Bottom Of Hole Research Articles

The impact of postglacial palaeoenvironmental changes on the properties of sediments in the kettle hole at the site of Jurki (NE Poland)

This research is focused on a small kettle hole located within the Morąg moraines (Ilawa Lake District, NE Poland). The study objective was to determine the impact of palaeoenvironmental changes in sedimentation and properties of sediments filling the bottom of the kettle hole. Sedimentological, geochemical, and palaeobotanical studies enabled us to distinguish several development phases of the kettle hole, and cluster analysis performed on physicochemical data yielded seven local geochemical zones (Ju I/I to Ju I/VII ). The beginning of biogenic sedimentation in the conditions of a small water body, functioning in the Late Glacial period (4.20–4.10 m), was determined on the basis of palaeobotanical research. Sediments deposited in the lake during its further evolution were rich in microelements such as Ca, Na, Mg, and K, and to a smaller extent – Fe and Mn (Ju I/I–III local geochemical zones). The Late Glacial lacustrine period ended with the accumulation of very silty, pollen-free gyttja, with a stratigraphic hiatus (Ju I/IV , 3.40–3.20 m). The sediments were enriched with SiO2ter, which indicates an increased rate of slope erosion, and concretions of Fe-Mn occurring below this layer (Ju III ) provide evidence for lowering of the water level and even desiccation. In the Holocene, the lacustrine period ended with the accumulation of coarse detrital gyttja (3.20–2.60 m). Palaeobotanical data indicate that the next group of sediments were deposited in the Late Subboreal and Subatlantic periods (2.60–0.0 cm, Ju I/V–VII ; sedge peat). Their properties were varied and related to hydrologic conditions, limited denudation, and vegetation succession. There was also a significant change in the trophic conditions of the water and consequently in the sediments of the kettle hole, which changed during the lacustrine period from basic to acid, and strongly acid in the surface layer. This reaction may be related to a change in the water regime as well as to human impact in the environment, which led to the colonization of the peat bog by Sphagnum moss.

Validation of horizontal auger drilling string assembly design based on dry bearings

The authors identify some factors that govern energy input of borings removal from hole bottom to an unloading point using auger drilling string assembly. Of specific significance appears to be the factor of insufficient reliability of anchor gears and centering devices of the drilling string assembly, which makes continuous drilling impossible without permanent servicing. The article gives the analysis of bench testing data of bearings with antifriction filler for drilling string mounting groups to be serviced outside the areas of drill holes. The design solutions based on the investigation results and aimed to improve reliability of anchor gears and centering devices of an auger drilling string assembly are described.

Angola Cameia Development Casing-Settlement Calculations

SummaryThe amount of axial settlement of casings supported by regions of axial elastic foundations is computed. The differential equation of axial equilibrium, including the foundation stiffnesses, is solved by use of cubic axial finite elements. The analysis is applied to 101 m of a vertical 914-mm (36-in.) casing supporting a 559-mm (22-in.) casing running from 3 m above the mudline to near the bottom of the 1201-m hole. The upper casing is supported by a region of layered clay sediments. The lower casing has a long openhole region, followed by a bottom region encased in cement. A series of loading increments is applied, with the connection of the tree/blowout preventer (BOP) as the last. The settlement at the mudline was calculated to be less than 0.1 m. This study shows that for weak upper foundations, a good cement job is needed to support the tree/BOP without large mudline settlements.

Effect of Template on the Structure of Carbon Nanotubes Grown by Catalytic Chemical Vapor Deposition Method

Carbon nanotubes (CNTs) have been synthesized on an anodized aluminum oxide (AAO) template with acetylene by using catalytic chemical vapor deposition (CVD). It was found that the structure of CNTs can be mostly depends on the quality of the catalyst deposition in the pores of AAO template. Straight CNTs were observed when Ni catalyst deposited only in the bottom of holes as nanoparticles, but when Ni catalyst fulfilled the holes of AAO template as nanowires (NWs), coiled CNTs observed. The characterization of as-prepared materials was examined by SEM and Raman spectroscopy. In addition, it is realized that the nanostructure of the AAO template strongly affected the properties of as-grown CNTs. In the other word, based on the obtained results the diameter and pitch of coiled CNTs tightly depend on the size of metallic catalyst and in the results it depend on the pore diameter of AAO template.

Study on the Gap Flow Simulation in EDM Small Hole Machining with Ti Alloy

In electrical discharge machining (EDM) process, the debris removed from electrode material strongly affects the machining efficiency and accuracy, especially for the deep small hole machining process. In case of Ti alloy, the debris movement and removal process in gap flow between electrodes for small hole EDM process is studied in this paper. Based on the solid-liquid two-phase flow equation, the mathematical model on the gap flow field with flushing and self-adaptive disturbation is developed. In our 3D simulation process, the count of debris increases with number of EDM discharge cycles, and the disturbation generated by the movement of self-adaptive tool in the gap flow is considered. The methods of smoothing and remeshing are also applied in the modeling process to enable a movable tool. Under different depth, flushing velocity, and tool diameter, the distribution of velocity field, pressure field of gap flow, and debris movement are analyzed. The statistical study of debris distribution under different machining conditions is also carried out. Finally, a series of experiments are conducted on a self-made machine to verify the 3D simulation model. The experiment results show the burn mark at hole bottom and the tapered wall, which corresponds well with the simulating conclusion.

吸引プラズマエッチング法を用いたSiO<sub>2</sub>ダイアフラム構造作製技術の開発

We propose a simple method to fabricate SiO2 diaphragms supported on a Si substrate by using the inward plasma etching. In this method, a Si substrate covered with SiO2 was locally etched with the inward plasma from the Si side. When using a SiO2 (280 nm)/Si (380 μm) substrate, a SiO2 diaphragm with a diameter of ∼50 μm was fabricated at the bottom of the bowl-like hole with an opening diameter of ∼1.2 mm. This method does not require lithographic processes which are inevitable for the conventional microfabrication techniques and may be used to fabricate MEMS devices in the lab.

Expansion of Smoothed Area on Hole Bottom Surface by Setting Magnetic Block in Large-area Electron Beam Irradiation

Expansion of Smoothed Area on Hole Bottom Surface by Setting Magnetic Block in Large-area Electron Beam Irradiation

Interaction of Magnesium Cations with Dioctahedral Smectites under HLRW Repository Conditions

AbstractIn some real and up-scale tests using high-level radioactive waste (HLRW), Mg accumulation was observed in smectites at the contact of heated Fe or Cu metal tubes. It is important to understand why Mg accumulated in order to model the long term performance of bentonites in HLRW systems. In some of these tests, an increased number of trioctahedral domains was measured in the smectites using X-ray diffraction (XRD) and infrared spectroscopy (IR). The trioctahedral domains either formed by the dissolution/precipitation of smectites or by the addition of Mg through a solid-state reaction similar to the Hofmann-Klemen effect. The Hofmann-Klemen effect is used in the Greene-Kelly test to distinguish montmorillonites from beidellites. Many studies have been carried out about Li-uptake by smectites, but Mg was rarely taken into account. The present study was, therefore, undertaken to compare the interactions of different bentonites with Li and Mg under various conditions. A significant CEC decrease was found for Li- and Mg-saturated bentonite samples after heating at 250°C under dry conditions. The extent of this CEC reduction depended on the octahedral to tetrahedral charge ratio and was smaller for Mg-saturated samples than Li-saturated samples. This finding proved that it is much more difficult for Mg to enter octahedral vacancies than Li, which probably can be explained by the larger hydration energy and/or slightly larger radius of Mg. The relationship between CEC reduction and the octahedral/tetrahedral charge ratio of both Li- and Mg-saturated samples, however, suggests a similar process. The Mg that can reside at the bottom of the pseudohexagonal holes would not explain this relationship. The important result with respect to understanding HLRW bentonite performance, on the other hand, is that Mg fixation only occurs under dry conditions and that Mg fixation acts as a sink for Mg and, hence, leads Mg to diffuse towards the heated metal surface.

Dynamic response prediction of non-obstructive particle damping using principles of gas-solid flows

Particle damping is a kind of passive and strongly nonlinear damping for energy dissipation. Many researchers have expended huge amounts of effort and time to study internal mechanism of particle damping. However, there is not a systematic and feasible approach for estimating damping performance of non-obstructive particle damping (NOPD). In this paper, we performed studies to mathematically evaluate the damping effect of particle damping based on principles of gas-solid flows. In consideration of the structural characteristics of NOPD which granular materials should be filled into sealed cavity of vibrating structure and the damping act on lateral and bottom of holes in NOPD technology, the gross damping is divided into lateral damping and bottom damping by Janson's theory of stress change direction. And the damping coefficients are compiled into a plug-in by MATLAB and are invoked in FEM software by enterprise integration kits of COMSOL. Meanwhile the frequency domain and time domain analysis of the experiment are used to verify the prediction accuracy of dynamic vibration response of an aluminium cantilever beam which ONPD is imposed at the free end with different packing rate and granular material, the result indicate that the mathematical model has excellent performance to predict the dynamic vibration response of NOPD. Then, the relationship damping effect with the particle filling ratio, particle density and length-diameter ratio of the hole is also researched using co-simulation, it should be noted that larger packing rate and particle density, smaller length-diameter ratio of the hole can play excellent damping effects in NOPD.

Determination of the Parameters of the Hole Bottom Zone of a Vertical Well from the Results of Thermodynamic Investigations

A computational algorithm for estimating the parameters of the hole bottom zone from the results of measuring pressure and temperature at the bottom hole of a vertical well is suggested. The ambiguity of determining the permeability and of the hole bottom zone radius depending on the original information is shown.

The changes of macular microstructure in large idiopathic macular hole after vitrectomy combined with internal limiting membrane transplantation or internal limiting membrane peeling

Objective To observe the different changes of macular microstructure in patients with large idiopathic macular hole (IMH) treated with vitrectomy combined with internal limiting membrane (ILM) transplantation or not. Methods Forty eyes in 40 consecutive patients with giant IMH (≥500 μm) were included in the study. Twenty eyes received vitrectomy with ILM transplantation (ILM transplantation group) and others with ILM peel off (ILM removal group). During the operation, a proper size of the ILM was removed and filled in the bottom of the macular hole. The age, duration of disease and the ocular laterality of the two groups of patients were not statistically significant (P>0.05). Minimum resolution angle in logarithmic (logMAR) best corrected visual acuity (BCVA) and frequency domain optical coherence tomography (SD-OCT) scan were examined. There was no statistically significant difference in logMAR BCVA, average defect diameter of photoreceptor ellipsoid (IS/OS) and average defect diameter of external limiting membrane (ELM) between two groups (t=0.128, 1.452, 1.321; P>0.05). The logMAR BCVA and SD-OCT were examined on 1, 3, 6, 12 months postoperatively. Results On 1 month after the surgery, there was no statistically significant difference in logMAR BCVA, average defect diameter of IS/OS and average defect diameter of ELM between two groups (t=1.226, 1.435, 1.018; P>0.05). On 3, 6, 12 months after the surgery, compared with ILM removal group, the logMAR BCVA (t=2.059, 2.871, 2.415) increased and the average defect diameter of IS/OS (t=2.070, 2.110, 2.121) and ELM (t=2.034, 3.647, 3.556) significantly reduced in ILM transplantation group (P 0.05). Conclusion Compared with vitrectomy combined with ILM peeling surgery, the diameter of IS/OS and ELM defect were significantly decreased after vitrectomy combined with ILM transplantation in the patients with large IMH. Key words: Retinal perforations/surgery; Vitreoretinal surgery; Macula lutea/physiopathology

Development of a mobile powered hole digger for orchard tree cultivation using a slider-crank feed mechanism

The powered hole digger is one of the most important orchard machines. The power consumption of its drill is an important factor affecting the performance and operation of the device. The drill power consumption of the digger at a constant feed rate is directly proportional to digging depth. This research discusses a newly designed powered hole digger using a slider-crank feed mechanism. The motion characteristics of the powered hole digger feeding mechanism was analysed. Additionally, an experiment was conducted to determine the characteristics of the drill power consumption. It can be concluded that there was a positive correlation between the drill power consumption and the powered hole digger feed rate. It was observed that when digging depth reached 200 mm, the drill power consumption reached the maximum power rating; subsequently the drill power consumption decreased with an increase of digging depth. When the drill reached the bottom of the hole, the power consumption of the new powered hole digger did not exceed the maximum designed power rating, hence the drill motor would not stall. Keywords: powered hole digger, crank-slider, drill power consumption, orchard tree DOI: 10.3965/j.ijabe.20160903.1784 Citation: Zong W Y, Wang J L, Huang X M, Yu D, Zhao Y B, Graham S. Development of a mobile powered hole digger for orchard tree cultivation using a slider-crank feed mechanism. Int J Agric & Biol Eng, 2016; 9(3): 48－56.

The effects of dub-off angle on chip evacuation in single-lip deep hole gun drilling

Without proper chip evacuation, gun drills will fail under intense thermal and mechanical loading during deep hole drilling of high temperature superalloys like Inconel 718. In gundrilling, the efficiency in evacuating chips is governed by the geometry of gun drills that defines the hydraulic boundary conditions for coolant and chip flow. In this paper, we propose a novel computational fluid dynamics (CFD) model that is capable to simulate and quantify the chip transportation behavior under high pressure coolant for drill geometry optimization. This is demonstrated through a case study on improving the shoulder dub-off design of commercial gun drills, which have a high tendency in trapping chips at the hole bottom. A more effective design criterion for the shoulder dub-off is thus proposed.

Tomographic inversion of near-surface Q factor by combining surface and cross-hole seismic surveys

The estimation of the quality factor Q plays a fundamental role in enhancing seismic resolution via absorption compensation in the near-surface layer. We present a new geometry that can be used to acquire field data by combining surface and cross-hole surveys to decrease the effect of geophone coupling on Q estimation. In this study, we drilled number of receiver holes around the source hole, each hole has different depth and each geophone is placed geophones into the bottom of each receiver hole to avoid the effect of geophone coupling with the borehole wall on Q estimation in conventional cross-hole seismic surveys. We also propose a novel tomographic inversion of the Q factor without the effect of the source signature, and examine its stability and reliability using synthetic data. We estimate the Q factors of the near-surface layer in two different frequency bands using field data acquired in the Dagang Oilfield. The results show that seismic absorption in the near-surface layer is much greater than that in the subsurface strata. Thus, it is of critical practical importance to enhance the seismic solution by compensating for near-surface absorption. In addition, we derive different Q factors from two frequency bands, which can be treated, to some extent, as evidence of a frequency-dependent Q.

Pentaerythritol Phosphate Melamine Salt, A New Aggregating Reagent for Oilfield Chemical Sand Control: Preparation, Properties, and Mechanism

The production of sands in oil well production has long been a crucial and thorny issue, but many related technologies are either costly or ineffective. This study introduced a new aggregating reagent, pentaerythritol phosphate melamine salt (PPMS for short), for controlling this problem. PPMS was the reaction product of pentaerythritol, phosphoric acid, and melamine, and there was an amine and a phosphate ester (both are positively charged) in its chemical structure. It could effectively change the ζ potentials of solid particles and help them aggregate through hydrogen bonds and electrostatic interactions, thereby aggregated particles could settle down at the bottom of the pore holes without severe formation permeability damage, which plays a remarkable role in eliminating the co-production of formation particles with oil. PPMS exhibited an excellent performance when the concentration was 0.8 wt % under 60 °C at a neutral environment, at which PPMS (positively charged) not only can highly condense the d...

Study on process and mechanism of laser drilling in water and air

An Inconel 718 sample was drilled in air and water using a diode-pumped nanosecond pulse laser with a pulse width of 8 ns and a wavelength of 532 nm. The surface, cross-section, and in-wall morphology were analyzed with a confocal laser scanning microscope and a scanning electron microscope. The pinnacle at the bottom of holes was more prone to exposure during water-assisted drilling. However, the in-wall of those holes was more rough. To better understand the mechanism of underwater drilling, the effects of pulse number, laser energy density, and water layer thickness were evaluated. An increase in the diameter of holes and a decrease in the debris and spatters on the surface were observed compared with the holes drilled in air. Also, an increase in the etching rate was observed under the high-energy condition. The physical effects of high pressure, fabricated by the bubbles and plasma in a water layer, were evaluated.

시스템 다이내믹스를 활용한 생태복원 설계 전략 - 2015 밀양시 자연마당 조성사업을 사례로 -

Jayeon Madang Development Project(JMDP) is a project being promoted by the Ministry of Environment to create a cultural space and a natural rest area within the city. Abuksan, located at Abuksan in Gyeongsangnam-do Miryang-si Naeil-dong, has suffered a substantial amount of environmental degradation over time, so the need for ecological restoration made it a natural choice for the location of the JMDP`s site. The purpose of this study is to examine ecological restoration design strategies used in Abuksan as part of the JMDP using system dynamics. The national archery center, hole, and arable land sites are key restoration areas in Abuksan that have faced with ecological problems. In this study, we identified the status of each site, determined key strategies being implemented, and designed based on the strategies implemented up to this point for solving problems associated with each sites through the use of causal loop diagrams. The results of the causal loop diagram analysis are as follows. The national archery center site was designed around strategies including planting green manure crops and introducing hugelkultur to reduce soil acidification and green network degradation. The hole site was designed as a constructed wetland based on the emergence of hygropreference vegetation, hydrated by rainwater collected at the bottom of hole, ecological and cultural benefits of such an environment. The arable land site restoration design was built around planting native vegetation on one part of the arable land site after soil quality improved and around restoration of grassland and a dry wetland on the other part of the site to reduce soil acidification, erosion, and green network degradation. This study is a significant attempt to apply principles of system dynamics to ecological restoration by providing the design strategies using comprehension of some problems in the ecosystem feedback loops, which has not been used before in general design processes for ecological restoration.

The Role of Rock-Chip Removals and Cutting-Area Shapes in Polycrystalline-Diamond-Compact-Bit Design Optimization

Summary Almost all previous cutter-force models assumed that cutting force was proportional to cutting area. Cutting-area-based single-cutter-force models were extensively used in polycrystalline-diamond-compact (PDC) -bit design optimization. This paper explains why cutting-area-based bit models failed to predict bit forces. A new cutter force model and a new bit model were developed and are discussed in the paper. In the new cutter force model, cutting force is a function of the shape of the cutting area. A common force model is developed for three types of cutting shapes. In the new bit model, 3D rock chips created in front of cutting face are modeled, meshed, and removed from the hole bottom by updating the hole bottom at each timestep. To validate the new model, four different PDC bits were designed, manufactured, and laboratory-tested under controlled conditions. Details from laboratory testing and field-test results are presented.

Analysis of Blind-Holes Applied in the Hole-Drilling Method for Residual Stress Measurements

The measurement of residual stress by the Hole-drilling method consists basically of drilling a blind-hole in the material under study. That relieves and redistributes the stresses around this hole promoting a surface deformation which adapts to a new equilibrium condition. This deformation provides, indirectly, information on the stress state to which the part or component is submitted. However, when not properly controlled, the drilling process can introduce additional stresses in the hole walls. Thus, the true value for the residual stress may be masked. Therefore, in this study, the hole-drilling process was investigated. More specifically, the influence of the feed and rotational speed on the hole walls and bottoms was evaluated. In addition, the hole geometry produced by the end-mill was investigated. Blind-holes were produced in the alloys A36 steel, AISI 304 L stainless steel and AA6061 aluminum, using an air-turbine, which provided an average rotational speed of 220,000 rpm. Only two feed rates were applied. The geometric measurement of both the tools and the holes produced showed that the hole geometry deviated from that recommended in ASTM E837-13a. Both decrements and increments in the hardness value for the hole walls and bottoms were observed, indicating that the process may have reached very high temperatures.

Electrostatic environment near lunar vertical hole: 3D plasma particle simulations

The dayside electrostatic environment near the lunar surface is governed by interactions among the solar wind plasma, photoelectrons, and the charged lunar surface, providing topologically complex boundaries to the plasma. Three-dimensional, particle-in-cell simulations are applied to recently discovered vertical holes on the Moon, which have spatial scales of tens of meters and greater depth-to-diameter ratios than typical impact craters. The vertical wall of the hole introduces a new boundary for both photo and solar wind electrons. The current balance condition established at a hole bottom is altered by the limited solar wind electron penetration into the hole due to loss at the wall and photoelectron current path connecting the hole bottom and wall surfaces. The self-consistent modeling not only reproduces intense differential charging between sunlit and shadowed surfaces, but also reveals the potential difference between sunlit surfaces inside and outside the hole, demonstrating the uniqueness of the near-hole electrostatic environment.