Plasticity Index Values Research Articles

Load Bearing Capacity of Cohesive-Frictional Soils Reinforced with Full-Wraparound Geotextiles: Experimental and Numerical Investigation

This research investigated the effects of types of cohesive-frictional soil and geotextile reinforcement configurations on the bearing capacity of reinforced soil foundation (RSF) structures, via laboratory test and numerical simulation. The four reinforcement configurations studied for the RSF included: (i) horizontal planar form of geotextile, (ii) full-wraparound ends of geotextile, (iii) full-wraparound ends of geotextile with filled-in sand, and (iv) full-wraparound ends of geotextile with filled-in sand and sand backfill. The foundation soils studied were mixtures of fine sand and sodium bentonite at replacement ratios of 0, 20, 40, 60, 80, and 100% by dry weight of sand to have various values of plasticity index (PI). The numerical analysis of RSF structures was performed using PLAXIS 2D software. Several factors were studied, which included: embedment depth of the top reinforcement layer (U), width of horizontal planar form of the reinforcement (W), and spacing between geotextile reinforcement layers (H). Number of reinforcement layers (N) was varied to determine the optimum parameters of U/B, W/B, H/B, and N, where B is the footing width. The most effective improvement technique was found for the full wraparound ends of geotextile with filled-in sand and sand backfill. The outcome of this research will provide a preliminary guideline in a design of RSF structure with different ground soils and other RSF structures with different geosynthetic types.

A comparative study on the application of artificial intelligence networks versus regression analysis for the prediction of clay plasticity

Plasticity is the significant integrated property of clay-water relationship that can be initially associated with the consistency which is an outstanding term used especially in cohesive soils to describe the geotechnical behavior characteristics depending upon the change of water content. In the context of this study, the consistency characteristics of plastic clays are investigated based on the analyses conducted with both applications of regression and artificial intelligence methods. In order to acquire an actual input mesh, a domain-specific dataset has been created with the evaluation of 350 soil investigation reports containing a huge number of consistency tests, including the districts located on the European side of Istanbul, Turkey. The results of the conducted laboratory tests are recorded for very high and high plastic clays which are dominantly situated in the southwest regions of Istanbul. Regression analyses and artificial intelligence techniques have been performed with a frequently used software to query the attainment of the values of plastic limit and plasticity index directly from only liquid limit test results. The main aim to acquire a direct relationship between the liquid limit versus plasticity index value is to reduce the dependency of the consistency limit tests to the operators’ experience and also the physical condition of the experimental application environment. As a result of the analyses carried out for this purpose, equations with sufficient reliability, which are applied to obtain the direct plasticity index, were acquired. This condition enables to eliminate the application of the tests of the plastic limit. At the same time, the concurrency of the technique used in obtaining the related equations was questioned comparatively by using regression analysis and artificial intelligence applications. Consequently, discussions are made with well-known studies of literature to validate the applicability of the obtained relationships.

Waterlogging tolerance of the invasive plant Aegilops tauschii translates to increased competitiveness compared to Triticum aestivum

In the cultivation of wheat (Triticum aestivum L.), waterlogging has been identified as one of the most important limiting factors. It affects the overall global wheat production as well as that for the People’s Republic of China. Aegilops tauschii Coss., so far known as the main malignant weed in the wheat fields but it is unclear whether its invasiveness and competition with wheat would be affected by waterlogging. To study this, we conducted a controlled pot experiment using the De Wit replacement method. Monocultured and mixed experimental setups of A. tauschii and wheat were performed to study the effects of 0 (control), 5, 10, 15, 20 and 25 days of water stress treatments on A. tauschii growth and its competition with wheat. The results showed that in terms of morphological characteristics, the height increase of A. tauschii plants showed strong water tolerance. While the leaf area and total biomass were significantly affected by water flooding stress. In terms of physiological characteristics, A. tauschii exhibited high superoxide dismutase (SOD) activity, which promptly removed active oxygen free radicals generated by water flooding stress. This activity reduced the accumulation of thiobarbituric acid (TBARS) in the plant, and thus exhibited stronger water tolerance than wheat. In addition, regarding phenotypic plasticity, the mean plasticity index (PI) values of most morphological and physiological parameters of A. tauschii were close to those of wheat. Yet the PI values of plant height and root biomass were significantly higher than those of wheat. It indicates that the waterlogging tolerance to A. tauschii may be related to the high values of some particular traits. Finally, with the prolonged waterlogging treating time, the relative yield (RY) value of A. tauschii was always greater than 1, while for wheat, the RY value was less than 1. In addition, the competitive balance (CB) value of A. tauschii was greater than 0 and its relative competitive intensity (RCI) was less than 0. This shows that the short-term waterlogging stress changed the competition relationship between A. tauschii and wheat. In it wheat was suppressed and the competitiveness of A. tauschii was enhanced. In summary, A. tauschii have a certain degree of tolerance to waterlogging, and short-term waterlogging would promote its competition with wheat, which is expected to increase its invasion potential.

Effect of iron ore tailings on the plasticity and compaction properties of selected tropical soils

The workability of any soil, when used as a construction material, is greatly affected by its plasticity and compaction characteristics. This research investigates the effect of iron ore tailings (IOT) on the plasticity and compaction properties of lateritic soil (LTS) and black cotton soil (BCS). Atterberg limit and compaction test using three energies, British standard Light, BSL, British standard Heavy, BSH, and West Africa standard, WAS were carried out. These tests were conducted on mixed ratios of 0, 2, 4, 6, 8, and 10 % of IOT mixed each with LTS and BCS separately. A Statistical conceptual model was developed using Minitab R15 to predict the values of the maximum dry density (MDD) and optimum moisture content (OMC) from the computed laboratory results. Analysis was then carried out on the predicted results using origin pro version 8 to test the efficacy of results obtained. The result of specific gravity test shows increase with IOT concentration. An improvement on the plasticity of the modified soil was noted. The liquid limit for both LTS and BCS decreased with increasing IOT concentration. Values drop from 43.4 to 42.7% for LTS and 56 to 52.6% for BCS at 0 and 10% of IOT content, respectively. Plastic limit increased with increasing IOT concentration for LTS and decreased for BCS. In the case of the Plasticity index, values decreased for LTS and marginally increased for BCS treated with IOT. MDD values increased and thereafter drop for LTS treated with IOT while for BCS values increased from natural up to 10% IOT content. OMC values increased for LTS treated with IOT and decreased for BCS treated with IOT. The effectiveness of the developed model was validated using the values of the correlation coefficient obtained from the statistical analysis, which showed a solid relationship between predicted and measured values. Plasticity index values obtained for IOT stabilized BCS did not meet up to the standard requirement when used as a sub-base and base course material respectively. However, the treatment of LTS and BCS with 8-10% IOT improved the soil properties and can be used for pedestrian walkways.

Microbial-Induced Calcite Precipitation Study on the Plasticity and Compaction Characteristics of Lateritic Soil Treated with Bacillus Megaterium in Urea-CaCl2 Culture Medium

An ecofriendly method of soil improvement known as Microbial Induced Calcite Precipitation (MICP) has received significant recognition in the past decade. This study presents a report on the capability of MICP in modifying the plasticity and compaction properties of lateritic soil bio-treated with different suspension densities of a ureolytic microorganisms - Bacillus megaterium (B. megaterium). Specimens were prepared with liquid limit moisture of the natural soil in three mix ratios of B. megaterium (B) and cementation reagent (C) (urea medium): 25 % B: 75 % C, 50 % B: 50 % C and 75 % B: 25 % C. Another set of specimens were prepared at optimum moisture content (OMC) equivalent covering 1/3 pore volume of B. megaterium and 2/3 pore volume of urea medium introduced in three sequences at 6-hour interval to steadily initiate MICP mechanisms. The results of the various mix ratios indicated improvement in plasticity index (PI) with higher B. megaterium suspension density. The best improved PI value was obtained for specimen treated with 75 % B: 25 % C mix ratio at B. megaterium suspension density of 2.40 × 109 cells/ml with an equivalent maximum 5.3 % CaCO3 content. The maximum dry density (MDD) and OMC values marginally increased with higher B. megaterium suspension density as well as calcite content. The micrographs obtained from scan electron microscope (SEM) showed changes from untreated to bio-treated state, which resulted in non-uniform precipitation of calcite in the soil. The variation in elemental quantifications displayed by the X-ray energy dispersive spectroscopy (EDS) validate the formation of calcite within voids and on surface of the soil particles.

Effect of Exploration Depth on Microstructural Behavior of Subsurface Soft Clayey Soil for Foundation Construction Purposes

The geomorphological, microstructural pattern and mineralogical configuration of subsurface soils explored from 1-meter, 3-meter and 7-meter depths have been studied for the purpose of foundation materials suitability. Soils samples arehauled from borrow sites to where they are utilized as foundation materials. In very most cases, this exploration is doneat varying depths and soil being an erratic geomaterial change in its important engineering characteristics with depth.This laboratory examination was necessary to establish the microstructural behaviour and pattern of soils when they areexplored from different depths. The samples collected from different depths showed to be A-3 soils according to AASHTOclassification method and poorly graded according to the USCS. Also varying depth of the soil sample was characterizedby a proportional increase in moisture content; this as well applies to the `liquid limit, plastic limit and plasticity indexvalues respectively with an exception in the shrinkage limit, which reduces with increase in depth of soil sample. This can beattributed to the erratic behavior of soil, which makes it change behavior from location to location and from depth to depth,clayey contents changes with depth likewise its desiccation properties. The geomorphology and microstructure of the soilsshow weaker configuration with increased depth of exploration to 7 meters. This shows that for any foundation purposes,soils at both 3 meter and 7-meter depths require treatment to be suitable for construction purposes. Geo-constructions likecompacted earth liner systems, mechanically stabilized earths or backfills, pavement subgrade systems can be constructedwith the studied soils but care must be taken to modify the soils to meet the basic design considerations.

Bilecik Şeyh Edebali Üniversitesi Kampüs Topraklarının Bazı Fiziko-Kimyasal ve Mekaniksel Özellikleri ve İşlenebilirlikleri

In this study, some physico-chemical and mechanical properties and appropriate moisture levels for workability of soil series in Bilecik Şeyh Edebali University Campus area in Turkey were determined. Soil samples were taken from 0 - 20 cm depth of 20 different points in Gülümbe and Aşağıköy series. Soils in the Gülümbe were clay (C) and clay loam (CL) in texture with a mean bulk density of 1.05 g cm-3, saturated hydraulic conductivity of 0.66 cm h-1, slightly alkaline (pH=7.74), medium soil organic matter (SOM) (2.01%), high lime (17.08%), insufficient available phosphorus (1.92 kg P2O5 da-1), sufficient available potassium (88.54 kg K2O da-1), cation exchange capacity (CEC) of 37.71 cmol kg-1, insufficient available Fe (2.35 mg kg-1) and available Mn (5.18 mg kg-1), sufficient available Zn (1.81 mg kg-1) and available Cu (1.00 mg kg-1) contents. Soils in the Aşağıköy were loamy (L) and sand-clay-loam (SCL) in texture with a bulk density of 1.31 g cm-3, saturated hydraulic conductivity of 2.32 cm h-1, slightly alkaline (pH=7.74), low organic matter (1.81%), medium lime (6.75%), high available phosphorus (18.76 kg P2O5 da-1), sufficient available potassium (133.94 kg K2O da-1), CEC of 25.26 cmol kg-1, sufficient available Fe (5.67 mg kg-1) and available Cu (2.57 mg kg-1), insufficient available Mn (3.21 mg kg-1) and available Zn (0.66 mg kg-1) contents. While the highest liquid limit (LL) (68.17%) and plastic limit (PL) (31.49%) values were determined in Gülümbe series with the highest clay content and the lowest LL (46.50%) and PL (24.80%) values were in Aşağıköy series with the lowest clay content. Plasticity index (PI) of the soils in Gülümbe and Aşağıköy series respectively varied between 32.73 - 40.26% with a mean of 36.17% and between 21.70 - 28.0% with a mean of 24.73%. Based on LL and PI values, Gülümbe soils were classified as “highly plastic inorganic clays” and Aşağıköy soils were classified as “moderately plastic inorganic clays”. LL values of the soils had significant correlations with clay (0.88**), sand (-0.71*), PL (0.75**), PI (0.89**), consistency index (0.57*), SOM (0.62*), CEC (0.75**) and available K2O (0.54*). The upper and lower moisture limits for optimum tillage were recommended as 29.15 - 23.50% for Gülümbe series and as 24.95 - 21.24% for Aşağıköy series. It was concluded that campus soils could be cultivated at field capacity without any structural deformations because of the consistency index values were between 0.75 - 1.00.

Correlation Between Indeks Plasticity (Pi) and California Bearing Ratio (Cbr) Value of Palangkaraya Soil

CBR (California Bearing Ratio) is an important parameter to determine the bearing capacity of the soil. CBR testing in the laboratory requires a relatively large amount of time and cost. Therefore it is necessary to simplify the determination of CBR value. One of the parameters of land that can be used to get the CBR value is the soil plasticity index (PI). It is expected that after knowing the PI value, the CBR can be known. This study aims to obtain a correlation between PI and CBR for the Palangkaraya clay. The test was carried out at the Soil Mechanics Laboratory of the University of Muhammdiyah Palangkaraya. Clay samples were taken at 6 (six) locations in the City of Palangkaraya. The clay test results then performed a correlation of PI values to CBR with analytical methods and linear graph methods. From the analysis conducted the results of the correlation obtained using analytical methods and linear graph CBR = -0.2854 + 8.4816PI. The result of the correlation value using linear regression graphs value at R = 0,801 and using analytical correlation methods worth R = 0,895. From the two results, the smallest value for R value is R = 0,801. It can be seen that the correlation equation of the result of this test has a very high relationship when viewed from the benchmark correlation results (R = 0,80-1,00).

Investigation of incessant road failure in parts of Abeokuta, Southwestern Nigeria using integrated geoelectric methods and soil analysis

A flexible pavement devoid of discontinuities allows for smooth movement of a vehicle load on the roadway. This study involved the use of integrated geoelectric methods comprised of 1D and 2D Electrical Resistivity Tomography (ERT) as well as soil analysis to investigate causes of unceasing road failures along busy Camp—Alabata Road, Abeokuta, Southwestern Nigeria. Four road sections (two failed portions and one fair section and one good section) were identified along which four resistivity traverses were established along the investigated roadway. Four 1D Vertical Electrical Sounding (VES) points were also carried out on the 2D ERT lines. Apparent resistivity data were measured along the four traverses using Schlumberger and Wenner arrays with the aid of a Campus Ohmega resistivity meter. The VES and 2D resistivity data were processed and inverted using WinResist and RES2DINV softwares, respectively. Twenty soil samples at a sampling depth (0–1.0 m) with an interval of 0.2 m were also collected on all designated road sections and analyzed for selected hydraulic/geotechnical properties related to pavement durability. Penetration resistance (PR) was measured in situ by a penetrologger while other subgrade soil properties were evaluated in the laboratory. The VES results delineate three geoelectic layers comprising topsoil, weathered basement (clayey), and fractured/fresh basement with their corresponding resistivity values ranging between 71 and 282 Ωm, 12–76 Ωm, and 261–10,094 Ωm. The thicknesses range between 0.9 and 3.2 m for topsoil and 4.5–19.1 m for weathered basement. 2D resistivity inverted sections delineate two lithologic layers: topsoil with resistivity values > 200 Ωm, devoid of linear geological structures as competent topsoil on a stable road section while incompetent topsoil on failed road sections were characterized by resistivity values < 200 Ωm. The weathered layers as depicted by 2D inverted resistivity sections were generally of resistivity less than 100 Ωm while fractured/fresh basement were not depicted in the 2D model. Failed road sections are underlain by topsoil with a resistivity (< 200 Ωm), shallow weathered (clayey) layer, and differential settlement of saturated subgrade materials. Soil analyses results showed that the stable portion depicts lowest mean values of plasticity index (5.12%) and liquid limit (22.21%), uniform sandy-loam textural class, highest mean value (1.24 cm/h) of saturated hydraulic conductivity (Ksat); % sand content (73.2%) and Penetration Resistance (PR) values that increased within the sampling depth (0–40 cm). However, one of the failed sections had lowest mean value (0.81 cm/h) of Ksat, % sand content (64.9%) and PR values that decreased within the sampling depth (0–40 cm). Analysis of variance (ANOVA) showed that there were significant differences at the 5% level among all designated road sections with respect to percent silt and moisture content (MC). Adequate engineering construction approaches should be adopted considering the thick layer of incompetent formation (clay) observed across the area investigated. Integrated interpretations present a better resolution and detailed characterization of the substratum underlying the pavement.

Leaflet phenotypic plasticity in three woody species in two strata of a gallery forest

ABSTRACT Background: Along the vertical canopy profile, natural light availability is variable and may induce leaves morphophysiological changes due to phenotypic plasticity. Morphological changes in juvenile and adult leaflet of compound leaves of plant species is still poorly understood, including in woody species of gallery forests. The present study evaluated the leaflet morphophysiological characteristics and plasticity index of three woody species in canopy and understory leaves in a gallery forest. Results: All morphophysiological characteristics varied within species (Myracrodruon urundeuva Allemao, Copaifera langsdorffii Desf. and Tapirira guianensis Aubl.). The leaflets of canopy trees showed significantly higher values of petiole length (PL) and diameter (PD), leaflet thickness (fresh - FT and dry - DT), specific leaf mass (SLM), in relation to understory leaflets. On the other hand, relative water content (RWC) did not change between adult trees and saplings, except for T. guianensis. The plasticity index of leaflet characteristics varied significantly within species. Plasticity index of three morphophysiological characteristics (PL, PD and DT) varied between species. PL and PD had the highest plasticity index values across species, whereas RWC had the lowest plasticity.. Conclusion: Plasticity index of the tree species associates these leaflet morphophysiological traits (PL, PD and DT) with variations in the physical environment between strata of a gallery forest.

Mineralogical, Geochemical and Physico-Chemical Characterization of Clay Raw Materials from Three Clay Deposits in Northern Cameroon

The characterization of clay raw materials of three clay deposits from Northern Cameroon was investigated. The three deposits, located in Gaschiga, Sekandé and Boulgou, are locally used as building materials, but no data are available on these materials and they are relatively unknown. Mineralogical, geochemical and physico-chemical characteristics were studied, using X-ray diffraction, X-ray fluorescence and physico-chemical analyses. Mineralogically, quartz was the most abundant mineral in the studied raw materials. It is associated to abundant quantity of smectite, kaolinite and K-feldspars, and slightly abundant to traces of hematite and amphibole. Geochemically, those clayey soils are more siliceous (SiO2, 51% - 59%) with significant amount of aluminum (Al2O3, 15% - 19%) followed by iron oxides (Fe2O3, 3% - 10%). Other oxides (K2O, MgO, TiO2, Na2O, MnO, CaO and P2O5) are in relatively lower proportion. High level of silica content explains the sandy nature of these clays. The results of granulometric analysis show that the studied raw material contain sand (39% - 68%) as major grain size followed by clay particles (17% - 38%), silt (1% - 36%) and gravels (0% - 16%). The studied clayey soils were moderately plastic, with plasticity index values ranging from 13% to 30%, and are also characterized by very high liquidity limits of 34% - 63%.

Estimation of consistency limits of fine-grained soils via regression analysis: A special case for high and very high plastic clayey soils in Istanbul

Consistency limits are essential and simple design parameters that are utilized as standard entries of all kinds of soil investigation programs conducted for geotechnical projects which are constructed in/on fine grained soils. These limits also represent mineralogical and physical properties of clayey soils directly and used to estimate their strength and rigidity properties indirectly. However, the consistency tests are assumed as the simple and basic tests of geotechnical engineering investigations, but the effects of operator, calibration of the device and environmental aspects at the tests damage the reliability and correctness of results. In this paper, it is aimed to overcome these challenges by evaluating the consistency characteristics of clayey soils considering only the values of liquid limit of specific clays with the use of simple regression analysis. A database is prepared by using 500 soil investigation reports that are involving the site characterization information, laboratory and field tests of Istanbul Province European side clayey soils, including Avcılar, Esenyurt, Küçükçekmece, Büyükçekmece, Çatalca, Zeytinburnu, Bahçelievler, Bakırköy districts. 1523 liquid limit tests are obtained from the mentioned database for high and very high plastic clays. The regression analyses have been applied to query the parameter effect ratio on the consistent characteristics and relationships have been tried to be developed to evaluate the values of plastic limit and plasticity index directly from only liquid limit test applications. The effects of fine material content, depth and natural water content is also investigated. Verifications of the suggested equations have been done for different cases and comparisons are made with the well-known sources of literature. Consequently, strong equations are acquired to determine the plasticity index value in terms of liquid limit, liquid limit-depth, liquid limit-fine content, natural water content-fine content respectively based on the actual experimental tests conducted in Istanbul.

Swelling potential of volcanic residual soils in Sumatra (Indonesia) in relation to environmental issues

Abstract Swelling potential characterization of clay-silt soil is an essential issue in stabilization, settlement, consolidation, and land suitability studies. This article attempts to explain the swelling characteristics of soils around the area of West Lampung, Lampung Province, Sumatra, Indonesia, in relation to environmental issues. An investigation in relation to the soil swelling potential was carried out using 15 disturbed soil samples collectd in the study area. The methods used were analyses of clay mineral geochemistry, physical characteristics, and the free swell ratio. These results showed that the soil in the study area was Quaternary tropical volcanic residual soil. These soils were formed in a proximal volcanic hydrothermal alteration environment. The soils of the study area have characteristics of high plasticity, a reddish-brown colour, and are clayey silt grained (MH) (USCS). The soils had loose physical characteristics in dry conditions; however, these soils tends to be plastic and sticky in wet conditions. Evidence of groove erosion was found at the soil surface. Based on XRD analysis, kaolinite, halloysite, and montmorillonite were types of clay minerals found in the soil. The soil had a clay content of 11.05–78.9%, a liquid limit value &gt; 50%, a plasticity index value of 16.7–36.9%, a shrinkage value of 14.24–36.89%, a soil activity of 0.38–2.47; and an FSR value of 0.69–0.95. These characteristics have implications for swelling soil potential. The results showed that the soils in the study area had medium to very high swelling potential. These results suggest a risk of erosion in the area, which could cause soil degradation and a change in water quality. These soils are likely to affect land productivity and aquifer replenishment and will cause negative environmental and economic impacts. Thus, soil improvement techniques are needed. It is important to maintaining vegetative cover these soils and revegetation may be required.

A study of linear optical properties of ternary blends PVA/CMC/aloe vera biofilm for UV shielding

In this study, the solvent casting method was applied to prepare ternary blend PVA/CMC/aloe vera (60%/20%/20%) biofilms in the form of the freestanding polymeric film. The X-ray diffraction pattern revealed 93% of crystallinity of the polymeric film. The presence of functional bonding on the biofilms was analyzed by Fourier-transform infrared spectroscopy. The hardness and Young’smodulus of the prepared biofilms were examined by the nanoindentation technique. Ultraviolet (UV) absorption spectroscopy study showed that the PVA/CMC/aloe vera (PCA) blended biofilm absorption was around 280 nm, indicating a well-defined n − π* electronic transition. From the UV spectroscopy study, the absorption coefficient; Urbach energy; direct, indirect, and forbidden bandgap; optical and dielectric constant, and loss tangent of the PCA biofilm were calculated. Viscoelastic behavior of the PCA polymeric film was verified from the determined plasticity index value. The shielding efficiency of this ternary biofilm could be considered as a potential candidate for future technology-based device/packaging applications.

The Physical Properties and Geochemical of Clay from the Bestari Jaya, Kuala Selangor, Selangor, Malaysia for Potential Usage

The study emphasis on physical properties and geochemical of the clays from Bestari Jaya area to determine its suitability for any commercial application. Nine samples collected from six boreholes as representative of white and dark clay in the study area. All samples examined through the optical properties test and physical properties such as moisture, specific gravity, Atterberg limit and particle size distributions. The geochemical and mineralogical conducted using XRF and XRD analysis. The clays from Bestari Jaya considered of having variation in the brightness from medium to high brightness as shown by Delta L value (51.32-73.49%). The moisture content ranges between 34.50-81.03%. The plasticity index (PI) and plasticity limit (PL) values found in ranges of 18-32% with an average of 22.22%, and 32-46% with an average of 37.11% respectively. The plasticity limit and index reveals that the Bestari Jaya clays can be classify as kaolinite clays that are suitable for pottery and brick making. The specific gravity ranges between 2.49 – 2.70 with an average of 2.61. The average value is similar to the value of pure china clay (2.6). The SiO2 content in Bestari Jaya clays is between 37.49 – 69.96 wt% and Al2O3 is between 18.92 – 33.02 wt%. While the L.O.I values are between 8.71-16.04%. Kaolinite as the dominant mineral phases in all clay samples with composition ranges from 65-97.7% and an average of 73.12%. Apart of that, quartz in ranges of 5.3 – 20.6%, identified in almost all samples. Muscovite, hematite and magnetite occur as accessory minerals. Referring to standard and result obtained on representative sample, the Bestari Jaya clays potentially used in the production of smaller tiles for unexclusive pedestrian traffic. The presence of significance amount of heavy metals makes it unsuitable to use in the pharmaceutical or paper industry.

The Physical Properties and Geochemical of Clay from the Bestari Jaya, Kuala Selangor, Selangor, Malaysia for Potential Usage

The study emphasis on physical properties and geochemical of the clays from Bestari Jaya area to determine its suitability for any commercial application. Nine samples collected from six boreholes as representative of white and dark clay in the study area. All samples examined through the optical properties test and physical properties such as moisture, specific gravity, Atterberg limit and particle size distributions. The geochemical and mineralogical conducted using XRF and XRD analysis. The clays from Bestari Jaya considered of having variation in the brightness from medium to high brightness as shown by Delta L value (51.32-73.49%). The moisture content ranges between 34.50-81.03%. The plasticity index (PI) and plasticity limit (PL) values found in ranges of 18-32% with an average of 22.22%, and 32-46% with an average of 37.11% respectively. The plasticity limit and index reveals that the Bestari Jaya clays can be classify as kaolinite clays that are suitable for pottery and brick making. The specific gravity ranges between 2.49 – 2.70 with an average of 2.61. The average value is similar to the value of pure china clay (2.6). The SiO2 content in Bestari Jaya clays is between 37.49 – 69.96 wt% and Al2O3 is between 18.92 – 33.02 wt%. While the L.O.I values are between 8.71-16.04%. Kaolinite as the dominant mineral phases in all clay samples with composition ranges from 65-97.7% and an average of 73.12%. Apart of that, quartz in ranges of 5.3 – 20.6%, identified in almost all samples. Muscovite, hematite and magnetite occur as accessory minerals. Referring to standard and result obtained on representative sample, the Bestari Jaya clays potentially used in the production of smaller tiles for unexclusive pedestrian traffic. The presence of significance amount of heavy metals makes it unsuitable to use in the pharmaceutical or paper industry.

Plasticity of Bead-on-Plate Welds Made with the Use of Stored Flux-Cored Wires for Offshore Applications.

Extreme atmospheric conditions in the marine and offshore industry are harmful to engineering materials, especially to welded joints, and may cause degradation of their properties. This article presents the results of research on the plasticity of bead-on-plate welds made using two types of seamless, copper plated flux-cored wires. Before welding, spools with wire were stored for 1 month in two distinct locations with different geographical and industrial conditions in Poland, and then subjected to visual examination. Bead-on-plate welds were subjected to a static tensile test and on this basis plasticity indexes showing the effect of storage on plasticity were determined. The fractures after tensile tests and the surfaces of the wires were examined on an electron scanning microscope. Additionally, diffusible hydrogen content in deposited metal measurements for each condition were carried out. The highest degradation level was found for wire stored in an agricultural building in north-eastern Poland—there was an almost fourfold decrease in the plasticity index value and the highest diffusible hydrogen content. For the same wire and the same location, the largest difference was also observed in fracture morphology after the tensile test—ductile fracture was obtained for wire at delivery condition while an almost full cleavage fracture was found after relatively short (1 month) storage of wire.

Ovarian and Uterine Blood Flow Indices in Patients with Unexplained Infertility Undergoing ICSI and their Relation to Clinical Pregnancy Rate

Background: Infertility is defined by the World Health Organisation (WHO) as a disease of the reproductive system defined by the failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse and is estimated to affect as many as 48.5 million couples worldwide. Unexplained infertility (UI) constitutes an important portion of the infertility reasons (up to 30%) and is diagnosed when the causes of male or female infertility remains unknown.Aim: The aim of the study was to compare ovarian, uterine artery and subendometrial vessels resistance by measuring PI and RI of patients diagnosed as UI undergoing ICSI in the day of embryo transfer and control group diagnosed as fertile by having at least one livebirth in peri-implantation period from day 19 to day 21.Materials and Methods:The current study is a prospective case control study, which was conducted at the Assisted Reproduction Technology unit of Ain Shams University Maternity Hospital during the period from September 2017 to July 2019. The current study included two groups of patients one group is unexplained infertility attending the Assisted Reproduction Unit and the other is control fertile group each group consists of 51 women.Results: There was statistically significant difference between the unexplained infertility group and control fertile group as regard Uterine and subendometrial artery PI, RI and ovarian artery RI in which resistance indexes was significantly higher in the UI group than control group. The cut off values of PI, RI between unexplained infertility and fertile group are ≥1.88, ≥0.8 for Uterine artery, and ≥ 0.87, ≥0.53 for subendometrial arteries, and ≥ 0.59 for ovarian artery RI. Among the unexplained infertility undergoing ICSI patients the pregnancy rate is 23.5%. There was no statistically significant difference between the two groups (pregnant group and non-pregnant group) as regard the age, BMI, duration of infertility or the basal hormonal profile.Conclusion: Doppler parameters are useful tools to assess endometrial receptivity in unexplained infertility patients undergoing ICSI. This study found that Uterine, Ovarian, subendometrial arteries plasticity index (PI) and resistance index RI measured on the day of embryo transfer higher than fertile women and have value in judging endometrial receptivity and predict the final outcome of IVF/ ICSI- ET. Uterine, ovarian and subendometrial blood flow assessed by measuring PI, RI of these arteries was impaired in unexplained infertility patients compared to fertile women. Also, uterine arteries PI, ovarian and subendometrial arteries PI, RI differ in pregnancy outcome in unexplained infertility patients undergoing ICSI.

Influence of fly-ash on the engineering characteristics of stabilised clay soil

Soil must be able to withstand the load and transfer it to ground within the range of allowable deformations, for which it must possess good physical and geotechnical properties. Clay soils become more adhesive once when it becomes wet and whereas if it is dry it is characterised by surface cracks. To overcome these circumstances in soil, it should be treated and stabilized in best way. In this study, the influence of two different kinds of Fly-Ashes namely, Class-F Fly-Ash and Class-C Fly-Ash along with the inclusion of lime in the improvisation of stability characteristics of clayey soil. Experiments were conducted to determine the Atterberg limits, Standard Proctor Compaction values and Un-Confined Compression strength of various soil samples with different mix ratios to evaluate influence of Fly-Ash in the stabilisation process. Addressing to the fact that Fly-Ash does not possess any plastic property, the Clay-Fly-Ash mixes show a decrease in Plasticity Index (P.I.) value with increase in the Fly-Ash content. Fly-Ash addition in the clay soil mix that contains lime decreases the plasticity of soil, and also escalates the workability. The workability is increased by modifications in its particle size and collision behaviour. It is concluded that, the addition of lime and Fly-Ash influenced to acquire to stronger and stiffer soil matrix by reducing the inter particle spacing. Based on the experimental study results, the addition of C-Class Fly-Ash was found to be more effective than F-Class Fly-Ash when supplemented along with lime.

Correlation between Plasticity Index and Methylene Blue Value to Determining Soil Classification

Most soil classification systems developed for geotechnical engineering purposes are based on simple index properties such as grain size distribution and plasticity. In Indonesia, the use of the methylene blue value, VBS, is still rarely used, compared to Atterberg limits that commonly used to determine the value of the plasticity index, PI. Therefore, this study aims to gain a correlation between PI and VBS. Coarse-grained soil with fines (clay and silt) contents varies from 12.36% to 29.45% are used of this study. The linear correlation between PI and VBS produces a linear equation with a coefficient of determination, R2 = 0.854 for 0.62 < VBS < 2.39. The PI obtained from the correlation to VBS that combined with the sieve analysis results can then be used for soil classification based on the Unified Soil Classification System (USCS).