Top Of Hill Research Articles

Cumulative production curve method for the quantitative evaluation on the effect of oilfield development measures: A case study of the nitrogen injection pilot in Yanling oilfield, Bohai Bay Basin

To evaluate the effect of oilfield development measures quantitatively, based on the theory of Arps production decline, this study deduced a linear relation between the product of cumulative production with production time (Npt) and production time (t), and established the cumulative production curve method for quantitative evaluation on the effect of development measures. The nitrogen injection pilot in Yanling oilfield was taken as an example to calculate the recoverable reserves before and after the nitrogen injection, and through the variation of recoverable reserves, the effect of the nitrogen injection on actual production was quantitatively evaluated. Similarity analysis of decline curve shape in the late period shows that the method is not restricted by decline types and the relationship curve between Npt and t in the late development is always tending to a straight line. The cumulative production curve method is not only suitable for single wells but also not restricted by reservoir types. Combined with derivative curve in diagnosis, it reflects the microscopic variations of the slope in the straight line segment and the variations of recoverable reserves and the process of reserve producing. The single wells in the Yanbei nitrogen injection pilot were evaluated quantitatively using the cumulative production curve method, the results show that: the nitrogen injection causes obvious productivity increase of the oil wells in the hillside of the buried hill, productivity decrease of the oil wells at the top of buried hill, and little influence on the productivity of oil wells in the margins of burial hill.

Wind direction field under the influence of topography: part II: CFD investigations

Though hilly topography influences both wind speeds and directions aloft, only the influence on wind speeds, i.e. the speed-up effect, has been thoroughly investigated. Due to the importance of a model showing the spatial variations of wind directions above hilly terrains, it is worthwhile to systematically assess the applicability and limitations of the model describing the influence of hilly topographies on wind directions. Based on wind-tunnel test results, a model, which describes the horizontal and vertical variations of the wind directions separately, has been proposed in a companion paper. CFD (Computational Fluid Dynamics) techniques were employed in the present paper to evaluate the applicability of the proposed model. From the investigation, it has been found that the model is acceptable for describing the vertical variation of wind directions by a shallow hill whose primary-to-secondary axis ratio (aspect ratio) is larger than 1. When the overall hill slope exceeds 20, the proposed model should be used with caution. When the aspect ratio is less than 1, the proposed model is less accurate in predicting the spatial variation of wind directions in the wake zone in a separated flow. In addition, it has been found that local slope of a hill has significant impact on the applicability of the proposed model. Specifically, the proposed model is only applicable when local slope of a hill varies gradually from 0 (at the hill foot) to the maximum value (at the mid-slope point) and then to 0 (at the hill top).

Carbonate rocks and American Civil War infantry tactics

The most studied battleground from the American Civil War, from a geological perspective, is the rolling terrain surrounding Gettysburg, Pennsylvania. Here, the mixture of harder diabase and softer sedimentary rocks produced famous geomorphic features such as Cemetery Hill and Little Round Top that provided strong defensive positions for the Union Army. Another even more common type of rock—carbonates—provided similarly formidable defensive positions at numerous other battlefields in both the eastern and western theaters of conflict. Limestones and dolostones shaped the terrain of multiple important battle sites, including Antietam, Stones River, Chickamauga, Franklin, Nashville, and Monocacy, and these rock types proved consequential with respect to the tactics employed by both Union and Confederate commanders. On many battlefields, outcropping limestone proved beneficial for attacking troops; differential weathering within carbonate formations produced rolling terrain that limited the range and effectiveness of both artillery and small arms (e.g., “Sunken Road” at Antietam). Thin regoliths above limestone also prevented tillage, and the resulting forests provided concealment and cover for advancing troops (e.g., Stones River). From a defensive perspective, on a larger geographic scale, carbonates provided natural high ground from chert-enriched limestones and dolostones (e.g., Missionary Ridge, Chickamauga, Franklin, and Nashville). On a smaller scale, erosion of these same rocks produced karrens that provided natural rock-lined trenches for defending troops (e.g., “Slaughter Pen” at Stones River). Analysis of casualty figures (killed and wounded only) indicates similar losses (∼15% of troops engaged) whether soldiers were attacking across carbonate rock, non-carbonate rock, or unconsolidated sediments. Soldiers defending ground underlain by limestones and dolostones had a slightly higher casualty rate (14%) than those defending terrain above non-carbonate rocks or unconsolidated sediments (12%). This suggests, in a limited manner, that the local smaller-scale defensive advantages provided by limestone, such as karrens, were not as important as the regional-scale advantages for attacking troops, including rolling terrain or forest cover.

ANÁLISE ECOFISIOLÓGICA DE GENIPA AMERICANA L. EM BANCO DE SEMENTES INDUZIDO

RESUMO Este trabalho foi realizado com o objetivo de estudar o comportamento de sementes de G. americana L. (Rubiaceae) em bancos de sementes induzidos. A pesquisa foi realizada no município de Lavras - MG em uma floresta estacional semidecídua da Universidade Federal de Lavras. As sementes coletadas foram beneficiadas e caracterizadas quanto ao conteúdo de água, viabilidade e tolerância à dessecação. Foram instalados bancos de sementes induzidos em duas áreas distintas (topo de morro e mata ciliar) localizados no sub-bosque da floresta. As sementes foram acondicionadas em redes de náilon e cobertas com camada de serapilheira previamente removida para instalação das redes. Foi realizada avaliação mensal da germinação, emergência das plântulas, conteúdo de água das sementes e do solo e a caracterização do crescimento inicial das plântulas. Foi observado que sementes de G. americana formam banco de sementes transitório, com manutenção de sua viabilidade somente até o quarto mês após dispostas em ambiente natural. De modo geral, o banco de sementes na área de mata ciliar foi o que apresentou o maior potencial para o estabelecimento de plântulas em ambiente natural o que está de acordo com as características ecológicas dessa espécie.

Geotecnologias para monitoramento florestal no município de Nova Palma - Rio Grande Do Sul – BR

Human land occupation has always been associated to gathering natural resources, where it is necessary to know about land coverage and usage dynamics. This way, the purpose of this work is to investigate temporal dynamics of forest coverage, by geotechnologies such as Remote Sensing. Methodology starts by multitemporal mapping of forest coverage in the municipality of Nova Palma, located in the Quarta Colônia de Imigração Italiana (fourth colony of italian imigration), Rio Grande do Sul. Using software SPRING, in monitored classification of satellite images of Landsat 5 Satellite in the year of 1985 Landsat 8 Satellite in the year of 2014. Afterwards spatial analysis, by Spatial Lenguage for Algebric Geopressessing (LEGAL), it was able to determine the following situation: forestal regeneration, deforestation and maintenance. Results show that reforestation areas concentrate in the influence area of Usina Hidreletrica de Dona Francisca (Hydroeletric Plant of Dona Francisca). Areas of deforestation ocurred in areas that the land are being prepared to production. The maintenance was by areas of greater terrain declivity, hill tops and watershed surroundings, areas considered Areas of Permanent Preservation (Área de Presevação Permanente - APP). In conclusion, the forestal expansion process was predominant in the municipality during monitoration season.

Análise de Conflito de Uso e Cobertura da Terra em Áreas de Preservação Permanente do Ifes – Campus de Alegre, Município de Alegre, Espírito Santo

RESUMOObjetivou-se analisar o conflito de uso e cobertura das terras em Áreas de Preservação Permanente (APP) do Ifes – Campus de Alegre, à luz do atual Código Florestal Brasileiro. Foram delimitadas e investigadas as APP de nascentes, cursos d’água, declividades e topos de morro. As APP de declividades e de topos de morro foram obtidas a partir do modelo digital de elevação global GEDM-ASTER. O uso e a cobertura da terra foram alcançados por fotointerpretação sobre imagem orbital do sensor Geoeye 1 (resolução espacial de 0,50 m), totalizando 36 classes temáticas. Os resultados revelam que as APP totalizam 34,33% da área do Ifes – Campus de Alegre, ocupando 114,32 ha de extensão. As APP de topos de morro e dos cursos d’água são as que ocupam maior área, correspondendo a 16,94% e 14,03%, respectivamente. As APP de cursos d’água são as mais atingidas e as principais classes responsáveis por conflitos são as pastagens naturais (20,41 ha) e as estradas não pavimentadas (1,18 ha).

Study on Buffering Capacity and Organic Matter of some Soil Samples from Rungicherra Tea-Estate, Bangladesh

In this study, soil samples from three different hills of three topographic positions were evaluated on the basis of buffer capacity and organic matter. Maximum soil samples were found to have good buffer capacity where soil samples of topographical positions hill base and hill top showed maximum and minimum values respectively, leaving hill slope samples in medium value of buffer capacity. Our study suggested this variation of buffer capacity may be due to the differences of organic matter amongst the topographical positions and profiles.

A GIS analysis of Early Bronze Age settlement patterns in Armenia

This paper presents an analysis of Early Bronze settlement patterns in the territory of Republic of Armenia, based on 128 sites, which have been mapped in GIS software. The analysis of land use pattern reveals that the establishments are from 500 m to 2200 m of altitude, during the all period of Kura–Araxes culture (∼3500–2500/2400 bce) and are distributed in six clusters. Three main types of establishments have been distinguished: the mound, the top of natural hill and the slope of hills or promontories. Some flat areas (Tsaghkahovit plain, Shirak plain, Masrik plain) lacked establishments during the Early Bronze Age but are flanked by establishments on the slope of hills or promontories. More than 70 sites have been dated based on 14C, pottery style, and stratigraphy. Comparison of two phases of Kura–Araxes culture does not reveal any land use or establishment type change, except its inter-regional organization with major sites surrounded by a few smaller sites during EB II, which raises the problem of the evolution of the regional organization of sites. Furthermore, the distribution of settlements and the natural resources (especially obsidian and copper) reveals a concentration of sites during EB II around the resources in northeast Armenia, and highlights the problem of economy and trade during the Early Bronze Age in Transcaucasia. These results also show the interest of interdisciplinary collaboration and the necessity to clarify the chronology of the Kura–Araxes culture, because of some problems which turn out only when we consider the different phases of Kura–Araxes culture separately.

Study on Buffering Capacity and Organic Matter of some Soil Samples from Rungicherra Tea-Estate, Bangladesh

In this study, soil samples from three different hills of three topographic positions were evaluated on the basis of buffer capacity and organic matter. Maximum soil samples were found to have good buffer capacity where soil samples of topographical positions hill base and hill top showed maximum and minimum values respectively, leaving hill slope samples in medium value of buffer capacity. Our study suggested this variation of buffer capacity may be due to the differences of organic matter amongst the topographical positions and profiles.

English

The present study was conducted to study the variability in soil properties in relation to landforms, in the present investigation, two transects that is, Aravalli mountain ranges and Malwa plateau, were selected in the Pratapgarh district having eight landforms namely hill, pediments, valley, and plain in the Aravalli Mountain ranges and Malwa plateau, respectively. Total eight pedons were examined in the field and investigated in the laboratory using standard laboratory procedures. The soils on hill top and pediment were shallow, gravely sandy loam to clay loam single grain in texture with medium coarse weak sub angular blocky structure and exhibited dark yellowish brown to dark reddish brown colour. The soils of valley were deep, sandy  loam to loam and silty clay loam to clay loam in texture with medium coarse weak sub angular blocky to medium fine moderate sub angular blocky structure and exhibited dark yellowish brown to dark reddish brown colour. The soils of plain were found deep, silty clay in texture with medium moderate to strong angular structure (angular and sub angular) and exhibited dark brown to very dark grayish brown colour. The available water capacity were recorded higher in the plain soils as compared to soils of other landforms as well as in Aravali mountain ranges and Malwa plateau. The pH was relatively higher in the soils of Aravali mountain ranges than Malwa plateau but EC was relatively lower in the soil of Aravali mountain ranges then Malwa plateau. Distribution of organic carbon was low in soils of all pedons but comparatively higher in soils of Malwa plateau. Base saturation was comparatively lower in the soils of lower topographic position. Cation exchange capacity was found positively correlated with clay and increases as clay increased down the slope as well as with depth. Concentration of exchangeable bases was in order of Ca2+>Mg2+>K+>Na+ in all the pedons soils.   Key words: Toposequence associated soil, morphological, physical, chemical properties, taxonomy.

Evolution of a small Eemian lake in a unique location on a kame hill: Haćki site, NE Poland

An Eemian lake in a unique location at the top of a kame hill was found in NE Poland. Results of pollen and microscopic plant remains analyses show that despite the unusual location, its development and terrestrialization were typical for small meso-/eutrophic lakes of the temperate zone. At the end of the interglacial period an overgrown basin was flooded with water and again transformed into a lake. It existed until the beginning of the Brørup interstadial, and then it was covered with diluvia and/or aeolian sediment and finally disappeared.

Diversity of Ants Inhabiting a Mosaic of Environmental Conditions in a Semi-Desert of Central Mexico

Biotic and abiotic factors affect the species richness and abundance of ants inhabiting arid and semiarid zones. We evaluated how soil surface temperature, texture, percentage of surface coarse fragments, and vegetation affected the composition, diversity, and distribution of ants inhabiting a mosaic of environmental conditions in a semiarid zone in central Mexico. We captured 22 ant species at five sites studied, with the top of Cutac hill (1,750 m altitude) and Terrace 2 (1,376 m altitude) the richest sites with 10 species each. Based on redundancy analyses, the percentage of clay followed by the percentage of coarse fragments at the surface of the soil were the variables most related to the composition of ants in these communities. Percentage of clay ranged from 16 to 26 and was positively related to abundance of Pheidole sp. 1 and negatively related to abundance of Dorymyrmex bureni Trager (R2 = 0.76, P = 0.04; R2 = 0.86, P = 0.02, respectively), whereas percentage of soil surface coarse fragments ranged from 0.8 to 59 and were negatively correlated to Pheidole sp. 1 (R2 = 0.76, P = 0.05), but positively correlated to abundance of Brachymyrmex sp. (R2 = 0.86, P = 0.06). When ants were analyzed by functional group, vegetative structure (ranging from 109 to 246 hits with vegetation) and percentage of coarse fragments in the soil were most correlated with their distribution. Although results of the redundancy analyses were not statistically significant, preliminary analysis of variables might explain the composition and distribution of an ant community. We suggested that soil characteristics might be important for explaining ant distribution and community composition.

Seismic site effects observed on sediments and basaltic lavas outcropping in a test site of Catania, Italy

Ambient noise measurements and a set of 44 moderate magnitude earthquakes were used to study the role of local geology and morphology on the site response of a small hill in the northern part of Catania, on top of which the University Astronomical Observatory is located. The study area has a gentle topography with a flat surface at the top, and it is characterized by a complex sedimentary sequence lying between a clayey basement and an upper volcanic formation. The recorded data were processed through standard spectral ratio and horizontal-to-vertical spectral ratio techniques. Directional effects were also investigated by computing the spectral ratios after rotating the horizontal components of motion and performing polarization analysis. Results of noise and earthquakes analysis, although showing significant differences in amplitude, are comparable in frequency, especially in the sedimentary terrains. On the lava flows, spectral ratios show significant amplification of the vertical component, which appear related to a higher P velocity contrast with underlying soft sediments. Directional effects were identified in two frequency bands (0.2–0.4 and 1.0–10.0 Hz). The effects observed at the lower frequency interval are rather stable, and it spreads out in all the studied area. At higher frequencies, directional effects are variable and mostly observed on the slopes rather than at the hill top. Our findings appear linked to the complex wave field generated by the lithologic heterogeneities existing in the area which seem to be related to the alternation of sediments and basaltic lavas.

Utilização de Geotecnologia para o Mapeamento de Áreas de Preservação Permanente no Município de João Neiva, ES

Este estudo propõe-se a demonstrar como a utilização de geotecnologias pode ajudar de forma eficaz no mapeamento de Áreas de Preservação Permanente (APPs), auxiliando no entendimento das áreas a serem preservadas. O estudo foi realizado em todo o município de João Neiva, ES, com o objetivo de elaborar mapas analógicos e digitais do município; delimitar as Áreas de Preservação Permanente na óptica da Legislação Ambiental; confrontar essas áreas com o uso da terra correspondente; e ressaltar a importância de identificar as áreas de forma automática, para que se possam implantar projetos ambientais que visem promover ações em busca de um relacionamento sustentável entre homem e ambiente de forma mais eficiente. O município de João Neiva possui uma área de 88,64 km² de APPs totais (32,55% da área total do município). As APPs ao redor de nascentes (buffer de 50 m), nas encostas com declividade superior a 45 graus, topos de morro (terço superior de morros) e margens dos cursos d’água (buffer de 30 m) representaram, respectivamente, 0,54 km² (0,20%), 1,92 km² (0,70%), 62,66 km² (23,01%) e 23,50 km² (8,63%) da área total do município.

Optimizing a catalyst many ways at once

Organic Chemistry Optimization strategies are often likened to hikes in a hilly landscape. If your goal is to get to the top of the highest hill, and you only take steps toward higher ground, you might never find a peak on a route that requires a preliminary descent. So it is in chemistry, where optimizing each structural feature of a catalyst consecutively might gloss over subtle tradeoffs that in combination offer the best performance. Milo et al. use multidimensional analysis techniques to generate a predictive model of how selectivity depends on multiple characteristics of the catalyst and substrate in a C-N bond-forming reaction (see the Perspective by Lu). They then apply this model to improve the catalyst globally. Science , this issue p. [737][1]; see also p. [719][2] [1]: /lookup/doi/10.1126/science.1261043 [2]: /lookup/doi/10.1126/science.aaa5624

Organic chemistry. A data-intensive approach to mechanistic elucidation applied to chiral anion catalysis.

Knowledge of chemical reaction mechanisms can facilitate catalyst optimization, but extracting that knowledge from a complex system is often challenging. Here, we present a data-intensive method for deriving and then predictively applying a mechanistic model of an enantioselective organic reaction. As a validating case study, we selected an intramolecular dehydrogenative C-N coupling reaction, catalyzed by chiral phosphoric acid derivatives, in which catalyst-substrate association involves weak, noncovalent interactions. Little was previously understood regarding the structural origin of enantioselectivity in this system. Catalyst and substrate substituent effects were probed by means of systematic physical organic trend analysis. Plausible interactions between the substrate and catalyst that govern enantioselectivity were identified and supported experimentally, indicating that such an approach can afford an efficient means of leveraging mechanistic insight so as to optimize catalyst design.

Basalt stratigraphy and silica gossans in Campo Grande and Serra de Maracaju, Mato Grosso do Sul, Paraná Volcanic Province

Thousands of silica gossans are exposed at the top of the Lower Cretaceous basalt hills in the Paraná volcanic province, strongly indicating the presence of calcite, amethyst and agate geode deposits along with native copper mineralization. The Embrapa silica gossan in the northwestern portion of the province (Campo Grande region) is an excellent example of such novel geological structure in the continental flood basalts. This silica gossan has a size of 450×350m standing out as a treeless area in the densely wooded savanna and makes part of the stratigraphy of six basalt flows of Paranapanema intermediate-Ti chemical type. The base of the volcanic column is constituted by two Pitanga types and the overlying column is Paranapanema type. Every basalt flow has a silicified sand layer or breccia at the top and these are fed by abundant sand dikes. The Anel Viário Norte (AVN) flow is the most intensely altered by hydrothermal fluids producing voluminous secondary calcite infillings in the amygdales and fractures. In this region the basalts contain higher copper content than the average of the volcanic province. The studied silica gossans display negative anomalies in gamma spectrometry as a response to K, U and Th depletion during alteration. We propose a new exploration methodology by observing GoogleEarth images complemented with field studies and geochemistry to readily locate favorable areas for amethyst and agate geode deposits and native copper mineralization.

Characterization and Classification of Soils in Eastern Himalayan Agro-climatic Region: A Case Study in Nongpoh Micro-watershed of Ri-Bhoi District, Meghalaya

Typical pedons representing major landforms of Nongpoh micro-watershed in Ri-Bhoi district of Meghalaya viz., hill top, hill slope and inter hill valley developed from granite–gneiss occurring under varying land use were characterized, classified and assessed. The soils were deep to very deep in depth, brown to greyish brown in colour, slightly acidic to extremely acidic in reaction and high to medium in organic carbon. Further, the soils were low to high in available nitrogen, low to high in available phosphorus and medium to high in available potassium. Pedon P2 and P3 which are located on the hill top and the hill slopes, respectively showed cambic (Bw) sub-surface diagnostic horizon and were classified as Typic Dystrudepts while the hill top pedon P1 and on hill slope pedon P4, sub-surface diagnostic horizon possessed argillic (Bt) horizon which was classified as Typic Paleudalfs. However, pedons located on the inter hill valley (P5 and P6) did not exhibit any diagnostic horizon and hence were classified as Oxyaquic Udifluvents and Aeric Endoaquents, respectively.

Land use in Permanent Preservation Areas of the Feliz Lembrança Stream Basin, Alegre, ES, Brazil

The study aimed to define the Permanent Preservation Areas (PPA) of hills and mountains tops, water courses and springs in the Feliz Lembrança stream basin (Alegre/ES), as well as identify which land uses predominate over others. PPA located in the margins of water courses of watershed, showed the largest area (154.40 ha), followed by the tops of hills and mountains (122.07 ha), and PPA in the springs had the smallest area (25.06 ha). The study showed that the predominant use of the soil within the PPA was pasture, for a total of 152.57 ha (54.83%). Only 19.63% of the area of PPA (53.96 ha) are covered by forest cover, showing their marked susceptibility, due to fragmentation of the landscape.

Exotic Plants and their Usage by Local Communities in the Sitakunda Botanical Garden and Eco-Park, Chittagong, Bangladesh

The study was carried out to assess the occurrence, invasion and usage of exotic plant species in the natural ecosystem of Sitakunda Botanical Garden and Eco-park, Chittagong, Bangladesh through transect and random sampling and Focused Group Discussion (FGD) during August 2013 to April 2014. A total of 103 exotic plant species (99 species of angiosperms and 4 gymnosperms) belonging to 90 genera and 43 families were recorded through transect method from the study area. Among the exotics, tree species constitute the major category (46 species, 21 families) followed by shrubs (33 species, 18 families), herbs (21 species, 17 families) and climbers (3 species, 3 families). Mimosaceae family was represented by maximum (9) exotic plant species followed by Caesalpiniaceae (8), Myrtaceae (8) and Malvaceae (7). Most of the exotic plants were introduced in the eco-park after its establishment. Exotic tree species are given priority as the dominant plantation species in the eco-park area because of their short rotation, wider adaptability and faster growth. A total of 74 tree species (52 native and 22 exotic) belonging to 33 families were recorded through random sampling method in the eco-park. Number of both exotic and native tree species in hill top, mid hill and hill bottom varied simultaneously. Density of exotic trees were found maximum (366.6/ ha) in the hill bottom. Holarrhena antidysenterica (14.77) and Stereospermum colais (14.53) were the two native tree species that showed maximum Importance Value Index (IVI). Besides, two exotics that showed maximum IVI were Xylia xylocarpa (10.05) and Psidium guajava (9.15). The enumerated exotic plant species were categorized under six different traditional use categories according to their habit form (tree, shrub, herb and climber). The study revealed 39 exotic species used for timber purpose indicates their prominent economic potentiality. Moreover, local communities extracting exotic plants for meeting their needs of fuel, housing implements, livelihoods etc. Control of the exotics in future plantation programs need to be considered and available native plants should give priority to ensure ex-situ conservation of the Botanical Garden and Eco-park.