Thin Branches Research Articles

Impact of harvesting methods and forest floor displacement on nutrient stock of Scots pine ecosystems in the Central Anatolia Region of Turkey.

Concern about the negative effects of logging residue extraction on the sustainability of forest ecosystems has been rising recently. Tree residues, including leaves, branches, bark and roots, left in the forest after logging may supply most of the nutrients for tree growth. The aim of this study was to (i) determine the carbon and nutrient stocks in different components and (ii) model the carbon and nutrient stocks in tree biomass of a mature Scots pine forest. The study site was located on the Turkmen mountain range in the Central Anatolia Region of Turkey. In sample plots, stand measurements were made, and samples collected from trees, soil and the forest floor for analysis of carbon and nutrients and the stock of each nutrient per unit area were calculated. Data were analysed using analysis of variance and regression analysis. Significant differences were found in carbon and nutrient concentrations and stocks between ecosystem components. C, Ca, Mg, Na, Fe, Cu and Mn stocks were higher in wood; the N stock was higher in needles, and P, K, S and Zn stocks were higher in roots. In the ecosystem, trees had the highest C stock; the soil had the highest N, P, K, Ca, Mg, Na, Cu, Zn and Mn stocks, and the forest floor had the highest Fe and S stocks. Therefore, it is critical that the forest floor is protected as it is an important element of the ecosystem nutrient cycle and source of Fe and S stocks. Maximum attention should be paid to leaving behind needles, bark, roots and thin branches with low economic value to minimise carbon and nutrient loss in the nutrient-limited forests. Equations predicting carbon and nutrient stocks through stem volume can be used for estimation of nutrient loss due to biomass removed from the system through interventions, contributing to sustainable forest management.

Structural Characteristics of the Si Whiskers Grown by Ni-Metal-Induced-Lateral-Crystallization.

Si whiskers grown by Ni-Metal-Induced-Lateral-Crystallization (Ni-MILC) were grown at 413 °C, intentionally below the threshold for Solid State Crystallization, which is 420 °C. These whiskers have significant common characteristics with whiskers grown by the Vapor Liquid Solid (VLS) method. The crystalline quality of the whiskers in both methods is the same. However, in VLS, a crystalline substrate is required, in contrast to the amorphous one in Ni-MILC for the growth of single crystalline whiskers. Moreover, whiskers grown by VLS have a polygonal cross-section with their diameter determined by the diameter of the hemispherical metallic catalysts. On the other hand, in the Ni-MILC, the cross-section of the whiskers depends on the size of the NiSi2 grain from which they are emanated. This was confirmed by observing the crossing whiskers and the rotational Moiré patterns in the crossing area. The structure of disturbed short and thin nonlinear branches on the side-walls of the whiskers was studied. In the whiskers grown by the VLS method, significant contamination occurs by the metallic catalyst degrading the electrical characteristics of the whisker. Such Si whiskers are not compatible with the current CMOS process. Whiskers grown by Ni-MILC at 413 °C are also contaminated by Ni. However, the excess Ni is in the form of tetrahedral NiSi2 inclusions which are coherent with the Si matrix due to the very low misfit of 0.4% between them. These whiskers are compatible with current CMOS process and Thin Film Transistors (TFTs).

Fire and drought: Shifts in bark investment across a broad geographical scale for Neotropical savanna trees

Savanna tree communities occurring in confluence zones with other biomes likely experience different environmental pressures, resulting in shifts in the selection of individual traits, the combinations of such traits, and species composition. In seasonally dry fire-prone environments, plant survival is presumably associated with adaptive changes in bark properties related to fire protection and water storage. Here, we integrated the multiple functions of the bark to investigate whether different selective pressures could influence patterns of variation in bark structure and allocation across species in a broad geographical range. We measured thickness, density, and water content of the inner and outer bark in branches and the main stem of the 51 most abundant species in three savanna communities differing in climatic aridity, one located at the core region of Cerrado in Central Brazil and the other two at its periphery, in the transition zones with Amazonia and Atlantic forest biomes. We found no difference in outer bark thickness but markedly difference in inner bark thickness between the three plant communities. In the central region, where dry season is long and fire is frequent, branches and main stem showed thicker inner bark. Contrastingly, in the south periphery region, where dry season is short, species showed thinner inner bark in both branches and main stem. Species from the north periphery region, where mean annual precipitation is higher, but fire is frequent and the dry season is also long, showed similar main stem inner bark thickness, but thinner branch inner bark compared to core region species. Our findings support the idea that investing in inner bark thickness and bark moisture may be the most advantageous strategy in plant communities that suffer from high evaporative demand during a long period and are at a high risk of fire.

The branching pattern of the middle temporal artery and the relation with the temporal fascia.

Although the middle temporal artery is used for maxillofacial and otological flap surgeries, the anatomical knowledge of the artery is insufficient to corroborate its usage. This study has investigated the interrelationship between the artery and the temporal fascia to enhance its availability. The middle temporal artery was dissected in ten cadavers, and its spatial relations with the temporal fascia and muscle and the adjacent structures were examined. The middle temporal artery arose behind the mandibular head or neck and in front of the external acoustic meatus. It penetrated the temporal fascia external to the junction between the zygomatic process and the supramastoid crest. The artery gave off a thin branch in the space between the superficial and the deep layers of the fascia and is divided into two branches piercing the deep layer to supply the temporalis. The anterior branch anastomosed with the deep temporal artery; furthermore, it gave off the slender ramus coursing on the base of the zygomatic process to communicate with the masseteric artery. The posterior branch passed along the supramastoid crest, gave off a slender ramus and ascended in the groove of the temporal bone. The branching pattern of the middle temporal artery and its positions relative to the temporal fascia and the landmark structures are helpful in identifying the artery, designing favourable flaps and avoiding unfavourable bleeding during surgery. They are also beneficial in developing the clinical usage of the artery.

Characterization and quantification of bioactive compounds from Ilex paraguariensis residue by HPLC-ESI-QTOF-MS from plants cultivated under different cultivation systems.

Ilex paraguariensis is a perennial plant used in the production of mate tea, "chimarrão" and "tererê," cosmetics, and other food products. Its leaves are harvested every 12 or 18 months. Approximately 2 to 5 tons of residue are generated per hectare during the harvest. The bioactive composition of this residue has not been characterized to date. Therefore, this paper presents for the first time, the simultaneous characterization of the bioactive compounds of the leaves, thin branches, and thick branches (residue) from I. paraguariensis grown under two cultivation systems: "full sun" and "shaded." The identification and quantification of the compounds was performed using high-performance liquid chromatography coupled to electrospray ionisation and quadrupole time-of-flight mass spectrometer (HPLC-ESI-QTOF-MS). Consequently, 35 compounds were identified. The average dry weight of phenolic compounds in the residue was 4.1g/100g, whereas that in the bark of the residue was 12.9g/100g, which was similar to the content found in leaves. The same compounds were identified in the two cultivation systems but with a difference in their contents. While the "full sun" cultivation had a higher content of phenolic acids, the "shaded" cultivation had a higher content of flavonoids and saponins. It was found that the I. paraguariensis residue, particularly the bark, is rich in bioactive compounds, such as quinic, 3-caffeoylquinic, 5-cafefoylquinic, 3,5-dicaffeoylquinic, and 4,5-dicaffeoylquinic acids as well as rutin, and their contents vary according to the cultivation system. Therefore, this residue is an underutilized natural resource with a potential for industrial applications. PRACTICAL APPLICATION: Yerba mate producers will be able to choose the best cultivation system ("full sun" or "shaded") to increase the content of bioactive compounds. New products may be developed with yerba mate residue due to its high concentration of compounds that are beneficial to the human health. New destinations may be applied to yerba mate residue from the harvest pruning, adding commercial value to this unexplored natural resource.

Collective colony growth is optimized by branching pattern formation in Pseudomonas aeruginosa

Branching pattern formation is common in many microbes. Extensive studies have focused on addressing how such patterns emerge from local cell–cell and cell–environment interactions. However, little is known about whether and to what extent these patterns play a physiological role. Here, we consider the colonization of bacteria as an optimization problem to find the colony patterns that maximize colony growth efficiency under different environmental conditions. We demonstrate that Pseudomonas aeruginosa colonies develop branching patterns with characteristics comparable to the prediction of modeling; for example, colonies form thin branches in a nutrient‐poor environment. Hence, the formation of branching patterns represents an optimal strategy for the growth of Pseudomonas aeruginosa colonies. The quantitative relationship between colony patterns and growth conditions enables us to develop a coarse‐grained model to predict diverse colony patterns under more complex conditions, which we validated experimentally. Our results offer new insights into branching pattern formation as a problem‐solving social behavior in microbes and enable fast and accurate predictions of complex spatial patterns in branching colonies.

Simultaneous Direct Depth Estimation and Synthesis Stereo for Single Image Plant Root Reconstruction.

Plant roots are the main conduit to its interaction with the physical and biological environment. A 3D root system architecture can provide fundamental and applied knowledge of a plant's ability to thrive, but the construction of 3D structures for thin and complicated plant roots is challenging. Existing methods such as structure-from-motion and shape-from-silhouette require multiple images, as input, under a complicated optimization process, which is usually not convenient in fieldwork. Little effort has been put into investigating the applications of deep neural network methods to reconstruct thin objects, like plant root systems, from a single image. We propose an unsupervised learning scheme to estimate the root depth from only one image as input, which is further applied to reconstruct the complete root system. The boundaries of the reconstructed object usually contain large errors, which is a significant problem for roots with many thin branches. To reduce reconstruction errors, we integrate a cross-view GAN-based network into the reconstruction process, which predicts the root image from a different perspective. Based on the predicted view, we reconstruct the root system using stereo reconstruction, which helps to identify the accurately reconstructed points by enforcing their consistency. The results on both the real plant root dataset and the synthetic dataset demonstrate the effectiveness of the proposed algorithm compared with state-of-the-art single image 3D reconstruction models on plant roots.

Simple methodological approach for assessing microbial mineralization rates in an aqueous anaerobic medium

Abstract: The aim of this study was to propose and discuss a simple manometric method to quantify the emission rates of gases resulting from the microbial anaerobic mineralization of organic resources, as leaves, thin branches, and macrophyte detritus. The proposed method can be used under laboratory conditions. The method consists of using a water pressure gauge attached to the reaction flask. The incubations were prepared with samples of water from Paranapanema River and Typha domingensis, the experiment lasted 9.8 months. The procedures for preparing the incubations are presented in detail, as well as the calculations for the conversion of the volumetric measurement into carbon mass (i.e., daily rate of carbon gas emissions). According to the results obtained from T. domingensis mineralization assays it was possible to demonstrate that, numerous events related to mineralization could be adequately addressed (e.g., the heterogeneous detritus composition). The results of this method were quite convergent with those obtained in kinetic experiments (used as a reference) after the 30th mineralization day, suggesting the use of this method mainly for medium- and long-term experiments. As exemplified by T. domingensis incubations, this method is particularly valuable for the systemic comparison of the several organic resources mineralization and for the primary measurement of the main parameters involved (e.g., reaction rates constants). This method combined with other short-term experiments can greatly improve the understanding of the cycling of organic resources in aquatic environments.

Age-related morphological changes of Caprine thymus

A total of 31 thymus samples collected from female goats with the age range from ten days after birth to 30 months were used for gross morphological studies. The results show that the thymus consists of thoracic, cervical and cranial lobes, which are superficially lobulated. The thoracic lobe considered as a single quadrilateral mass present in the dorsal part of the left of the pericardial mediastinum and connected to the cervical lobe by a cervicothoracic isthmus. The cervical lobe divided into right and left portions. In the caudal third of the neck, the right and left portion adhere together, forming a single caudal part called the body and cranially to diverge, forming two limbs. The cranial lobe of the thymus is ovoid in shape. The morphological changes and the arterial blood supply of the thymus gland are recorded. At group I and II, the thymus gland was well developed, and all lobes and isthmus of the thymus gland were found. At Group III thymus gland highly decreased in size, and the cranial part of the right limb of the cervical lobe was wholly involuted. At group IV and V, the right and left limbs of the cervical lobe and the isthmus were involuted entirely. At group VI the cranial lobes are completely involuted, and the thymus gland consists of the remnant caudal cervical and thoracic lobe only. At the age of 27- 30 months complete involution of the thymus gland, there was a thin remnant of the thymus gland in the cranial mediastinum and complete disappearance of the cervical lobe and replaced by adipose tissue. It was seen that the thoracic lobe of the thymus was supplied by three branches from the brachiocephalic trunk, left internal thoracic artery to give rise to pericardiophrenic artery, this artery gave a thin branch to the caudal pole of the thoracic lobe of the thymus. Cervicothoracic isthmus takes its arterial blood supply from the right internal thoracic artery. The body of the cervical lobe takes its arterial blood supply from 3-4 direct branches from the common carotid artery, and offshoots branches from arterial branches descend for the trachea and the esophagus. The cranial two limbs take its arterial blood supply from 3-4 thymic branches from the caudal thyroid artery. It also found that the cranial lobe of the thymus gland takes its arterial supply from two Indirect branches from the external carotid artery.

A reintroduced ecosystem engineer species may exacerbate ongoing biological invasion: Selective foraging of the Eurasian beaver in floodplains

Species reintroductions aim to re-establish populations of locally extinct, often keystone species. As a consequence of the reintroduction and protection of the Eurasian beaver (Castor fiber), the species has recolonized the suitable habitats (including floodplains) across Europe in the past few decades. Floodplain habitats have already been significantly altered during the period when the beaver was listed as a locally extinct species. Nowadays, alluvial forests are being highly impacted by rapidly spreading invasive woody species. We examined the supply of woody species and their utilization by beaver in this changed environment, with a fine-scale method, at 20 sites, along 39 transects (Danube catchment area, Hungary). The invasive species (Acer negundo, Fraxinus pennsylvanica and Amorpha fruticosa) were utilized by beaver, but the utilization ratio of softwood genera (Salix and Populus) dominated by native species was usually higher. Based on the preference analysis, performed for the thin branches category, at least one of the softwood genera was significantly preferred along 17 transects, and they were never avoided. In parallel, at least one of the invasive woody species was significantly avoided along 17 transects, and preferred along only one transect. We conclude that beaver’s forage selection is capable of indirectly accelerating the spread of already present invasive species, a negative process from a nature conservation perspective. This adverse impact points to the need for increased attention on changes that can occur within the habitat of a reintroduced species, and on the possibility of unexpected conflicts among conservation targets.

(2777) Proposal to conserve the name Philippodendrum regium (Plagianthus regius) (Malvaceae) against Betula bella

(2777) Proposal to conserve the name <i>Philippodendrum regium</i> (<i>Plagianthus regius</i>) (<i>Malvaceae</i>) against <i>Betula bella</i>

Relevant phenotypic descriptors of the resonance Norway spruce standing trees for the acoustical quality of wood for musical instruments

Identifying high-grade valuable wood resources by the visible individual traits of trees is a challenge for foresters and a requirement for sustainable resource management. The aim of this study was to identify the most relevant phenotypic descriptors of the acoustic quality of Norway spruce standing timber. Two highly valuable Norway spruce (Picea abies) stands located in the Romanian Carpathians were selected for this purpose. A total of 27 tree, bole, bark, and crown variables and nine variables related to wood structure were statistically checked against the velocities of stress waves measured on standing trees at breast height, and the derived parameters: the radiation, the impedance, and the moduli of elasticity in L and R directions. Principal component analysis was used for exploratory data analysis as well as mixed linear models were involved in explaining these acoustics. There were consistent variations in the measured acoustics from tree to tree, according to the age and social class. Wood acoustical parameters measured in the R direction are better predicted by tree phenotype than the acoustical parameters measured in the L direction. Bark thickness and branch width were the best predictors, while tree ring features were less predictive. At a given age, trees with high velocity had thinner and reddisher bark, thinner branches, and a narrower crown. Trees with high velocity anisotropy had narrower branches and wider sapwood. Furthermore, the phenotypic traits used had a poor explanatory power of the radiation ratio. In conclusion, spruce standing trees from the studied area bring forward certain outside features that enable us the multitrait identification of highly valuable wood for string instruments.

What drives grassland-forest boundaries? Assessing fire and frost effects on tree seedling survival and architecture.

Fire and frost represent two major hurdles for the persistence of trees in open grassy biomes and have both been proposed as drivers of grassland‐forest boundaries in Africa.We assess the response of young tree seedlings, which represent a vulnerable stage in tree recruitment, to traumatic fire and frost disturbances.In a greenhouse experiment, we investigated how seedling traits predicted survival and resprouting ability in response to fire versus frost; we characterized survival strategies of seedlings in response to the two disturbances, and we documented how the architecture of surviving seedlings is affected by fire versus frost injury.Survival rates were similar under both treatments. However, different species displayed different levels of sensitivity to fire and frost. Seedling survival was higher for older seedlings and seedlings with more basal leaves. Survivors of a fire event lost more biomass than the survivors of a frost event. However, the architecture of recovered fire‐ and frost‐treated seedlings was mostly similar. Seedlings that recovered from fire and frost treatments were often shorter than those that had not been exposed to any disturbance, with multiple thin branches, which may increase vulnerability to the next frost or fire event. Synthesis. Fire caused more severe aboveground damage compared with a single frost event, suggesting that fire is an important driver of tree distribution in these open grassland systems. However, the impact of repeated frost events may be equally severe and needs to be investigated. Also, woody species composition may be influenced by phenomena that affect the timing and frequency of seedling exposure to damage, as mortality was found to be dependent on seedling age. Therefore, changes in fire regime and climate are likely to result in changes in the composition and the structure of the woody components of these systems.

Study of the Portal Branches Arising from the Cranial Part of the Umbilical Portion of the Left Portal Vein: Implications for Anatomic Right Hepatic Trisectionectomy.

In "anatomic" right hepatic trisectionectomy for advanced perihilar cholangiocarcinoma, the left hepatic duct is divided at the left side of the umbilical portion (UP) of the left portal vein (LPV). For this reason, the left hepatic duct is completely detached from the UP after all division of the portal branches arising cranially from the UP. However, little is known about these thin portal branches. Using 3D imaging processing software, we examined the portal branches arising cranially from the UP of the LPV in 100 patients who underwent multidetector row computed tomography (MDCT). Special attention was paid to the portal branch running to the left lateral sector, designated as the left cranio-lateral branch. The left cranio-lateral portal branch number was 0 in 57 patients, 1 in 32 patients, and 2 in 11 patients. Thus, 54 left cranio-lateral branches were identified, arising from near the cul-de-sac of the UP, from near the elbow of the LPV, or from the UP trunk. The median volume of the territory supplied by the left cranio-lateral portal branch was 21mL (range, 5-47mL), and the median ratio to the left lateral sector was 11.8% (range, 1.7-25.0%). Approximately 40% of patients had the left cranio-lateral portal branches arising cranially from the UP and running to the left lateral sector. When planning anatomic right hepatic trisectionectomy, the presence or absence of this branch should be checked by using 3D imaging with MDCT.

Pest survey card on Xylosandrus crassiusculus

This pest survey card was prepared in the context of the EFSA mandate on plant pest surveillance (M-2017-0137) at the request of the European Commission. Its purpose is to guide the Member States in preparing data and information for Xylosandruscrassiusculussurveys. These are required to design statistically sound and risk-based pest surveys, in line with current international standards.Xylosandruscrassiusculusis an ambrosia beetle within the subfamily Scolytinaeand is a clearlydistinguished taxonomic entity. The pest is present on all continents.Within the EU,X.crassiusculusis currently present in Italy, France and Spain and transient in Slovenia.Although itis currently reported in Mediterranean areas, the pest appears able to become established in many countries and regions of the Union territory. The ambrosia beetle is highly polyphagous and able to attack several broadleaf trees species. However, in Europe only three tree species have been reported as infested:Ceratonia siliqua, Cercissiliquastrum and Castaneasativa.The beetle may attack both thin branches of living trees (or saplings) and freshly cut wood.Trade of plants for planting, timber and wood products, as well as woodpacking material are major pathways for the introduction of X. crassiusculus into the EU and this is also confirmed by multiple interceptions at points of entry. Hence, international airports and seaports and surrounding areas with trading activities are considered risk locations and risk areas. In addition, as a lot of information on attacks on saplings in nurseries is available from North America, large nurseries with international trade may also be considered risk locations. Trapping is recommended when the females emerge and start attacking new hosts. Their flight activity is linked to warm daily temperatures and can start in early spring and last until October.

ОСОБЛИВОСТІ РОЗПОДІЛУ 137Сs У КОМПОНЕНТАХ ЛІСОВОГО БІОГЕОЦЕНОЗУ СВІЖИХ БОРІВ УКРАЇНСЬКОГО ПОЛІССЯ

Вивчено особливості розподілу 137Cs у компонентах лісового біогеоценозу свіжих борів Українсь-кого Полісся. Щільність радіоактивного забруднення ґрунту на пробній площі становила 267±9,6 кБк/м2. Питома активність 137Cs у компонентах біогеоценозу відрізнялася на кілька поряд-ків, з мінімумом у глибинних горизонтах ґрунту (28–30 см шар – 40 Бк/кг) і максимумом у надземнійфітомасі окремих видів рослин (щитник шартрський – 85937 Бк/кг). Компоненти соснового дерево-стану можна розмістити в такий ряд за зменшенням величини питомої активності 137Cs: пагони &gt;кора внутрішня &gt; шпильки &gt; кора зовнішня &gt; гілки тонкі &gt; гілки товсті &gt; деревина, а для трав’яно-чагарничкового покриву характерний такий ряд: щитник шартрський &gt; чорниця &gt; верес звичайний&gt; брусниця &gt; плаун булавовидний &gt; ортилія однобока &gt; ожика волосиста. Моховий покрив характе-ризується вищими величинами питомої активності радіонуклідів порівняно з лишайниковим покри-вом, де епіфітні види лишайників мають менший вміст 137Cs, ніж епігейні. У сосновому біогеоценозіґрунтовий покрив утримує основну частку сумарної активності радіонуклідів (76,66 %), з них на лі-сову підстилку припадає – 14,24 %, а на мінеральні шари ґрунту – 62,42 %. На інші компоненти при-падає – 23,34 %, де сосновий деревостан та моховий покрив відповідно становлять 12,02 та11,04 %, а на підріст, лишайниковий та трав’яно-чагарничковий покрив припадає лише 0,28 %. Осно-вна частка фітомаси фітоценозу припадає на деревний ярус – 85,10 %, на моховий покрив – 14,48 %,а роль інших ярусів рослинності в цьому екотопі була незначною та становила 0,42 %. Розподіл су-марної активності 137Cs по компонентах значно відрізняється порівняно з розподілом фітомаси наодиницю площі. Так, максимальну частку валового запасу 137Cs утримує деревний ярус (51,49 %) тамоховий покрив (47,32 %). Частка решти ярусів незначна, становить 1,19 % і представлена у тако-му порядку за зменшенням утримуючої здатності радіонуклідів: трав’яно-чагарничковий покрив &gt;лишайниковий покрив &gt; підріст. У сосновому біогеоценозі ключовими компонентами в утримуванійздатності та інтенсивності біогеохімічного кругообігу радіонуклідів є лісовий ґрунт, деревний яруста моховий покрив.

Assessment of the Characteristics of Recent Major Wildfires in the USA, Australia and Brazil in 2018–2019 Using Multi-Source Satellite Products

This study analysed the characteristics of the recent (2018–2019) wildfires that occurred in the USA, Brazil, and Australia using Moderate Resolution Imaging Spectroradiometer (MODIS) active fires (AF), fire radiative power (FRP, MW) and burned area (BA) products. Meteorological and environmental parameters were also analysed. The study found various patterns in the spatial distribution of fires, FRP and BA at the three sites, associated with various vegetation compositions, prevailing meteorological and environmental conditions and anthropogenic activities. We found significant fire clusters along the western and eastern coasts of the USA and Australia, respectively, while vastly distributed clusters were found in Brazil. Across all sites, significant fire intensity was recorded over forest cover (FC) and shrublands (SL), attributed to highly combustible tree crown fuel load characterised by leafy canopies and thin branches. In agreement, BA over FC was the highest in the USA and Australia, while Brazil was dominated by the burning of SL, characteristic of fire-tolerant Cerrado. The relatively lower BA over FC in Brazil can be attributed to fuel availability and proximity to highly flammable cover types such as cropland, SL and grasslands rather than fuel flammability. Overall, this study contributes to a better understanding of wildfires in various regions and the underlying environmental and meteorological causal factors, towards better wildfire disaster management strategies and habitat-specific firefighting.

Briquettes Produced With a Mixture of Urban Pruning Waste, Glycerin and Cassava Processing Residue

The briquette is considered a solid biofuel, made from the compaction of lignocellulosic residues used for the generation of energy. This work aimed to study the production of briquettes from mixtures of Urban Pruning Waste (RPU) (pruning of leaves and thin branches of trees), glycerin and cassava bagasse (Manihot esculenta). Samples of RPU, cassava bagasse and glycerol were mixed to yield treatments T1 (100% RPU), T2 (92% RPU and 8% cassava bagasse), T3 (97% RPU and 3% glycerin), T4 (89% RPU, 8% cassava bagasse and 3% Glycerin), T5 (94.5% RPU, 4% cassava bagasse and 1.5% glycerin) and T6 (control). Following this step, physical, chemical and energetic analyses (moisture content, volatile material content, fixed carbon and ash content, superior, inferior and useful calorific value, mechanical resistance, apparent and energetic density) of the briquettes were carried out. Treatment T2 had a lower fixed carbon value and volatile content, as well as higher ash content and mechanical strength. The percentages of carbon, hydrogen and nitrogen did not differ statistically between the treatments. The higher, lower and useful heating values were higher in treatment T3. The results showed that treatments T1, T2 and T3 were more efficient, producing briquettes with properties that meet market specifications, besides presenting great energetic potential, being good substitutes for firewood.

Robustly computing restricted Voronoi diagrams (RVD) on thin-plate models

Voronoi diagram based partitioning of a 2-manifold surface in R3 is a fundamental operation in the field of geometry processing. However, when the input object is a thin-plate model or contains thin branches, the traditional restricted Voronoi diagrams (RVD) cannot induce a manifold structure that is conformal to the original surface. Yan et al. (2014) are the first who proposed a localized RVD (LRVD) algorithm to handle this issue. Their algorithm is based on a face-level clustering technique, followed by a sequence of bisector clipping operations. It may fail when the input model has long and thin triangles. In this paper, we propose a more elegant/robust algorithm for computing RVDs on models with thin plates or even tubular parts. Our idea is inspired by such a fact: the desired RVD must guarantee that each site dominates a single region that is topologically identical to a disk. Therefore, when a site dominates disconnected subregions, we identify those ownerless regions and re-partition them to the nearby sites using a simple and fast local Voronoi partitioning operation. For each site that dominates a tubular part, we suggest add two more sites such that the three sites are almost rotational symmetric. Our approach is easy to implement and more robust to challenging cases than the state-of-the-art approach.

Produção de lenha e forragem de &lt;i&gt;Poincianella pyramidalis&lt;/i&gt; (Tul.) L. P. Queiroz submetida à poda anual

Algumas espécies lenhosas da caatinga possuem potencial para produzir forragem de qualidade a baixo custo. Suas folhas e ramas finas podem ser consumidas no campo ou fornecidas como feno, se forem coletadas na estação chuvosa, período de abundância, para suplementar a dieta dos animais no período seco do ano. Poincianella pyramidalis (Tul.) L. P. Queiroz (catingueira) aparece com bom potencial para a produção de forragem. O objetivo deste trabalho foi avaliar a produção de forragem de catingueira em função da intensidade de poda de suas ramas em dois anos consecutivos, e o efeito desta no DAP e acúmulo de biomassa lenhosa, e na forragem herbácea produzida sob e fora da projeção da copa. O trabalho foi desenvolvido na Fazenda Lameirão, Santa Terezinha-PB, Brasil. As ramas foram coletadas de 20 catingueiras adultas, de acordo com 5 intensidades de poda: T1 = 0%, T2 = 25%, T3 = 50%, T4 = 75% e T5 = 100% de poda. A produção média de forragem variou entre os tratamentos de 2,19 a 7,07 kg. árvore-1 (MS) em 2016 e de 1,33 a 2,41 kg. árvore-1 (MS) em 2017. A produção de forragem herbácea foi maior sob (1,60 t. ha-1) (MS) do que fora (1,07 t. ha-1) (MS) da copa. O corte das ramas não afeta o acúmulo de biomassa lenhosa e nem a produção herbácea. A composição química das forragens é satisfatória à alimentação animal.