Higher Absolute Density Research Articles

Qualitative Analysis of Sanitation Management in Residential Area around Gampong Jawa Landfill in 2021 Based on Fly Distribution Pattern

Abstract Aim: Residents are concerned about the presence of flies, especially in areas near landfills, so it is important to study the distribution patterns of fly communities and community responses to the presence of flies. This study focuses on two main topics: fly distribution in various zones and people’s perspectives on fly prevention initiatives. Materials and Methods: Data were collected by dividing the sampling location into four clusters and collecting data three times per day (morning, noon, and afternoon). Flypaper was used to collect the insects, which were then separated based on their morphology. The data were tabulated and analyzed using the Shannon-Wiener equation for the diversity index, and the Morisita index equation for the distribution pattern. The observation was then continued by asking people about the existence of the fly community. Results: Cluster 4 has the strongest dynamics with varying absolute density. The morning has the highest absolute density, with an average of 26.56. The findings of the relative density analysis suggest that Musca domestica has the highest percentage, with an average percentage of 74.36%. Only 45% of respondents took actions to combat the presence of flies. The study’s findings also revealed that 97% of the population had never been socialized about sanitary management and attempts to control fly communities. Conclusions: Community sanitation, the prevalence of trash, and the presence of insects are not successfully regulated. The residential sector of the Gampong Jawa Community, which has the most direct access to the landfill, is at a higher risk of getting affected by hazardous diseases conveyed by flies.

Lábrea

Lábrea, Amazonas, Brazil officially has 64.4% of its public streets lined with trees. However, there is no information available on the qualitative and quantitative aspects of this afforestation. The aim of the study was to inventory the urban afforestation of Lábrea to quantify and qualify the municipal road afforestation. The census of arboreal vegetation on the public roads covered parking lots and areas for pedestrian traffic (sidewalks and curbs) on the streets of the neighborhoods that make up the urban area, being recorded geolocated images of individuals. A total of 507 individuals were counted, distributed in 38 species and 15 botanical families, planting trees in the city’s public streets. The species ficus (Moraceae, Ficus benjamina) and jambeiro (Myrtaceae, Syzygium malaccense) had the highest absolute density. Afforestation is concentrated in the Centro district (50%). Disregarding the neighborhood, the most tree-lined street was October 22nd. The species are partially of native national origin (19 species, 50%), of which 63% are Amazonian (12 species). In absolute terms, individuals are mostly of exotic origin (79%). The individuals are in good structural condition, with type 1 phytosanitary status, located in sidewalks, conflicting or not with the electrical network (413 ind., 81%) without conflicts with the pavement (402 ind., 79%), outside the phenological period. Some common problems already reported also occur in the region. The low diversity of species in afforestation may indicate a certain loss in the quality of the urban physical and environmental structure.

STEMFLOW NUTRIENT INPUT IN TREES IN A TROPICAL FOREST IN PERNAMBUCO, BRAZIL

Rainfall is the main source of water in forest ecosystems and stemflow is an important pathway for nutrients to enter these ecosystems. Thus, this study aimed to evaluate effective precipitation in a fragment of tropical forest and stemflow nutrient input of tree species in different periods of rainfall. Total precipitation and throughfall were measured using rain gauges inside and at the edge of the fragment. After a phytosociological survey, nine species with the highest absolute density in the fragment were chosen and three individuals were selected. Water collectors were fixed around their trunk to collect stemflow water. The stemflow water was measured in milliliters, and pH, electrical conductivity and the input of K, P and Na were determined. Based on the throughfall and stemflow, the effective precipitation was calculated. The stemflow nutrient input presented the following decreasing order: Na>K>P. The high input of Na can be explained by the fact that the fragment is close to the coastal area. Stemflow of forest species proved to be an important pathway for nutrients to enter forest ecosystems, effectively participating in nutrient cycling.

Carbon in forest species of the Atlantic Forest as an indicator of stocks and quality

The objective is to quantify the carbon content (C) of the reservoirs of plant biomass of different species in a fragment of the Atlantic Forest in Northeast Brazil. Ten species of high absolute density were selected. We sampled biomass from the leaf and wood compartments of each species to determine the C content. There was a difference in leaf C levels between species. The C content in leaves of species varied between 451.4 and 456.7 g kg-1. The C content of the wood of species varied between 451.7 and 456.8 g kg-1. The group formed by the families Burseraceae, Moraceae, and Sapotaceae showed higher average levels of C in leaves. The Burseraceae family had the highest average C content in the species' wood. The use of a pre-established carbon content (500 g kg-1) may generate inconsistent estimates higher than the real values for the species and families in an Atlantic Forest environment. We suggest that C stock estimates use specific levels for species and/or families, contributing to a more realistic estimate of C storage patterns in the shoot biomass of Atlantic Forest species.Keywords: Carbon concentration; Carbon sequestration; Tropical Rainforest.

Characterization of physical and mineralogical properties of anthracite and bituminous coal tailings

ABSTRACT In this paper, the physical and mineralogical properties of two types of tailings produced from anthracite and bituminous coals were studied and compared. The following characteristics were determined: absolute density, particle size, and elemental and mineral compositions. The goal of this research is to provide basic characterizations of the two common coal tailings for potential future coal tailings reprocessing and combustion. Anthracite tailings (i.e., tailings from the higher rank coal) are characterized to have higher absolute densities, coarser grain size distributions, higher hydrophobicity, and less platy particles, compared to bituminous coal tailings. The uniformities of grain size are similar for both coal tailings. Based on these properties, analyses show that coal fines are easier to be extracted or separated from anthracite tailings. The average particle size of both coal tailings, however, may need to be modified accordingly to meet the specifications of available combustion techniques.

Nutritional Efficiency of Forest Species in Natural Regeneration of Tropical Forest in Brazil

The knowledge of the nutritional aspects of native species, mainly in natural regeneration, may be important for understanding their establishment, particularly in areas with low nutrient availability soils, such as tropical soils. This study aimed to determine the biological utilization efficiency (BUE) of the nutrients N, P, K, Ca, and Mg of forest species of natural regeneration in a Lowlands Dense Ombrophilous forest fragment in Pernambuco, Brazil. A phytosociological study of the fragment was carried out and were defined the ten species with the highest absolute density (AD). Three individuals per species were selected. The N, P, K, Ca, and Mg contents were determined in the sample leaves of the species, and the foliar biomass was determined “in loco”. Nine individuals of each species were collected according to the following diameter intervals at the base (DBs): DBs<5 cm; 5≤DBs<10 cm and 10≤DBs<15 cm. The content, stock and BUE of nutrients were calculated per species. The BUE of nutrients by species varied according to the following decreasing order: P>Mg>K>Ca>N. The highest BUE of nutrients was of the species Protium heptaphyllum. In tropical soils of low natural fertility, the use of these species can be recommended in environmental reforestation projects. The difference in the nutritional demand of the forest species can indicate the planting of those with greater capacity of absorption and BUE of nutrients, being more efficient in areas of soils with low natural fertility like in the tropical forests.

DIVERSIDADE E ESTRUTURA HORIZONTAL DE SISTEMAS AGROFLORESTAIS EM MONTE ALEGRE, PARÁ

RESUMO: O estudo da fitossociologia é importante para a avaliação de sistemas agroflorestais, pois fornece dados que possibilitam manejo mais adequado do sistema. O objetivo desse trabalho foi identificar espécies e caracterizar a estrutura horizontal e diversidade de sistemas agroflorestais no município de Monte Alegre, PA. Foram instaladas parcelas amostrais de 30 x 30 metros, onde coletou-se dados de diâmetro a altura do peito, número de espécies e altura total dos indivíduos. O sistema estudado possui seis arranjos com diferentes idades, no qual sua estrutura horizontal foi analisada através da abundância, dominância, frequência absoluta e relativa, obtidas a partir dos dados de indivíduos com DAP ? 5 cm. Para obter a diversidade de espécies foi usado o índice de Shannon-Weaver (H’). Os SAFs avaliados obtiveram um total de 253 indivíduos, em 12 famílias botânicas e 14 espécies. O índice de Shannon-Weaver (H') foi de 2,28, o que denota diversidade intermediária de espécies nos SAFs. A análise estrutural constatou que o mogno brasileiro (Swietenia macrophylla) foi a espécie com maior índice de importância, enquanto o mogno africano (Khaya ivorensis) obteve o maior índice de cobertura e dominância absoluta. Já o café (Coffea arabica) foi a espécie com maior densidade absoluta e a teca (Tectona grandis) a espécie com maior frequência absoluta.PALAVRAS-CHAVE: Agrossilvicultura, Arranjos florestais, Fitossociologia.

Processing and Properties of Ni-Based Bulk Metallic Glass via Spark Plasma Sintering of Pulverized Amorphous Ribbons

ABSTRACTNi-based bulk metallic glasses and composites with high absolute densities exceeding 11 g/cm3 were synthesized via spark plasma sintering of Ni45Co10Ta25Nb20 powders produced from pulverized, melt-spun amorphous ribbons. Optimizing the synthesis via selection of sintering temperature, uniaxial load pressure, and powder mechanical screening yielded samples with relative densities of nearly 100% and hardness values in excess of 12.5 GPa without cracking. Mechanical testing included Weibull modulus determination for hardness and compression testing at 10-3 s-1 and 103 s-1 strain rates. The capability of using spark plasma sintering to fabricate high hardness, high density, large scale metallic glasses is demonstrated. The mechanical properties of these compacted comminuted melt-spun glass ribbons are presented.

Effect of the Intra-Particle Diffusion and Porous Structure on Models for Adsorption and Storage of Methane onto Activated Carbons

Activated carbons were produced by chemical activation with H3PO4 (CAQ1) and ZnCl2 (CAQ2), and used for the methane storage under compression and adsorption. Storage evaluations were performed in a semi-pilot unit where temperature and pressure evolutions were measured (charge pressure: 3.0 MPa). Textural characteristics, absolute densities and specific heats of the activated carbons were measured and related to the performance of the storage system. Mathematical models were developed to predict temperature and pressure evolutions during the gas loading. Our results showed that activated carbon CAQ1 had higher absolute density and lower specific heat than CAQ2. Models that consider the pore-size distribution were the most representative of experimental data for both activated carbons.

Regeneração de espécies arbóreas e relações com componente adulto em uma floresta estacional no vale do rio Uruguai, Brasil

O estudo de fenômenos relacionados às variações na estrutura das comunidades vegetais tem cada vez mais envolvido a avaliação do potencial de regeneração das espécies arbóreas, uma vez que a regeneração torna as florestas capazes de se restaurarem após distúrbios naturais ou antrópicos. Neste sentido, objetivou-se avaliar o componente arbóreo regenerante, identificando composição e abundância, grupos funcionais de dispersão, estratificação vertical e necessidades de luz para germinação, além de estimativas de riqueza e diversidade e comparar estes valores com o respectivo componente adulto. O levantamento foi realizado em 20 unidades amostrais de 10 x 10 m, sendo amostrados todos os indivíduos com altura > 0,30 m e diâmetro a altura do solo < 4,7 cm. O levantamento do componente adulto, avaliado em estudo anterior, foi estabelecido em unidades amostrais de 20 x 20 metros, sendo amostrados todos os indivíduos com diâmetro à altura do peito > 4,7 cm. Foram amostrados 1.649 indivíduos em regeneração, pertencentes a 64 espécies, com densidade total estimada em 8.245 ind.ha-1. As espécies com maior densidade absoluta foram Gymnanthes concolor Spreng., Trichilia elegans A.Juss. e Calyptranthes tricona D.Legrand. Uma análise de coordenadas principais indicou nítida separação das unidades amostrais amostradas e um teste de Mantel revelou haver independência entre as matrizes de composição e abundância dos componentes adulto e regenerante (r = 0,19; p = 0,1). Dentre os grupos funcionais, verificou-se que o componente regenerante está mantendo as mesmas proporções observadas para o componente adulto, com maior proporção de espécies zoocóricas, dependentes de luz para germinação e formadoras do dossel florestal. Ao contrário do esperado, houve diminuição da riqueza no componente regenerante (p < 0,001) e manutenção da equabilidade ao longo da área.

Caracterização fitossociológica em áreas de ocorrência natural de candeia (Eremanthus erythropappus (D.C.) MacLeish)

A candeia vem sendo submetida a uma exploração desordenada, devido ao seu elevado potencial econômico. A solução para o controle da exploração de forma desordenada é o desenvolvimento e a execução de planos de manejo florestal, sendo, o conhecimento da estrutura de Eremanthus erythropappus (candeia), tanto na forma específica quanto na forma florestal, de fundamental importância para o desenvolvimento de um manejo adequado. Os objetivos deste trabalho foram estudar a estrutura de E. erythropappus, em diferentes ambientes, e caracterizar os parâmetros das estruturas horizontal, vertical e interna e as distribuições de diâmetro, área basal e volume da espécie. Foram utilizados dados de cinco áreas: as áreas 1, 2 e 3, maciços de candeia na forma específica; área 4, ocorrência rara de candeia; e área 5, ocorrência de candeia na forma florestal. Foram amostradas cinco parcelas de 400 m² distribuídas sistematicamente em cada área. Após as análises, verificou-se que com o decorrer do tempo, cresce a população de outras espécies e decresce a população de candeia. A área 1 apresentou maiores valores de densidade absoluta, enquanto os melhores indivíduos de candeia, tanto em tamanho quanto em qualidade de fuste, ocorreram na área 5. Os indivíduos arbóreos das áreas estudas foram agrupados em dois estratos de altura total, porém os limites dos estratos verticais diferiram de uma área para outra. A distribuição da densidade (n ha-1) por classe de diâmetro para a comunidade arbórea e considerando apenas os indivíduos de candeia não diferiu significativamente pelo teste de Qui-quadrado.

Distribution of hydrous aluminium and iron over density fractions depends on organic matter load and ultrasonic dispersion

Studies of organic–mineral interactions in soils often include physical fractionation according to particle size and density to separate organic debris and mineral-associated matter. For density fractions, it has been noticed that Fe hydrous compounds, although having a high absolute density, can be found in fractions supposed to contain only compounds of lower density. Probable reasons are incomplete wetting due to nanopores, thus reduced apparent density, the slow settlement during centrifugation because of the small particle size, and association with organic matter, reducing the absolute density and favouring dispersion. Allocation of associations of organic matter and hydrous mineral phases to light fractions may affect the estimation of mineral-associated organic matter in soils. We tested the distribution of goethite, 2-line ferrihydrite, and amorphous Al(OH) 3), associated with different amounts of organic matter, across density fractions obtained by floating in Na polytungstate solutions of 1.6, 2.0, and 2.4 g cm − 3 density, followed by centrifugation at 5000 g. Without organic matter, the two Fe minerals with absolute densities > 3.9 g cm − 3 , were recovered almost completely in the fraction > 2.4 g cm − 3 , irrespective the mode of dispersion (manual agitation or sonification with an energy input of 300 kJ ml − 1 ). Amorphous Al(OH) 3, having a density of 2.2 g cm − 3 , was recovered entirely in the fraction 2.0–2.4 g cm − 3 when agitated manually while little material (< 5%) was found in the fraction 1.6–2.0 g cm − 3 after ultrasonic dispersion. Thus density fractionation properly separates pure mineral particles according to their absolute density, neither affected by small particle size nor by incomplete wetting. Organic–mineral associations, resulting either from sorptive interactions or co-precipitation, had smaller absolute densities than the pure mineral phases, according to their content of organic matter. When agitated manually, > 95% of them were completely recovered in the appropriate density fraction, except for associations with extremely large organic contents (co-precipitates), of which small portions were found in the next lighter fraction. The application of ultrasonic energy, in contrast, resulted in up to 100% of the organic–mineral materials to be found in lighter fractions. The portion of material recovered in lighter fractions related positively to the content of mineral-associated organic matter. The results suggest that the application of ultrasonic energy to disrupt soil aggregates can cause dispersion of negatively charged organic–mineral associations in Na polytungstate solution, resulting in erroneous allocation to density fractions.

Estimates of high absolute densities and emergence rates of demersal zooplankton from the Agatti Atoll, Laccadives

Direct sampling of the sandy sub stratum of the Agatti Lagoon with a corer showed the presence of very high densities of epibenthic forms. On average, densities were about 25 times higher than previously estimated with emergence traps. About 80% of the organisms migrated into the water column within an hour after sunset, and maximal resettlement occurred soon after dawn.

An experimental study of habitat selection by the deer mouse, Peromyscus maniculatus, on Mandarte Island, B.C.

Mandarte Island, British Columbia, Canada, consists of a mosaic of shrubbery and grassland habitats. In a 6-month study, deer mice, Peromyscus maniculatus, were found to live at high absolute density and at higher relative densities in shrubbery habitat. A removal experiment was conducted to investigate how the habitat preference and density of mice affect their distribution on Mandarte Island. All resident mice were removed from an area containing both shrubbery and grassland. This gave mice dispersing from other areas the opportunity to colonize these two vacant habitats. Mice settled first in the shrubbery. As population density increased, some later colonists occupied the less favoured grasslands. I suggest that intraspecific interaction, associated with high density, was sufficient to prevent settlement of some individuals in the preferred habitat.

Some structural and developmental characteristics of cetacean (odontocete) radii. A study of adaptive osteogenesis.

AbstractOdontocete radii are short, flattened, longer than the humeri, and lacking in open medullary cavities. Their cross‐section is essentially a semi‐streamlined wedge. End‐on articulation at the elbow is a synchondrosis. In the streamlined, amuscular antebrachium, the radius sustains loadings predominantly in the mediallateral transverse plane as flipper movements (at the shoulder) counter body inertia and water resistance in controlling body attitude.This study treats secondary marine adaptation as reflected in radial development, growth and mechanical organization. Early osteogenesis is similar to that we reported for cetacean humeri, and parallels conditions in the manatee. Later differential growth is analyzed in extenso. Geometry of growth is visualized radiographically in the relationship of endochondral to periosteal bone in the absence of medullary cavitation. Furthermore, the neonatal outline is distinguishable within the porous structure of (only) beluga radii, so that pre‐ and postnatal phases may be differentiated. Radiographs and models demonstrate that as elongation occurs, circumferential increments to growth cartilages are eccentric, i.e., minimal anteriorly, moderate medially and laterally and maximal posteriorly. By this method, the centers of epiphyseal cartilage plates migrate posteriad with time. Periosteal depositions follow the same pattern and are deepest posteriorly. Eccentric growth of the ulna is in the opposite sense. Additionally, proximal growth cartilages of radii tilt posteriad as the bone elongates. Some alterations in growth occur at birth and later. Eccentric growth is an adaptation by which anterior and posterior margins, respectively, of radius and ulna move apart as the bones elongate, and by which functional cross‐sections are maintained in antebrachial bones, singly and as a pair.Bone is concentrated on medial and lateral sides of the radius. This feature, and porosity of the central region, varies with species. Radii, like humeri, thus mimic an engineered box‐beam, and trabecular orientation resembles trajectorial distribution in a loaded beam.Radii have higher absolute densities than do humeri, although both bones have the same range of mineralization as typical mammalian bones. The beluga radius is half again as dense as that of the pilot whale, and thus is intermediate in density between those of most odontocetes and that of the hypothyroid, pachyostotic manatee. The possible evolution of odontocete bones from a more dense dense form, as well as the phylogenetic implications of density changes, are discussed. It is suggested that some of the characteristics of growth and structure, including an apparent periodicity in structural density, may be related to temperature and vascular supply in the high‐area, low‐volume flipper in colder waters.

I. On the specific heats of gases at constant volume. Part II. Carbon dioxide

In the former experiments on this gas, recorded in the first part of this research, the highest absolute density at which the specific heat was determined was 0·0378. In the present observations the determinations of specific heat have been carried to densities at which the substance was partly in the liquid state at the lower limit of temperature of the experiments. Observations dealing with true specific heat, uncomplicated by the presence of thermal effects due to the presence of liquid, are limited by the density 0·1444. At this density the mean specific heat over the range, 12° C. to 100° C., is 0·2035.