scholarly journals Reduction and distribution of lateral seismic inertia forces on base isolated multistorey structures

1991 ◽  
Vol 24 (3) ◽  
pp. 225-237 ◽  
Author(s):  
Takim Andriono ◽  
Athol J. Carr
Keyword(s):  
Distribution Patterns ◽  
Seismic Behaviour ◽  
Isolation System ◽  
Wide Range ◽  
Inertia Forces

This paper presents some important results of a thorough investigation into the seismic behaviour of a wide range of Base Isolated multistorey structures. The benefits of implementing BI systems are highlighted. The reduction and distribution patterns of lateral inertia forces due to the inclusion of this isolation system are specifically discussed.

Harmonic Coefficients of Engine Torque Curves

1943 ◽  
Vol 10 (1) ◽  
pp. A33-A48
Author(s):  
Frederic P. Porter
Keyword(s):  
Diesel Engines ◽  
Combined Effects ◽  
Connecting Rod ◽  
Engine Torque ◽  
Wide Range ◽  
Inertia Forces ◽  
Gas Pressures

Abstract Engine torque curves depend upon the combined effects of gas pressures, inertia forces, and weights. Tables for the harmonic coefficients of the torque due to inertia and weight effects are given for a wide range of crank-to-connecting-rod ratios. Families of indicator diagrams, representative of various types of engines, are shown and tables of the harmonic coefficients of the resulting torques are given. The types of engines considered are two-cycle gas, semi-Diesel, single-acting Diesel, double-acting Diesel, two-shaft opposed-piston Diesel, and four-cycle gasoline and Diesel engines.

scholarly journals Potential impacts of climate change on Mongolia’s plant protection status quo

2018 ◽  
Vol 24 (02) ◽  
pp. 26-32
Author(s):  
Batkhuyag B ◽  
Batnaran Kh
Keyword(s):  
Climate Change ◽  
Climate Modeling ◽  
Plant Protection ◽  
Current Trend ◽  
Animal Husbandry ◽  
Distribution Patterns ◽  
Agricultural Pests ◽  
Migratory Locust ◽  
Colorado Beetle ◽  
Wide Range

Mongolia’s 2030 Sustainable Development Vision set a goal to be a self-sufficient in grain, potatoes and vegetables by 2030. However, Mongolia’s pastoral animal husbandry and rain-fed agriculture are extremely sensitive to climate change. The Asian migratory locust is considered as the most harmful grasshopper in the world. Until 1970th, these locust’s distribution areas in Mongolia were confined to oasis of Gobi deserts. A study on Asian migratory locust in Russia predicts distribution and formation of new permanent habitats of the locust in Chita oblast, Krasnoyarsk territory and Republic of Tyva. The Colorado beetle is one of the world’s most infamous invasive species due to its rapid adaptation to a wide range of ecological conditions and ability to disperse long distances. The climate modeling of Colorado beetle showed that with current trend, the beetle will expand its distribution into the most eastern and north-eastern regions of the Russian Federation. In China, the Colorado beetle was first detected in Xinjiang in 1993 and subsequently spread eastward. In China the Colorado beetle is currently expanding its areas at rate of 25 kms year (12-45 kms/year). Both species’ distribution patterns in neighboring countries show eventual establishment of permanent habitats around Mongolia. Their invasion to Mongolia will threaten country’s food security due to direct destruction of cereal and potato crops, and increased application of highly toxic pesticides. In light of these threats, Mongolia should start taking serious preventive measures by increasing surveillance and dedicated risk assessment studies for potential agricultural pests and diseases.

scholarly journals Fusarium incarnatum-equiseti complex from China

2019 ◽  
Vol 43 (1) ◽  
pp. 70-89 ◽  
Author(s):  
M.M. Wang ◽  
Q. Chen ◽  
Y.Z. Diao ◽  
W.J. Duan ◽  
L. Cai
Keyword(s):  
Rna Polymerase ◽  
Elongation Factor ◽  
Distribution Patterns ◽  
Morphological Characters ◽  
Ribosomal Gene ◽  
Internal Transcribed Spacers ◽  
Translation Elongation ◽  
Cultural Methods ◽  
Wide Range

The Fusarium incarnatum-equiseti species complex (FIESC) is shown to encompass 33 phylogenetic species, across a wide range of habitats/hosts around the world. Here, 77 pathogenic and endophytic FIESC strains collected from China were studied to investigate the phylogenetic relationships within FIESC, based on a polyphasic approach combining morphological characters, multi-locus phylogeny and distribution patterns. The importance of standardised cultural methods to the identification and classification of taxa in the FIESC is highlighted. Morphological features of macroconidia, including the shape, size and septum number, were considered as diagnostic characters within the FIESC. A multi-locus dataset encompassing the 5.8S nuclear ribosomal gene with the two flanking internal transcribed spacers (ITS), translation elongation factor (EF-1α), calmodulin (CAM), partial RNA polymerase largest subunit (RPB1) and partial RNA polymerase second largest subunit (RPB2), was generated to distinguish species within the FIESC. Nine novel species were identified and described. The RPB2 locus is demonstrated to be a primary barcode with high success rate in amplification, and to have the best species delimitation compared to the other four tested loci.

The elevation gradient of lichen species richness in Nepal

2009 ◽  
Vol 42 (1) ◽  
pp. 83-96 ◽  
Author(s):  
Chitra Bahadur BANIYA ◽  
Torstein SOLHØY ◽  
Yngvar GAUSLAA ◽  
Michael W. PALMER
Keyword(s):  
Species Richness ◽  
Endemic Species ◽  
Elevation Gradient ◽  
Distribution Patterns ◽  
Lichen Species ◽  
Ecological Niches ◽  
Published Data ◽  
Elevation Gradients ◽  
Wide Range ◽  
Taxonomic Groups

AbstractThis study of elevation gradients of lichen species richness in Nepal aimed to compare distribution patterns of different life-forms, substratum affinities, photobiont types, and Nepalese endemism. Distribution patterns of lichens were compared with elevational patterns shown by a wide range of taxonomic groups of plants along the Nepalese Himalayan elevational gradient between 200–7400m. We used published data on the elevation records of 525 Nepalese lichen species to interpolate presence between the maximum and minimum recorded elevations, thereby giving estimates of lichen species richness at each 100-m elevational band. The observed patterns were compared with previously published patterns for other taxonomic groups. The total number of lichens as well as the number of endemic species (55 spp.) showed humped relationships with elevation. Their highest richness was observed between 3100–3400 and 4000–4100m, respectively. Almost 33% of the total lichens and 53% of the endemic species occurred above the treeline (>4300m). Non-endemic richness had the same response as the total richness. All growth forms showed a unimodal relationship of richness with elevation, with crustose lichens having a peak at higher elevations (4100–4200m) than fruticose and foliose lichens. Algal and cyanobacterial lichen richness, as well as corticolous lichen richness, all exhibited unimodal patterns, whereas saxicolous and terricolous lichen richness exhibited slightly bimodal relationships with elevation. The highest lichen richness at mid altitudes concurred with the highest diversity of ecological niches in terms of spatial heterogeneity in rainfall, temperature, cloud formation, as well as high phorophyte abundance and diversity implying large variation in bark roughness, moisture retention capacity, and pH. The slightly bimodal distributions of saxicolous and terricolous lichens were depressed at the elevational maximum of corticolous lichens.

Modeling and Control Analysis of a 3-PUPU Dual Compliant Parallel Manipulator for Micro Positioning and Active Vibration Isolation

2011 ◽  
Vol 134 (2) ◽  
Author(s):  
Y. Yun ◽  
Y. Li
Keyword(s):  
Vibration Control ◽  
Parallel Manipulator ◽  
Vibration Isolation ◽  
Active Vibration Control ◽  
Parallel Robots ◽  
Control Analysis ◽  
Isolation System ◽  
Wide Range ◽  
Active Vibration ◽  
Active Vibration Isolation

In recent years, many applications in precision engineering require a careful isolation of the instrument from the vibration sources by adopting active vibration isolation system to achieve a very low remaining vibration level, especially for the very low frequency under 10 Hz vibration signals. This paper presents a 3-PUPU dual parallel manipulator for both rough positioning and active vibration isolation in a wide-range workspace based on our previous research experiences in the systematical modeling and study of parallel robots. The manipulator is designed as a kind of macro/micro hybrid robot. Both the kinematics model for macro motion and dynamics model for micro motion are established by using stiffness equation and the Kane’s method, respectively. An active vibration control strategy is described by using the H2 method. Moreover, numerical simulations on the inverse solution for macro motion, workspace, and the active vibration control effects are performed at the end of this paper.

Mapping and analysis of distribution patterns of lichens on rural medieval churches in north-eastern Germany

2001 ◽  
Vol 33 (3) ◽  
pp. 231-248 ◽  
Author(s):  
Bettina Weber ◽  
Burkhard Büdel
Keyword(s):  
Statistical Analysis ◽  
Environmental Conditions ◽  
Distribution Patterns ◽  
Lichen Species ◽  
Habitat Factors ◽  
Wide Range ◽  
North Eastern ◽  
Detailed Statistical Analysis ◽  
Stone Walls ◽  
Important Habitat

AbstractLichen communities were examined on 62 churches in Mecklenburg–Vorpommern, Germany. Ninety-six lichen species and subspecies, and three species of lichenicolous fungi identified. Tylothallia biformigera and Lecanora campestris subsp. dolomitica are reported as new Germany, and another 20 species are considered as threatened. This implies that the stone walls churches represent an extremely important habitat in Mecklenburg–Vorpommern, where natural outcrops are rare. The distribution of lichen species was analyzed quantitatively in relation to several habitat factors. Aspect, substratum and inclination were found to be important factors for 35, 34 31 species, respectively. The height of the relevé was a significant factor for many species. Twenty-three species, which are described in the literature with oceanic to suboceanic distributions, occur significantly more frequently near the coast. The ways in which microclimate affects each these habitat factors and contributes to the presence or absence of a species or group of species discussed. Some species have narrow and specific habitat demands, whereas others thrive under wide range of environmental conditions. The advantages of a strictly schematic approach with detailed statistical analysis are discussed.

scholarly journals Mesocell Study Area Snow Distributions for the Cold Land Processes Experiment (CLPX)

2008 ◽  
Vol 9 (5) ◽  
pp. 957-976 ◽  
Author(s):  
Glen E. Liston ◽  
Christopher A. Hiemstra ◽  
Kelly Elder ◽  
Donald W. Cline
Keyword(s):  
Snow Water Equivalent ◽  
Distribution Patterns ◽  
Snow Accumulation ◽  
Meteorological Model ◽  
Meteorological Forcing ◽  
Spatial And Temporal Scales ◽  
Wide Range ◽  
Snow Water ◽  
Grid Points ◽  
Evolution Modeling

Abstract The Cold Land Processes Experiment (CLPX) had a goal of describing snow-related features over a wide range of spatial and temporal scales. This required linking disparate snow tools and datasets into one coherent, integrated package. Simulating realistic high-resolution snow distributions and features requires a snow-evolution modeling system (SnowModel) that can distribute meteorological forcings, simulate snowpack accumulation and ablation processes, and assimilate snow-related observations. A SnowModel was developed and used to simulate winter snow accumulation across three 30 km × 30 km domains, enveloping the CLPX mesocell study areas (MSAs) in Colorado. The three MSAs have distinct topography, vegetation, meteorological, and snow characteristics. Simulations were performed using a 30-m grid increment and spanned the snow accumulation season (1 October 2002–1 April 2003). Meteorological forcing was provided by 27 meteorological stations and 75 atmospheric analyses grid points, distributed using a meteorological model (MicroMet). The simulations included a data assimilation model (SnowAssim) that adjusted simulated snow water equivalent (SWE) toward ground-based and airborne SWE observations. The observations consisted of SWE over three 1 km × 1 km intensive study areas (ISAs) for each MSA and a collection of 117 airborne gamma observations, each integrating area 10 km long by 300 m wide. Simulated SWE distributions displayed considerably more spatial heterogeneity than the observations alone, and the simulated distribution patterns closely fit the current understanding of snow evolution processes and observed snow depths. This is the result of the MicroMet/SnowModel’s relatively finescale representations of orographic precipitation, elevation-dependant snowmelt, wind redistribution, and snow–vegetation interactions.

scholarly journals Seismic Response of a Base Isolated Cable-Stayed Bridge Under Near-Fault Ground Motion Excitations

2018 ◽  
Vol 15 (1) ◽  
pp. 1-14
Author(s):  
Ahad Javanmardi ◽  
Zainab Ibrahim ◽  
Khaled Gheadi ◽  
Mohammed Jameel ◽  
Usman Hanif ◽  
...  
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Nonlinear Dynamic Analysis ◽  
Dynamic Responses ◽  
Base Shear ◽  
Seismic Behaviour ◽  
Isolation System ◽  
Near Fault ◽  
Cable Stayed Bridge ◽  
Near Fault Ground Motion

Nowadays, development of cable-stayed bridges is increasing around the world. The mitigation of seismic forces to these bridges are obligatory to prevent damages or failure of its structural members. Herein, this paper aimed to determine the near-fault ground motion effect on an existing cablestayed bridge equipped with lead-rubber bearing. In this context, Shipshaw cable-stayed bridge is selected as the case study. The selected bridge has a span of 183.2 m composite deck and 43 m height of steel tower. 2D finite element models of the non-isolated and base isolated bridges are modelled by using SAP2000. Three different near-fault ground motions which are Tabas 1978, Cape Mendocino 1992 and Kobe 1995 were subjected to the 2D FEM models in order to determine the seismic behaviour of the bridge. The near-fault ground motions were applied to the bridge in the longitudinal direction. Nonlinear dynamic analysis was performed to determine the dynamic responses of the bridge. Comparison of dynamic response of nonisolated and base isolated bridge under three different near-fault ground motions were conducted. The results obtained from numerical analyses of the bridge showed that the isolation system lengthened the period of bridge and minimised deck displacement, base shear and base moment of the bridge. It is concluded that the isolation system significantly reduced the destructive effects of near-fault ground motions on the bridge.

scholarly journals A REVIEW OF AIR DISTRIBUTION PATTERNS IN SURGERY ROOMS UNDER INFECTION CONTROL FOCUS

2005 ◽  
Vol 4 (2) ◽  
Author(s):  
M. L. Pereira ◽  
A. Tribess
Keyword(s):  
Distribution Systems ◽  
Control Strategies ◽  
Ventilation System ◽  
Distribution Patterns ◽  
Infection Process ◽  
Air Distribution ◽  
Detailed Knowledge ◽  
Surgical Infections ◽  
Airborne Contamination ◽  
Wide Range

The problem of airborne contamination in surgical infections still raises discussion. The success of the aseptic methods and the use of medicines for the combat of infections are making most surgeons contempt the danger of the aerial particles course. A detailed knowledge of the characteristics of the contamination sources and of the ventilation system performance used at surgery rooms is necessary to guarantee that the ventilation system supplies the pollutant control in ventilation rates that assure the health and the comfort of the occupants. There are many configurations of air distribution systems and a wide range of potential conditions inside a surgery room that are influenced by their performance. In the same way, it is evident the lack of information in the literature regarding which characteristics of the systems of air treatment have stronger influence on the amount of particles in suspension. This paper provides a review of the distribution patterns and air movement at surgery rooms, describing the importance of airborne particles in the infection process, making a comparative analysis of the efficiency of microbiological control of the main airflow systems, identifying and demonstrating the control strategies that can reduce the risks of airborne contamination in surgical infections.

CFD Analysis of Fuel Distribution in Concentric Swirling Flows in a Reverse Flow Gas Turbine Combustor

2006 ◽  
Author(s):  
K. Sudhakar Reddy ◽  
D. N. Reddy ◽  
C. M. Vara Prasad
Keyword(s):  
Gas Turbine ◽  
Reverse Flow ◽  
Distribution Patterns ◽  
Swirling Flows ◽  
Cfd Analysis ◽  
Fuel Injector ◽  
Gas Turbine Combustor ◽  
Fuel Distribution ◽  
Wide Range ◽  
Injection Pressures

This paper presents the results of numerical investigations of a turbulent, swirling and recirculating flow without combustion inside a reverse flow gas turbine combustor. In order to establish the characteristics of fuel distribution patterns of the fuel spray injected into swirling flows, flow fields are analyzed inside the swirl combustor for varying amount of swirl strength using a commercial CFD code fluent 6.1.22. Three Dimensional computations are performed to study the influence of the various parameters like injection pressure, flow Reynolds number and Swirl Strength on the fuel distribution patterns. The model predictions are compared against the experimental results, and its applicability over a wide range of flow conditions was investigated. It was observed from the CFD analysis, that the fuel decay along the axis is faster with low injection pressures compared to higher injection pressures. With higher Reynolds numbers the fuel patterns are spreading longer in the axial direction. The higher momentum of the air impedes the radial mixing and increases the constraint on the jet spread. The results reveal that an increase in swirl enhances the mixing rate of the fuel and air and causes recirculation to be more pronounced and to occur away form the fuel injector. The CFD predictions are compared with the experimental data from the phototransistor probe measurements, and good agreement has been achieved.

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