165,060 research outputs found

    Effects of Harvesting Equipment on Soil Compaction in Sugarcane Farms

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    This study was performed in a cane field in Iran to investigate the effects of harvesting equipment on soil compaction. The study was conducted in a factorial experiment based on the completely randomized blocks design having three replications. Two models of bins, three travel speeds and two tyre inflation pressures were imposed as main plots, subplots and subsubplots respectively. Results showed that harvester traffic significantly increased soil compaction in the 0-20 cm depth profile; however the difference of soil cone indexes before and after bin traffic was not statistically significant. Other than 0-10 cm and 30-40 cm depth profiles, other layers of soil were significantly affected by exerted treatments. Compaction effect of Shaker bin was lower compared to HEPCO bin because of wider tyres and lesser tread height. By decreasing tyre inflation pressure from 240 to 290 kPa, soil compaction effects of bin traffic decreased. Results also showed that the effect of travel speed treatment mostly appeared in toper layers of soil whereas the effects of bin type and inflation pressure treatments mostly appeared in deeper layers of soil

    Hydraulic factors limiting the use of subirrigation in fine textured soils : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Philosophy in Agricultural Engineering at Massey University

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    Subirrigation is a method of supplying water directly to the plant root zone under the ground surface by means of subsurfce drains which are also used to remove excess water from the root zone. Subsurface drainage systems are used to maintain appropriate levels of soil moisture in the root zone of a crop by managing the water table. Subirrigation is seen as being an economic alternative to conventional sprinkler irrigation systems on dairy farms where mole drainage systems are already installed. However, information on subirrigation of these fine textured soils is very limited. The primary focus of this study was to evaluate the hydraulic parameters limiting the use of subirrigation in fine textured soils. A field experiment was carried out on the Massey University No. 4 Dairy Farm in Palmerston North. During the study, a subsurface tile drainage system, with mole channels, was used to subirrigate 1248 m2 of Tokomaru silt loam soil. The depth of irrigation applied was 185.71mm (232 m3 of water added to the system). Time Domain Reflectometry (TDR) was used to measure the soil moisture content to a depth of 400mm at three positions, 5 m away from the drainage lateral and at three control points in an adjacent unirrigated plot. A theoretical daily water balance was developed for the irrigated plot and unirrigated control, based on the available weather data. The results from field experiment showed that sufficient water did not move from the drainage lateral to the moles. Reasons for this may include: (a) Not enough water applied, (b) Not enough pressure head was available to force water from the drainage lateral to the moles or (c) hydraulic conductivity of the backfill was too low. Having identified, from the field experiment, that the hydraulic connection between the lateral and mole was a potential problem, a bin model experiment was carried out in the hydraulic laboratory of the Agricultural Engineering Department. Two different backfill materials (gravel and tokomaru silt loam soil) were used with two mole positions in the bin relative to the drainage lateral. The flow rate and head losses through the system were measured for different applied pressure heads. The saturated hydraulic conductivity (Ksat) of the backfill materials were measured in the laboratory and were measured other relevant physical properties (bulk density, particle density and porosity). The bin model experiment showed that flow rate through the system increases as the pressure head increases for both gravel and Tokomaru silt loam soil backfills. The flow rate with gravel backfill was eight times more than the flow rate with Tokomaru silt loam soil. For a gravel backfill the efficiency of hydraulic connection between the lateral and moles must only be in the order of 2 to 3% for successful subirrigation. With a backfill of Tokomaru silt loam the efficiency of connection must be 10 to 20%. This may not be achieved in the field as the hydraulic conductivity of the backfill will be of a similar magnitude to the surrounding soil leading to significant water losses vertically downward as well as horizontally. It is recommended that further field studies be conducted using gravel backfill. Further laboratory studies using other alternative backfill materials are also suggested

    ISRU Soil Mechanics Vacuum Facility: Soil Bin Preparation and Simulant Strength Characterization

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    Testing in relevant environments is key to exploration mission hardware development. This is true on both the component level (in early development) and system level (in late development stages). During ISRU missions the hardware will interface with the soil (digging, roving, etc) in a vacuum environment. A relevant test environment will therefore involve a vacuum chamber with a controlled, conditioned simulant bed. However, in earth-based granular media, such as lunar soil simulant, gases trapped within the material pore structures and water adsorbed to all particle surfaces will release when exposed to vacuum. Early vacuum testing has shown that this gas release can occur violently, which loosens and weakens the simulant, altering the consolidation state. The Vacuum Facility #13, a mid-size chamber (3.66m tall, 1.5m inner diameter) at the NASA Glenn Research Center has been modified to create a soil mechanics test facility. A 0.64m deep by 0.914m square metric ton bed of lunar simulant was placed under vacuum using a variety of pumping techniques. Both GRC-3 and LHT-3M simulant types have been used. An electric cone penetrometer was used to measure simulant strength properties at vacuum including: cohesion, friction angle, bulk density and shear modulus. Simulant disruptions, caused by off gassing, affected the strength properties, but could be mitigated by reducing pump rate. No disruptions were observed at pressures below 2.5Torr, regardless of the pump rate. However, slow off gassing of the soil lead to long test times, a full week, to reach 10-5Torr. This work highlights the need for robotic machine-simulant hardware and operations in vacuum to expeditiously perform (sub-)systems tests

    Benefits in environment-related measures for company due to EMS implementation

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    In the urban development, Environmental Management System (EMS) is known as a standardization of working system that thoroughly considered environmental improvement by the management of environmental data and information in the company. In line with that, this chapter is aimed to discuss the benefits of ISO 14001 between two differences companies, which are certified and non-certified in finding the possible solutions in order to maintain the highest quality of environmental in industry. As the ISO 14001 certificate holder, the particular organization such as Corporation Commission of Malaysia (SMM) can improve their environmental performance by top management commitment. Thus, the cost savings can be achieved through the improvement of energy consumption and waste minimization. Other than that, the implementation of ISO 14001 also reduced the risk of pollution incidents and other releases to the environment which helps a lot in finance of that company

    APPRAISAL OF TAKAGI–SUGENO TYPE NEURO-FUZZY NETWORK SYSTEM WITH A MODIFIED DIFFERENTIAL EVOLUTION METHOD TO PREDICT NONLINEAR WHEEL DYNAMICS CAUSED BY ROAD IRREGULARITIES

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    Wheel dynamics play a substantial role in traversing and controlling the vehicle, braking, ride comfort, steering, and maneuvering. The transient wheel dynamics are difficult to be ascertained in tire–obstacle contact condition. To this end, a single-wheel testing rig was utilized in a soil bin facility for provision of a controlled experimental medium. Differently manufactured obstacles (triangular and Gaussian shaped geometries) were employed at different obstacle heights, wheel loads, tire slippages and forward speeds to measure the forces induced at vertical and horizontal directions at tire–obstacle contact interface. A new Takagi–Sugeno type neuro-fuzzy network system with a modified Differential Evolution (DE) method was used to model wheel dynamics caused by road irregularities. DE is a robust optimization technique for complex and stochastic algorithms with ever expanding applications in real-world problems. It was revealed that the new proposed model can be served as a functional alternative to classical modeling tools for the prediction of nonlinear wheel dynamics

    Development of a Sinkhole Raveling Chart Based on Cone Penetration Test (CPT) Data

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    Naturally occurring sinkholes in Florida are formed when the soluble limestone bedrock weathers and creates cavities at its interface with the overburden finer-grained soils. The overburden soil then erodes into the limestone fissures, thus weakening the strength and holding capacity of the soil above. This initial stage of a sinkhole is referred to as soil raveling and is considered to be the most effective time to perform soil improvements measures, such as grouting, to mitigate further expansion of the subterranean void. Geotechnical engineers and scientists use subsurface exploration techniques such as Cone Penetration Testing (CPT) to stratify soils and estimate soil properties. This paper presents a CPT-based raveling chart, to be used in identifying raveled soils in Central Florida during initial subsurface exploration. The raveling-chart was developed by collecting a large sample of CPT data (i.e cone tip resistance, qc, and sleeve frictional resistance, fs) from multiple sites within the same geological formation. CPT data was grouped within three categories: collapsed sinkholes, suspected raveling, and no1n-raveled, and plotted using a scatter of data points with coordinates (fs, Qtn,); that is sleeve friction resistance, and normalized tip resistance. A simple statistical analysis was applied for the resulting data group to create envelopes, or threshold lines, which bound the data to create certain categories. The resulting chart provides quantifiable measure of sinkhole raveling due to soil erosion

    Joint UK Land Environment Simulator (JULES) Version 2.2 User Manual

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    The Joint UK Land Environment Simulator (JULES) is a computer model that simulates many soil and vegetation processes. This document describes how to run version 2.2 of JULES. It primarily describes the format of the input and output files, and does not include detailed descriptions of the science and representation of the processes in the model. The first version of JULES was based on the Met Office Surface Exchange System (MOSES), the land surface model used in the Unified Model (UM) of the UK Met Office. After that initial split, the MOSES and JULES code bases evolved separately, but with JULES2.1 these differences were reconciled, so that all versions since v2.1 have had identical code in both the standalone version (as described here) and in the UM

    Ecological and Genomic Attributes of Novel Bacterial Taxa That Thrive in Subsurface Soil Horizons.

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    While most bacterial and archaeal taxa living in surface soils remain undescribed, this problem is exacerbated in deeper soils, owing to the unique oligotrophic conditions found in the subsurface. Additionally, previous studies of soil microbiomes have focused almost exclusively on surface soils, even though the microbes living in deeper soils also play critical roles in a wide range of biogeochemical processes. We examined soils collected from 20 distinct profiles across the United States to characterize the bacterial and archaeal communities that live in subsurface soils and to determine whether there are consistent changes in soil microbial communities with depth across a wide range of soil and environmental conditions. We found that bacterial and archaeal diversity generally decreased with depth, as did the degree of similarity of microbial communities to those found in surface horizons. We observed five phyla that consistently increased in relative abundance with depth across our soil profiles: Chloroflexi, Nitrospirae, Euryarchaeota, and candidate phyla GAL15 and Dormibacteraeota (formerly AD3). Leveraging the unusually high abundance of Dormibacteraeota at depth, we assembled genomes representative of this candidate phylum and identified traits that are likely to be beneficial in low-nutrient environments, including the synthesis and storage of carbohydrates, the potential to use carbon monoxide (CO) as a supplemental energy source, and the ability to form spores. Together these attributes likely allow members of the candidate phylum Dormibacteraeota to flourish in deeper soils and provide insight into the survival and growth strategies employed by the microbes that thrive in oligotrophic soil environments.IMPORTANCE Soil profiles are rarely homogeneous. Resource availability and microbial abundances typically decrease with soil depth, but microbes found in deeper horizons are still important components of terrestrial ecosystems. By studying 20 soil profiles across the United States, we documented consistent changes in soil bacterial and archaeal communities with depth. Deeper soils harbored communities distinct from those of the more commonly studied surface horizons. Most notably, we found that the candidate phylum Dormibacteraeota (formerly AD3) was often dominant in subsurface soils, and we used genomes from uncultivated members of this group to identify why these taxa are able to thrive in such resource-limited environments. Simply digging deeper into soil can reveal a surprising number of novel microbes with unique adaptations to oligotrophic subsurface conditions

    Effect of operating temperature on direct recycling aluminium chips (AA6061) in hot press forging process

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    A method of solid-state recycling aluminum alloy using hot press forging process was studied as well as the possibility of the recycled chip to be used as secondary resources. This paper presents the results of recycled AA6061 aluminium alloy chip using different operating temperature for hot press forging process. Mechanical properties and microstructure of the recycled specimens and as-received (reference) specimen were investigated. The recycled specimens exhibit a good potential in the strength properties. The result for yield strength (YS) and ultimate tensile strength (UTS) at the minimum temperature 430˚C is 25.8 MPa and 27.13 MPa. For the maximum operating temperature 520˚C YS and UTS are 107.0MPa and 117.53 MPa. Analysis for different operating temperatures shows that the higher temperatures giving better result on mechanical properties and finer microstructure. The strength of recycled specimen increases due to the grain refinement strengthening whereas particle dispersion strengthening has minor effects. In this study, the recycled AA6061 chip shows the good potential in strengthening as the comparison of using only 17.5% of suggested pressure (70.0/400.0) MPa, the UTS exhibit 35.8% (117.58/327.69) MPa. This shows a remarkable potential of direct recycling by using hot press forging process

    Comparative study on indoor fungi growth incorporated with different antifungal and wall finishings

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    Indoor air quality is important to the health and comfort of building occupants. There are many sources of pollutants that can be found in the building. One of the sources of pollutants is fungus. Fungi are present almost everywhere in indoor and outdoor environments. Building materials supporting fungal growth must be remediated as rapidly as possible in order to ensure a healthy environment. The goal of this study is to compare the growth of indoor fungal by using three different antifungals such as potassium sorbate, zinc salicylate and calcium benzoate. The indoor fungi were isolated from selected room at Faculty of Civil and Environmental Engineering (FKAAS). The objective is to enumerate the growth of indoor fungal after incorporate with antifungal at different types of wall finishes and evaluate its efficiency. This research was done on three main substrates which are wood, plasterboard and concrete. These main materials were each coated with four types of coating which are thin wallpaper, thick wallpaper, glycerol based paint and acrylic paint. The growth rate was monitored as all the materials was applied with the antifungal. The antifungal has reduced the growth rate of the fungus but depending on the type of material and coating that is used. Results shows that for wood substrate, the best antifungal treatment is a mix of thick wallpaper and calcium benzoate, where the growth stops at 53% (CB 53% < PS 87% < ZS 90% < CTRL 93%). As for plasterboard substrate, thin wallpaper and potassium sorbate hinders the growth at 40% (PS 40% < ZS 73% < CB 80% < CTRL 97%) whereas for concrete substrate, acrylic paint and glycerol based paint incorporated with calcium benzoate renders the growth of fungi to stop at 0% throughout the test (Acrylic Paint = CB 0% < ZS 7% < PS 7% < CTRL 33%) and (Glycerol Based Paint = CB 0% < PS 70% < ZS 73% < CTRL 87%). Thus, the best building material would be concrete with the application of calcium benzoate for paint type of wall finishing’s
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