Seasonal variations of Fo, Fm, and Fv/Fm in an epiphytic population of the lichen Punctelia subrudecta (Nyl.) Krog

2007 ◽  
Vol 39 (6) ◽  
pp. 555-565 ◽  
Author(s):  
Laurence BARUFFO ◽  
Mauro TRETIACH
Keyword(s):  
Central Italy ◽  
Field Measurements ◽  
Climatic Conditions ◽  
Light Regime ◽  
Structural Adaptation ◽  
Epiphytic Lichen ◽  
Rapid Changes ◽  
Microclimatic Conditions

Abstract:Chlorophyll a fluorescence was measured every three months from December 2003 to December 2004 in ten, randomly selected thalli of the epiphytic lichen Punctelia subrudecta (Nyl.) Krog occurring in a deciduous, thermophilous downy oak wood in southern Tuscany (central Italy). In situ measurements were carried out with a photosynthesis yield analyser Mini-PAM (Walz, Effeltrich, Germany) on the same measuring points of 30-minute dark-adapted, fully hydrated thalli. The results show a remarkable seasonal change in Fo, Fm, and Fv/Fm, probably caused by a long-term physiological-structural adaptation of the photobiont to the gradual modification of the climatic conditions of each measurement period and the light regime of the understorey. However, P. subrudecta is also sensitive to rapid changes in microclimatic conditions as the PSII functionality is affected by the light regime of the days preceding the field measurements. Some critical observations on the statistical analysis of chlorophyll a fluorescence parameters are also made.

scholarly journals Mass balance of Trambau Glacier, Rolwaling region, Nepal Himalaya: in-situ observations, long-term reconstruction and mass-balance sensitivity

2019 ◽  
Vol 65 (252) ◽  
pp. 605-616 ◽  
Author(s):  
SOJIRO SUNAKO ◽  
KOJI FUJITA ◽  
AKIKO SAKAI ◽  
RIJAN B. KAYASTHA
Keyword(s):  
Mass Balance ◽  
High Elevation ◽  
Climatic Conditions ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Balance Study ◽  
Nepal Himalaya ◽  
In Situ Data

ABSTRACTWe conducted a mass-balance study of debris-free Trambau Glacier in the Rolwaling region, Nepal Himalaya, which is accessible to 6000 m a.s.l., to better understand mass-balance processes and the effect of precipitation on these processes on high-elevation Himalayan glaciers. Continuous in situ meteorological and mass-balance observations that spanned the three melt seasons from May 2016 are reported. An energy- and mass-balance model is also applied to evaluate its performance and sensitivity to various climatic conditions. Glacier-wide mass balances ranging from −0.34 ± 0.38 m w.e. in 2016 to −0.82 ± 0.53 m w.e. in 2017/18 are obtained by combining the observations with model results for the areas above the highest stake. The estimated long-term glacier mass balance, which is reconstructed using the ERA-Interim data calibrated with in situ data, is −0.65 ± 0.39 m w.e. a−1for the 1980–2018 period. A significant correlation with annual precipitation (r= 0.77,p< 0.001) is observed, whereas there is no discernible correlation with summer mean air temperature. The results indicate the continuous mass loss of Trambau Glacier over the last four decades, which contrasts with the neighbouring Mera Glacier in balance.

Field Study on Pump Vibration and ISO’s New Criteria

1999 ◽  
Vol 121 (4) ◽  
pp. 798-803 ◽  
Author(s):  
Toshiyuki Osada ◽  
Takashi Kawakami ◽  
Tadashi Yokoi ◽  
Yoshinobu Tsujimoto
Keyword(s):  
Rotational Speed ◽  
Work Group ◽  
Field Measurements ◽  
Rotating Machinery ◽  
International Organization ◽  
Vibration Level ◽  
Term Operation ◽  
New Criteria

ISO 10816-3 (a new standard of International Organization for Standardization) was established as vibration criteria for industrial rotating machinery based on the bearing housing vibration in situ. The appropriateness of the application of the proposed vibration criteria to pumps was discussed and studied by a work group in Japan. For the assessment, the data of vibration level in field were measured, and the effects of driver output, rotational speed, and pump type were studied. This paper describes the applicability of the new ISO criteria to the evaluation of vibration level of pumps, based on the results of the field measurements. It was found that the new boundaries of evaluation zones, which are acceptable for unrestricted long-term operation of pumps, are quite appropriate and satisfactory.

scholarly journals Energy Efficiency of a Greenhouse for the Conservation of Forestry Biodiversity

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Alvaro Marucci ◽  
Maurizio Carlini ◽  
Sonia Castellucci ◽  
Andrea Cappuccini
Keyword(s):  
Energy Efficiency ◽  
Central Italy ◽  
Climatic Conditions ◽  
Forest Biodiversity ◽  
Heating And Cooling ◽  
Material Systems ◽  
Microclimatic Conditions ◽  
Two Phases ◽  
Cover Material ◽  
Vegetable Material

Forest biodiversity conservation is one of the most interesting and crucial problems in forestry world. Currently, the conservation methods are based on two phases: the conservation of seeds at low temperatures and the multiplication of vegetable material. This latter operation can be successfully developed in properly designed greenhouses. The aim of this paper is to define a type of greenhouse which is particularly suitable for plant material propagation in order to preserve forest biodiversity in the area of the Central Italy. Some general parameters were first defined for a correct planning of the structure, such as: the shape of the section, volume, cover material, systems for heating and cooling, and those for the control of the internal microclimate parameters (light, air temperature, and relative humidity). Considering the construction characteristics and the climatic conditions of the place, the internal microclimatic conditions have been later determined by the useful implementation in TRNSYS in order to analyse the energy efficiency of the greenhouse.

scholarly journals Evaluation of new laser spectrometer techniques for in-situ carbon monoxide measurements

2012 ◽  
Vol 5 (10) ◽  
pp. 2555-2567 ◽  
Author(s):  
C. Zellweger ◽  
M. Steinbacher ◽  
B. Buchmann
Keyword(s):  
Carbon Monoxide ◽  
Measurement Techniques ◽  
Field Measurements ◽  
Current Data ◽  
Atmospheric Composition ◽  
Environmental Research ◽  
Spectroscopic Techniques ◽  
New Techniques

Abstract. Long-term time series of the atmospheric composition are essential for environmental research and thus require compatible, multi-decadal monitoring activities. The current data quality objectives of the World Meteorological Organization (WMO) for carbon monoxide (CO) in the atmosphere are very challenging to meet with the measurement techniques that have been used until recently. During the past few years, new spectroscopic techniques came to market with promising properties for trace gas analytics. The current study compares three instruments that have recently become commercially available (since 2011) with the best currently available technique (Vacuum UV Fluorescence) and provides a link to previous comparison studies. The instruments were investigated for their performance regarding repeatability, reproducibility, drift, temperature dependence, water vapour interference and linearity. Finally, all instruments were examined during a short measurement campaign to assess their applicability for long-term field measurements. It could be shown that the new techniques perform considerably better compared to previous techniques, although some issues, such as temperature influence and cross sensitivities, need further attention.

In Situ Conservation of the Roman Mosaics at the Villa of Boscéaz (Orbe, Switzerland): Diagnosis of Risks Involved

1996 ◽  
Vol 462 ◽  
Author(s):  
R.J. Flatt ◽  
F.J. Girardet ◽  
D.C. Weidmann
Keyword(s):  
In Situ Conservation ◽  
Chemical Properties ◽  
Climatic Conditions ◽  
The Alps ◽  
Thermal Dilatation ◽  
High Degree ◽  
Physical And Chemical

ABSTRACTIn order to maintain the archaeological integrity of the site of Boscéaz, one of the most remarkable north of the Alps because of the number and quality of its roman mosaics, it is intended to maintain these in situ and on their original support. This mode of conservation implies many risks, mainly linked to the climatic variations and to the presence of water and salts in the ground and the mosaics. The high degree of damage observed on these mosaics discovered more than 150 years ago illustrates this fact.The aim of this study has been to establish a diagnosis of the risks linked to the uncovering and the in situ conservation of a mosaic recently discovered (currently covered with protective materials). This diagnosis has been established on the basis of the measurement of the physical and chemical properties of the mosaic and the ground.It turned out that the rising of salts from the ground to the mosaic would be the major problem and that consequently a dessalaision will have to be carried out. Concerning the choice of the climatic conditions for conservation, the critical zone in which the salts present crystallize was determined. The thermal dilatation of the materials appeared relatively small, but might become damageable in the long term because of a possible hysteresis. The hydrie dilatation turned out to be negligible.

scholarly journals In-flight calibration of double-probe DC electric field measurements on Cluster

2014 ◽  
Vol 4 (1) ◽  
pp. 85-107
Author(s):  
Y. V. Khotyaintsev ◽  
P.-A. Lindqvist ◽  
C. M. Cully ◽  
A. I. Eriksson ◽  
M. André
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Field Measurements ◽  
Calibration Procedure ◽  
Double Probe ◽  
Ac Electric Fields ◽  
Dc Electric Field ◽  
Electric Field Measurements

Abstract. Double-probe electric field instrument with long wire booms is one of the most popular techniques for in situ measurement of DC and AC electric fields in plasmas on spinning spacecraft platforms, which have been employed on a large number of space missions. Here we present an overview of the calibration procedure used for the EFW instrument on Cluster, which involves spin fits of the data and correction of several offsets. We also describe the procedure for the offset determination and present results for the long-term evolution of the offsets.

scholarly journals Analysis of the formation of fog and haze in North China Plain (NCP)

2011 ◽  
Vol 11 (4) ◽  
pp. 11911-11937 ◽  
Author(s):  
J. Quan ◽  
Q. Zhang ◽  
H. He ◽  
J. Liu ◽  
M. Huang ◽  
...  
Keyword(s):  
North China Plain ◽  
North China ◽  
Aerosol Particles ◽  
Rapid Changes ◽  
Low Visibility ◽  
Aerosol Number Concentration ◽  
The Impact ◽  
The Relationship

Abstract. North China Plain (NCP) is one of the most populated and polluted regions in China. During the recent years, haze and fog occur frequently and cause severely low visibility in this region. In order to better understand the impact of aerosol particles on the formation of haze and fog, a long-term record of haze and fog occurrences in the past 56 years (from 1954–2009) over NCP is analyzed. The results show that there are rapid changes in the occurrences of haze and fog over NCP. The occurrences of haze and fog were low during 1970–1980, and reached a maximum during 1981–1998. After 1999, the occurrences of haze and fog slightly decreased. There was a nonlinear relationship between the occurrences of haze and fog. When the occurrence of haze was lower than 40 days yr−1, the occurrence of fog was strongly proportional to the occurrence of haze. However, when the occurrence of haze was high (larger than 75 days yr−1), the occurrence of fog was not sensitive to the occurrence of haze. In order to better understand the relationship between the occurrences of haze and fog as well as the effect of aerosol particles on the formation of haze and fog, an in-situ field experiment was conducted during a period with a mixed occurrence of haze and fog. The analysis of the experiment suggests that there were considerably high aerosol concentrations during the measurement period, with an averaged aerosol number concentration of 24 000 cm−3. The measurement also shows that a large amount of aerosol particles can act as condensation nuclei to enhance the formation of fog droplets. As a result, a large amount of fog droplets (>1000 cm−3) with small size in radius (5–6 μm) were observed during the fog period, resulting in extremely low visibility (less than 100 m).

scholarly journals Analysis of the formation of fog and haze in North China Plain (NCP)

2011 ◽  
Vol 11 (15) ◽  
pp. 8205-8214 ◽  
Author(s):  
J. Quan ◽  
Q. Zhang ◽  
H. He ◽  
J. Liu ◽  
M. Huang ◽  
...  
Keyword(s):  
North China Plain ◽  
North China ◽  
Aerosol Particles ◽  
Rapid Changes ◽  
Low Visibility ◽  
Aerosol Number Concentration ◽  
The Impact ◽  
The Relationship

Abstract. North China Plain (NCP) is one of the most populated and polluted regions in China. During the recent years, haze and fog occur frequently and cause severely low visibility in this region. In order to better understand the impact of aerosol particles on the formation of haze and fog, a long-term record of haze and fog occurrences in the past 56 yr (from 1954–2009) over NCP is analyzed. The results show that there are rapid changes in the occurrences of haze and fog over NCP. The occurrences of haze and fog were low during 1970–1980, and reached a maximum during 1981–1998. After 1999, the occurrences of haze and fog slightly decreased. There was a nonlinear relationship between the occurrences of haze and fog. When the occurrence of haze was lower than 40 days yr−1, the occurrence of fog was strongly proportional to the occurrence of haze. However, when the occurrence of haze was high (larger than 75 days yr−1), the occurrence of fog was not sensitive to the occurrence of haze. In order to better understand the relationship between the occurrences of haze and fog as well as the effect of aerosol particles on the formation of haze and fog, an in-situ field experiment was conducted during a period with a mixed occurrence of haze and fog. The analysis of the experiment suggests that there were considerably high aerosol concentrations during the measurement period with an averaged aerosol number concentration of 24 000 cm−3. The measurement also shows that a large amount of aerosol particles can act as condensation nuclei to enhance the formation of fog droplets. As a result, a large amount of fog droplets (>1000 cm−3) with small size (5–6 μm) were observed during the fog period, resulting in extremely low visibility (less than 100 m).

Assessing Performance of Leaf Area Index in a Monitored Mountain Ecosystem on Mount Elgon-Uganda

2019 ◽  
pp. 791-808
Author(s):  
Tonny Oyana ◽  
Ellen Kayendeke ◽  
Samuel Adu-Prah
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Global Climate ◽  
Field Measurements ◽  
Area Index ◽  
Temporal Differences ◽  
Mountain Ecosystem ◽  
Mount Elgon

This study investigated the performance of leaf area index (LAI) and photosynthetically active radiation (PAR) in a mountain ecosystem. The authors hypothesized that significant spatial and temporal differences exist in LAI and PAR values in the Manafwa catchment on Mt. Elgon. This was accomplished through field measurements of actual LAI and PAR values of diverse vegetation types along a ~900m altitudinal gradient (1141–2029 masl) in the catchment. In-situ measurements were obtained from 841 micro-scale study plots in 28 sampling plots using high resolution LAI sensors. The findings showed a significant positive relationship exists between elevation and observed LAI (r = 0.45, p = 0.01). A regression model further shows that elevation and curvature of the landscape slope were highly significant (p < 0.00002) predictors of LAI. Finally, the authors detected significant spatial and temporal differences in LAI and PAR values in the study area. The study provides a critical basis for setting up long-term monitoring plans to understand mountain ecosystems and global climate change.

scholarly journals Evaluation of three new laser spectrometer techniques for in-situ carbon monoxide measurements

2012 ◽  
Vol 5 (4) ◽  
pp. 4735-4769 ◽  
Author(s):  
C. Zellweger ◽  
M. Steinbacher ◽  
B. Buchmann
Keyword(s):  
Carbon Monoxide ◽  
Measurement Techniques ◽  
Field Measurements ◽  
Current Data ◽  
Atmospheric Composition ◽  
Environmental Research ◽  
Spectroscopic Techniques ◽  
New Techniques

Abstract. Long-term time series of the atmospheric composition are essential for environmental research and thus require compatible, multi-decadal monitoring activities. However, the current data quality objectives of the World Meteorological Organization (WMO) for carbon monoxide (CO) in the atmosphere are very challenging to meet with the measurement techniques that have been used until recently. During the past few years, new spectroscopic techniques came on the market with promising properties for trace gas analytics. The current study compares three instruments that are recently commercially available (since 2011) with the up to now best available technique (vacuum UV fluorescence) and provides a link to previous comparison studies. The instruments were investigated for their performance regarding repeatability, reproducibility, drift, temperature dependence, water vapour interference and linearity. Finally, all instruments were examined during a short measurement campaign to assess their applicability for long-term field measurements. It could be shown that the new techniques provide a considerably better performance compared to previous techniques, although some issues such as temperature influence and cross sensitivities need further attention.

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