Deep Borings Research Articles

Below ground carbon stock and carbon sequestration potentials of mangrove sediments in Eastern Niger Delta, Nigeria: Implication for climate change

The carbon sequestration capacity and climate change mitigation potentials of mangrove sediments in eastern Niger Delta were investigated. The aim was to determine the carbon stock in the sediments as a measure of carbon sequestration. A total of 312 sediment samples were obtained from 24 sampling 100 cm deep borings at seven locations using an open-cylindrical gouge auger of 100-cm length and 5-cm diameter. The procedures for field sampling, laboratory analysis and result presentation followed protocols for forest carbon measurement, monitoring and reporting. The lithology at the site, which is a major control on the distribution of organic carbon, included peat, peaty clay, and clayey peat with pockets of sands. Sediment bulk density (SBD), organic carbon concentration (%C), were used to estimate the organic carbon stock, carbon dioxide equivalent (CO2e), and to calculate carbon sequestration rate (CSR) and sequestration potential (CSP). Mean values of SBD were 1.30 g/cm3) and 12.48 %) respectively. Similarly, carbon averaged 39.80 Mg ha–1. The total carbon stock of the study area was estimated at 199,617.36 ± 55.64 Mg C, equivalent to 732,595.71 ± 55.64 Mg CO2. CSR was estimated at 4.54 g C cm–2 yr–1 while CSP of mangrove sediments was estimated at 21.56 Mg C yr–1. The result showed that 732,595.71 ± 55.64 Mg of carbon dioxide could either be removed or released to the atmosphere by the mangrove forest of Niger Delta through forest management practices and/or degradation. The study reinforces the need for the protection of mangroves against all anthropogenic-related degradation to improve carbon sequestration potential and achieve target in line with Sustainable Development Goal 13.

Hydrogeochemical evolution of the shallow and deep basaltic aquifers in Tamborine Mountain, Queensland (Australia)

Tamborine Mountain, Queensland (Australia), is a prime example of a basalt fractured-rock aquifer. Yet very little is known about the hydrochemistry of this groundwater system. Both analytical (major ions and stable isotopes) and multivariate (hierarchical cluster analysis, principal component analysis and factor analysis) analyses were used in this study to investigate the factors that interact within this aquifer system, in order to determine groundwater hydrogeochemistry. A new approach was applied to the data by classifying hydrographs by water type to clearly identify differing aquifer zones. Three distinct groundwater chemistry types were identified, and they were differentiated by variations in depth. Shallow bores were dominated by Na–Cl waters, deep bores were dominated by Na–HCO3 and Ca–HCO3 waters, and the two deepest bores were dominated by mixed water types. The evaluation of hydrogeochemical data has determined that both mineral weathering processes and groundwater/surface-water interaction had a strong influence on the hydrogeochemistry. Seasonal effects were minimal in the study area based on physicochemical parameters and ion chemistry. However, stable isotopic data show temporal trends. Increased rainfall events during the wet season produced a depletion in δ18O and increased d-excess values. The opposite is found during the dry season as a result of higher evaporation rates that are not hindered by intense rainfall events.

Spatio-temporal monitoring of leachates dispersion beneath a solid wastes dump in basement complex of southwestern Nigeria

For real-time monitoring and modeling of leachates dispersion beneath Arada wastes dump, Ogbomoso geologically located within Southwestern Nigeria basement complex, an integrated technique involving time-lapse Electrical Resistivity Tomography (ERT), hydrogeology, and geotechnic was used. ERT was performed using Wenner electrodes configuration in a Northeast-Southwest azimuth on the wastes dump monthly from March to September, and twice in March and September, at the control site, during the wet season. The Total Dissolved Solids (TDS), Electrical Conductivity (EC) and static water level of two monitoring wells on the dumpsite were measured during every ERT surveying. Twenty four soil samples were taken at 0.5 m intervals from 2.0 to 3.0 m deep bores on the anomalously low resistivity spots discovered on the subsurface resistivity distribution of the wastes dump, and sieve analysis and permeability tests were performed in the laboratory on these samples. Using the approach of grain-size analysis, the hydraulic conductivity and porosity were calculated empirically. On the wastes dump and control site, the resistivities of spatially distributed lenses of material ranged within 1.45–37.3 Ωm and 22.5–52.6 Ωm, respectively, suggesting leachates and clay anomalies. The wastes dump subsurface might be regarded as a porous medium since its porosity ranged between 38.2 and 44.2%, and the permeability range of (5.4–9.6) x 10−5 m/s showed that water could freely drain from it. Water samples taken from the monitoring wells on the waste dump had TDS and EC that ranged from 520 to 970 ppm and 1.05 to 2.37 mS/cm, respectively, but decreased in the southwest direction of groundwater flow, indicating leachates dispersion. The hydraulic conductivity ranged within 0.00285–0.176 m/s but varied anomalously and spatially indicating heterogeneous hydraulic conductivity field capable of initiating local variation in velocity that caused leachate to disperse longitudinally and transversely. The rate of longitudinal and transverse leachates dispersion as revealed by subsurface resistivity distribution images ranged within 0.000–0.250 m/day and 0.001–0.045 m/day, respectively. The former rate was 5.6 folds the latter rate and hence fell within the stipulated 5–100 for dispersion process that conformed to natural consequence of dispersivity. The conductivity-time curves (CTCs) of the leachates anomalies' steepness and doubly-peaked properties indicated Fickian dispersion, while different proportion times; t-1.588 and t-2.478, which are not equal to t-0.5, showed that the CTCs described non-Fickian dispersion at a significantly later time.

Effect of metal pollution on the distribution and co-occurrence pattern of bacterial, archaeal and fungal communities throughout the soil profiles

Metal pollution has raised negative impact on microbes, but little is known about the distribution and co-occurrence pattern of bacterial, fungal and archaeal communities along the soil profiles at multiple metal contamination sites. Here, we characterized the variations of metal concentrations and microbial communities with soil depth along five deep bores at the Tanghe Sewage Reservoir, a typical metal contamination area on the North China Plain. Co, Cd, Mg, Se, and Li were identified as the major contaminants in this area, and the pollution load index was 1.88, 1.54 and 1.62 in the shallow layer (0–0.6 m), deep layer (>2.0 m) and middle layer (0.6–2.0 m), respectively. The diversities and compositions of bacterial, archaeal and fungal communities varied significantly along the soil profiles. Deterministic process played a crucial role in shaping the difference of microbial community compositions among different soil layers, in which metal levels contributed more than soil physiochemical parameters. Furthermore, the interspecific co-occurrence network was most complex in the middle layer, indicating that metal pollution could decrease microbial network complexity. Bacterial keystone species in the co-occurrence networks showed both positive and negative correlations with polluted metals, whereas most archaeal and fungal keystone species were negatively related to multiple metals. These findings increased our understanding of distribution patterns, co-occurrence networks and environmental drivers of microbial communities in metal pollution soils.

Increased stiffness and vibration resistance during deep boring

Increased stiffness and vibration resistance during deep boring

Influence of the cutting edge on the surface integrity in BTA deep hole drilling - part 1: Design of experiments, roughness and forces

The BTA deep hole drilling process is used to machine deep bores with a large diameter. The cutting process, consisting of the material removal by cutting edge and the surface burnishing by the guidepads influence the surface of the bore. To separate the impact of the cutting edge from that of the guidepads on the surface of the bore and the subsurface zone an experimental model setup in analogy to the BTA process was developed. This paper covers the differences to the conventional BTA deep hole drilling, the experimental boundary conditions and the measurement of the surface roughness. The results are compared to previous analysis of the surface integrity of BTA deep hole drilled specimens. Furthermore, conclusions about the process forces are drawn from the documented loads occurring for the machine axes. In part 2 of this study, the surface integrity of the specimens is further analyzed using destructive and non-destructive methods.

Cutting Performance of Austenitic and Duplex Stainless Steels with Drills of Three Cutting Edges

Austenitic and duplex stainless steels are considered be the best in corrosion resistance among different grades of stainless steels. Due to high strength, duplex stainless steels applications are increasingly as an alternative to the austenitic stainless steels. In this sense, the machining study of this materials is an important issue, in order to better understand the performance of the tools and the quality of the parts manufactured for high-demand industries. In this research, the machinability of both stainless steels was evaluated in the drilling operation, using drills with three cutting edges. This type of drill geometry is particularly useful when conventional solid carbide drills fail. The drill point of triple edge is very stable, demonstrating optimal positioning accuracy and better performance in deep bores. Using the same tool geometry, a comparative analysis of drilling performance on austenitic and duplex stainless steels was made. In experimental procedure, external low-pressure cooling or internal high-pressure cooling was applied alternatively. The cutting vibration, the tool wear, the roughness and the hole diameter accuracy were evaluated in the series of holes made. The obtained results show that the most important factor to increase the number of holes made is the use of high-pressure internal cooling. When external cooling is used, AISI 304 have a worse behaviour than duplex stainless steel, due to greater susceptibility to built-up-edge formation and work hardening. The tool deterioration is mainly non-uniform chipping for external cooling and flank wear for internal cooling.

Investigation into the Cause of Iron-Related Clogging of Groundwater Bores Used for Viticulture in the Limestone Coast, South Australia

Iron-related clogging of boreholes, pumps and dripper lines is a significant and costly problem for irrigators worldwide. The primary cause of iron-related clogging is still debated. Previous studies have described complex interactions between biological clogging and inorganic iron/manganese oxide precipitation. This case study examined groundwater bores used for viticulture irrigation in the Limestone Coast region, a highly productive wine growing area in the SE of South Australia. Iron clogging of bore screens, pumps and dripper systems has been a persistent problem in the region and the issue is perceived to be growing, with irrigators suggesting the widespread introduction of iron-related bacteria (IRB) through drilling equipment to be the root cause of the problem. Analysis of the groundwater microbiology and inorganic chemistry found no apparent correlation between the presence of IRB and the clogging status of wells. In fact, IRB proved to be widespread throughout the limestone aquifer. However, a clear correlation could be found between clogging affected bores and the redox potential of the groundwater with the most severely affected bores strongly oversaturated in respect to iron oxide minerals. Elevated dissolved concentrations of Fe(II) thereby tended to be found in deeper bores, which also were generally more recently drilled. Following decades of less than average rainfall, a tendency to deepen bores in response to widespread declines in water levels has been documented for the SE of South Australia. The gradually widening clogging problem in the region is postulated to be related to the changes in climate in the region, with irrigators increasingly driven to rely on deeper, anoxic iron-rich groundwater resources.

Analysis slope stability of transmission tower 150 kV on moderately-cemented-sand due to soil excavation

T.66, transmission tower of 150 kV line Cilegon Baru – Asahimas was in high light for the threaten of slope stability because of soil mine excavation around tower area. Massive Excavation soil were occurring next to tower foundation, which is the depth approximately 14 m (height) and the inclination almost 80°. Therefore, analysis was highly needed to ensure that tower stand on stable spot. The method used in this research were study literature, soil investigation (deep boring and hand boring) and laboratory test for undisturbed samples, geoelectric test, and topography mapping. The type of soil was ‘moderately cemented sand’ slope. It has a complete characteristics and tends more challenging in determine the slope stability. By considering that, the data parameters input were approached in conservative way, which was considering literature and soil investigation data. In this case, slope stability was modeled with Finite Element Method (FEM) by doing back analysis. The result shown that tensile stress was relative small (near 0).

WITHDRAWN: Application of GIS software in analyzing hydrodynamics of sub surface water demeanor zones in Gondwana sedimentary terrain of eastern India

Abstract Gondwana study terrain of Orissa, India has diverse geological, geophysical, hydrological, hydrogeological and meteorological information which have been integrated for extensive study. The study aims at acknowledging the geology and hydrogeology of the region backing up with the type and existence of aquifers around the region. To get the detailed features 225 observation wells, 40 National Hydrograph Network Stations (NHNS), 40 groundwater monitoring (GWM) stations and 83 exploratory wells were collected from different sources to analyse the groundwater occurrence in the study area. The data obtained were integrated and initiated for lithological distribution, groundwater flow directions, depth to water levels in pre- and post-monsoon. Limited aquifer thickness of unconfined aquifer and poor yield from deeper aquifers has been studied intricately. Groundwater occurrence has provided a paradigm to in-depth study in association with detailed lateral and vertical demarcation and behaviour of aquifers. Taking into consideration about lithology, the area can be hydrogeologically divided into consolidated, semiconsolidated and unconsolidated zones. The semi and unconsolidated zones are the groundwater potential zones where the aquifer remains under saturated condition. Though semiconsolidated zones bear abundant volume of water but hydrological parameters illustrate that they do have the potentiality for shallow water wells whereas the fissured and fractured zones in consolidated formations yield perennial source of groundwater illustrating deep borings.

Water Quality in Pokhara: A Study with Microbiological Aspects

Obviously, water management is challenging issue in developing world. Dwellers of Pokhara use water from government supply along with deep borings and other sources as well. Nowadays, people are also showing tendency towards more use of processed water. In spite of its importance, quality analysis of water has been less emphasized by concerned sectors in our cities including Pokhara. The study aimed for qualitative analysis of water in the city with focus on microbiological aspects. For this purpose, results of laboratory examination of water samples from major sources of government supply, deep borings, hospitals, academic institutions as well as key water bodies situated in Pokhara were analyzed. Since water borne diseases are considered quite common in the area, presence of coliform bacteria was considered for the study to assess the question on availability of safe water. The result showed that all the samples during wet seasons of major water sources of water in Pokhara were contaminated by coliform bacteria. Likewise, in all 20 locations of Seti River, the coliform bacteria were recorded. Similar results with biological contamination in all samples were observed after laboratory examination of more than 60 locations of all three lakes: Phewa Lake, Begnas Lake and Rupa Lake in Pokhara. The presence of such bacteria in most of the water samples of main sources during wet seasons revealed the possibilities of spreading water related diseases. Again, microbiological contamination observed from significant number of bottled water samples as well as boring sources clearly alarmed the preoccupied belief in such supply of water. On the other hand, fluctuating water quality of academic institutions and hospitals questioned on the priority of the management and seriousness against possible spreading of water borne diseases. For obtaining the safe water, various treatment options have been recommended from World Health Organization (WHO) with chlorination in top priority due to affordability and simplicity. Urgent execution of such option could be important with due consideration of negative aspects from the possible byproducts. However, proper implementation of filtration technique and planning of further advanced technology could be valuable for fulfilling the need of metropolitan dwellers to get wholesome water for their daily consumption.

Screw driving sounding test; a new technology in soil investigation work particularly for soft soil

Screw Driving Sounding (SDS) test has been developed in Japan as the improved version of the Swedish Weight Sounding (SWS) test. The development of SDS is to reduce the drawbacks of the SWS with the integration of rod friction estimation. Deep boring with Standard Penetration Tests (SPT) together with soil sampling for laboratory tests have been the common procedure for determining the subsurface soil profile and geotechnical engineering properties. However, the SPT which is associated with deep boring, uses high fossil fuels, needs high skilled workers and expensive. This paper presents the SDS technology and the SDS test results in comparison with the existing SPT data from six (6) selected sites in Malaysia. Results show that there is a strong correlation between SPT and SDS data, and the soil profile is better identified using SDS than the SPT. It is predicted that SDS test has the potential to replace conventional soil investigation methods, particularly in soft soils area. It is not just fast, cheap and does not require highly skilled workers but SDS tests supports green technology and sustainability in construction. Quality results are guaranteed from the usage of Industrial Revolution 4.0 technology through automation in testing and making use of the cloud computing to manage the data.

On the self-excitation of vibrations of a boring bar in the process of deep boring

The article presents equivalent mathematical models of a boring bar designed for deep boring, in a distributed and a discrete idealizations. A mathematical model describing coupled torsional and lateral vibrations of a boring bar is constructed in the form of a set of differential equations with lagging of the cutting process dynamics. A methodology for studying stability in small of the deep boring process using a characteristic quasi-polynomial is presented. The numerical-analytical results of the studies made it possible to discern stability regions in the parameter space of the model and to obtain relations for maximal cutting depth as a function of geometrical and technological parameters (stiffness, cutting velocity, feeding etc.) of the boring bar considered. It is noted that the obtained numerical-analytical results are in good agreement with experimental data.

Production of Deep Bore Holes with Non-Circular Profiles

Deep hole drilling is a process for the production of cylindrical bore holes with a large length to diameter ratio. The variation of parameters is limited to those ones of the conventional drilling process such as rotation and feed motion. A special deep hole drilling process, named “chamber-boring”, was developed for the production of contoured bore holes in axial direction [1]. For specific applications not only a contouring in axial direction is required but also a radial contouring is necessary. In the course of a ZIM – project (Central Innovation Programme for SMEs), supported by the Federal Ministry for Economic Affairs and Energy (BMWi) and in close collaboration with the BGTB GmbH and the Institute of Machining Technology (ISF), a new “chamber boring system” which allows contouring of boreholes in axial and radial directions was developed. Based on this machining system, the manufacturing of pipes with a wavelike cross section in radial direction is possible.

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.

Investigation of Ablation Behaviour in Micro-EDM of Nonconductive Ceramic Composites ATZ and Si3N4-TiN

Micro-EDM is a well-known process for precision micro machining of difficult to cut materials. It is especially beneficial for machining of complex micro structures such as deep bores, grooves or undercuts in highly wear resistant materials.In the last years, research has successfully applied the assisting electrode method as a suitable process for machining non-conducting ceramics by micro-EDM. There, the EDM process is initiated after applying an electrically conductive starting layer onto the surface of the ceramic. Due to the great variety of ceramics like oxide ceramics, non-oxide ceramics or ceramic composites, different mechanisms for material removal can be observed depending on the raw material and its composition. Particularly for production oriented reasons it is necessary to determine the specific ablation behaviour of each ceramic with regard to the used process parameters. In this study two different ceramic composites, ATZ (Alumina Toughened Zirconia, ZrO2-Al2O3) and Si3N4-TiN (Titanium Nitride toughened Silicon Nitride), were investigated considering their ablation behaviour. Experiments were carried out to determine the maximum achievable aspect ratios of micro bores, the resulting surface quality and the possibility for machining complex 3D-structures by EDM-milling.

Drinking Water Quality of Kathmandu Valley

This research was conducted to analyze drinking water quality of Kathmandu valley. Total 969 water samples (392 from dug wells, 287 from deep boring, 218 from treated water, 46 from tap and 26 from other water sources) received from different places of Kathmandu, Lalitpur and Bhaktapur districts during March 2012 to March 2013. These samples were analyzed for the determination of physical (pH, temperature, conductivity, turbidity), chemical (hardness, chloride, iron, arsenic, ammonia, nitrate) and microbiological (total Coliform) parameters. It was found that the temperature and nitrate were within the WHO standards while pH, conductivity, turbidity, chloride, iron, arsenic, ammonia, and Coliform bacteria exceeded the WHO standard guideline. In ground water ( well and Boring), pH, conductivity, hardness, turbidity, iron, arsenic, chloride, ammonia and total Coliform count crossed WHO standards as 5%, 2%, 0.8%, 36%, 51%, 0.1%, 2%, 11% and 86 % respectively. Hardness was within the standard in both reated and tap water samples. Compared to treated water, pH, arsenic and chloride were within the standard in tap water. The common problematic parameters of different sources of drinking were turbidity, iron, ammonia and conductivity. Coliform bacteria were found in 36% samples of treated water whereas 80% tap water samples were contaminated from Coliform bacteria.DOI: http://dx.doi.org/10.3126/njst.v15i1.12027Nepal Journal of Science and TechnologyVol. 15, No.1 (2014) 115-120

Performance Assessment of Installed Arsenic Removal Technologies and Development of Protocol for Alternative Safe Drinking Water Supply Options for Arsenic Hit Areas of Pakistan

After identifications of arsenic contamination in Pakistan, lot of technological based arsenic mitigation interventions were carried out which could not last longer due to non-availability of filtration media and running spare parts of arsenic removal tanks units in the local market. The in-depth performance analysis of arsenic removal technology (ART) units, clay pitchers and PUR sachet was carried out which showed un-sustainability of these interventions. The main reasons are lack of awareness, illiteracy and unfavorable socio-economic conditions which make the end users in villages/rural areas the most vulnerable to the adverse impacts of any type of contaminated water and own the installed arsenic removal interventions. Therefore, before taking up any arsenic removal project, it is worthwhile to explore those interventions which are compatible to local socio-economic environments. Deeping boring options have been found best suited, as most of the agricultural practices are dependent on ground water- at shallow depths. The soil analysis at deeper depth will help in ascertaining the causes of arsenic contamination due to presence of arseno-pyrites or due to leaching of sustained applications of pesticides & fertilizers. Therefore, in case of absence of arseno-pyrite sediments at deeper depths. Then the best option for provisioning of arsenic free water is deep boring. The active participation of the communities who are the intended beneficiaries of arsenic mitigation is vital for the success of the programme. Lack of awareness and generally unfavorable conditions are also obstacles to mobilizing communities to get the best out of community-based programmes and projects. Therefore, a well designed protocol for alternative water supply has been evolved which will help in provisioning of sustainable arsenic free water.

Study on Dynamic Properties of Damping Boring Bar with Large Ratio of Length to Diameter

In the deep hole boring, the vibration of the boring bar is greater. In order to improve the machining processing efficiency and quality of the deep hole boring, this paper designs the deep hole damping boring bar with a single oscillator firstly. It builds a simplified dynamic model of the damping boring bar and calculates its relevant parameters. Moreover, with different external excitation force frequency, the maximum amplitude variation of the boring bar tip position is obtained from the simulation analysis. Finally, the experiments show that: Compared with the hollow boring bar and the solid boring bar, the damping effect of large aspect ratio vibration boring bar increases about 75%.

Micro-EDM Milling of Electrically Nonconducting Zirconia Ceramics

Micro-EDM is a well-known process for precision micro machining of difficult to cut materials. It is especially beneficial when machining complex micro structures such as deep bores, grooves or undercuts in highly wear resistant materials. One constraint is its limitation to electrically conductive materials.Advanced materials such as high-temperature resistant engineered ceramics are gaining more and more importance, nonetheless due to their manifold applications in transport, energy and also biomedical areas.An adaption of micro-EDM to nonconducting ceramics could bring together the design freedom implemented in the EDM process and the beneficial material properties of engineered ceramics.In the last years, research has successfully applied the assisting electrode method to zirconia material, allowing for the micro-EDM to proceed notwithstanding the electrically nonconducting properties. Using suitable dielectric and process parameters, the machining continues even after the electrically conducting starting layer has been removed.Within this study the micro-EDM milling of zirconia is investigated in order to further understand the mechanisms of ceramics machining. Roughness and surface characteristics are analyzed and compared to the equivalent metal parts.The voltage and current signals are recorded using high speed deep memory A/D converters to allow for an insight into the process. With the findings the process can be improved in terms of speed, accuracy and achievable structures.