scholarly journals Waterbirds roosting on gas drilling platforms in Mahakam Delta, East Kalimantan: the Unexpected Impact of Landscape Transformation

2021 ◽  
Vol 879 (1) ◽  
pp. 012009
Author(s):  
A Mardiastuti ◽  
Y A Mulyani ◽  
T Sutrisna ◽  
Y Hidayat ◽  
A S Widodo ◽  
...  
Keyword(s):  
Shrimp Ponds ◽  
Free Zone ◽  
Root Cause ◽  
Gas Drilling ◽  
Ecological Requirements ◽  
East Kalimantan ◽  
Landscape Transformation ◽  
Nesting Site ◽  
Mahakam Delta

Abstract Since 2014 some offshore gas platforms operated by Pertamina Hulu Mahakam near Mahakam Delta has been used by hundreds of egrets as roosting sites, causing nuisance to the platform and hampering the duty of workers/operator. The objective of this paper was to analyse the situation of the waterbirds’ nuisance, analyse the possible causes, and provide some recommendations. Field visits were conducted in August 2019 and February 2020 to three unmanned platforms (Ax, D, C) that suffered the most from the bird roost. Birds that infested the platforms were identified as great egret and intermediate egret, both are very similar in appearance and ecological requirements. The maximum number of egrets visiting C-Platform (the worst platforms) was 671 birds. These birds roost at night in the platform and leave the platform in the morning to forage for fish, eel, and shrimps in the wetlands of Mahakam Delta, about 2-4 km from the platform. The root cause of the infestation was believed to be the landscape transformation in the Mahakam Delta. Mangrove forest has been diminished and heavily converted into shrimp-ponds. The egrets’ foraging areas became ubiquitous, while the roosting/nesting site greatly decreased, forcing the egrets to roost on gas platforms. In the short-medium term, platforms need to be managed as bird tolerated-zone and bird-free zone (using deterrent), while in the long term, land-use in Delta Mahakam need to be restored.

scholarly journals Distribution and ecological segregation on regional and microgeographic scales of the diploidCentaurea asperaL., the tetraploidC. seridisL., and their triploid hybrids (Compositae)

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5209 ◽  
Author(s):  
Alfonso Garmendia ◽  
Hugo Merle ◽  
Pablo Ruiz ◽  
Maria Ferriol
Keyword(s):  
Anthropogenic Disturbance ◽  
Large Scale ◽  
Latitudinal Gradient ◽  
Soil Parameters ◽  
Fine Scale ◽  
Contact Zones ◽  
Ecological Requirements ◽  
Adaptive Processes ◽  
Sympatric Cytotypes

Although polyploidy is considered a ubiquitous process in plants, the establishment of new polyploid species may be hindered by ecological competition with parental diploid taxa. In such cases, the adaptive processes that result in the ecological divergence of diploids and polyploids can lead to their co-existence. In contrast, non-adaptive processes can lead to the co-existence of diploids and polyploids or to differentiated distributions, particularly when the minority cytotype disadvantage effect comes into play. Although large-scale studies of cytotype distributions have been widely conducted, the segregation of sympatric cytotypes on fine scales has been poorly studied. We analysed the spatial distribution and ecological requirements of the tetraploidCentaurea seridisand the diploidCentaurea asperain east Spain on a large scale, and also microspatially in contact zones where both species hybridise and give rise to sterile triploid hybrids. On the fine scale, the position of eachCentaureaindividual was recorded along with soil parameters, accompanying species cover and plant richness. On the east Spanish coast, a slight latitudinal gradient was found. TetraploidC. seridisindividuals were located northerly and diploidC. asperaindividuals southerly. Tetraploids were found only in the habitats with strong anthropogenic disturbance. In disturbed locations with well-developed semi-fixed or fixed dunes, diploids and tetraploids could co-exist and hybridise. However, on a fine scale, although taxa were spatially segregated in contact zones, they were not ecologically differentiated. This finding suggests the existence of non-adaptive processes that have led to their co-existence. Triploid hybrids were closer to diploid allogamous mothers (C. aspera) than to tetraploid autogamous fathers (C. seridis). This may result in a better ability to compete for space in the tetraploid minor cytotype, which might facilitate its long-term persistence.

Culturally Responsive School Discipline: Implementing Learning Lab at a High School for Systemic Transformation

2018 ◽  
Vol 55 (5) ◽  
pp. 1007-1050 ◽  
Author(s):  
Aydin Bal ◽  
Kemal Afacan ◽  
Halil Ibrahim Cakir
Keyword(s):  
High School ◽  
Culturally Responsive ◽  
School Discipline ◽  
Public High School ◽  
Life Outcomes ◽  
Expansive Learning ◽  
Root Cause ◽  
Local Stakeholders ◽  
School Learning

Youth from racially minoritized communities disproportionately receive exclusionary school discipline more severely and frequently. The racialization of school discipline has been linked to long-term deleterious impacts on students’ academic and life outcomes. In this article, we present a formative intervention, Learning Lab that addressed racial disparities in school discipline at a public high school. Learning Lab successfully united local stakeholders, specifically those who had been historically excluded from the school’s decision-making activities. Learning Lab members engaged in historical and empirical root cause analyses, mapped out their existing discipline system, and designed a culturally responsive schoolwide behavioral support model in response to diverse experiences, resources, practices, needs, and goals of local stakeholders. Analysis drew on the theory of expansive learning to examine how the Learning Lab process worked through expansive learning actions. Implications for research and practice are discussed.

First Application Drilling New Wells with HWU in Swamp Environment, Mahakam Delta

2021 ◽  
Author(s):  
R. A. S Wijaya
Keyword(s):  
Drilling Rate ◽  
Shallow Gas ◽  
Field Development ◽  
Drilling Rig ◽  
East Kalimantan ◽  
Well Location ◽  
Shallow Wells ◽  
Drilling Unit ◽  
Mature Field ◽  
Mahakam Delta

Tunu is a mature giant gas and condensate field locate in Swamp Area on Mahakam Delta, East Kalimantan, Indonesia. The field has been in developed for more than 40 years and considered as a mature field. As mature field, finding an economic well has become more challenging nowadays. The deeper zone of Tunu (TMZ) has no longer been considered profitable to be produced and the focus is shifted more on the producing widespread shallow gas pocket located in the much shallower zone of Tunu (TSZ). Facing the challenge of marginal reserves in the mature field, Pertamina Hulu Mahakam (PHM) take two approaches of reducing well cost thus increase well economics, improving drilling efficiency and alternative drilling means. Continues improvement on drilling efficiency by batch drilling, maxi drill, maximizing offline activities and industrialization of one phase well architecture has significantly squeezed the well duration. The last achievement is completing shallow well in 2.125 days from average of 6.5 days in period of 2017-2019. Utilization of Swamp Barge Drilling Rig on swamp area had been started from the beginning of the field development in 1980. Having both lighter and smaller drilling unit as alternative drilling means will give opportunity of reducing daily drilling rate. Hydraulic Workover Unit (HWU) comes as the best alternative drilling means for swamp area. In addition, fewer and smaller footprint equipment requires smaller barges with purpose of less civil works to dredge the river and preparing well location. Drilling with HWU project has been implemented at Tunu area with 5 wells has been completed successfully and safely. HWU drilling concept considered as proven alternative drilling means for the future of shallow wells development.

One Phase Well OPW : Unlock Shallow Reservoir Efficient and Economically by Eliminating Surface Casing

2021 ◽  
Author(s):  
Irfan Hanif ◽  
Bramarandhito Sayogyo ◽  
R Riko ◽  
Praja Hadistira ◽  
Karina Sari
Keyword(s):  
Shallow Gas ◽  
Two Phase ◽  
East Kalimantan ◽  
Drilling Operations ◽  
The Common ◽  
Mature Field ◽  
The Cost ◽  
Mahakam Delta ◽  
Common Architecture ◽  
Drilling Time

Abstract Tunu is a mature giant gas and condensate field locate in Mahakam Delta, East Kalimantan, Indonesia. The field has been in development for almost 30 years and currently has been considered as a mature field where to put a state of an economic well has become more challenging nowadays. The deeper zone of Tunu has no longer been considered as profitable to be produced and the current focus is more on the widespread shallow gas pocket located in the much shallower zone of Tunu. One phase well is architecture without 9-5/8" surface casing. OPW is one-section drilling using a diverter mode from surface to TD without using BOP. Historical for OPW is began from 2018, where drilling reservoir section using diverter mode in two-phase. In 2018 also succeeded in performing perforated surface casing. Due successfully in drilling operation using diverter and perforated surface casing, in 2019 drilling trials for OPW were carried out. Until now, the OPW architecture has become one of the common architecture used in drilling operations as an optimization effort. Until December 2020 PHM has completed 15+ OPW wells. A general comparison of OPW and SLA well is at the cost of constructing a well of approximately 200,000 - 300,000 US$. The disadvantages of OPW wells are more expensive in the mud and cement section when using a 9-1/2" hole, but in terms of the duration, OPW drilling time is more efficient up to 2-3 days. If viewed from the integrity of the OPW wells, from 15 OPW wells that have been completed, only 2 of them have SCP.

Introduction

2020 ◽  
pp. 1-22
Author(s):  
Neil Macmaster
Keyword(s):  
Social History ◽  
Colonial State ◽  
Root Cause ◽  
The First World War ◽  
The Rich ◽  
Peasant Community ◽  
Client Relations ◽  
The Village ◽  
Organized Resistance

A key aspect of the colonial state was a geo-political dualism of space in which settlers occupied the rich agricultural plain and urban centres while Algerian peasants inhabited the communes mixtes, the forests and mountains of the interior. After the First World War the caids, the traditional élites that governed the peasants through indirect rule and patron-client relations, entered a crisis of legitimacy and were challenged by communist and nationalist movements. Marxists and historians have tended to perceive the peasants as lacking in political consciousness, incapable of organized resistance, but a new social history, by restoring agency to the lowest strata of the colonized, demonstrates that they assumed a key role in the long-term move towards insurrection. Contrary to the conventional interpretation of rural revolution as a movement initiated by a vanguard party of urban militants, the nationalists adapted to, and built upon, the traditional social and political structures of the peasant community, including the village assemblies. The colonial state largely failed in its attempts to cut the root cause of rebellion through economic modernization of the peasant economy. After 1956 the French launched Opération Pilote, a massive counterinsurgent experiment that deployed anthropology and psychological warfare, but signally failed to contain an insurrection that was embedded within the family, kin, and associational structures of rural society.

Are There Different Kinds of Rogue Waves?

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Paul C. Liu ◽  
Keith R. MacHutchon
Keyword(s):  
Rogue Wave ◽  
Rogue Waves ◽  
Rayleigh Distribution ◽  
The Other ◽  
South Indian Ocean ◽  
Gas Drilling ◽  
Wave Measurements ◽  
South Indian ◽  
Theoretical Considerations

There is clearly no immediate answer to the question posted by the title of this paper. Inasmuch as that there are not much definitively known about rogue waves and that there is still no universally accepted definition for rogue waves in the ocean, we think there might just be even more than one kind of rogue waves to contend with. While the conventional approach has generally designated waves with Hmax∕Hs greater than 2.2 as possible rogue waves, based on Rayleigh distribution considerations, there is conspicuously no provision as to how high the ratio of Hmax∕Hs can be and thus not known how high can a rogue wave be. In our analysis of wave measurements made from a gas-drilling platform in South Indian Ocean, offshore from Mossel Bay, South Africa, we found a number of cases that indicated Hmax∕Hs could be valued in the range between 4 and 10. If this were to be the case, then these records could be considered to be “uncommon” rogue waves, whereas a record of Hmax∕Hs in the range between 2 and 4 could be considered to comprise “typical” rogue waves. On the other hand, the spikes in the Hmax data could have been caused by equipment malfunction or some other phenomenon. Clearly, the question of whether or not there are different kinds of rogue waves cannot be readily answered by theoretical considerations alone and there is a crucial need for long-term wave time-series measurements for studying rogue waves.

scholarly journals Failure of a warehouse floor by subsoil settlement

2019 ◽  
Vol 284 ◽  
pp. 04004 ◽  
Author(s):  
Sławomir Kwiecień
Keyword(s):  
Surface Area ◽  
Maximum Depth ◽  
Industrial Building ◽  
Floor Level ◽  
Floor Slab ◽  
Root Cause ◽  
On Site Inspection ◽  
Geotechnical Tests ◽  
Test Loading

This paper discusses the failure of a warehouse floor (with an approximate surface area of 1.550 m2) inside an industrial building with a total developed area of approx. 8.200 m2 along with the testing of the failure and its repair. Over ten-odd years of operation of the industrial building, its floor was found to develop non-uniform settlement with a maximum depth of approximately 150 mm from the original floor level. The completed survey inspections, geotechnical tests and FEM studies demonstrated that the root cause of these non-uniform settlement events was the foundation of the warehouse floor, built on a subsoil which featured high and long-term deformability. Given the investigated conditions, it was decided to modify the foundation of the new warehouse floor slab by reinforcing the subsoil with drilled micropiling. The calculations completed, test loading of a drilled micropile and on-site inspection of the warehouse flooring in use confirmed that the modification was rational.

Are There Different Kinds of Rogue Waves?

2006 ◽  
Author(s):  
Paul C. Liu ◽  
Keith R. MacHutchon
Keyword(s):  
Time Series ◽  
Rogue Waves ◽  
Rayleigh Distribution ◽  
The Other ◽  
South Indian Ocean ◽  
Gas Drilling ◽  
Wave Measurements ◽  
South Indian ◽  
Theoretical Considerations

Inasmuch as there is as yet still no universally accepted definition for rogue waves in the ocean, we think there might just be more than one kind of rogue waves to contend with. While the conventional approach has generally designated waves with Hmax/Hs greater than 2.2 as possible rogue waves, based on Rayleigh distribution considerations, there is conspicuously no provision as to how high the ratio of Hmax/Hs can be. In our analysis of wave measurements made from a gas-drilling platform in South Indian Ocean, offshore from Mossel Bay, South Africa, we found a number of cases that indicated Hmax/Hs could be valued in the range between 4 and 10. If this were to be the case these records could be considered to be “uncommon” rogue waves, whereas a record of Hmax/Hs in the range between 2 and 4 could be considered to comprise “typical” rogue waves. On the other hand the spikes in the Hmax data could have been caused by equipment malfunction or some other phenomenon. Clearly the question of whether or not there are different kinds of rogue waves can not be readily answered by theoretical considerations alone and there is a crucial need for long-term wave time series measurements for studying rogue waves.

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