scholarly journals Addition Effect of Petrasoil Additive Material on CBR Value of Soil in Swamp Areas

2019 ◽  
Vol 3 (2) ◽  
pp. 67-70 ◽  
Author(s):  
Andi Herius ◽  
Indrayani Indrayani Indrayani ◽  
Arfan Hasan ◽  
Ahmad Mirza
Keyword(s):  
Water Content ◽  
Soil Water Content ◽  
Construction Projects ◽  
Soil Stabilization ◽  
Road Construction ◽  
Dry Weight ◽  
Soil Conditions ◽  
Index Properties ◽  
Soil Density ◽  
Road Project

Some road construction projects use petrasoil additive to increase soil stabilization, one of then is the Improvement of Tabarfane-Hokmar (Chemical Petrasoil) Road Project in Aru Selatan Timur District, Aru Islands. To obtain the influence of petrasoil aditive material as soil stabilization in swamp areas, a research is needed. petrasoil additives that powder shape are dissolved in water with 3 variations, namely 500 liters, 750 liters, and 1000 liters of water. Tests which carried out include compaction testing, index properties, and CBR. The results showed that the addition of petrasoil mixture with water without being combined with other added ingredients could lead to increasingly unstable soil conditions where the soil water content increased and the dry weight of the soil diminished, meaning that soil density decreases, and the CBR value of soil decreases.

Effects of Superabsorbent Polymer on Soil Water Content and Sugarcane Germination and Early Growth in Sandy Soil Conditions

Sugar Tech ◽  
2018 ◽  
Vol 21 (3) ◽  
pp. 444-450 ◽  
Author(s):  
Kenta Watanabe ◽  
Samran Saensupo ◽  
Yanischa Na-iam ◽  
Peeraya Klomsa-ard ◽  
Klanarong Sriroth
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Sandy Soil ◽  
Early Growth ◽  
Soil Conditions ◽  
Superabsorbent Polymer

scholarly journals Multimodel assessment of climate change-induced hydrologic impacts for a Mediterranean catchment

2018 ◽  
Vol 22 (7) ◽  
pp. 4125-4143 ◽  
Author(s):  
Enrica Perra ◽  
Monica Piras ◽  
Roberto Deidda ◽  
Claudio Paniconi ◽  
Giuseppe Mascaro ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Climate Models ◽  
Actual Evapotranspiration ◽  
Soil Conditions ◽  
Hydrologic Models ◽  
The Future ◽  
The Mediterranean

Abstract. This work addresses the impact of climate change on the hydrology of a catchment in the Mediterranean, a region that is highly susceptible to variations in rainfall and other components of the water budget. The assessment is based on a comparison of responses obtained from five hydrologic models implemented for the Rio Mannu catchment in southern Sardinia (Italy). The examined models – CATchment HYdrology (CATHY), Soil and Water Assessment Tool (SWAT), TOPographic Kinematic APproximation and Integration (TOPKAPI), TIN-based Real time Integrated Basin Simulator (tRIBS), and WAter balance SImulation Model (WASIM) – are all distributed hydrologic models but differ greatly in their representation of terrain features and physical processes and in their numerical complexity. After calibration and validation, the models were forced with bias-corrected, downscaled outputs of four combinations of global and regional climate models in a reference (1971–2000) and future (2041–2070) period under a single emission scenario. Climate forcing variations and the structure of the hydrologic models influence the different components of the catchment response. Three water availability response variables – discharge, soil water content, and actual evapotranspiration – are analyzed. Simulation results from all five hydrologic models show for the future period decreasing mean annual streamflow and soil water content at 1 m depth. Actual evapotranspiration in the future will diminish according to four of the five models due to drier soil conditions. Despite their significant differences, the five hydrologic models responded similarly to the reduced precipitation and increased temperatures predicted by the climate models, and lend strong support to a future scenario of increased water shortages for this region of the Mediterranean basin. The multimodel framework adopted for this study allows estimation of the agreement between the five hydrologic models and between the four climate models. Pairwise comparison of the climate and hydrologic models is shown for the reference and future periods using a recently proposed metric that scales the Pearson correlation coefficient with a factor that accounts for systematic differences between datasets. The results from this analysis reflect the key structural differences between the hydrologic models, such as a representation of both vertical and lateral subsurface flow (CATHY, TOPKAPI, and tRIBS) and a detailed treatment of vegetation processes (SWAT and WASIM).

scholarly journals Enhancing Soil Water Content for Increased Food Production in Semi-Arid Areas of Kenya Results From an On-Farm Trial in Mwala District, Kenya

2014 ◽  
Vol 6 (4) ◽  
pp. 125 ◽  
Author(s):  
Anne Karuma ◽  
Peter Mtakwa ◽  
Nyambilila Amuri ◽  
Charles K. Gachene ◽  
Patrick Gicheru
Keyword(s):  
Soil Moisture ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Conservation ◽  
Crop Yields ◽  
Conservation Tillage ◽  
Cropping Systems ◽  
Soil Conditions ◽  
Tillage Methods

Soil water conservation through tillage is one of the appropriate ways of addressing soil moisture deficit in rainfed agriculture. This study evaluated the effects of tillage practices on soil moisture conservation and crop yields in Mwala District, Eastern Kenya during the long rains (LR) and short rains (SR) of 2012/13. Six tillage systems: Disc plough (MB), Disc plough and harrowing (MBH), Ox-ploughing (OX), Subsoiling – ripping (SR), Hand hoe and Tied Ridges (HTR) and Hand hoe only (H) and, three cropping systems namely, sole maize, sole bean and maize - bean intercrop, were investigated in a split-plot design with four replicates. Data on soil water content was monitored at different weeks after planting and the crop yields at end of each growing season. A three-season average shows that soil water content and crop yields were higher in conventional tillage methods compared to the conservation tillage methods. Long term tillage experiments are thus required at different locations, under various environmental and soil conditions to validate the study findings.

scholarly journals Jambi and Palembang clay soil stabilization for pavement matrix in road construction by using Portland cement type I

2019 ◽  
Vol 276 ◽  
pp. 05005
Author(s):  
Wawan Kuswaya ◽  
Wahyudi Marsiano ◽  
Syafalni Syafalni ◽  
Jonbi
Keyword(s):  
Portland Cement ◽  
Soil Stabilization ◽  
Clay Soil ◽  
Test Procedure ◽  
Road Construction ◽  
Dry Weight ◽  
Type I ◽  
Curing Time ◽  
Cement Type ◽  
Highly Active

The need for a pavement matrix in road construction, especially in Sumatra area, is now more difficult and expensive because the deposit materials are concentrated in Java and most of them are not available. For this reason, soil stabilization is a way out of this problem. On this basis it is necessary to conduct stabilization research with highly active stabilization material by using Portland cement type I. The soil to be stabilized is clay soil which is derived from the areas of Jambi and Palembang and which has a low CBR value less than the requirement for sub base or pavement (< 10%), with the expected CBR value of stabilization to be suitable for road construction. This research covers physical and soil mechanical properties which are compaction parameter and CBR value with 3 days of dry curing time and 4 days of soak curing time using ASTM test procedure. Variations of cement addition were used of 6%, 8%, and 10% for the clay soil from Palembang and 8%, 10%, and 12% for the clay soil from Jambi, by percentage of dry weight of the sample test. The results of this study showed that the CBR value significantly increased with the addition of cement, with Palembang soil CBR value rising from 3.46% to 130.74% and Jambi soil CBR value rising from 7.20% to 206.43% respectively.

scholarly journals Effect of Soil Saturation Duration and Soil Water Content on Root Rot of Maize Caused by Pythium arrhenomanes

Plant Disease ◽  
1997 ◽  
Vol 81 (5) ◽  
pp. 475-480 ◽  
Author(s):  
Y. Yanar ◽  
P. E. Lipps ◽  
I. W. Deep
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Root Rot ◽  
Dry Weight ◽  
Negative Slope ◽  
Silty Clay ◽  
Shoot Dry Weight ◽  
Soil Saturation ◽  
Flooding Duration

Three aggressive isolates of P. arrhenomanes (201-25, 7E, and 5E) were used to evaluate the effect of soil saturation duration and soil water content on maize root rot. Maize seedlings grown in infested and noninfested soil:sand mixtures were subjected to saturation durations of 0, 6, 12, 24, or 40 h. Four silty-clay loam soil:sand mixtures (100:0, 80:20, 50:50, and 0:100) were used to evaluate the effect of soil water content on disease development. Matric water potential was maintained at -1 J/kg during the experiment except for the saturation period. Multiple regression analysis was used to evaluate the effect of saturation duration and soil water content on root and shoot dry weight. Negative slope values were obtained for increasing saturation duration and reduced water content (increased proportion of sand to soil). Intercepts of regression lines for shoot and root dry weights were lower for the infested soil:sand treatments than the noninfested treatments. These results indicated that growth of maize plants was negatively affected by increased flooding duration, lower soil water content, and presence of the pathogen. Growth of maize was significantly (P = 0.05) less in the presence of the pathogen than in non-inoculated control treatments at each soil water content and flooding duration.

Field calibration of a capacitance soil water probe in heterogeneous fields

Soil Research ◽  
2004 ◽  
Vol 42 (3) ◽  
pp. 289 ◽  
Author(s):  
Dieter Geesing ◽  
Martin Bachmaier ◽  
Urs Schmidhalter
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Samples ◽  
Soil Conditions ◽  
Site Specific ◽  
Field Calibration ◽  
Calibration Methods ◽  
Significant Difference ◽  
Capacitance Probe

Soil water research requires methods to perform accurate measurements. A capacitance probe gauge has characteristics that seem to make it an attractive replacement for neutron scatter gauges to measure soil water content, but there is evidence that capacitance systems should be calibrated for individual soils. Laboratory calibrations and many field calibration methods are costly and time-consuming, and controlled conditions and disturbed soil samples do not always reflect field conditions, and thus, they are inadequate for practical use. The objectives of the present study were (i) to test a simple field calibration method for a recently developed capacitive sensor even under highly variable soil texture conditions, and (ii) to validate this approach under various soil moisture conditions. Soil samples were taken 0.5 m from the access tube of the sensor and a whole field calibration and several site-specific calibrations were developed using 10–142 observations per site under different soil water regimes. A regression of soil water content estimated by sensor reading on water content obtained by core sampling showed no significant difference in the slope and intercept of the 1:1 line when the field calibration was applied. However, the precision of the calibration was only considerably increased if the estimations were based on site-specific calibrations developed on at least 35 observations per site. The precision and accuracy of the calibration equations were not affected when data were obtained only under wet or dry soil conditions. The method presented in this paper is a speedy and cheap way to calibrate capacitance probe sensors.

scholarly journals Influence of Time Management on Implementation of Road Construction Projects in Kilifi County, Kenya

2020 ◽  
Vol 5 (2) ◽  
pp. 67-92
Author(s):  
Njebi Mark Mutugi ◽  
Prof. Dorothy Ndunge Kyalo
Keyword(s):  
Regression Analysis ◽  
Time Management ◽  
Construction Projects ◽  
Stakeholder Involvement ◽  
Road Construction ◽  
Institutional Capacity ◽  
Project Implementation ◽  
Resource Estimation ◽  
Road Project ◽  
Road Projects

Purpose: Major road construction projects across Kilifi County have experienced delays in delivery due to a majority of contractors, both local firms and government agencies, failing to adhere to agreed-upon completion dates.it is in the backdrop of these problems that influenced the researcher to establish the influence of time management on the implementation of road projects in Kilifi County. The main purpose of this study was to examine the influence of time management on the implementation’s road constructions projects in Kilifi County.Methodology: The study adopted cross sectional research design and collect data using questionnaires from 120 engineers/project managers, supervisors/inspectors and technicians/foremen from 12 organizations including five construction companies involved in urban road construction projects in Kilifi County, five service providers whose utility facilities run along road construction corridors in Kilifi County, and two state corporations charged with the management of road construction in Kenya. Data was analysed using both descriptive and inferential statistics with the help of IBM SPSS Statistics. Descriptive analysis involved the use of frequencies, percentages, mean and standard deviation in order to summarize the results of the various study variables. Inferential analysis involved the application of Pearson correlation and regression analysis to determine the nature of relationship between time management and implementation of road projects in Kilifi County.Results: The study found out that activity sequencing positively and significantly affects road constructions projects in Kilifi County (r = 0.688, P=0.000 < 0.01). The study further determined that a unit improvement in activity sequencing would lead significantly lead to improvement in road project implementation (β = 0.127, t = 2.037, P=0.044 <0.05). It was also determined that resource estimation positively and significantly affects implementation of road constructions projects in Kilifi County (r = 0.721, P = 0.002 < 0.01). the analysis also showed that a unit improvement in resource estimation would lead to a unit improvement in road project implementation (β = 0.218, t = 2.741, P = 0.005<0.05). The study also determined that activity control significantly and positively predicts implementation of road constructions projects in Kilifi County (r = 0.909, P= 0.000< 0.01). The regression analysis showed that a unit improvement in activity control would significantly lead to an improvement in implementation of road construction projects in the county (β = 0.173, t =3.045, P = 0.003<0.05). Finally, the study found out that institutional capacity affects road projects implementation (r = 0.558, P=0. .003 < 0.01). It was also determined that institutional capacity has moderating influence on the relationship between time management and road project implementation (β = 0.185, t = 4.302, P=0.000 < 0.05).Unique contribution to theory, policy and practice: The study recommended that for effective time management during implementation of road construction projects, there should be stakeholder involvement as this will facilitate ideas and perspective. Stakeholder involvement in time management and planning, will better their correspondence, improve accuracy of information, increase credibility and acceptance findings and finally improve the quality road constructions projects in Kilifi County.

scholarly journals ANALISA FAKTOR-FAKTOR YANG MEMPENGARUHI PENERAPAN MANAJEMEN WAKTU PADA PROYEK KONSTRUKSI JALAN DI KOTA SAWAHLUNTO

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Abadi Palusia
Keyword(s):  
Time Management ◽  
Research Method ◽  
Construction Projects ◽  
Quantitative Research ◽  
Construction Project ◽  
Road Construction ◽  
Timely Completion ◽  
Road Project ◽  
Road Projects ◽  
Construction Works

Currently, many road projects are performing poorly for timely completion, an analysis of time road project implementation needs to be done on the contractor company, so that it can be known that the shortcomings and weaknesses done so far, which later can be an input for contractor, to be even better in the implementation of time management of a road construction project. In 2017 many packages of road construction works in Sawahlunto City. The purpose of this study is to determine the factors that affect the implementation of time management of road construction projects in Sawahlunto. The research method used is quantitative research method by spreading questionnaires to the respondents involved in road construction project in Sawahlunto City. Kata Kunci : Time Management, road, late

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