scholarly journals Small-Scale Drop Size Variability: Impact on Estimation of Cloud Optical Properties

2005 ◽  
Vol 62 (7) ◽  
pp. 2555-2567 ◽  
Author(s):  
Y. Knyazikhin ◽  
R. B. Myneni ◽  
A. Marshak ◽  
W. J. Wiscombe ◽  
M. L. Larsen ◽  
...  
Keyword(s):  
Drop Size ◽  
Water Drop ◽  
Small Scale ◽  
Size Dependent ◽  
Radiative Impact ◽  
Size Variability ◽  
The Mean ◽  
Conventional Models ◽  
Processing Techniques ◽  
The Impact

Abstract Most cloud radiation models and conventional data processing techniques assume that the mean number of drops of a given radius is proportional to volume. The analysis of microphysical data on liquid water drop sizes shows that, for sufficiently small volumes, this proportionality breaks down; the number of cloud drops of a given radius is instead proportional to the volume raised to a drop size–dependent nonunit power. The coefficient of proportionality, a generalized drop concentration, is a function of the drop size. For abundant small drops the power is unity as assumed in the conventional approach. However, for rarer large drops, it falls increasingly below unity. This empirical fact leads to drop clustering, with the larger drops exhibiting a greater degree of clustering. The generalized drop concentration shows the mean number of drops per cluster, while the power characterizes the occurrence frequency of clusters. With a fixed total number of drops in a cloud, a decrease in frequency of clusters is accompanied by a corresponding increase in the generalized concentration. This initiates a competing process missed in the conventional models: an increase in the number of drops per cluster enhances the impact of rarer large drops on cloud radiation while a decrease in the frequency suppresses it. Because of the nonlinear relationship between the number of clustered drops and the volume, these two opposite tendencies do not necessarily compensate each other. The data analysis suggests that clustered drops likely have a stronger radiative impact compared to their unclustered counterpart; ignoring it results in underestimation of the contribution from large drops to cloud horizontal optical path.

Small-Scale Drop-Size Variability: Empirical Models for Drop-Size-Dependent Clustering in Clouds

2005 ◽  
Vol 62 (2) ◽  
pp. 551-558 ◽  
Author(s):  
Alexander Marshak ◽  
Yuri Knyazikhin ◽  
Michael L. Larsen ◽  
Warren J. Wiscombe
Keyword(s):  
Drop Size ◽  
Power Laws ◽  
Companion Paper ◽  
Small Scale ◽  
Aircraft Measurements ◽  
Cloud Drop ◽  
Size Dependent ◽  
Individual Drop ◽  
Size Variability

Abstract By analyzing aircraft measurements of individual drop sizes in clouds, it has been shown in a companion paper that the probability of finding a drop of radius r at a linear scale l decreases as lD(r), where 0 ≤ D(r) ≤ 1. This paper shows striking examples of the spatial distribution of large cloud drops using models that simulate the observed power laws. In contrast to currently used models that assume homogeneity and a Poisson distribution of cloud drops, these models illustrate strong drop clustering, especially with larger drops. The degree of clustering is determined by the observed exponents D(r). The strong clustering of large drops arises naturally from the observed power-law statistics. This clustering has vital consequences for rain physics, including how fast rain can form. For radiative transfer theory, clustering of large drops enhances their impact on the cloud optical path. The clustering phenomenon also helps explain why remotely sensed cloud drop size is generally larger than that measured in situ.

scholarly journals Depression, Suicidal Ideation, and Resilience among Rural Farmers in a Drought-Affected Area of Trichy District, Tamil Nadu

2019 ◽  
Vol 10 (02) ◽  
pp. 238-244 ◽  
Author(s):  
Deepak Justine Viswanathan ◽  
Veerakumar A. M ◽  
Hemalatha Kumarasamy
Keyword(s):  
Suicidal Ideation ◽  
Tamil Nadu ◽  
Pearson Correlation ◽  
Small Scale ◽  
Cluster Sampling ◽  
Years Of Experience ◽  
Affected Area ◽  
Prevalence Of Depression ◽  
The Mean ◽  
The Impact

ABSTRACTBackground: Changes in climatic conditions and other factors including trade and commerce have influenced agriculture worldwide. These factors have created a crisis among farmers. Objectives: The objective of this study was to find out the prevalence of depression and suicidal ideation, to measure the resilience, and to find out the factors that influence depression and resilience among farmers. Materials and Methods: A community-based cross-sectional analytical study was performed among farmers residing in a drought-affected area of Tiruchirappalli district of Tamil Nadu. The sample size was 191 and cluster sampling was used to select the participants. Structured, pretested questionnaires were used to find the prevalence of depression, suicidal ideation, and resilience among farmers. Pearson Correlation, Student’s t-test, analysis of variance, and Pearson Chi-square test were used to identify the factors influencing depression and resilience. Results: A total of 194 farmers participated in the study. The mean age of the farmers was 46.68 ± 12.6 years, majority 64% were males and 89% were literates. Among the participants, 97.4% had some form of depression, and 67% had severe depression. About 60% of the farmers had suicidal ideation. Male farmers, farmers with few years of farming experience, and severe reduction in yield had a higher level of depression. Suicidal ideation was influenced by gender, small-scale farming, fewer years of experience in farming, and the impact of drought on yield. The mean resilience score was 49.4 ± 10. Gender and years of experience in farming had a significant association with resilience. Conclusion: High prevalence of depression and suicidal ideation and low level of resilience has been observed among the farmers. Interventions need to be provided for marginal and small-scale farmers, male farmers in the affected area to reduce the impact of drought in these farmers.

The Effect of Microsite Variation on Seed-Germination and Seedling Survival of Eucalyptus delegatensis

1993 ◽  
Vol 41 (2) ◽  
pp. 169 ◽  
Author(s):  
M Battaglia ◽  
JB Reid
Keyword(s):  
Seed Germination ◽  
Seedling Survival ◽  
Soil Conditions ◽  
Small Scale ◽  
Root Penetration ◽  
Mean Survival Time ◽  
The Mean ◽  
Developmental Characteristics ◽  
The Impact ◽  
Eucalyptus Delegatensis

The correlation between microsite and seedling numbers was determined in field sowings, and the impact of microsites on germination and seedling survival tested in artificial seedbeds in the glasshouse. Small scale variation in soil conditions, at the scale of tens of centimetres, markedly affected the germination and establishment of Eucalyptus delegatensis R.T.Baker seeds and seedlings. Under conditions of limiting soil moisture, microsites that afforded protection, and probably resulted in increased humidity, caused a marked increase in germination number and rate. The mean survival time was significantly higher on these protected microsites than on less protected microsites, or on microsites that restricted root penetration. The importance of this variability in microtopography was strongly influenced by season and the level of environmental stress, and was diminished as seedlings aged. Due to the different requirements for seed germination and seedling growth, a favourable microsite for germination was not necessarily a favourable site for seedling survival. A comparison of seed and seedling responses to water stress indicated that for E. delegatensis, at least, selection due to microsite differences at the time of germination may not have an impact on the developmental characteristics of the seedlings.

PP20 A retrospective service evaluation of the presentation of anaphylaxis to a UK ambulance service

2019 ◽  
Vol 36 (10) ◽  
pp. e9.2-e9
Author(s):  
Nicholas Groom ◽  
Sarah Taylor ◽  
Ed England ◽  
Helen Pocock ◽  
Charles D Deakin
Keyword(s):  
Service Evaluation ◽  
Ambulance Service ◽  
Small Scale ◽  
Patient Records ◽  
Electronic Patient Records ◽  
Self Administration ◽  
Patient Demographics ◽  
The Mean ◽  
The Impact ◽  
To Receive

BackgroundThere is a lack of data relating to frequency and presentation of anaphylaxis to the ambulance service in England. Little research exists relating to the patients’ self-treatment of anaphylaxis and there is an absence of evidence to evaluate the impact of self-administered adrenaline, there is a need to describe this patient group to evaluate any potential to develop their care.MethodsRetrospective data were collected from the electronic patient records of a single NHS ambulance service serving a population of approximately four million. Records between 1stApril 2017 and 31st March 2018 were included where a diagnosis of anaphylaxis was recorded. Gender, age, incident location, allergy history, were summarised to identify any trends in presentation. The frequency of patient self-administration, as well as ambulance administration, of adrenaline was also included for analysis to determine any correlation.Results326 records were included in the analysis. The mean, median and modal patient ages were 34, 29 and 20 respectively. Patient ages ranged from six months to 95 years. Patients were 65% female, 35% male and 59% of incidents occurred at home. 76% of patients reported having a known allergy with food being the most common allergen (44%). Peak times for calling 999 were midday and 6pm. 35% of patients had self-administered adrenaline. 52% received ambulance-administered adrenaline. The doses of self-administered adrenaline ranged from 0–3 doses and ambulance administered adrenaline ranged from 0–8 doses. Patients who self-administered adrenaline were less likely to receive further adrenaline from the ambulance service. No correlation was found between the number of self-administered doses and ambulance administered doses.ConclusionPatient demographics such as age, gender and allergies were consistent with two previous small-scale studies. This study suggests that early self-administration of adrenaline is beneficial. Opportunities for improvements in data recording as well as patient education were identified.

scholarly journals Drop Size Distribution Variability in Central Argentina during RELAMPAGO-CACTI

2021 ◽  
Vol 13 (11) ◽  
pp. 2026
Author(s):  
Candela Casanovas ◽  
Paola Salio ◽  
Victoria Galligani ◽  
Brenda Dolan ◽  
Stephen W. Nesbitt
Keyword(s):  
Size Distribution ◽  
Complex Terrain ◽  
Drop Size ◽  
Region Of Interest ◽  
Bimodal Distribution ◽  
Drop Size Distribution ◽  
Frequency Distributions ◽  
Central Argentina ◽  
The Mean ◽  
The Impact

The Remote sensing of Electrification, Lightning, And Meso-scale/micro-scale Processes with Adaptive Ground Observations (RELAMPAGO) and the Cloud, Aerosol, and Complex Terrain Interactions Experiment Proposal (CACTI) field campaigns provided an unprecedented thirteen-disdrometer dataset in Central Argentina during the Intensive (IOP, 15 November to 15 December 2018) and Extended (EOP, 15 October 2018 to 30 April 2019) Observational Periods. The drop size distribution (DSD) parameters and their variability were analyzed across the region of interest, which was divided into three subregions characterized by the differing proximity to the Sierras de Córdoba (SDC), in order to assess the impact of complex terrain on the DSD parameters. A rigorous quality control of the data was first performed. The frequency distributions of DSD-derived parameters were analyzed, including the normalized intercept parameter (logNw), the mean volume diameter (D0), the mean mass diameter (Dm), the shape parameter (μ), the liquid water content (LWC), and the rain rate (R). The region closest to the SDC presented higher values of logNw, lower D0, and higher μ, while the opposite occurred in the farthest region, i.e., the concentration of small drops decreased while the concentration of bigger drops increased with the distance to the east of the SDC. Furthermore, the region closest to the SDC showed a bimodal distribution of D0: the lower values of D0 were associated with higher values of logNw and were found more frequently during the afternoon, while the higher D0 were associated with lower logNw and occurred more frequently during the night. The data were analyzed in comparison to the statistical analysis of Dolan et al. 2018 and sorted according to the classification proposed in the cited study. The logNw-D0 and LWC-D0 two-dimensional distributions allowed further discussion around the applicability of other mid-latitude and global precipitation classification schemes (startiform/convection) in the region of interest. Finally, three precipitation case studies were analyzed with supporting polarimetric radar data in order to relate the DSD characteristics to the precipitation type and the microphysical processes involved in each case.

Asteroid and Comet Impact Speeds upon Mars: Significance for Panspermia and the Supply of Organics

1997 ◽  
Vol 161 ◽  
pp. 197-201 ◽  
Author(s):  
Duncan Steel
Keyword(s):  
Probability Distributions ◽  
Regions Of Interest ◽  
Significant Fraction ◽  
Organic Chemicals ◽  
Impact Speed ◽  
The Mean ◽  
The Impact

AbstractWhilst lithopanspermia depends upon massive impacts occurring at a speed above some limit, the intact delivery of organic chemicals or other volatiles to a planet requires the impact speed to be below some other limit such that a significant fraction of that material escapes destruction. Thus the two opposite ends of the impact speed distributions are the regions of interest in the bioastronomical context, whereas much modelling work on impacts delivers, or makes use of, only the mean speed. Here the probability distributions of impact speeds upon Mars are calculated for (i) the orbital distribution of known asteroids; and (ii) the expected distribution of near-parabolic cometary orbits. It is found that cometary impacts are far more likely to eject rocks from Mars (over 99 percent of the cometary impacts are at speeds above 20 km/sec, but at most 5 percent of the asteroidal impacts); paradoxically, the objects impacting at speeds low enough to make organic/volatile survival possible (the asteroids) are those which are depleted in such species.

Sound Production Treatment for Acquired Apraxia of Speech: An Examination of Dosage in Relation to Probe Performance

2020 ◽  
pp. 1-16
Author(s):  
Julie L. Wambaugh ◽  
Lydia Kallhoff ◽  
Christina Nessler
Keyword(s):  
Retrospective Analysis ◽  
Sound Production ◽  
Apraxia Of Speech ◽  
Practice Schedule ◽  
Practice Schedules ◽  
Baseline Performance ◽  
The Mean ◽  
Number Of Treatment ◽  
The Impact

Purpose This study was designed to examine the association of dosage and effects of Sound Production Treatment (SPT) for acquired apraxia of speech. Method Treatment logs and probe data from 20 speakers with apraxia of speech and aphasia were submitted to a retrospective analysis. The number of treatment sessions and teaching episodes was examined relative to (a) change in articulation accuracy above baseline performance, (b) mastery of production, and (c) maintenance. The impact of practice schedule (SPT-Blocked vs. SPT-Random) was also examined. Results The average number of treatment sessions conducted prior to change was 5.4 for SPT-Blocked and 3.9 for SPT-Random. The mean number of teaching episodes preceding change was 334 for SPT-Blocked and 179 for SPT-Random. Mastery occurred within an average of 13.7 sessions (1,252 teaching episodes) and 12.4 sessions (1,082 teaching episodes) for SPT-Blocked and SPT-Random, respectively. Comparisons of dosage metric values across practice schedules did not reveal substantial differences. Significant negative correlations were found between follow-up probe performance and the dosage metrics. Conclusions Only a few treatment sessions were needed to achieve initial positive changes in articulation, with mastery occurring within 12–14 sessions for the majority of participants. Earlier occurrence of change or mastery was associated with better follow-up performance. Supplemental Material https://doi.org/10.23641/asha.12592190

Quantification of small-scale heterogeneity in aquatic aminopeptidase activity

2020 ◽  
Vol 84 ◽  
pp. 127-140
Author(s):  
BM Gaas ◽  
JW Ammerman
Keyword(s):  
Chlorophyll Fluorescence ◽  
Leucine Aminopeptidase ◽  
Hudson River ◽  
Aminopeptidase Activity ◽  
Small Scale ◽  
Analysis Instrument ◽  
Sequential Samples ◽  
Degree Of Confidence ◽  
The Mean ◽  
Hydrolysis Of

Leucine aminopeptidase (LAP) is one of the enzymes involved in the hydrolysis of peptides, and is sometimes used to indicate potential nitrogen limitation in microbes. Small-scale variability has the potential to confound interpretation of underlying patterns in LAP activity in time or space. An automated flow-injection analysis instrument was used to address the small-scale variability of LAP activity within contiguous regions of the Hudson River plume (New Jersey, USA). LAP activity had a coefficient of variation (CV) of ca. 0.5 with occasional values above 1.0. The mean CVs for other biological parameters—chlorophyll fluorescence and nitrate concentration—were similar, and were much lower for salinity. LAP activity changed by an average of 35 nmol l-1 h-1 at different salinities, and variations in LAP activity were higher crossing region boundaries than within a region. Differences in LAP activity were ±100 nmol l-1 h-1 between sequential samples spaced <10 m apart. Variogram analysis indicated an inherent spatial variability of 52 nmol l-1 h-1 throughout the study area. Large changes in LAP activity were often associated with small changes in salinity and chlorophyll fluorescence, and were sensitive to the sampling frequency. This study concludes that LAP measurements in a sample could realistically be expected to range from zero to twice the average, and changes between areas or times should be at least 2-fold to have some degree of confidence that apparent patterns (or lack thereof) in activity are real.

Can Values of Honesty, Hard Work, Loyalty and Discipline Predict Entrepreneurial Orientation of Muslim Owner Managers?

2015 ◽  
Vol 3 (1) ◽  
pp. 31 ◽  
Author(s):  
Rohani Mohd ◽  
Badrul Hisham Kamaruddin ◽  
Khulida Kirana Yahya ◽  
Elias Sanidas
Keyword(s):  
Entrepreneurial Orientation ◽  
Two Dimensions ◽  
Hard Work ◽  
Small Scale ◽  
Sampling Frame ◽  
Policy Makers ◽  
Learning Institutions ◽  
Innovative Orientation ◽  
The Impact ◽  
True Values

The purpose of the present study is twofold: first, to investigate the true values of Muslim owner managers; second, to examine the impact of these values on entrepreneurial orientations of Muslim small-scale entrepreneurs. 850 Muslim owner managers were selected randomly using the sampling frame provided by MajlisAmanah Rakyat Malaysia (MARA). 162 completed questionnaires were collected and analyzed. For this paper only two dimensions of entrepreneurial orientations were analyzed: proactive orientation and innovative orientation. Interestingly, the findings revealed that Muslim businessmen/women are honest, loyal, disciplined and hard working. Loyalty and honesty are positively related to proactive orientation, while discipline and hard-work are positively related to innovative orientation. The findings provide implications for existing relevant theories, policy makers, practitioners and learning institutions. 

Impact of changing rainfall conditions on surface and groundwater resources in an experimental watershed in Greece

2013 ◽  
Vol 12 (2) ◽  
pp. 119-125
Keyword(s):  
Groundwater Resources ◽  
Annual Runoff ◽  
Annual Rainfall ◽  
Rainfall Regime ◽  
Winter Rainfall ◽  
Rainfall Depth ◽  
Rainfall Volume ◽  
The Mean ◽  
Groundwater Reserves ◽  
The Impact

The present study concerns the impact of a change in the rainfall regime on surface and groundwater resources in an experimental watershed. The research is conducted in a gauged mountainous watershed (15.18 km2) that is located on the eastern side of Penteli Mountain, in the prefecture of Attica, Greece and the study period concerns the years from 2003 to 2008. The decrease in the annual rainfall depth during the last two hydrological years 2006-2007, 2007-2008 is 10% and 35%, respectively, in relation to the average of the previous years. In addition, the monthly distribution of rainfall is characterized by a distinct decrease in winter rainfall volume. The field measurements show that this change in rainfall conditions has a direct impact on the surface runoff of the watershed, as well as on the groundwater reserves. The mean annual runoff in the last two hydrological years has decreased by 56% and 75% in relation to the average of the previous years. Moreover, the groundwater level follows a declining trend and has dropped significantly in the last two years.

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