubber. Consequently, latex harvesting might disturb carbon dynamics in the whole tree, far beyond the trunk where the tapping was performed. These results exhibit the impact of climatic conditions and tapping system in the carbon budget of rubber plantations.

A statistical approach to root system classification.

Plant root systems have a key role in ecology and agronomy. In spite of fast increase in root studies, still there is no classification that allows distinguishing among distinctive characteristics within the diversity of rooting strategies. Our hypothesis is that a multivariate approach for “plant functional type” identification in ecology can be applied to the classification of root systems. The classification method presented is based on a data-defined statistical procedure without a priori decision on the classifiers. The study demonstrates that principal component based rooting types provide efficient and meaningful multi-trait classifiers. The classification method is exemplified with simulated root architectures and morphological field data. Simulated root architectures showed that morphological attributes with spatial distribution parameters capture most distinctive features within root system diversity. While developmental type (tap vs. shoot-borne systems) is a strong, but coarse classifier, topological traits provide the most detailed differentiation among distinctive groups. Adequacy of commonly available morphologic traits for classification is supported by field data. Rooting types emerging from measured data, mainly distinguished by diameter/weight and density dominated types. Similarity of root systems within distinctive groups was the joint result of phylogenetic relation and environmental as well as human selection pressure. We concluded that the data-define classification is appropriate for integration of knowledge obtained with different root measurement methods and at various scales. Currently root morphology is the most promising basis for classification due to widely used common measurement protocols. To capture details of root diversity efforts in architectural measurement techniques are essential.

Complex magma mixing, mingling, and withdrawal associated with an intra-Plinian ignimbrite eruption at a large silicic caldera volcano: Los Humeros of central Mexico

Los Humeros is the largest caldera volcano in the Mexican volcanic belt. Its second largest caldera-forming eruption, the ca. 0.1 Ma Zaragoza eruption, is recorded by two Plinian pumice-fall layers and a zoned intra-Plinian ignimbrite. Diverse pumice types within the ignimbrite provide insights about the way that different magmas within a single magmatic system interact, and the way in which this can give rise to a major explosive ignimbrite-forming eruption. Normal-and-reverse compositional zoning in the ignimbrite is defined by vertical variations in the relative abundance of rhyodacitic (69–71 wt%% SiO 2 ) and andesitic (54–63 wt% SiO 2 ) pumice lapilli: Lower parts are dominated by rhyodacite and pass gradationally up into a central part with andesitic and rhyodacite pumice, and this passes up into a rhyodacitic uppermost part, with no andesite. Petrographic and microprobe analyses of coexisting glass and phenocrysts provide mixed evidence of equilibrium and disequilibrium conditions in the magmas at the time of eruption. The Fe-Ti oxides record magma temperatures of ∼850 °C (andesite) and 780 °C (rhyodacite). The andesitic pumice contains euhedral labradorite (∼An 60 ), and orthopyroxene and clinopyroxene, in a dacitic glass groundmass, which yield equilibrium Na-Ca K d pl/liq and Fe-Mg K d pl/liq ratios. It also contains highly calcic plagioclase (to An 82 ) that in some cases is highly resorbed and mantled by the more sodic plagioclase, which may record early mixing between andesitic and plagioclase-bearing basaltic magmas, followed by equilibrium crystallization within the hybrid magma. The rhyodacite contains euhedral crystals of more-evolved plagioclase (∼An 30-40 ) and euhedral pyroxenes in a rhyolitic glass groundmass (74–75 wt% SiO 2 ). The pyroxenes yield disequilibrium Fe-Mg K d pl/liq ratios and indicate formation from a liquid that was more mafic than the liquid that formed the glass groundmass of the dacitic pumice. Subordinate pumices with interbanded rhyodacite and a scarcity of intermediate-composition pumices indicate that the magmas remained separate for most of the time, and mingled only immediately prior to, and during eruptive quenching. Rather than a simple density-stratified magma chamber, the Zaragoza eruption may have occurred in response to intrusion of a hybridized andesitic magma into a rhyodacitic magma reservoir, possibly arranged as semiconnected high-melt lenses or zones within a partially consolidated crystal mush. However, contrary to assumptions of simple replenishment, tapping, and fractionation-type systems, the Zaragoza magmas contain no record of previously erupted highly evolved rhyolites that developed when zircon joined the fractionating assemblage. This absence indicates that the highly evolved rhyolites had either been completely tapped or solidified prior to the Zaragoza eruption eruption, or that interaction was prevented by contrasting magma densities and viscosities.

Ethephon: a tool to boost gum arabic production from Acacia senegal and to enhance gummosis processes

Gum arabic production from Acacia senegal is lower in sub-humid areas than arid areas. Water stress is thought to be the reason for higher yields in arid areas. The application of ethephon is thought to mimic the effect of water stress in other plants. The objective of this study was to determine if the application of ethephon would increase the gum yields of Acacia senegal under sub-humid conditions in Cameroon. Trees receiving 40 or 120 mg ethephon were compared to controls in field experiments at a semi-arid and a sub-humid location in Northern Cameroon, over two seasons. Two provenances from drier areas (Sudan) were compared to the local one. In the first season, gum yield of the local provenance treated with ethephon was increased by 400–600 % compared to the untreated trees. Gum yield at the semi-arid location was 77, 313 and 214 g/tree with 0, 40 and 120 mg ethephon/tree, respectively, while at the sub-humid location, it was 30, 186 and 114 g/tree with 0, 40 and 120 mg ethephon/tree. However, in the second season, the effect of ethephon was not significant in the semi-arid area, whereas it was evident in the sub-humid area (up to 478 g/tree). Moreover, ethephon did not affect gum yield of provenances from drier areas (Sudan). This showed that the water-stress hypothesis has to be refined. The development of ethephon-based tapping systems is promising, but requires further studies with a wider range of environmental conditions and A. senegal provenances.

Producción y propiedades químicas del caucho en clones de Hevea según los estados fenológicos

El objetivo de este trabajo fue evaluar el desempeño productivo y el contenido de macronutrientes del caucho extraído de cuatro clones de Hevea brasiliensis, en diferentes sistemas de sangría y estados fenológicos de las plantas. El experimento fue realizado en los años agrícolas de 2010 y 2011, en diseño experimental de bloques completos al azar, en parcelas subdivididas, con cuatro repeticiones. Los tratamientos principales - clones GT 1, PB 235, IAN 873 e RRIM 600 - fueron ubicados en las parcelas, y los subtratamientos, que fueron los sistemas de sangría ½S d/2, ½S d/4 ET 2,5% y ½S d/7 ET 2,5%, se ubicaron en las subparcelas. Las variables analizadas fueron producción y contenido de macronutrientes. Las muestras fueron obtenidas en los estados fenológicos de brotación foliar, hojas maduras y senescencia foliar. La producción y los contenidos de macronutrientes del caucho son más influenciados por la práctica de sangría que por el material genético en los estados fenológicos más restrictivos para el follaje de caucho.

Tapping panel diagnosis, an innovative on-farm decision support system for rubber tree tapping

Latex is a key product for many tropical countries, of which 80% is produced by smallholders. Latex is produced by the rubber tree (Hevea brasiliensis). Given the 7-year immature unproductive period, establishing a rubber plantation requires considerable investment by smallholders, emphasizing the need for sustainable management. The difficulty of performing an agronomic diagnosis of a tree crop is to obtain an accurate picture of current and past cultivation practices, to be able to assess their impacts on the agro-ecosystem as well as on sustainability. Smallholders do not usually keep records of latex yield or of their technical practices, making it impossible to perform a diagnosis based on productivity. As latex harvesting involves tapping the bark, which leaves scars on the trunk, we hypothesised that these morphological traces would be good indicators of current and past practices and would thus enable a diagnosis based on the economic lifespan of plantation. To this end, we formalised a tapping panel diagnosis that involved reproducing the scars on tapping panel diagrams, and analysing them using two indicators: the amount of virgin bark consumed and the number of tapping years that remained. We validated this tapping panel diagnosis in a sample of 25 smallholder plantations in Cameroon, where we characterised eight tapping management systems reflecting different levels of tapping intensity. The assessment of the respective share of each tapping practice on virgin bark consumption revealed major effects of tapping frequency and of shaving thickness. We showed that the tapping panel diagnosis used as a decision support tool can increase remaining tapping years by 33% to 355%. To conclude, the tapping panel diagnosis formalised here for the first time will be a useful support for the participatory development of innovating tapping management schemes involving both technicians and smallholders.

Relationship between tapping intensity and tapping panel dryness susceptibility of some clones of Hevea brasiliensis in Southwestern Côte d’Ivoire

It is well known that the productivity and the susceptibility to the tapping panel dryness (TPD) of Hevea brasiliensis are determined by the intrinsic feature of each clone but also by the tapping system. Thus, in order to establish the tapping system that minimizes the TDP occurrence an experiment was carried out in Cote d'Ivoire with four high yielding clones including, PB 235, PB 255, IRCA 18 and IRCA 111. Five tapping systems (d2 6d/7 0/y, d3 6d/7 4/y, d4 6d/7 6/y, d5 6d/7 8/y, d6 6d/7 10/y) were applied to these clones, corresponding to a range of 100 % to 30 % of tapping intensities. The results show that the occurrence of TPD is closely related to the tapping intensity and the tapping system which consists in tapping twice per week with one day rest (S/2 d3 6d/7 4/y), was found to be the best tapping system. A quadratic relation was found between the rate of the TPD and the tapping intensity. Thus the clones IRCA 18 and IRCA 111, like PB 235 and PB 255, belong to the active metabolism clones. These clones also showed their adherence to the group of high rubber producer clones. This experiment also gave further evidence that the production of a tree for the tapping strongly depends on the intensity of tapping. It has also indicated that the intensity of tapping governed the tapping panel dryness rate among the clones having active metabolism, such as IRCA 18, IRCA 111, PB 235 and PB 255. (Resume d'auteur)