scholarly journals Aggregate stability and penetration resistance after mobilization of a dystrocohesive Ultisol

2017 ◽  
Vol 21 (11) ◽  
pp. 752-757 ◽  
Author(s):  
Uilka E. Tavares ◽  
Mario M. Rolim ◽  
Djalma E. Simões Neto ◽  
Elvira M. R. Pedrosa ◽  
Adriana G. Magalhães ◽  
...  
Keyword(s):  
Soil Aggregates ◽  
Aggregate Stability ◽  
Penetration Resistance ◽  
Soil Tillage ◽  
Soil Fraction ◽  
Soil Penetration Resistance ◽  
Before And After ◽  
The Impact ◽  
The City ◽  
Coarse Soil

ABSTRACT Evaluation of mobilized soil profiles can provide important information on soil compaction reduction processes. In this context, the objective of this study was to evaluate alterations in soil penetration resistance and the impact on the aggregate stability of a cohesive Ultisol cultivated with sugarcane. The experiment was carried out at the Carpina Sugarcane Experimental Station (EECAC/UFRPE), located in the city of Carpina, PE. Penetration resistance, mobilized area and depth, and percentage of soil aggregates were evaluated before and after soil tillage. Soil mobilization improved soil aggregate uniformity and decreased penetration resistance in the 0-0.20 m layer. Coarse soil fraction, moisture and organic carbon positively contributed to the increase in soil mobilization.

scholarly journals Impact of COVID-19 Pandemic on Retail Structure in Barcelona: From Tourism-Phobia to the Desertification of City Center

2021 ◽  
Vol 13 (15) ◽  
pp. 8215
Author(s):  
Lluís Frago Clols
Keyword(s):  
Multiple Scales ◽  
Real Estate Market ◽  
Structured Interviews ◽  
City Center ◽  
Urban Theory ◽  
The Real Estate ◽  
Tourist Flows ◽  
Before And After ◽  
The Impact ◽  
The City

COVID-19 has meant major transformations for commercial fabric. These transformations have been motivated by the collapse of consumer mobility at multiple scales. We analyzed the impact of the collapse of global tourist flows on the commercial fabric of Barcelona city center, a city that has been a global reference in over-tourism and tourism-phobia. Fieldwork in the main commercial areas before and after the pandemic and complementary semi-structured interviews with the main agents involved highlight the relationship between global tourist flows and commercial fabric. The paper shows how the end of global tourism has meant an important commercial desertification. The end of the integration of the city center into global consumer flows has implications for urban theory. It means a downscaling of the city center and the questioning of traditional center-periphery dynamics. It has been shown that the tourist specialization of commerce has important effects on the real estate market and makes it particularly vulnerable. However, the touristic specialization of commercial activities as a strategy of resilience has also been presented. This adaptation faces the generalized commercial desertification that drives the growing concentration of consumption around the online channel.

scholarly journals Assessing the impact of case mobility: issues and recommendations from Greece

2021 ◽  
Vol 68 (1) ◽  
pp. 1-12
Author(s):  
Athanasios Thanos Giannopoulos
Keyword(s):  
Performance Indicators ◽  
Evaluation Framework ◽  
Transport Systems ◽  
Intelligent Transport Systems ◽  
Intelligent Transport ◽  
Before And After ◽  
Mobility Matrix ◽  
Living Labs ◽  
The Impact ◽  
The City

AbstractThis paper is concerned with the assessment of future applications of CASE (Co-operative, Autonomous, Shared, and Electric) mobility—a term that is also taken to include the more traditionally known applications of ITS (Intelligent Transport Systems). It sets the objective of making such assessments more holistic and horizontal in nature because future CASE mobility applications will include many technologies and service concepts as an integrated whole serving specific mobility objective. Traditional evaluation methodologies will therefore have to be modified to account for this situation, and to this end, the paper focuses on assessing and adapting such “traditional” methodologies. It draws from the experience gained in Greece in the last decade when a substantial number of ITS applications were implemented and assessed, especially in the second largest urban area of the country, the city of Thessaloniki (part of the EU’s European Network of Living Labs). Four basic methodologies are selected: the use of KPIs (Key Performance Indicators), focused interviews, the CMME (CASE Mobility Matrix Evaluation), and the use of safety audits before and after the CASE mobility application. For the first three, the paper suggests specific indicators and/or content. It also gives an example of the use of CMME based on a use case from Thessaloniki. The contents and recommendations of this paper provide a better understanding of the emerging situation as regards CASE mobility applications and point to the need for establishing a timely and comprehensive CASE mobility evaluation framework at both national and European levels, for future implementations.

Stabilization of Soil Aggregates in Relation to Soil Redistribution by Intensive Tillage on a Steep Hillslope

2014 ◽  
Vol 955-959 ◽  
pp. 3566-3571 ◽  
Author(s):  
Yong Wang ◽  
Zhuang Xiong ◽  
Wu Xian Yan ◽  
Yue Qun Qiu
Keyword(s):  
Soil Aggregates ◽  
Geometric Mean ◽  
Aggregate Stability ◽  
Aggregate Size ◽  
Soil Aggregate ◽  
Soil Aggregate Stability ◽  
Mean Weight Diameter ◽  
Tillage Operation ◽  
Sloping Land ◽  
The Impact

The objective of this study was to investigate soil aggregate stability within landscape on hillslopes by intensive tillage. Traditional tillage by consecutive hoeing was performed 5 and 20 times on steeply sloping land of the Sichuan Basin, China, by using the methods of simulated tillage to analyze the impact of long-term tillage on soil aggregates at different slope positions. The dry-sieved method was used to determine distribution of aggregate size in the different landscape positions, and mean weight diameter (MWD) and geometric mean diameter (GMD) as indices of soil aggregate stability. The different times of tillage resulted in different soil aggregate distributions. The results showed that the MWD and GMD values of aggregates were significantly decreased (p< 0.05) after 20-tillage operation, compared with pre-tillage operation. The differences in distributions of MWD and GMD demonstrate that the choice of the tillage times can be an important factor in changing soil aggregate stability and productivity in steeply sloping fields.

Using a penetrometer to predict the effects of soil compaction on the growth and yield of wheat on uniform, sandy soils

1989 ◽  
Vol 40 (3) ◽  
pp. 497 ◽  
Author(s):  
CWL Henderson
Keyword(s):  
Soil Compaction ◽  
Wheat Yield ◽  
Sandy Soils ◽  
Penetration Resistance ◽  
Growth And Yield ◽  
Single Index ◽  
Yield Variation ◽  
Soil Penetration Resistance ◽  
Good Potential ◽  
The Impact

The relationships between soil penetration resistance and the growth and yield of wheat were examined for a range of tillage and compaction experiments conducted on earthy sands near Geraldton, W.A. Overall, a single index of penetration resistance explained around 50% of the growth and yield variation, across sites and seasons. Equations using this index showed good potential for predicting the impact of various tillage and traffic practices on wheat yield.

scholarly journals Aggregate Stability in Soils of Twelve Argo-ecological Zones of Bangladesh Based on Organic Carbon and Basic Cations

2019 ◽  
Vol 23 (2) ◽  
pp. 27-36
Author(s):  
S Arofi ◽  
MM Rahman ◽  
HK Shiragi ◽  
MA Alam ◽  
MM Islam ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Aggregates ◽  
Soil Health ◽  
Aggregate Stability ◽  
Soil Aggregate ◽  
Soil Samples ◽  
Negative Effects ◽  
Ecological Zones ◽  
Soil Fraction ◽  
Basic Cations

Soil aggregate is one of the vital indicators of soil health that depends on organic carbon (OC), texture and basic cations. A total of 206 soil samples were collected from 12 agro-ecological zones (AEZs) of Bangladesh to study the effects of organic carbon (OC), basic cations (Ca, Mg, K and Na) and different sized soil particles on soil aggregate stability. Soil samples were analyzed for bulk density, pH, OC, texture, basic cations and water stable soil aggregates (WSA) following standard protocols. Data revealed that OC positively increased WSA, while monovalent basic cations Na+ and K+ showed negative effects. Water stable soil aggregates and C stock of 0.25 mm sized soil fraction were found higher than that of larger sized soil fractions of 0.5, 1.0 and 2.0 mm. The roles of divalent basic cations Ca2+ and Mg2+ on WSA were found to be indistinct and need to be studied further. Ann. Bangladesh Agric. (2019) 23(2) : 27-36

scholarly journals Electoral competition in the elections of the representative local self-government bodies in Chelyabinsk: before and after the 2014 reform

2021 ◽  
Vol 4 ◽  
pp. 69-82
Author(s):  
Oleg Vydrin ◽  
Keyword(s):  
Electoral Competition ◽  
Electoral System ◽  
Municipal Elections ◽  
Agent Model ◽  
Observation Units ◽  
Before And After ◽  
Principal Agent Model ◽  
The Impact ◽  
First Time ◽  
The City

Introduction. The article examines the dynamics of electoral competition over four electoral cycles from 2005 to 2019 as exemplified by forming representative bodies of local self-government in the city of Chelyabinsk. Particular attention is paid to the impact that the transition of Chelyabinsk to a twotier model of forming local self-government bodies in 2014 had on the electoral competition. The purpose of the paper is to study the dynamics of electoral competition in municipal elections in Chelyabinsk before and after the 2014 reform. Methods. The empirical basis of the study is the database “Electoral competition in the elections of municipal deputies of Chelyabinsk (2005—2019)”, which includes 414 observation units. The analysis of the empirical material is carried out according to the method of G.V. Golosov’s triangle of relative sizes, proposed for classifying party systems and adapted for analyzing elections in single-mandate constituencies. Scientific novelty. The author suggests a methodology for analyzing electoral competition in singlemandate constituencies. For the first time, the phenomenon of “controlled competition” is analyzed on the basis of 4 municipal elections cycles. Results. The analysis makes it possible to speak about fluctuations in electoral competition, its decline in 2009 and 2014 compared to the 2005 elections and increasing by the 2019 elections Conclusions. The “controlled competition” was formed in Chelyabinsk in the period preceding the reform of 2014. The reform introduced a level of local self-government, the effectiveness and necessity of which is not obvious with the existing design of the electoral system. In the course of the reform, the principal-agent model of relations between local self-government bodies and state authorities was finally consolidated. The reform contributed to conserving the “controlled competition”.

The effect of lodging tax increases on US destinations

2019 ◽  
pp. 135481661989075 ◽  
Author(s):  
Simon Hudson ◽  
Fang Meng ◽  
Kevin Kam Fung So ◽  
Scott Smith ◽  
Jing Li ◽  
...  
Keyword(s):  
Time Series ◽  
Economic Loss ◽  
The United States ◽  
Tax Rates ◽  
Daily Rate ◽  
States Data ◽  
Before And After ◽  
The Impact ◽  
The City ◽  
Room Time

This study examined the impact of lodging tax increases on eight different destinations of the United States. Data were collected via in-depth stakeholder interviews and monthly statistics provided by Smith Travel Research including average daily rate, occupancy, and revenue per available room. Time series analysis was employed to estimate the impact of tax increases in each destination by analyzing that time series before and after the imposition of the tax. Overall, our results did not fully support the hypothesis that when a city’s hotel tax greatly increases above that of an easily accessible competitor, it will result in an economic loss to the city with the disproportionate tax rates. Hotels appear to have absorbed any tax increases with little impact to their businesses, but there was concern among stakeholders as to how the lodging tax was spent.

Persistent improvements in the structure and hydraulic conductivity of a Ferrosol due to liming

Soil Research ◽  
2007 ◽  
Vol 45 (3) ◽  
pp. 218 ◽  
Author(s):  
J. M. Kirkham ◽  
B. A. Rowe ◽  
R. B. Doyle
Keyword(s):  
Hydraulic Conductivity ◽  
Organic Carbon ◽  
Soil Structure ◽  
Aggregate Stability ◽  
Aggregate Size ◽  
Soil Surface ◽  
Penetration Resistance ◽  
Organic C ◽  
Soil Penetration Resistance ◽  
Wet Aggregate Stability

Changes in the soil structure and hydraulic conductivity of an Acidic Red Ferrosol were measured in a long-term (1968–2003) fertiliser experiment on pasture in north-western Tasmania, Australia. Studies were initiated following observations of both softer soil surface and cracking on plots that had received 15 t/ha of ground agricultural limestone. Liming decreased penetration resistance and increased hydraulic conductivity. These structural improvements were associated with increased mean dry aggregate size, a small increase in wet aggregate stability, higher exchangeable calcium levels, and increased plant growth, but a 9% decrease in total soil organic carbon in the surface 50 mm. This decrease in organic carbon was not associated with deterioration in soil structure, as may have been anticipated. This was probably because total organic C was still 82 g/kg on unlimed plots. Decreases in soil penetration resistance due to liming increased the likelihood of pugging from livestock but may improve ease of tillage. This research demonstrates that liming can improve the structure of a well-aggregated Ferrosol as well as its previously reported effects of increasing soil pH and yields of pasture and barley despite decreasing organic C.

The role of brush mats in mitigating machine-induced soil disturbances: an assessment using absolute and relative soil bulk density and penetration resistance

2019 ◽  
Vol 49 (2) ◽  
pp. 164-178 ◽  
Author(s):  
Eric R. Labelle ◽  
Benjamin J. Poltorak ◽  
Dirk Jaeger
Keyword(s):  
Bulk Density ◽  
Penetration Resistance ◽  
Soil Bulk Density ◽  
Soil Disturbance ◽  
Forest Harvesting ◽  
Soil Penetration Resistance ◽  
Before And After ◽  
Density Values ◽  
Post Impact ◽  
Mean Differences

Forest soils often exhibit low bearing capacities and as a result are often incapable of withstanding high axle loads. In New Brunswick, Canada, five different brush amounts (0, 5, 10, 15, and 20 kg·m–2) were applied as brush mats on machine operating trails during a cut-to-length harvesting operation in a softwood stand to analyze soil disturbance as a result of off-road forest harvesting machine traffic. Soil absolute and relative bulk density and soil penetration resistance measurements were completed below the varying brush mats both before and after forwarding. The mean differences between pre- and post-impact absolute soil dry bulk density values recorded on track areas were 0.24 g·cm–3 for 5–20 kg·m–2 of brush and 0.33 g·cm–3 for 0 kg·m–2 of brush. On average, 40.5%, 17.9%, 14.3%, 15.5%, and 3.6% of all post-forwarding measurements exceeded the threshold for growth-impeding soil bulk density (80% standard Proctor density) for 0, 5, 10, 15 and 20 kg·m–2 of brush, respectively. Soil penetration values >3.0 MPa represented 23.7%, 15.0%, 9.4%, 4.6%, and 0.7% of all post-forwarding test plots with 0, 5, 10, 15, and 20 kg·m–2 of brush, respectively. The results suggest that softwood brush mats of 10 to 20 kg·m–2 placed on machine operating trails play a considerable role in reducing forwarder-induced soil compaction and penetration resistance.

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