Assessment of Long-Term Gas Sampling Design at Two Commercial Manure-Belt Layer Barns

The flow fields in and around two versions of a water-cooled gas-sampling probe, situated downstream of a gas turbine combustor, were numerically studied in an elevated pressure and temperature environment. The probes are of triple-walled stainless steel assembly, where the gas sample is transported through a centre tube, while preheated and pressurized cooling water flows through two surrounding annuli. Complex conjugate heat transfers amongst the exhaust mixture, cooling water and probe walls were modelled at a selected operating condition. The numerical results indicate over-heating and possible vaporization of water or cavitation in the upstream tip region of the probe with the original design. This is consistent with the evidence of damage observed in these probes from prolonged testing under similar conditions. For the modified probe, the effectiveness of cooling water is much improved, which is confirmed by long-term combustor rig testing. From this investigation, some recommendations for probe design and operation are provided. Moreover, the present study has proved that the numerical simulation is a valuable tool for probe design and trouble-shooting, and to accurately predict conjugate heat transfers in such flows, the laminar sub-layer in the near-wall region should be adequately resolved.

Download Full-text

Long-Term Validation and Governance Role in Contemporary Urban Tree Monitoring: A Review

Sustainability ◽

10.3390/su12145589 ◽

2020 ◽

Vol 12 (14) ◽

pp. 5589

Author(s):

Blaz Klobucar ◽

Johan Östberg ◽

Märit Jansson ◽

Thomas Barfoed Randrup

Keyword(s):

Urban Areas ◽

Sampling Design ◽

Lateral Approach ◽

Urban Trees ◽

Limited Attention ◽

Governance Arrangement ◽

Urban Tree ◽

Primary Focus ◽

Longitudinal Sampling

Urban trees provide important ecosystem services, across ownership and governance structures, and tree inventories are an important tool enabling urban foresters and green space managers to monitor and perform the sustainable management of urban trees. For optimal management of urban trees, a better understanding is needed concerning how urban tree inventories can provide long-term monitoring overviews across administrative borders, and how inventory protocols should be adapted to address specific practitioner issues. In this review, 98 articles on urban tree inventories were examined, the primary focus being sampling design. A governance arrangement approach was applied to identify the policy-making arrangements behind the inventories. Stratification is commonly used in the sampling design, despite being problematic for long-term representativeness. Only 10% of the stratification sampling designs identified were considered as having long-term validity. The studies frequently relied on an individual sampling design aimed at a particular issue, as opposed to using an existing longitudinal sampling network. Although private trees can constitute over 50% of the urban tree population, 41% of the studies reviewed did not include private trees at all. Urban tree inventories focused primarily on tree data on a local scale. Users or private tree owners are commonly not included in these studies, and limited attention is paid to economic, cultural or social factors. A long-term validation of sampling methods in urban areas, and a multi-lateral approach to tree inventories, are needed to maintain long-term operational value for local managers in securing ecosystem service provisions for entire urban forests.

Download Full-text

Complex national sampling design for long-term monitoring of protected dry grasslands in Switzerland

Environmental and Ecological Statistics ◽

10.1007/s10651-013-0263-2 ◽

2013 ◽

Vol 21 (3) ◽

pp. 453-476 ◽

Cited By ~ 5

Author(s):

Yves Tillé ◽

Klaus Ecker

Keyword(s):

Sampling Design ◽

Dry Grasslands ◽

Long Term Monitoring ◽

Term Monitoring

Download Full-text

Foreword

Zootaxa ◽

10.11646/zootaxa.2318.1.3 ◽

2009 ◽

Vol 2318 (1) ◽

pp. 5-7

Author(s):

PIERFILIPPO CERRETTI ◽

FRANCO MASON ◽

ALESSANDRO MINELLI ◽

GIANLUCA NARDI ◽

DANIEL WHITMORE

Keyword(s):

Forest Ecosystems ◽

Sampling Design ◽

Late Summer ◽

Arthropod Diversity ◽

Regional Administration ◽

Icp Forests ◽

Standard Sampling ◽

State Forestry ◽

Set Up

It was the late summer of 2003 when we first travelled to Sardinia to set up traps in the forest of Marganai, an area owned by the regional administration, in the south-western part of the island. Our Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale in Verona—a research institute of the Italian State Forestry Service—had been entrusted with the assessment of arthropod diversity in permanent monitoring sites of the ICP Forests network, a European body for long-term research in forest ecosystems (Mason et al. 2006). The project included a total of twelve forests in Italy, and we were setting up a standard sampling design at each site.

Download Full-text

Local pivotal method sampling design combined with micro stands utilizing airborne laser scanning data in a long term forest management planning setting

Silva Fennica ◽

10.14214/sf.1414 ◽

2016 ◽

Vol 50 (2) ◽

Cited By ~ 2

Author(s):

Rami Saad ◽

Tomas Lämås ◽

Jörgen Wallerman ◽

Johan Holmgren

Keyword(s):

Forest Management ◽

Laser Scanning ◽

Sampling Design ◽

Airborne Laser Scanning ◽

Management Planning ◽

Forest Management Planning ◽

Airborne Laser

Download Full-text

Temporal trends in opportunistic citizen science reports across multiple taxa

AMBIO ◽

10.1007/s13280-021-01550-w ◽

2021 ◽

Author(s):

Jonas Knape ◽

Stephen James Coulson ◽

René van der Wal ◽

Debora Arlt

Keyword(s):

Sampling Design ◽

Temporal Change ◽

Temporal Trends ◽

Sources Of Information ◽

Weather Variables ◽

Online Platforms ◽

User Communities ◽

In The Wild ◽

Taxonomic Groups

AbstractOpportunistic reporting of species observations to online platforms provide one of the most extensive sources of information about the distribution and status of organisms in the wild. The lack of a clear sampling design, and changes in reporting over time, leads to challenges when analysing these data for temporal change in organisms. To better understand temporal changes in reporting, we use records submitted to an online platform in Sweden (Artportalen), currently containing 80 million records. Focussing on five taxonomic groups, fungi, plants, beetles, butterflies and birds, we decompose change in reporting into long-term and seasonal trends, and effects of weekdays, holidays and weather variables. The large surge in number of records since the launch of the, initially taxa-specific, portals is accompanied by non-trivial long-term and seasonal changes that differ between the taxonomic groups and are likely due to changes in, and differences between, the user communities and observer behaviour.

Download Full-text

Level up ocean carbon observations: Successful implementation of a novel autonomous total alkalinity analyzer on a commercial Ship of Opportunity

10.5194/egusphere-egu2020-12861 ◽

2020 ◽

Author(s):

Katharina Seelmann ◽

Tobias Steinhoff ◽

Arne Körtzinger

Keyword(s):

Ocean Acidification ◽

Main Part ◽

Sea Surface ◽

Total Alkalinity ◽

Global Ocean ◽

Observation System ◽

Successful Implementation ◽

Gas Sampling ◽

Ocean Carbon

The observation and documentation of the marine carbon cycle is of utmost importance because of probable future changes such as ocean acidification, warming or deoxygenation. Over decades, ship-based observatories (Ships of Opportunity &#8211; SOOP) equipped with sensors measuring the CO2 partial pressure (pCO2) in the surface seawater form the backbone of the global ocean carbon observation system. However, one severe shortcoming of the current carbon-SOOP observatory is the fact that it mostly only measures pCO2 which is required to calculate the net air-sea CO2 flux. Full insight into the marine CO2 system for important aspects such as net biological production, ocean acidification, and marine calcification requires the measurement of two out of the four measurable variables of the marine CO2 system which are pCO2, total alkalinity (AT), dissolved inorganic carbon (CT) and pH. The so far common workaround is the calculation of AT from sea surface temperature and sea surface salinity using established parameterizations. Unfortunately, this procedure leads to high uncertainties and is particularly prone to regional bias. Therefore, autonomous AT measurements are necessary. Our study describes the implementation of a novel autonomous analyzer for seawater AT, the CONTROS HydroFIA&#174; TA system (Kongsberg Maritime Contros GmbH, Kiel, Germany) on a North Atlantic SOOP line based on the merchant vessel M/V Atlantic Sail (Atlantic Container Line). The first main part of this work deals with the installation of the analyzer, for which several circumstances must be taken into account: 1) The system&#8217;s typical drift behavior, 2) stabilization measurements and cleaning procedures, and 3) the waste handling. We present our installation in detail and how we handle the named issues. Another major problem during automated long-term campaigns is the provision of sufficient reference seawater for regular quality assurance measurements and subsequent drift correction. We tested ten different container types and materials with minimum 5L volume (e.g. gas sampling bags) for their suitability as long-term seawater storage. As a result, only one gas sampling bag based on polyvinylidene fluoride (PVDF) featured the high-quality requirements and was chosen as reference seawater storage. The second main part focusses on the measured sea surface AT data from the first four unattended measurement campaigns. In order to prove the success of the installation, we compared the measurements with 1) discrete samples (taken manually only during the first two transits), and 2) calculated AT values based on established parameterization. The gained results show very promising consistency between the measured values and the AT range and variability of the monitored region. We conclude that the implementation of the CONTROS HydroFIA&#174; TA system on a SOOP line was successful and brings ocean carbon observations to a new level.

Download Full-text