Harsh Areas Research Articles

Consistent and Proficient Algorithm for Data Gathering in Wireless Sensor Networks

Problem statement: A wireless sensor network is usually deployed in a harsh geographical area to gather data that can be delive red to the remotely located base station. Sensor no des have irreplaceable energy source, limited computati onal capability and limited memory. It is a challen ge to maximize the use of energy of these sensor nodes to extend the network lifetime. Approach: This study proposes a Rank-Based Data Gathering Algorithm for wireless sensor networks. Sensor nodes were randomly distributed in a network field of differen t sizes. For every round of data communication, the algorithm steps were as follows: A set of sensor no des or vertices were given a random rank between 0 and 1. A link formed between any two nodes if they were within each other's transmission range. If a sensor node had the highest rank among its neighbor s, then it considered an associate node, else it fa lls into the leaf node. Next, the associate nodes form a complete graph among them and later form a Rooted Directed Tree (RDT) after an implementation of Kruskal's Minimum Spanning Tree algorithm and the Breadth First Search algorithm. Finally, a model th at takes into account the energy when deciding what type of node a sensor was implemented. Results and Conclusion: After recording the simulation results, it is concluded that the RBDG yields a better outco me in terms of lifetime and delay per round for TDMA than other popular data gathering algorithms.

A LONG-TERM FIELD MONITORING SYSTEM WITH FIELD SERVERS AT A GRAPE FARM

Monitoring image data at a field site provides important and useful information concerning plant and environmental conditions for agricultural users. We propose an image monitoring system that makes it possible to work in harsh areas, collect large amounts of data in real time, and analyze the data according to users’ requests. The system is constructed for use via the Internet with Web-based sensor nodes, an agent program, and Web analysis applications. Web-based sensor nodes such as Field Servers allow the monitoring of various types of sensor data, including image data, via the Internet. The agent program performs complicated operations on the sensor nodes from a remote site via the Internet; it can also analyze monitoring data easily using Web applications. To evaluate the effectiveness of the image monitoring system, we executed a long-term field experiment at a grape farm in Obuse-town, Nagano, Japan. Four types of sensor data concerning environmental condition and 2 types of image data concerning plant detail and field overview were collected and stored at a remote site via the Internet. The image data were analyzed using a filtering approach operated by the agent program and Web applications which were used for calculations in a background subtraction model. The proposed system has worked stably since May 2006 and provided results in which approximately 84% of unnecessary image data were filtered. Due to its construction with a distributed architecture based on the Internet, this system has the advantage that non-expert users can easily obtain the monitoring data on the Web and image processing can be provided for users without changing the system architecture.

A California grasslands alkali specialist, Hemizonia pungens ssp. pungens, prefers non‐alkali soil

AbstractQuestion: Edaphically severe habitats commonly support edaphic endemics, specialized plant species that do not occur elsewhere. The endemism of native plant species in edaphically specialized habitats suggests either (a) that these native endemic species are uniquely specialized to survive and grow better under the conditions prevalent in these harsh areas, or (b) that these areas represent refuges from competition with other (often exotic) species.Location: Central Valley, California, USA.Methods: We surveyed the vegetation distribution in alkali sinks and carried out a reciprocal transplant greenhouse experiment crossed with a competition treatment to examine the interplay between interspecific competition and edaphic factors in determining relative performance of an alkali endemic forb (Hemizonia pungens ssp. pungens) and its exotic grass competitor (Lolium multiflorum).Results: Lolium consistently performed better in non‐alkali soil. In contrast, Hemizonia, in the absence of competition, performed significantly better on the non‐alkali soils, but in competition with Lolium, performed equally well on alkali and non‐alkali soils.Conclusions: These results suggest that Hemizonia does not inherently prefer harsh alkali soil, but is better able to tolerate alkali soil and may be excluded from more moderate soils by competition. Therefore, edaphic and biotic effects may interact to determine the spatial distribution of this edaphic endemic. Our data suggest a mechanism by which competition between native and exotic species on impoverished soils leads to dominance of native species and creation of refugia for native species where exotic species are unable to thrive.

Survival, height and health status of 20‐year‐old pinus sylvestris and pinus contorta after different scarification treatments in a harsh boreal climate

Survival, height, and health status of Pinus sylvestris and Pinus contorta were studied in a randomized factorial experiment in northern Sweden. Treatments studied per species were no scarification (control), patch scarification, and mounding. The experiment was evaluated 18 years after planting. For both species, survival was higher in mounded plots than in control plots. Pinus contorta was 11% higher than P. sylvestris in the treatment with highest survival, but this difference was not significant. Ninety‐three per cent of the P. contorta trees were infected and 22% killed by Gremmeniella abietina compared with 21% and 5% for P. sylvestris. Eighty‐three per cent of the P. sylvestris trees were infected and 24% killed by Phacidium infestans compared with 8% and 2% for P. contorta. Leaning P. contorta trees were more severely damaged by G. abietina than those not leaning. Mounding reduced the mortality caused by G. abietina in P. contorta and by Ph. infestans in P. sylvestris. Due to the increasing mortality of P. contorta during the past 6 yrs, and the high frequency of G. abietina, the number of surviving trees of the two species are approaching equality. Significantly more P. contorta than P. sylvestris trees were leaning and had poor stem quality. Regardless of species, mounded plots showed the highest frequency of broken tops. Results suggest that more than 20 yrs need to elapse before regeneration efforts with these two species in harsh areas can be evaluated reliably.

The Ruling Elites of Siberia

Siberia is a very unusual region of Russia. Its agriculture never knew serfdom. During the period following the Stolypin reforms, people accustomed to self-reliance migrated into these harsh areas from the central regions of the country. During the Civil War the inhabitants of Western Siberia formed a peasant republic independent of Kolchak and of the center; they created an army headed by a simple peasant, Mamontov, from Barnaul, and drafted their own fundamental laws. The Bolsheviks, who arrived after defeating Kolchak, were, of course, very concerned by such independent activity. It is no accident that in 1937 the NKVD decided to expose an underground rebellious army in Western Siberia.

Zonal plant distribution and edaphic and micrometeorological conditions on a coastal sand dune

AbstractSome edaphic and meteorological conditions were examined to detect environmental gradients from shoreline to inland at the Kado‐ori coast, Ibaraki, Japan, in 1989. Zonal distribution patterns of coastal dune plant species, including three ubiquitous perennials, Calystegia soldanella, Carex kobomugi and Ischaemum anthephoroides, were described in relation to the environmental gradients. Environmental gradients were found in water availability, evaporative demand and soil‐water salinity. Water availability, evaluated by thickness of capillary water layer, increased from 10 cm at 20 m to 48 cm at 85 m from the shoreline, reflecting the percentage of fine sand. Evaporative demand, which was evaluated by the evaporation rate from a wet black filter paper, decreased with increasing distance from the shoreline. Soil‐water salinity was lowest (15 mmol/L) at 85 m from the shoreline and highest (90 mmol/L) at 30m. On the coast, C. soldanella, a salt‐tolerant perennial, was distributed mainly in the environmentally harsh area 40–60 m from the shoreline. Ischaemum anthephoroides and C. kobomugi, less salt‐tolerant perennials, occurred mainly 70–80 m from the shoreline, where environmental conditions were more hospitable.

Spatial Patterns of Westerschelde Meiobenthos

The meiobenthic fauna of the Westerschelde, a highly polluted and physically disturbed estuary in the south-west Netherlands, was investigated. Samples were taken in spring from six transects, including the intertidal, subtidal and channel area, and located along the salinity gradient. The samples were subdivided into slices to examine the vertical distribution of meiobenthos. Meiobenthos densities were higher in the intertidal than in most permanently submersed areas; the subtidal sites below 7 salinity were nearly devoid of meiobenthic life. Nematodes were by far the most abundant meiobenthic organisms in the intertidal, but were less dominant in the other areas. Gastrotrichs, turbellarians, copepods and large ciliates were usually more numerous in the subtidal and channels compared to the intertidal, both in relative and absolute terms. Vertical distribution of the meiobenthos was rather heterogeneous. Most intertidal stations exhibited a subsurface density peak, whereas in the subtidal and channel area, both subsurface and surface maxima were found. The nematode fauna was examined in more detail and the distributional characteristics of the most important species, with respect to salinity, grain size, water depth and sediment depth were reported. The majority of species had their centre of distribution in the intertidal, although some extended substantially into the subtidal zone. Only a few species had a predominantly subtidal distribution. Most nematode species penetrated relatively deep into the sediment and only some species were real surface dwellers. The nematode diversity per unit of surface reflected more or less the density differences and was higher in the intertidal than in the subtidal sites within a comparable salinity regime. When expressed per common number of individuals, however, there were no differences in diversity in the different areas. Canonical correspondence analysis showed sediment depth to be as important as water depth, salinity or sedimentary characteristics in the determination of community structure. Intertidal communities exhibited a well-developed community gradient with depth into the sediment, whereas the vertical structure of subtidal and channel stations was different from the intertidal zonation and in some cases showed a distorted pattern. This was probably caused by sediment disturbance due to higher current velocities and dredging activities in these regions. It is argued that, although at some subtidal sites a characteristic subtidal nematode population may persist, in many cases the sublittoral of the Westerschelde is either too dynamic an environment or food availability is too low to meet requirements for growth and reproduction of the nematodes. The populations are probably not self-sustaining but persist due to continuous replenishment from less harsh areas by means of the estuarine circulation.

Effects of provenance transfer on survival in nine experimental series with Pinus sylvestris (L). In northern Sweden

Survival at a mean height of 2.5 m was studied in eight experimental series comprising provenances of Pinus sylvestris (L.). A ninth series of planting experiments was used for verifying functions predicting local provenance survival. The estimated survival of local provenances declined as the temperature sum decreased, with the decline being most rapid close to timberline. Variation in survival within the same climatic region was large, especially in moderately harsh areas. Southward transfer increased survival. Transfer effects differed depending on the temperature sum at the growth site; the greatest effects were found in moderately harsh areas. Altitudinal transfer effects were small and inconsistent. Local provenance survival differed between series. Local provenance survival varied depending on topography and humidity. Transfer effects did not vary between series, nor were they influenced by site factors. Prediction confidence limits were used to estimate the risk for failure of single reforestation...

Land and Water Management in Tibet

The modernization process of Tibet is a seldom treated issue, because of its controversial nature. This paper reviews some policy changes related to land and water management. The Tibetans inhabit a harsh and ecological sensitive land area. The population in Tibetan Autonomous Region was 2 096 000 in 1990. The lamaist feudalship was abolished in 1959 and replaced by a system of collective agriculture. Since 1980 a household based agrarian system coupled to a set of preferential policies has been introduced. Though still a poor region, Tibet has especially since the beginning of the 1980s undergone a profound modernization change. This change includes emphasis on land and water conservation works and a general rise in the standard of living.

Domestic and regional satellite systems

The technical characteristics of domestic and regional satellite systems are discussed. Spacecraft technology is reviewed, communication payload technology developments are discussed, and resources and economics are considered. It is seen that, compared to the installation of terrestrial microwave or optical cable networks in remote and harsh areas, satellite systems offer both lower costs and shorter time to bring on line. Proven technology and mature hardware is available for regions where orbit/spectrum space is still plentiful. As in North America, the sequence of growth is likely to be C-band and then K-band. Corresponding earth station advances in efficient modulation techniques and time-division multiple access will increase the capacity per transponder channel, while frequency and spatial reuse will provide more channels per satellite. >

Harsh areas in Finland

Harsh areas in Finland

Performance in freezing tests and field experiments of full-sib families of Pinussylvestris (L.)

Full-sib families from plus trees of Pinussylvestris (L.) were tested in four 10-year field experiments and three 1-year experiments. Survival and height were assessed in the field experiments and plant height, dry matter content, and damage following artificial freeze testing during the hardening process in the 1-year experiments. Positive correlations between pairs of field experiments were found for breeding values for 10-year survival (rmean = +0.71) and 10-year height (rmean = +0.38). Positive correlations were also obtained between survival and height within field experiments. Breeding values for 10-year field survival and height were not correlated with the latitude of origin. Positive correlations were found between field mortality and both damage after freeze testing (0.61 < r < 0.85) and plant height (r = 0.75) for the 1-year-old seedlings. Results indicated that a low degree of damage after freeze testing of 1-year-old progenies is a better predictor of field survival than is northern geographical origin when establishing seed orchards of P. sylvestris for harsh areas in north Sweden.

Current and Future Offshore Activities in Canada

Summary. The development of innovative exploratory drilling systems for Canada's harsh Arctic offshore areas over the past decade and future activity in these areas, including possible production concepts, are discussed. The results can be applied in other Arctic areas of the world, including offshore Alaska. This operating experience will advance drilling technology and serve as a basis for the design of Arctic offshore production and transportation systems. Unique technology has been developed and successfully used in the discovery of major accumulations of hydrocarbons. Continued technological advances are anticipated to have widespread Arctic applications in both exploratory and production operations. Introduction Drilling has been successfully conducted in most of Canada's offshore areas despite the extremely harsh environmental conditions. During the past decade, technology has advanced very significantly particularly in the Beaufort Sea and Canadian Arctic Islands. particularly in the Beaufort Sea and Canadian Arctic Islands. Operating experience gained during the exploratory drilling phase is being used in the conceptual design of production systems. Undoubtedly, there will also be an evolution of technology during the development and production phases as the vast frontier reserves are exploited. Canada's offshore frontier areas typically have high costs and lengthy time spans between discovery and production. These factors present major engineering challenges for the design of safe, cost-effective, and timely exploratory and development systems. Confidence in the reservoir extent and predicted performance may permit large-scale development projects, while performance may permit large-scale development projects, while uncertainties may result in a phased approach where possible. The latter is attractive because earlier revenue is generated. Giant discoveries in the Beaufort Sea may not be essential to trigger development and a transportation system, because a combination of several pools may justify limited tankers or a small-diameter pipeline. Similarly, in such areas as the Grand Banks, phased pipeline. Similarly, in such areas as the Grand Banks, phased development with floating production platforms may be feasible. Artificial islands, first started in 1972, are still being constructed but with improved designs and equipment. A step forward has been the use of subsea berms on which concrete or steel segmented caissons have been placed. Integrated-type steel caissons have also been adapted for placement on subsea berms. One is one-half of a crude oil tanker and a second is a purpose-built steel caisson first used in 1984. Four drillships were converted and/or strengthened for Arctic service in the Beaufort Sea, and three have drilled since 1976. The second-generation floating vessel for the area is the Kulluk conical drilling unit, which began drilling in 1983 and has extended the operating season. In the Canadian Arctic Islands, drilling off artificially thickened ice in water depths exceeding 1,200 ft [365 ml has proceeded successfully since it began in 1973. On Canada's east coast, use of dynamically positioned vessels and iceberg towing have permitted seasonal drilling in positioned vessels and iceberg towing have permitted seasonal drilling in ice-infested waters. Production of oil from Hibernia and gas from Venture will be possible early in the next decade. Production of oil from the possible early in the next decade. Production of oil from the Beaufort Sea is also possible in the early 1990's and from the Canadian Arctic Islands in about the mid-1990's. Systems for such production will be discussed. production will be discussed. The focus will continue to be on exploratory drilling and delineation drilling for several years in most areas. Conceptual and preliminary engineering design for development will accelerate as new discoveries are made and others delineated. Wildcat exploratory drilling will also continue to satisfy exploration agreements and will tap the vast potential reserves of Canada's offshore areas. Geologic Potential The hydrocarbon potential of Canada's offshore frontiers has been recognized for several decades. Permits to explore for oil and natural gas were granted in several areas during the 1960's, when offshore drilling began on the east coast. Drilling in the Mackenzie delta and Canadian Arctic Islands (Fig. 1) in the 1960's was a forerunner to drilling offshore in those regions in the early 1970's. Encouraging hydrocarbon reservoirs have been discovered in all frontier areas except the west coast and Hudson Bay. The search has been primarily for oil in an effort to achieve self-sufficiency, security of supply, and economic returns. Significant reserves of nonassociated natural gas have also been discovered offshore and may be produced in conjunction with solution gas from offshore oil production and with nearby land-based gas reserves when a transportation system is available and demand and economic conditions warrant such production. Estimates of the potential recoverable oil and gas reserves for the frontier areas have recently been published by the Canadian federal government's Geological Survey of Canada (GSC) and are shown in Table 1. JPT P. 717

Offshore World Petroleum Frontiers: ABSTRACT

The potential to find the large oil and gas fields of the future lies in the offshore frontiers. Exploration for petroleum in the coming decades must be concentrated on discovering commercial supplies of the hydrocarbons that lie untapped in these areas. New and better uses of geology, geophysics, petroleum engineering, and technology must be employed in all aspects of exploration, development, and production. Vital to accomplishing these tasks is an in-depth knowledge of the characteristics of basin areas and offshore frontier regions. New exploration strategies must be formulated for exploration in both moderate and harsh offshore areas. New technology for drilling and producing oil and gas, especially in Arctic regions and at greater depths globally than heretofore con idered feasible, must also be advanced rapidly. As part of a unified exploration effort, each specialized discipline--whether geology, geophysics, or petroleum engineering--has to provide the bold and innovative thinking that will lead to the offshore discoveries of the oil and gas the world needs for future energy survival. This paper illustrates with slides the location of these promising offshore areas and the basins involved. End_of_Article - Last_Page 477------------

Foreign Frontiers--An Overview: ABSTRACT

Undiscovered potential in foreign frontiers is believed to be substantial. This potential is located in moderate and harsh physical environments. Very little exploration has been conducted in these basins and the majority are classified as essentially unexplored. These areas are not geologic mysteries and it is highly possible that they can contribute large increments of discovery. The attractive possibilities which exist in these foreign frontiers must not be overlooked, therefore, all must be adequately explored. Major exploration activities should begin in these areas as soon as possible if they are to have any impact on new reserves and production before the end of this century. Governments controlling harsh frontier areas are beginning to recognize the high costs and risks incurred in exploring and operating therein and are beginning to offer greater incentives to those willing to undertake the environmental challenges. End_of_Article - Last_Page 716------------

Acceleration in Global Exploration--Requirement for Survival

Although the demand for petroleum continues to increase as the availability of alternative energy sources lags, exploratory activities are not increasing accordingly. Exploratory wells, geophysical crew months, and acreage holdings all indicate that global exploration is not increasing and the resultant new discoveries of oil and gas required to supply the world's needs in the 1980s and 1990s are declining. There must be an immediate acceleration in exploration in all sedimentary basins: intensely drilled, moderately explored, partially explored, and essentially unexplored basins. It is estimated that nearly two-thirds of future commercial potential may be found in basins which are productive today. Terms for exploring frontier areas should reflect costs, including research for technologic advances, and risks, which are very high in the harsh environment areas. For there to be acceleration in exploration, dedication is required not only of geoscientists and private companies, but also of governments in order that coordinated, effective, and equitable working relations among the various groups can be achieved.

The Principles of Termite Control in Forestry (O.D.C. 453)

SummaryThe difficulty in defining the factors controlling termite attack on living trees is explained. Until the full picture is known, accurate prediction of expected reaction in an area cannot be made, nor can one be sure of the most efficient control methods.Damage is newly grouped into two categories. These are colonies with (1) restricted range, confined to single trees and (2) with free range, able to extend depredations over a wide area.Descriptions of each kind of damage are given, with worldwide examples, and a summary of the position in Africa. The biological background is considered with particular reference to conditions in East Africa. Control measures are reviewed in relation to the habits of the termites concerned. Particular emphasis is given to Africa's main termite forestry problem, the protection of new plantations, especially exotics. Even with our imperfect state of knowledge, adequate control methods are known, which are usually an economic proposition. Search goes on for cheaper and simpler techniques.Attention is drawn to the necessity for good silvicultural practice in harsh areas where termite attack often occurs, but where the termite is frequently a scapegoat.