Sand Rock Research Articles

Technical Review of Slope Failure (Case Study of Tawangmangu-Cemorosewu Sta. 4+600 Section)

Tawangmangu-Sarangan highway is a national strategic road connecting two districts in two provinces; Karanganyar in Central Java and Magetan in East Java. The topography of the area is relatively high due to stiff hill and valley with the problematic geologic condition of weathered rock and silt sand. During rainy season, slope failures at some sections of this road were very often. The study to understand the cause of the failures is very important. Deep boring may have the best result to obtain soil parameter and stratigraphy of soil layer. However, this method was impossible due to the safety reason. The use of geophysic instrument such as geoelectric for the investigation combined with hand boring for soil sampling was a reasonable choice. Geoelecetric was utilized to predict soil layers properties and potential failure surface of the slope. This study was focused on the investigation on a slope failure location of Tawangmangu-Cemorosewu at Sta 4+600. Finite element software was utilized to understand the cause of previous failure and to model the most critical failure surface that may occurre in the future. Based on the modeling, the safety factor of the slope was 1.18 and 0.930 before and during construction. The condition of the slope after failure is still very critical due to the very low safety factor of 1.03 causing the potential of failure. It also recommended that geometrical method such as terrasering might be one of the solutions producing the safety fractor of 1.5.

Habitat use byCentropomus undecimalisin a rocky area of estuarine beach in north‐east Brazil

The influence of habitat, diel period, tidal phase and moon phase on the spatial distribution of Centropomus undecimalis was investigated at the mouth of the Timbo estuary, north-east Brazil. Underwater visual censuses were conducted in three areas comprising a mix of mud, sand and beach rock substrata; with one of the areas having additional structural complexity in the form of unused wooden debris. The area with debris housed significantly higher densities of juvenile and adult C. undecimalis whereas sub-adults were more abundant in an area lacking the wooden debris. Juvenile abundance was greatest during the day, whereas sub-adult and adults were more abundant at night. There were significant interactions between habitat, diel period, tidal phase and moon phase for all ages of C. undecimalis. These results emphasize the need to account for a range of environmental factors when planning for the conservation of estuarine and coastal habitats.

Analisis dan Pemanfaatan Unsur Belerang dan Salinitas Lumpur Bledug Kuwu di Desa Kuwu, Kecamatan Kradenan, Kabupaten Grobongan, Jawa Tengah

This study was conducted to determine the levels of elemental sulfur and salinity of the mud Bledug Kuwu. The research area has a subsurface lithology bedding rock mud, sand stone and rocks submerged in saltwater, brackish water and sea water. Bledug Kuwu is a phenomenon of volcanic mud. Around Kuwu found several indications of an ancient sea that connect up to the east, that is to Cepu and westward to the region Boja and Cirebon. Judging from geological formations, estimated Kuwu to Cepu was once the sea. The ancient sea stretching from Bledug Kuwu region to the southwest that is to Sangiran and also to Boyolali. Bledug Kuwu mud has a high sulfur and salt contents, evidenced from the results of laboratory analysis where the average concentration of sulfur 62,883 x102 mg/Kg with UV-vis spectrophotometry method and the average of salinity 57,15 mg/L by the Conductometry method. From the analysis, Bledug Kuwu mud can be used for tourism and an additional income for the local community. the mud of Bledug kuwu has high content of sulfur can be used as a treatment especially for skin diseases and salinity can be used for making salt.

Hydrogen and chlorine abundances in the Kimberley formation of Gale crater measured by the DAN instrument on board the Mars Science Laboratory Curiosity rover

AbstractThe Dynamic Albedo of Neutron (DAN) instrument on board the Mars Science Laboratory Curiosity rover acquired a series of measurements as part of an observational campaign of the Kimberley area in Gale crater. These observations were planned to assess the variability of bulk hydrogen and neutron‐absorbing elements, characterized as chlorine‐equivalent concentration, in the geologic members of the Kimberley formation and in surface materials exposed throughout the area. During the traverse of the Kimberley area, Curiosity drove primarily over the “Smooth Hummocky” unit, a unit composed primarily of sand and loose rocks, with occasional stops at bedrock of the Kimberley formation. During the Kimberley campaign, DAN detected ranges of water equivalent hydrogen (WEH) and chlorine‐equivalent concentrations of 1.5–2.5 wt % and 0.6–2 wt %, respectively. Results show that as the traverse progressed, DAN observed an overall decrease in both WEH and chlorine‐equivalent concentration measured over the sand and loose rocks of the Smooth Hummocky unit. DAN measurements of WEH and chlorine‐equivalent concentrations in the well‐exposed sedimentary bedrock of the Kimberley formation show fluctuations with stratigraphic position. The Kimberley campaign also provided an opportunity to compare measurements from DAN with those from the Sample Analysis at Mars (SAM) and the Alpha‐Particle X‐ray Spectrometer (APXS) instruments. DAN measurements obtained near the Windjana drill location show a WEH concentration of ~1.5 wt %, consistent with the concentration of low‐temperature absorbed water measured by SAM for the Windjana drill sample. A comparison between DAN chlorine‐equivalent concentrations measured throughout the Kimberley area and APXS observations of corresponding local surface targets and drill fines shows general agreement between the two instruments.

Crushed rock sand – An economical and ecological alternative to natural sand to optimize concrete mix

Summary The study investigates the use of crushed rock sand as viable alternative to Natural River sand that is being conventionally used as fine aggregate in cement concrete. Various mix designs were developed for different grades of concrete based on IS, ACI and British codes using Natural River sand and crushed rock sand. In each case, the cube compressive strength test, and beam flexure tests were conducted. The results of the study show that, the strength properties of concrete using crushed rock sand are nearly similar to the conventional concrete. The study has shown that crushed stone sand can be used as economic and readily available alternative to river sand and can therefore help to arrest the detrimental effects on the environment caused due to excessive mining of river sand.

Migration and transformation characteristics of DOM in fine sand and marl rock

This paper mainly studied migration and transformation characteristics of dissolved organic matter (DOM) in underground aquifers. To achieve the research purpose, we carried out the dynamic column experiments of the DOM at different conditions indoors. In the experiment, the water of Wujiang River from Pingdingshan Coal-field is used as water sample, meanwhile, fine sand and marl rock are used as testing rock sample. A comparative study on migration and transformation characteristics of the DOM in different rock samples is done. The results show that, in the fine sand, the main effects are convection and dispersion, while the adsorption and biological effects are very weak. However, in the marl rock, besides existing convection and dispersion, the adsorption and biological effect are quite significant. And in the marl rock, convection and dispersion plays a major role in the early experiment, while adsorption is the main effect in the medium term, then the biodegradation dominates the final stage. With the increasing of temperature and seepage velocity in the fine sand, the impact of the convection effect becomes gradually weak, the dispersion effect gradually enhances, and, however, convection effect is still playing a dominant role. With the temperature rising in the marl rock, the adsorption effect becomes weak, but biodegradation is enhanced. As the seepage velocity increases in the marl rock, the adsorption and biodegradation both decrease.

Analysis of capillary pressure and relative permeability hysteresis under low-salinity waterflooding conditions

In this work, we analyze measurements of drainage, spontaneous imbibition and forced imbibition capillary pressure curves in conjunction with two-electrode resistivity on sandstone core samples under low- and high-salinity waterflooding conditions. State-of-the-art laboratory equipment able to work with actual reservoir fluids at reservoir conditions was designed and built to conduct these measurements. Unsteady-state coreflooding experiments under similar experimental conditions to those in the capillary pressure tests were also carried out. A black-oil reservoir simulation model was set up to history match experimental production and pressure data to obtain multi-phase flow functions. Two experiments were conducted on Minnelusa formation (eolian sand) rock samples at 93°C with TC crude oil and synthetic brines. Placement of an oil-wet membrane on one plug end and a water-wet disk on the other end guaranteed that only one phase was able to flow through each sample end at any given time. In one experiment, a 57,491ppm-brine (High-Salinity) was used during the imbibition process, while a 20-fold dilution of the High-Salinity brine (Low-Salinity) was used in the other experiment. Correspondingly, two unsteady-state experiments at fixed injection rate were completed on Minnelusa formation rock samples placed in the coreflooding system using comparable experimental conditions as those in the capillary pressure experiments. Comparison of high- and low-salinity experimental results shows that more noticeable capillary hysteresis toward water-wetness arose in the low-salinity experiment. High-salinity experiment results showed that the imbibition resistivity index was higher than that corresponding to drainage. History matching of the transient production data in capillary pressure experiments along with end-points obtained from unsteady-state core flooding experiments was used to obtain relative permeability curves. Availability of high-quality capillary pressure data at reservoir conditions improved the accuracy of relative permeability curves obtained from history matching unsteady-state core flooding experiments. Our results show a substantial improvement in obtaining both capillary pressure and relative permeability curves at reservoir conditions resulting from a combination of steady- and unsteady-state experiments. Capillary pressure results confirm that hysteresis is more prominent under low-salinity conditions and apparent higher oil trapping is observed during imbibition, compared to high-salinity conditions. Unsteady-state coreflooding results also show that low-salinity brine is not conducive to enhanced oil recovery in low-salinity waterflooding. Geochemical effects appear to negatively impact beneficial interfacial mechanisms proposed to benefit oil recovery such as the formation of more viscoelastic interfaces under low-salinity conditions. We conclude that coupling of fluid–fluid and rock–fluid interactions, including geochemical reactions, needs to be accounted for to better explain low-salinity waterflooding mechanisms.

Numerical and experimental research on the rock-breaking process of tunnel boring machine normal disc cutters

A common drawback presented by several numerical rock-breaking studies was that the rocks beneath disc cutters were cut off excessively while the rocks between disc cutters remained, which usually resulted in a smaller cutter spacing than the proper value. To overcome this limitation, the constitutive equations of different rock parts were defined separately using VUMAT, an ABAQUS-based material subroutine. The constitutive model of rock was an application of the Drucker-Prager yield criterion coupled with the Lemaitre damage model. Full-scale rock-breaking tests on a rotary cutting machine were conducted, and 25 groups of orthogonal numerical simulations were carried out. By comparing the normal force, rolling force, and specific energy of numerical results with those of experimental results, the optimal values of the defined parameters D c1, k, and B were determined to be 9☓10-4, 0.1 and 0.8, respectively. With the presented numerical method and the determined parameters, the influences of cutter spacing on normal force, rolling force, and specific energy were studied. Both the normal and rolling forces of the first cutting generally remained constant, whereas the forces of the second cutting generally increased linearly with the cutter spacing. The optimal cutter spacing for the studied rock type (Hard sand rock collected from West Qinling tunnel) was approximately 72 mm, which was in accordance with the cutter spacing of the tunnel boring machine applied in this tunnel project.

Strength of Laterite Rock Concrete

This paper presents the results of laboratory tests conducted to investigate a concrete made with laterite rock coarse aggregates. The structural properties considered were strength and elasticity. Laterite concrete mix proportions of 1:3:6, 1:2:4 1:1½:3 by weight of cement, river sand and laterite rock respectively at varying water/cement ratios of 0.55-0.90 were used. The results established an optimum water/cement ratio of 0.75, 0.60 and 0.55; with characteristic strengths of 12.00N/mm2,18.69N/mm2 and 22.88N/mm2 for mix 1:3:6, 1:2:4 1:1½:3 respectively. Flexural and splitting test results were about 6 - 21% of the compressive strength of the laterite rock concrete. The static modulus elasticity of laterite rock concrete is 22.72kN/mm².

زحف الرمال في عُرَيْق البُلْدَان وآثاره البيئية في التنمية الزراعية

تشير کثير من الدراسات إلى أن التکوينات الرملية في شبه الجزيرة العربية ظهرت خلال الفترة الأکثر جفافا في الزمن الثالث والرابع بعد الفترة الرطبة، حيث نشطت عوامل التعرية الريحية في أواخر عصر البلايستوسين Pleistocene قبل حوالي 17000 سنة، وکان تکوينها تدريجيا خلال العصور التالية لعصر البلايستوسين Pleistocene (Chapman, 1978, p. 262)، ويعود مصدر التکوينات الرملية في المملکة العربية السعودية إلى ما تذروه الرياح من إرسابات الأودية المختلفة في مجاريها، أو مراوحها الفيضية، ومن مرتفعات وهضاب الدرع العربي، بالإضافة إلى الرمال المتوضعة على السواحل، وما انکشف من الصخور الرسوبية؛ خاصة الطبقات المؤلفة من الحجر الرملي، حيث تنشط حرکة نقل الرياح للرمال في فترات الجفاف المتعاقبة (الوليعي، 1419هـ، 133). والبيئات الصحراوية الجافة التي تمثل المملکة العربية السعودية أنموذجا مثاليا لها، أکثر لبيئات حساسية، وأقل قدرة على تحمل متطلبات التنمية المختلفة، وقد ساعد وسهل حرکة الرمال في أنحاء مختلفة من المملکة الممارسات الخاطئة لبعض السکان؛ المتمثلة في: الاحتطاب والرعي الجائرين؛ خاصة في المناطق المحيطة بالصحاري والعروق الرملية، وينتشر في المملکة عدد من الصحاري تجاوزت مساحتها أکثر من 33% من إجمالي مساحة المملکة العربية السعودية. ومشکلة زحف الرمال مشکلة قائمة في شبه الجزيرة العربية منذ استيطان الإنسان فيها، لکن تأثيرها برز وظهرت خطورته مع زيادة أعداد السکان في المملکة العربية السعودية، وتوسع أنشطتهم الاقتصادية المختلفة؛ خاصة النشاط الزراعي، والعمراني، وقيام بعض هذه الأنشطة؛ خاصة الأنشطة الزراعية على أطراف الصحاري، وبالقرب من التکوينات الرملية، مما أدى إلى تأثرها المباشر بزحف الرمال عليها، وزيادة کلفتها الاقتصادية. وستحاول دراسة زحف الرمال وآثاره البيئية في التنمية الزراعية في عريق البلدان في محافظة شقراء؛ عرض موجز لجيولوجية، وجيومورفولوجية منطقة الدراسة، وظروفها المناخية السائدة، وأهم الأنشطة الزراعية القائمة في منطقة الدراسة، ونماذج لبعض أثار زحف الرمال، وقياس المعدل السنوي لزحف الکثبان في منطقة الدراسة، والآثار البيئية لزحف الرمال في التنمية الزراعية في منطقة الدراسة. Abstract: Many studies indicate that the sand in the Arabian Peninsula emerged during the drier, where wind erosion has been active in the late Pleistocene about 17,000 years ago. Because the source of sand in Saudi Arabia is carried from the valleys, hills and highlands in the Arabian Shield, and in addition to coastal sand and sedimentary rock formations in the Arabian Shield, particularly sandstone, with active movement of sand in the wind for successive periods of drought. Saudi Arabia is a perfect example of the dry desert environments, the most sensitive, has been facilitated by the movement of sand in Saudi Arabia due to wrongful acts of certain populations, such as cutting trees and grazing unregulated, especially in areas close to the sandy deserts. The problem of sand movement exist in the Arabian Peninsula since the first settlement of population, but with the impact on population growth in Saudi Arabia and the expansion of agricultural and urban activities, which reached in the desert's edge, leading to be to direct affect of sand movement and increase the cost of economic development. The study will start by mentioning the ancient climatic conditions in study area, which created the sand, then sand geomorphologic study in Urayq al Bildan in Shaqra province, and the most important environmental impacts due to sand encroachment on farms, through field visits, measure sand evaluate Remote Sensing images, and measuring the annual rate of advance of sand dunes in the study area.

Thermodynamic modeling of water-rock systems to evaluate their generative potential for hydrocarbons

The hydrocarbon generative potential of rocks was evaluated by modeling chemical interactions in the systems carbonate rock—seawater, silty sand rock—seawater, argillaceous rock—seawater, basalt—seawater, and granite—seawater at 25, 100, 200, and 300°C and over a pressure range from saturated vapor pressure to the platform thermal gradient. The term seawater is used here to describe the composition of marine solutions at the halite (SW2), epsomite (SW3), and sylvite (SW4) stages of evaporation. The hydrocarbon generative potential of rocks in these systems increases in the order clays > silty sands > carbonates > mafic rocks, while felsic rocks are nongenerative. It was shown that an increase in the rock—water mass ratio (R/W), which can be considered as a proxy for the duration (grade) of metamorphism, led to an increase in the reduction potential (logfH2) and hydrocarbon generative potential of rocks. At R/W → 1, logfH2 for carbonates, clays, and silty sands is equal to −2.74, −2.45, and −2.57 at 100°C; −1.2, −1.1, and −1.0 at 200°C; and −0.5, +0.3, and −1.2 at 300°C, which suggests that at higher temperatures (pressures) clays are more capable of reducing chemical elements in the water—rock system.

Editorial: Recent Advances in Borehole Geophysics in Unconventional Resources: Applications, Techniques and Challenges

More percentage of new productions in oil industry is from unconventional oil and gas such as oil shale, tar sand, laminated sand, tight oil (siltstone), tight gas, gas hydrate, and igneous rock, because the conventional oil and gas can no longer meet the need of the world. Researchers in response pay more attentions to the unconventional resources. Formation properties such as total organic carbon (TOC), porosity, permeability and saturation are critical for exploration and development of the unconventional reservoirs. Recent developments in wire-line methods to determine these properties have led to the completion and production strategies based on those mentioned properties. Logging-WhileDrilling measurements have the capability of determining some of these properties in real-time, so that completion decisions can be made rapidly and wells can be steered using the real-time data [1].

Contrasting sapling bark allocation of five southeastern USA hardwood tree species in a fire prone ecosystem

Fire affects numerous aspects of plant growth and anatomy, particularly in those species adapted to persist in fire‐prone environments. A key aspect of tree survival is rapid accumulation of protective bark within fire return intervals. We compared bark accumulation in five co‐occurring hardwood species within a longleaf pine (Pinus palustris) ecosystem in the mountains of northeastern Alabama, USA. Sampled species included blackjack oak (Quercus marilandica), sand hickory (Carya pallida), common persimmon (Diospyros virginiana), rock chestnut oak (Quercus montana), and red maple (Acer rubrum). Using bark thickness and inside bark diameter measurements taken at 20‐cm intervals along the main stem of saplings (average age 4–5 years) we found that, while average wood diameter did not differ across species, significant differences occurred in the ratio of bark to wood. Bark comprised over half (bark:wood = 0.55) of the basal diameter of blackjack oak, which was 3×, 4×, and 6× greater than the bark:wood ratio of sand hickory and rock chestnut oak, common persimmon, and red maple, respectively. Bark taper revealed that while other species allocated similarly to bark along the length of their stem, blackjack oak allocated much more at its base (in the flaming zone) and relatively less as height increased. Red maple, a commonly cited invader during fire‐free intervals, invested the least in bark thickness and, with rock chestnut oak, had an average height and height:diameter ratio significantly greater than blackjack oak and all other species, respectively. These results confirm the adaptive importance of bark thickness to enhancing species survival in frequent fire regimes.

Experimental study on remodeling strength of granular materials under different loads and lengths of time

Remodeled clay and sand rock specimens were prepared by designing lateral confinement and water drainage experiments based on the stress exerted on granular materials in a waste dump. An in situ test was conducted in an internal waste dump; the physical and mechanical parameters of the remodeled rock mass dumped at different time and depths were measured. Based on statistics, regression analysis was performed with regard to the shearing stress parameters acquired from the two tests. Other factors, such as remodeling pressure (burial depth), remodeling time (amount of time since waste was dumped), and the corresponding functional relationship, were determined. Analysis indicates that the cohesion of the remodeled clay and its remodeling pressure are correlated by a quadratic function but are not correlated with remodeling time length. In situ experimental results indicate that the shear strength of reshaped granular materials in the internal dump is positively correlated with burial depth but poorly correlated with time length. Cohesion C and burial depth H follow a quadratic function, specifically for a short time since waste has been dumped. As revealed by both in situ and laboratory experiments, the remodeling strength of granular materials varies in a certain pattern. The consistency of such materials verifies the reliability of the remodeling experimental program.

An Analysis of the Design of Holding System in Rocks Containing Esfahan Metro Tunnel-Southern Segment (Sofeh-Azadi)

Esfahan metro with 12745 m length is being constructed in north-south direction as two parallel tunnels. This tunnel has 3737m length in southern segment and is constructed as horseshoe form with 6.5m height and 7m width.To determine the type of holding system regarding pressure entering to system various methods were used such as 1- Experimentalmethod that includes RMR geomechanic classification, Qualitative index of tunneling in Q rock and geological strength index GSI, 2- GSIA method; at the end on the basis of achieved data from sampling during excavation the most proper holding system was estimated. By considering conditions of holding system that are offered by two experimental methods, it can be inferred that the suggested system of experimental method is conservative. But sand rocks don't need holding system according to analytical methods. If wedges are created by collision of joint sets, holding system may become necessary.DOI: http://dx.doi.org/10.3126/ijls.v9i4.12639

EVALUATION OF SOME SOILS IN NORTH WESTERN PARIS OASIS (EGYPT) USING STORIE INDEX AND SYS MODELS

The North Western of Paris Oases represents one of the highest priority areas for future development in the country. The study area is located between longitudes 30 11 34.9 to 30 26 59.4 East and latitudes 24 40 9.3 to 24 51 8.7'' North and covers an area about 123966 feddans. The purpose of this study is to evaluate some soils in north western Paris oasis using Remote Sensing (RS) and Geographic Information System (GIS). For this purpose, Forty-Three soil profiles were described in the field and their representative samples were analyzed. Using geomorpholical map, geological map and visual interpretation of satellite data a physiographic soil map was created to present mapping units of the study area. The area under investigation was classified into three landscape units, i.e. Plain, Dunes and Hills. Soil characteristics of the obtained mapping units were discussed and soil taxonomic unit were identified. Two models of land capability were used to evaluate the soils of study area. According to Storie Index model, the area under investigation was classified into three capability grades reflect the limitation factors, i.e. grade 1 (67.4 %), grade 3 (26.16 %) and grade 6 (6.44 %). on the other hand and according to Sys model the study area was classified into three capability classes, i.e. S2, S3 and N2. The soils of S2 have moderate limitations for agricultural crops, where texture is the main limiting factor (67.4 % of the total area). The main limiting factors of soils of S3 are texture, depth and salinity (26.16 %), while the soils of N2 (6.44 % of the total study area) include sand dunes, rock crops and shallow to very shallow soils. Five crops were selected to assess soil suitability for cultivation in the study area, i.e. wheat, barley, maize, tomato and olive. The results indicated that olive was more suitable for growing in such soils.

Groundwater quality and hydrogeological characteristics of Malacca state in Malaysia

Abstract Groundwater quality and aquifer productivity of Malacca catchment in Peninsular Malaysia are presented in this article. Pumping test data were collected from 210 shallow and 17 deep boreholes to get well inventory information. Data analysis confirmed that the aquifers consisting of schist, sand, limestone and volcanic rocks were the most productive aquifers for groundwater in Malacca state. GIS-based aquifer productivity map was generated based on bedrock and discharge capacity of the aquifers. Aquifer productivity map is classified into three classes, namely high, moderate and low based on discharge capacity. Groundwater potential of the study area is 35, 57 and 8% of low, moderate and high class respectively. Fifty two shallow and 14 deep aquifer groundwater samples were analyzed for water quality. In some cases, groundwater quality analysis indicated that the turbidity, total dissolved solids, iron, chloride and cadmium concentrations exceeded the limit of drinking water quality standards.

Selected Unsuitable Problematic Rocks in Geotechnics

The aim of this publication is to highlight some selected case studies that relate to issues of interaction of the geological environment with engineering construction. This is an issue of flysch sediments, karst areas, liquefied sand, loess sediments and basalt rocks. This geological environment is causing many problems. This can cause problems during the construction process, or in trying to preserve the long life of these constructions. Mentioned problematic rocks can complicate future or existing construction through landslides, low bearing capacity, differential settlement, karstification, filtration faults and many other disorders. Labelling the rock as problematic rock is debatable. Each geological environment is affected by a large amount of geofactors. These geofactors input to deciding about the appropriateness or unsuitability of the foundation soil and their risks. Generally, the unsuitability of the foundation soil is determined by a combination with geofactors such as ground water, earthquakes, sloping terrain and many others. Therefore, it is necessary to designate “problematic rocks” understood as an environment with many problems. That means problems with foundation engineering and existing constructions at a high rate. This designation also includes an environment where the consequences of construction failure have unforeseen consequences. Problematic rocks also include soft rock, which is dedicated to a number of other publications. Although each environment is completely unique, learning from mistakes and lessons learned from other countries is very important.

Effect of organic manures and rock phosphate on growth and yield of Bengal gram (Cicer arietinum L.)

A field experiment was conducted on vertisolsat Natural Resources Protection and Development Society Research Station, Namakkal during Rabi season of 2012-13 and 2013-14 to study the effect of organic manure sand rock phosphate on growth and yield of Bengal gram (Cicer arietinum L.) in vertisols of Tamil Nadu. Significantly higher grain yield was recorded with rock phosphate application @ 200 kg/ha (2140 kg/ha) over 50 kg and 100 kg of rock phosphate per hectare except rock phosphate @ 150 kg /ha (2069kg/ha). Interaction effect of compost 5 t along with rock phosphate 200 kg/ha recorded significantly higher grain yield 2130 kg/ha) and haulm yield (3300kg/ha) over other treatment combinations except either for organic manures FYM 5 to rcompost 5 t along with 150 to 200 kg rock phosphate per ha. Significantly higher B:C ratio (3.32)was recorded with rock phosphate @ 200 kg / ha over other lower levels. Similarly, combination of compost @ 5 t/ ha with 150 kg rock phosphate resulted in higher B:C ratio (3.37).

The microstructure of the North American oil market

Recent developments in production of oil and natural gas from the tight sand and shale rock formations (primarily hydraulic fracturing and horizontal drilling) have a profound impact on the North American energy markets. The paper reviews recent crude oil production trends and their impact on the price relationships across different geographical locations in the US and Canada. Price disparity between different market hubs is attributed to the collision between growing volumetric flows of crude oil (as well as changing quality mix of produced crudes) and rigidity of the existing midstream and refining infrastructure. We continue with a discussion of how the North American oil industry adjusts to new disruptive technologies in exploration and production of hydrocarbons.