scholarly journals Procedure of computation and automatic marking of drill hole spacing at excavation of horizontal workings

2020 ◽  
Vol 177 ◽  
pp. 01011
Author(s):  
Maxim Kononenko ◽  
Ruslan Ganiev ◽  
Roman Kuzminykh
Keyword(s):  
Drill Hole ◽  
Modular Architecture ◽  
Clear Trend ◽  
Blasting Pattern ◽  
Geometrical Features ◽  
Effective Option ◽  
Calculation Results ◽  
Real Objects ◽  
Time Required ◽  
Drill Holes

Contemporary approaches and techniques impacting subsurface penetration performance and penetration rate are studied and analyzed. Two main dimensions are identified, and the works performed during operation were compared. A solution based on implementation of modular architecture of the system with optional connection of modules, performing computations according to various techniques, enabling comparison of calculation results and selection of the most effective option, is proposed. A computational experiment based on real-objects data was conducted. The factors effecting drilling-and-blasting operations were identified during its course. A model designing the optical projections over targeted drill holes is also obtained. The proposed approach is more effective and accurate than manual application of drill hole spacing by paint; in addition, is saves a lot of time required for setting-up. Another highlighted advantage of the developed approach is high quality and accuracy at marking of the drill hole spacing for blasting pattern in accordance with geometrical features of the surfaces, vs. approaches and techniques used at preparation to drilling earlier. Aside from that, a clear trend of consistent improvement and perfection by means of application of intelligent algorithm is observed in this scope.

PATTERNS OF GASTROPOD MOLLUSK PREDATION ON BIVALVE MOLLUSKS ALONG THE UPPER TEXAS GULF COAST

2018 ◽  
Vol 70 (1) ◽  
Author(s):  
Serena J. Randolph ◽  
Alan D. Maccarone
Keyword(s):  
Shell Thickness ◽  
Prey Species ◽  
Gulf Coast ◽  
Prey Selection ◽  
Drill Hole ◽  
The United States ◽  
Hole Diameter ◽  
Bivalve Mollusks ◽  
Collection Site ◽  
Drill Holes

Abstract Predation on bivalve mollusks by gastropod mollusks is common in coastal regions of the United States; however, few previous studies have examined whether drilling gastropods exhibit prey selection. In 2016, shells with small holes drilled by as many as two gastropod predators were collected at three sites separated by 30 km along the Texas Upper Gulf Coast on the Bolivar Peninsula (29° 40′N, 94° 90′W). The likeliest predators in these waters are the southern oyster drill (Stramonita haemastoma Linnaeus 1767) and the moon snail (Neverita duplicate Say 1822). Collected shells were identified to species and measurements were taken to examine statistical relationships between predators and prey species. These measurements included drill-hole diameter, shell thickness, drill-hole completeness, number of drill attempts, and collection site. Across the three locations, 17 different species of shells with drill holes were collected; of these, we focused on the ten most abundant species (n = 277 shells). The sample showed high variation in drill-hole diameter, shell thickness, and drill-hole completeness. Both the total number of holes and mean drill-hole diameter differed significantly among prey species (ANOVA, both P < 0.0001). In addition, drill-hole diameter correlated directly with prey shell thickness (P < 0.0001). Shells whose drill holes were complete were significantly thinner than shells with incomplete holes (P < 0.0001). Mean prey shell thickness, mean drill-hole diameter, and mean number of drill holes all differed significantly by collection site (all P < 0.0001). Ecological and morphological implications related to gastropod predation on mollusks are discussed.

Large Drill Holes Are Still Present in the Long Term After Arthroscopic Bankart Repair With Absorbable Tacks: An 18-Year Randomized Prospective Study

2020 ◽  
Vol 48 (8) ◽  
pp. 1865-1872
Author(s):  
Christina Chrysanthou Constantinou ◽  
Ninni Sernert ◽  
Lars Rostgård-Christensen ◽  
Jüri Kartus
Keyword(s):  
Study Groups ◽  
Drill Hole ◽  
Ct Images ◽  
Bankart Repair ◽  
Plain Radiographs ◽  
Arthroscopic Bankart Repair ◽  
Absorbable Tacks ◽  
Drill Holes

Background: Studies have demonstrated the development of an osseous reaction at the drill sites of anchors after arthroscopic shoulder surgery. Purpose: To investigate the drill-hole size at 18 years after arthroscopic Bankart repair using either fast polygluconate acid (PGA) or slow polylevolactic acid (PLLA) absorbable tacks and to compare the functional outcomes and development of osteoarthritis. Study design: Randomized controlled trial; Level of evidence, 2. Methods: 40 patients with unidirectional anterior shoulder instability, treated with arthroscopic Bankart repair, were randomized into the PGA group (n = 20) or the PLLA group (n = 20). Plain radiographs of both shoulders, as well as computed tomography (CT) images of the operated shoulder, were used to evaluate the drill-hole size, volume, and degenerative changes. Functional outcomes were assessed by use of the Rowe score, Constant score, and Western Ontario Shoulder Instability (WOSI) index. Results: Of the 40 patients, 32 patients returned for the follow-up (15 PGA and 17 PLLA). No significant differences were found in the population characteristics between the study groups. The mean follow-up time was 18 years for both groups. No significant differences were seen in range of motion, strength in abduction, or Constant, Rowe, and WOSI scores between the groups. Recurrence rate was 33% in the PGA group and 6% in the PLLA group during the follow-up period ( P = .07). The drill-hole appearance on plain radiographs (invisible/hardly visible/visible/cystic) was 11/2/2/0 and 6/5/5/1 for the PGA and PLLA groups, respectively ( P = .036). The mean ± SD drill-hole volume as estimated on CT images was 89 ± 94 and 184 ± 158 mm3 in the PGA and PLLA groups, respectively ( P = .051). Degenerative changes (normal/minor/moderate/severe) on plain radiographs were 7/4/4/0 and 3/8/5/1 for the PGA and PLLA groups, respectively ( P = .21), and on CT images were 5/7/3/0 and 2/6/6/3 for the PGA and PLLA groups, respectively ( P = .030). Conclusion: This long-term follow-up study demonstrated that the PLLA group had significantly more visible drill holes than the PGA group on plain radiographs. However, this difference was not evident on CT imaging, with both groups having several visible cystic drill holes and a substantial drill-hole volume defect. No significant differences were found between the study groups in terms of clinical outcomes.

Investigation of Drill Hole Quality of Multi-Layer PWBs for High Current Capacity

2007 ◽  
Author(s):  
Eiichi Aoyama ◽  
Toshiki Hirogaki ◽  
Keiji Ogawa ◽  
Kenichi Mori ◽  
Yuusuke Itagaki
Keyword(s):  
Copper Foil ◽  
Drill Hole ◽  
Foil Thickness ◽  
Electronic Systems ◽  
Hole Quality ◽  
Large Current ◽  
Drill Holes ◽  
Objective Variable ◽  
Chip Load ◽  
Through Hole

Recently, as a result of changes in the automotive industry, a large number of electronic systems have been installed in cars. The thickness of the copper foil used for printed wiring boards (PWBs) has tended to increase in response to the large current capacity required for such electronic equipment. Therefore, the nail head generated in the inner layer copper foil was examined with respect to the influence of the thickness of the copper foil on the through-hole quality. In the present study, the size of the nail head generated in the copper foil after drilling a through hole was used as the objective variable. The explaining variables included drill wear, frequency, feed rate, chip load, drill temperature, copper foil thickness, copper foil cutting distance, and number of drill holes. We investigated the relationships between these explaining variables and the objective variable and found that the copper foil cutting distance was a very important parameter in generating nail heads. In addition, we found that the chip load is important for controlling nail head generation.

Geometric Optimization of Crack Arresting Holes in an Operational Component

2010 ◽  
Author(s):  
Onome Scott-Emuakpor ◽  
Tommy George ◽  
Charles Cross
Keyword(s):  
Crack Growth ◽  
Fatigue Testing ◽  
Growth Arrest ◽  
Real Life ◽  
Design Procedure ◽  
Drill Hole ◽  
Geometric Optimization ◽  
Foreign Object Damage ◽  
Square Plate ◽  
Drill Holes

Crack-growth arrest is analyzed in this study with the simulation of real-life fatigue of a structure during service. Unlike conventional crack-growth arrest studies, this research does not analyze an opening mode (Mode I) crack extension from an induced crack-tip specimen. The work in this analysis focuses on designing drill-holes into a structure, without a preexisting crack, that will operate under cyclic loads. The purpose of the holes is to prevent through-crack propagation if a crack initiates during service of the structure. Prevention reduces the possibility of a phenomenon like Foreign Object Damage (FOD) by a fragment of a fractured structure in heavy operating machinery and over-looked cracks during routine inspections. The drill-hole design procedure for crack growth arrest explores the use of two, three and four-hole configurations as well as the effect of inserting hard Viton-rubber pins into each drill hole of a square plate test specimen. Each specimen configuration is geometrically designed with the following in mind: minimized the hole-to-fatigue zone stress ratio, minimize damping loss between the original and the new designs with holes and pins, and experimentally validating the theory of the crack arresting methods. The geometric optimization for the square plate specimen was developed in accordance with a vibration-based fatigue testing method for uniaxial bending, which is the benchmark method for this study.

A new technique for sampling water and gas from deep drill holes

1986 ◽  
Vol 23 (9) ◽  
pp. 1450-1454 ◽  
Author(s):  
Pekka A. Nurmi ◽  
Ilmo T. Kukkonen
Keyword(s):  
Drill Hole ◽  
Back Pressure ◽  
New Technique ◽  
Dissolved Gases ◽  
A New Technique ◽  
Drill Holes ◽  
Water Profile

A new technique for sampling water and gas from deep (500–1500 m) drill holes is described. The principle of the technique is to raise a continuous column of water inside a thin polyamide tube with a back-pressure valve at the lower end and with shutoff valves every 50 m. The equipment is easily assembled from standard parts. Sampling can be performed by three people without mechanical apparatus. Descent to 1000 m takes 2 hours and retrieval 1 hour. The method makes it possible to obtain a practically undisturbed continuous water profile from a drill hole. Dissolved gases remaining inside the tube can be sampled at the surface. To demonstrate the efficiency of the technique, selected results from the deepest drill hole in Finland, having a vertical depth of 1100 m, are presented.

scholarly journals MPFL SURGICAL SIMULATION WITH FEMORAL DRILL HOLE ALLOWING FOR ADJUSTABLE GRAFT TENSION

2019 ◽  
Vol 7 (3_suppl) ◽  
pp. 2325967119S0004
Author(s):  
Cooper Shea ◽  
Audrey Rustad ◽  
Nicolas G. Anchustegui ◽  
Stockton Troyer ◽  
Aleksei Dingel ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Surgical Simulation ◽  
Femoral Condyle ◽  
Drill Hole ◽  
3D Models ◽  
Mpfl Reconstruction ◽  
Exit Point ◽  
Graft Tension ◽  
Patella Fractures ◽  
Drill Holes

Background: In skeletally immature patients, the MPFL femoral origin as near or below the physis in most age groups. Although MPFL reconstruction procedures that employ patella drill holes facilitate graft tension adjustment, recent research demonstrates significant risk of patella fractures if patella drill holes are utilized. For this reason, the use of patella drill holes may be best avoided, but this technical alteration makes graft tension fixation more challenging during MPFL reconstruction in the skeletally immature. The purpose of this study was to evaluate the feasibility of developing a physeal respecting femoral drill for the MPFL origin with surgical model simulation, which allows for graft tensioning during MPFL reconstruction. Methods: Pediatric cadaveric specimens (n=5) were dissected by a group of fellowship trained pediatric and/or sports orthopaedic surgeons, and these specimens were then subject to CT Scans for the creation of 3D models. Specimens, aged 7, 9, 10, 11 and 11 years, were used to develop surgical simulations. CT Scans were loaded into Osyrix, converted to appropriate file structure, and then 3D models were loaded into Blender (Stichting Blender Foundation, Buikslotermeerplein 161, 1025 ETAmsterdam, the Netherlands). These models were used to evaluate 3D models of the knee, with placement of medial femoral condyle drill holes starting at the MPFL femoral origin, and entering the joint just anterior to the PCL femoral origin. The anatomic goals of the surgical simulation include: 1. Place drill hole at the MPFL origin on the femur. 2 Enter the intercondylar notch region of the femur anterior to the PCL origin allowing for arthroscopic visualization. 3. avoiding the articular cartilage on the medial femoral condyle. 4. Avoid the femoral physis throughout the course of drilling from the femoral MPFL Origin point to the entry location into the intercondylar notch. In the specimens, a full length drill hole was placed with either a 4 or 5 mm drill hole. Results: All specimens were subject to the surgical modeling and simulated drill hole placement. In each case, a drill hole was successfully placed meeting all the goals of the simulation: 1. Starting Point at MPFL, 2. Exit point anterior the PCL origin, 3. Exit point posterior to the articular cartilage, and 4. Avoidance of direct physeal injury. Figures 1 and 2. Conclusion: Setting graft tension during MPFL reconstruction is one of the significant technical challenges during MPFL reconstruction, and appropriate graft position and tension may be the most critical elements of successful MPFL reconstruction. Historically, graft tension has been set on the patella, using drill holes for the MPFL attachment point on the patella, but this technique has been associated with patella fractures. In order to allow for adjustment of graft tension on the femoral side of the MPFL graft during surgical reconstruction, a surgical simulation was developed to confirm the anatomic appropriateness and safety of placement of femoral drill holes which allow for adjustment of graft tension. This surgical simulation model confirms that MPFL femoral origin anatomy can be reproduced with injury to the physis, the PCL, or the articular cartilage of the femoral condyle. This drill hole and graft can be visualized arthroscopically and allow for appropriate graft tensioning during the procedure. [Figure: see text][Figure: see text]

COMBINED GEOELECTRICAL AND DRILL‐HOLE INVESTIGATIONS FOR DETECTING FRESH‐WATER AQUIFERS IN NORTHWESTERN MISSOURI

Geophysics ◽  
1974 ◽  
Vol 39 (3) ◽  
pp. 340-352 ◽  
Author(s):  
Reinhard K. Frohlich
Keyword(s):  
Fresh Water ◽  
Salt Water ◽  
Salt Content ◽  
Drill Hole ◽  
Stream Channels ◽  
Water Conductivity ◽  
Near Surface ◽  
Appreciable Increase ◽  
Lower Permeability ◽  
Drill Holes

A geoelectrical investigation was conducted in an area of northwestern Missouri which was previously explored by drill holes. The purpose of the survey was to evaluate the effectiveness of the method in locating potable groundwater. It was found that resistivity depth soundings using the Schlumberger arrangement can partially localize and determine the thickness and depth of both near‐surface and basal fresh‐water‐bearing gravel bodies in glacial deposits. The basal gravel is usually confined to preglacial stream channels and has a particular importance as a fresh‐water aquifer. Only in a few cases does the resistivity increase at the depth of the bedrock. More often the depth soundings show an appreciable increase of resistivity at a depth well within the bedrock. High permeability and porosity at a lower water conductivity in the gravel is compensated by lower permeability and porosity at a higher water conductivity in the bedrock. This can explain why the formation resistivities found from depth soundings are basically the same. An increase of resistivity in the deeper bedrock occurs due to a tightening of fissures containing salt water. In one particular well, which penetrates a basal gravel, it can be shown that the salt content of the well water originates from salt water encroachment, most likely from the bedrock.

The chemistry and isotopic composition of saline groundwaters from the Sudbury Basin, Ontario

1982 ◽  
Vol 19 (4) ◽  
pp. 645-661 ◽  
Author(s):  
S. K. Frape ◽  
P. Fritz
Keyword(s):  
Drill Hole ◽  
Shallow Waters ◽  
Isotopic Data ◽  
Subsurface Environment ◽  
Sulphide Ores ◽  
Groundwater Samples ◽  
Isotopic Analyses ◽  
Saline Waters ◽  
Shallow Wells ◽  
Drill Holes

The results of geochemical and isotopic analyses are discussed for groundwater samples obtained from five mines and several shallow wells in the Sudbury Basin. Mine samples were usually obtained from abandoned diamond drill holes or fractures, which were found from depths of 152–1219 m (500–4000 ft). Two very distinctive water types are recognized in the subsurface environment. Fresh to brackish waters were found from surface to approximately 800 m (2600 ft) in depth. However, below 914 m (3000 ft) very saline or briny waters occur at most of the localities sampled. The geochemistry of the shallow waters shows gradual increases in concentration for most elements; locally effects from the proximity of sulphide ores or drill hole grouting were observed. Isotopic data (2H, 18O, and tritium) indicate that the major component of these waters is less than 30 years of age and represents local meteoric waters. The saline waters have dissolved loads often in excess of 200 g∙L−1 and are dominated by calcium and chloride. The chemistry and isotopic contents of the Sudbury brines are very distinct from highly saline waters or brines of sedimentary or geothermal origin. The brines appear to represent very old, stagnant "groundwaters," which may have undergone prolonged chemical and isotopic alteration since their original emplacement. At the present a variety of possible origins for the deep Sudbury waters can be postulated, but most models for brine formation found in the literature are unsatisfactory to explain the origin and genesis of these deep Canadian Shield brines.

scholarly journals Productivity of Column Casting Heavy Equipment in the Construction of 31 Sudirman Suites Makassar Apartment

2021 ◽  
Vol 3 (3) ◽  
pp. 10-20
Author(s):  
Fedelia Randan ◽  
Junus Mara ◽  
Lintje Tammu Tangdialla
Keyword(s):  
Construction Projects ◽  
Material Transfer ◽  
Work Time ◽  
Tower Crane ◽  
Heavy Equipment ◽  
Equipment Construction ◽  
Calculation Results ◽  
Real Value ◽  
Time Required ◽  
Equipment Operator

In the world of heavy equipment construction projects it is important to help complete human work. Tower Crane is one of the tools in the implementation of construction projects. In the implementation of the construction of Apartment 31 Sudirman Suites Makassar, there are 2 Tower Crane tools that operate with limited work time due to covid 19. This research was carried out by direct observation in the field and calculating the real value of the specifications to compare productivity. Tower Crane productivity is the result achieved or output, namely the amount of material moved by Tower Crane with all resources or inputs, namely the time required for material transfer. Based on the calculation results that the productivity of the specification is greater than the productivity of observations in the field, this is due to constraints on the weather that occurs and the equipment operator. For productivity, the average obtained on the 4th floor is 71,544 (%) and on the 5th floor it is obtained that is 73,727 (%).

Sign in / Sign up

Export Citation Format

Share Document