Drilling Method Research Articles

Geometric and Flow Characterization of Additively Manufactured Turbine Blades With Drilled Film Cooling Holes

Abstract As designers investigate new cooling technologies to advance future gas turbine engines, manufacturing methods that are fast and accurate are needed. Additive manufacturing facilitates the rapid prototyping of parts at a cost lower than conventional casting but is challenged in accurately reproducing small features such as turbulators, pin fins, and film cooling holes. This study explores the potential application of additive manufacturing and advanced hole drill methods as tools to investigate cooling technologies for future turbine blade designs. Data from computed tomography scans are used to nondestructively evaluate each of the cooling features in the blade. The resulting flow performance of these parts is further related to the manufacturing through benchtop flow testing. Results show that while total blade flow is consistent for all additively manufactured cooled blades, flow through smaller regions of the blades shows variations. Shaped film cooling holes manufactured using a high-speed electrical discharge machining method are within tolerance in the metering section but do not expand at the specified angle in the diffuser even though design tolerances are met. In contrast to high-speed EDM, conventional EDM holes are undersized throughout the length of the hole. Due to the additive manufacturing process, the surface roughness was higher on the additively manufactured parts in the current study than has been previously reported for surface roughness of commonly used cast components. The roughness results show high levels on thin walls, particularly at the trailing edge as well as on downskin surfaces. Internal surface roughness is higher than external roughness at most locations on the blade. The results of this study confirm that additive manufacturing along with advanced hole drilling techniques offers faster development of blade cooling designs.

The Influence of the Beyond Centers and Circles Time (BCCT)Approach and the DRILL Method on Children's CognitiveDevelopment in PAUD Ambon City

This research aims to determine the effects of the drill method, the BCCT approach, and a combination of both (the drill method and BCCT approach) in improving children’s cognitive development in PAUD Ambon City. This research uses an ex po facto research design. The subject of this research is the grades of Xaferius Kindergarten students in Ambon City in 2022 using the drill method on 15 students in the age group of 5-6 years. The learning outcomes of 25 students involved in this research was studied. The subjects in this research were homogeneous according to the characteristics of the learning method. The data were collected through 1). The scores obtained by students in the school on the pretest. 2). Conduct the treatment during 6 meetings. 3). Conduct the post test. In this research, the data collected was analyzed using analytical techniques: 1). Descriptive analysis was used to describe inferential variables, and 2). In inferential statistics, the level of students’ cognitive development of students who were given BCCT treatment was higher compared to the group of students who were given drill method treatment. Through the test criteria, if tcount ≤ ttable then H0 is accepted, it turns out tcount ≤ ttable, is -23,216 > 0.000, so H0 is rejected and H1 is accepted. Where the calculated t value is greater than the r table, it indicates that there are differences between the two groups so that the BCCT learning approach is good to use in developing the cognitive development of children aged 5-6 years. Keywords: beyond centers and circles time (BCCT) approach, drill method, cognitive development

METODE GURU PENDIDIKAN AGAMA KRISTEN DALAM MEMBANTU SISWA TUNANETRA (GANGGUAN PADA PENGLIHATAN) DALAM BELAJAR

The purpose of this study is to find out and provide appropriate teaching methods for Christian Religious Education (PAK) teachers to help visually impaired students in learning. Because there are still Christian religious education teachers in teaching the visually impaired only use conventional methods (lectures) which are monotonous and less interesting. As a result, students often feel bored and have difficulty understanding the learning material. For this reason, this research uses a qualitative method with a literature research approach. Data was collected by reviewing various literature, articles, books, and related sources of information. The results show that Christian Religious Education teachers can use several teaching methods that are suitable for the characteristics of visually impaired students, such as the lecture method, question and answer method, discussion method, and drill method. In addition, Christian Religious Education teachers must give special attention, guide, and motivate blind students to help them learn. The conclusion of this research is that Christian Religious Education teachers must be able to apply a variety of appropriate and interesting teaching methods in an innovative, creative, and versatile manner to optimize the learning experience of blind students, making learning more effective and enjoyable. Appropriate teaching methods and supportive approaches significantly improve students' engagement and understanding of the teaching materials.

Fragmentation characteristics of abrasive particles for hard rock drilling with waterjet energy parameter

The use of abrasive waterjets (AWJs) for rock drilling offers advantages in urbanized areas, locations that are vulnerable to damage, and piling operations. However, the overall operational cost of AWJ systems remains high compared to that of conventional drilling methods, which constrains the long-term industrial application of AWJs. For instance, the abrasive costs account for over 60% of the total process cost, but the recycling of abrasives remaining after drilling could significantly reduce machining costs. In this study, the post-impact characteristics of abrasives were explored, aiming to enhance their recyclability. The physical properties and particle distribution of used abrasives vary depending on the jet energy, ultimately affecting their recyclability and recycling rate. The particle properties of used abrasives (particle size distribution, particle shape, and mean particle size) were compared under different waterjet energy variables (standoff distance (SOD) and water pressure) and test conditions (dry and underwater). Furthermore, the collision stages of the abrasive particles within a waterjet system were classified and analyzed. The results revealed that abrasive fragmentation predominantly occurred due to internal collisions within the mixing chamber. In addition, an attempt was made to optimize the waterjet parameters for an economical and efficient operation. The findings of this study could contribute to enhancing the cost-effectiveness of AWJ systems for rock drilling applications.

Effect of Ce co-doping on radiation resistance behavior and laser performance of Er/Yb/Ce co-doped high-phosphorous polarization-maintaining silica fiber

Er/Yb/Ce co-doped high-phosphorus silica fiber core glasses with varying Ce2O3 concentrations were prepared and systematically studied. Based on this research, optimized Er/Yb/Ce co-doped high-phosphorus polarization-maintaining silica fibers were subsequently fabricated using the modified chemical vapor deposition (MCVD) technique and hole drilling method. The study confirmed that there is an optimal range of Ce doping concentrations for spectral performance, Ce doping effectively suppressing the formation of P-related defects during X-ray irradiation, and the dynamic valence state transformation of Ce3+/Ce4+ ions during irradiation enhanced the radiation-resistant properties, as demonstrated through radiation-induced absorption (RIA), electron paramagnetic resonance (EPR), and L3-edge X-ray absorption near edge structure (XANES) spectra. The homemade fiber, with optimized element concentrations, exhibited high laser efficiency comparable to commercial high-power fibers. Furthermore, the radiation-induced background loss of the fiber was 0.16 dB/m under 60 krad γ-rays at a low dose rate of 100 rad/h, and the radiation-induced gain variation (RIGV) was 0.019 dB/krad.

The Chemerpil gravimagnetic anomaly as a modern reflection of the unique Precambrian volcanic-plutonic magnetite-gold mineralisation structure of the Ukrainian Shield (Middle Bug area)

The article is devoted to the peculiarities of genesis and mineralogical potential of Chemerpol iron-magnetite structure, its difference from other similar objects of Central Bug area. As an independent geological-geophysical object it was established according to the data of gravimetric and magnetometric survey of medium scale as a complex localised maximum of subisometric shape with diameter of 1.7 km and area of 2.8 km2. In regional structural and tectonic terms, this maximum is confined to the Sinitsiv block of the Golovanovsk suture zone. As of today, the Chemerpol structure has been sufficiently investigated by mapping drilling and various geophysical methods at the level of the crystalline basement surface. Based on the obtained data, the main petrophysical complexes involved in its structure have been determined. The industrial and mineralogical potential of the Chemerpolska structure is estimated at 100 million tons of magnetite quartzites and carbonate formations, as well as 2 tons of exogenous gold in the weathering crust. No estimates have been made of the underlying gold deposits. Copper mineralisation, represented by the natural copper, chalcopyrite and chalcosine, has been identified in the weathering crust and crystalline basement. By structural and tectonic features, petrophysical and mineralogical diversity, the Chemerpolska structure can be attributed to local pipe volcanic-magmatic objects. Its closest well-studied geological analogues may be such Precambrian "stratified" iron-oxide-gold-copper deposits as Solobot and others of the Carajas ore district in Brazil. For geological verification of new conclusions about the peculiarities of the Chemerpol structure and its actual ore potential, it is necessary to continue its study based, first of all, on the data of targeted structural exploration drilling and deep seismic and electrical exploration methods. The economic efficiency of extraction of the main mineral components of the Chemerpolska structure - gold and magnetite iron - can be increased due to the accompanying use of non-metallic calcifiers for the manufacture of sintering flux, soil deoxidation, raw materials for road pavement.

Upaya Peningkatan Keterampilan Passing Bawah Bola Voli Melalui Metode Drill

This The aim of this research is to find out whether the drill training approach can improve the volleyball passing skills of class VI-D students at SDN Lidah Wetan II/462 Surabaya. The aim of this classroom action research is to improve basic passing technique skills in volleyball. The research population was 30 students, and each student was sampled using the Total Sampling method. Data was collected using the lower passing skills research rubric. The results of the analysis show an increase in volleyball underpassing skills with an average score of 57, so the pre-cycle completion score is 43%. Completeness increased to 60% with an average score of 78 in cycle I. In cycle II, there were 25 students who completed, and the students' completeness score again increased to 83% with an average score of 84.5. These results show the effectiveness of the drill method approach in improving volleyball bottom passing skills

Heat Generation and Pain Assessment in Piezosurgery Versus Conventional Drilling for Implant Placement: A Systematic Review.

The development of new technologies in implant dentistry has led to the introduction of piezosurgery, which utilizes ultrasonic vibrations for micrometric and selective bone cutting. It is hypothesized to reduce trauma to bone tissue, thereby potentially improving the healing process compared to traditional drilling methods. This systematic review examines the differences in heat generation and pain perception between piezosurgery and conventional drilling techniques for dental implant placement. An extensive review of literature was performed using various databases, includingPubMed via MEDLINE, EBSCO, and Google Scholar. Out of an initial pool of 2,279 articles, nine studies met the predefined inclusion criteria and were included in the final analysis following title and abstract screening and subsequent full-text evaluation. The quality of the selected studies was rigorously assessed using the Risk of Bias (RoB 2.0), Risk of Bias in Non-randomized Studies - of Interventions (ROBINS-I), and Quality Assessment Tool for In Vitro Studies (QUIN) tools. Data pertaining to thermal effects and postoperative pain associated with piezosurgery relative to conventional drilling protocols were collected. The results indicated a significant reduction in postoperative pain with piezosurgery; however, the technique was associated with higher intraoperative temperatures during osteotomy. These findings provide valuable insights into the potential benefits and limitations of piezosurgery in dental implant procedures.

Investigation of the specific charge variations in determining the optimal methods for drilling and blasting of tunnels

In this research, in order to compare and select the optimum patterns, two parameters of specific charge and specific drilling are used. Two explosive substances, including ammonium nitrate and fuel oil (ANFO) and Amulet, are used to charge the holes located on the cross-section of the tunnels in order to advance by 3 meters. Also, the cross-section of the selected tunnels was 19, 28, 32, 40, 48, 50, 65, and 76 square meters with horseshoe, circle and D-shaped. The diameter of the explosive hole is 48 mm for the Norwegian method and 51 mm for the two energy balance models and the Swedish method to compare them. A total of 160 designs are prepared for three types of limestone, sandstone and marl. The results obtained for two parameters of specific charge and special drilling for the selected rock material are completely opposite. Also, in the Swedish methods, according to the Amulet, the values of the calculated parameters are close to the energy balance model. Finally, according to the geomechanical parameters of the rock, for the Swedish method and the energy balance model in charging with amulet explosives, the energy balance model and the Holemberg-Persson method are proposed in the optimal design for the tunnel drilling and blasting pattern. In addition, for the Norwegian method and the energy balance model in charging the holes with ANFO, the energy balance model is prior to the Norwegian method. The amount of stemming of holes in different parts of the tunnel face is less for the Swedish method than the Norwegian and energy balance models.

Determination of elastic modulus and anisotropy for rocks using digital drilling method

The main purpose of this study is to provide a digital drilling-based method for determining rock elastic modulus and evaluating the anisotropy. By considering a concept of crushed zone, the drilling response was characterized as the function of specific energy and drilling strength. On this basis, an equivalent elastic modulus was proposed to evaluate the rock elastic modulus. Moreover, an anisotropy index was proposed according to the difference in specific energy under different borehole directions. Digital drilling experiments were conducted for three lithologies at drilling directions namely 0, 60, and 120° (Based on vertical orientation), revealing the anisotropic effect exhibited in the rock. To validate the measurement of rock elastic modulus and its anisotropy, the compressive tests under same conditions were carried out. The results suggested that the proposed indicator provided an accurate evaluation for the rock's elastic modulus, with an error margin of less than 10%. Drilling-based anisotropy is identified in the drilling response, especially the critical state between cutting and friction. The statical indicator CoV (coefficient of variation) was utilized to characterize the anisotropy along the borehole. This research's innovation lies in providing an approach to evaluating rock anisotropy and determining its elastic modulus by considering the drilling response.

Hole position correction method for robotic drilling based on single reference hole and local surface features

Hole position correction method for robotic drilling based on single reference hole and local surface features

Comparing Modified Light Bulb with Multiple Drilling Methods in Treating Non-Traumatic Femoral Head Osteonecrosis: A Cohort Study

Comparing Modified Light Bulb with Multiple Drilling Methods in Treating Non-Traumatic Femoral Head Osteonecrosis: A Cohort Study

TBM Advanced Geological Prediction via Ellipsoidal Positioning Velocity Analysis

Traditional seismic wave-based tunnel advanced geological forecasting techniques are primarily designed for drill and blast method construction tunnels. However, given the fast excavation speed and limited prediction space in tunnel boring machine (TBM) construction tunnels, traditional methods have significant technical limitations. This study analyzes the characteristics of different types of TBM construction tunnels and, considering the practical construction conditions, identifies an effective observation system and data acquisition method. To address the challenges in advanced forecasting for TBM construction tunnels, a method of ellipsoid positioning velocity analysis, which takes into account the constraints of three-component data directions, is proposed. Based on the characteristics of the advanced forecasting observation system, this method compares the maximum values on the spatial isochronous ellipsoidal surface to determine the average velocity of the geological layer rays, thereby enabling accurate inversion of the spatial distribution ahead. Utilizing numerical simulation, a model for the advanced detection of typical unfavorable geological formations is established by obtaining the wave field response characteristics of seismic waves in three-dimensional space, and the velocity structure of the model is retrieved through this velocity analysis method. In the engineering example, the fracture property, water content, and weathering degree of the surrounding rock are predicted accurately.

Strategic Management Approaches for Enhancing English-Speaking Proficiency in Language Education

This study explores effective strategies for teaching English speaking skills and the factors that influence implementing these strategies. The study discussed the strategies used in speaking learning, why they are chosen, and their implications for students speaking success. The strategies referred to in this study encompass methods, resources, and media used in achieving success in learning to speak English. The research method employed is qualitative with a case study approach. The study was conducted in March 2023 at some schools and English courses, with ten teachers serving as informants. Data collection was carried out through indirect interviews via WhatsApp and GoogleForm. The main findings show that role-play and chain drill methods are the most frequently applied strategies and are considered effective in improving students speaking skills. The main factors that influence the use of these strategies include students interest and the relevance of the material. The implications of this study highlight the importance of selecting strategies that are appropriate to students characteristics and learning contexts, and this study shows the need to adapt teaching methods based on the availability of resources and environmental support. The results of this study provide insights for educators to design and implement more effective speaking learning strategies and encourage further discussion on innovation in English language learning.

Analysis of the Effectiveness of Learning Methods in Improving the Ability to Read Al Qur’an in Elementary School Age in Indonesia

Many people read the Qur'an without paying attention to the rules of reading (tajwid), so that in reading it many are wrong, this can change the meaning of what is actually. Based on the background description above, the author intends to examine the extent to which the methods used in Indonesia are effective in learning the Qur'an for elementary school children. The aims of this study through the Literature Review method is to draw conclusions from the most effective to the least effective methods in learning the Qur'an for elementary school children. The result of this research is there are 14 different methods of learning the Qur’an over the last 4 years among others : Methods Jibril, Iqra’, Tilawah, Talaqqi, Bil Qalam, Musyafahah, Tajdid, Drill, Yanbu’a, Tartil, Tahsin, Wafa, Qiroati and Ummi method. Each learning method has different advantages, disadvantages, opportunities, and threats. The ratio of effectiveness is seen from two assessments based on the efficacy points and the theory of Bloom's Txonomi. The conclusion is that this study has three categories of methods in the study of the Qur'an that improve the ability to read is the most effective, effective and less effective method.

Upaya Meningkatkan Kemampuan Passing Bawah Bola Voli Melalui Media Dinding Sekolah dengan Metode Drill Pada Siswa Kelas IV SD Negeri Salem 02

This research aims to improve students' bottom passing skills using school wall media using the Drill method. This research is Classroom Action Research which was carried out in 2 cycles. The research was carried out in April of the 2023/2024 academic year. Researchers collaborate with teachers and colleagues. This research procedure refers to the Kemmis & Mc model. Taggart which includes planning, implementing actions, observing and reflecting. The research subjects were fourth grade students at SD Negeri Salem 02, totaling 20 students, 9 male students and 11 female students. The instruments used are teacher activity observation assessment sheets, student activity observation sheets, and performance assessment sheets. The results of the research showed that there was an increase in cooperation in the first cycle, namely students' bottom passing skills using school wall media. Of the 20 students at meeting 1, there were 10 students (50%) who had entered the criteria for completion, while at meeting 2 there were 12 students (60%) who had entered. in the complete criteria. In cycle II, students' underpassing skills used school wall media. Of the 20 students at meeting 1, 15 students (75%) had entered the completion criteria, while at meeting 2 there were 18 students (90%) had entered the completion criteria. Based on these data, it can be concluded that the use of the Drill method with school walls can improve students' bottom passing skills in class IV of SD Negeri Salem 02, Salem District, Brebes Regency.

Antimicrobial Efficacy of Chemomechanical Carie Removal Agents-A Systematic Integrative Review.

Dental caries is the most common oral disease in the world. When treatable, the drilling method continues to be used. This technique has its disadvantages because it is invasive and nonspecific. Chemomechanical carious tissue removal agents (CCRAs) such as Carisolv™ or Papacarie® are non-invasive products that allow for the specific elimination of infected dentin. On the other hand, cariogenic bacteria are largely responsible for the initiation and development of lesions. The aim is to analyze whether CCRAs have a relevant antimicrobial effect on cariogenic bacteria. A bibliographic search strategy was carried out in online databases using PRISMA 2020. The evaluation of the antibacterial efficacy of CCRAs was carried out through the analysis of the reduction in CFUs of cariogenic bacteria, and the presence of bacterial deposits, TVC, SVC and LVC by comparison with conventional drilling methods. The results showed that the percentage of reduction in TVC, SVC and LVC for each agent is mostly high, but not significantly different from mechanical methods. The best results were found with CCRAs when compared to polymeric drills. The results also showed that there is a lack of methodological standardization. CCRAs have been shown to have a relevant antimicrobial effect on cariogenic bacteria; however, more studies need to be carried out using standardized methodologies.

STRATEGI IMPLEMENTASI BUKU “BELAJAR BAHASA ARAB TERPADU” DALAM PEMBELAJARAN BAHASA ARAB DI SMP IT PELITA PROBOLINGGO

This research aims to analyze the strategy for implementing “Belajar Bahasa Arab Terpadu” books in Arabic language learning at Pelita Integrated Islamic Junior High School Probolinggo. The research method used is descriptive qualitative using observation, interviews and documentation as data collection techniques. Triangulation is used to test the validity of the data obtained. The results of the research show that teachers use various methods in teaching, such as the hiwar method for maharah kalam, the qiro'ah jahriyah and saamitah methods for maharah qiroah, the audio-lingual method for istima', and the drill method in maharah kitabah teaching. The supporting factor in this implementation is information technology (IT) support, while the inhibiting factor is the diversity of student backgrounds

Enhancement of basic tennis technical skills: Game and drill training methods of male athletes reviewed by age group

Background Problems: The lack of variety in exercises applied by coaches makes players feel bored, so they must be given training variations by looking at training methods that significantly improve basic tennis technique skills between game training methods and drills. Research Objectives: This study aims to determine differences in the effect of game and drill training methods on improving basic tennis technical skills based on the age groups of 10-12 years and 13-15 years. Methods: In this context, the method used was experimental research with a 2x2 factorial design. The sample consisted of 24 male athletes in Lampung who were separated into 4 groups. Findings and Results: (i) There are differences in the effect of game practice and drill methods on improving basic tennis technique skills. (ii) There is a difference in improving basic tennis technique skills between the age groups of 10-12 years and 13-15 years. (iii) There is an influence of interaction between training methods and age groups on improving basic tennis technique skills. Conclusion: The age group 10-12 years is more appropriate if given the game training method, and the age group 13-15 years is more appropriate if given the practice training method. The findings of this study provide an important contribution by highlighting the importance of both applied training methods for basic tennis technique. This training method is also adapted for age-based characteristics. Therefore, the recommendation to use game and drill training methods as part of tennis training can help athletes cope with intense playing conditions. Based on the analysis above, the novelty of the research developed by the researcher was two exercise methods compared, two age groups that were sampled, and research instruments using International Tennis Number (ITN) On Court Assessment. Researchers used game and drill training methods that could affect the sample after treatment. Different from previous research, the sample used was male athletes aged 10-15 years.

Laser and mechanical micro-drilling for aerospace applications

Traditional laser percussion drilling encounters challenges related to poor geometry and thermal defects. At the same time, mechanical micro-drilling while generating high-quality holes, faces issues such as premature drill breakage and difficulty drilling at acute angles. This review paper introduces a novel approach to micro-drilling Inconel 718 alloy sheets at acute angles by combining sequential laser and mechanical drilling. The study showcases the feasibility and fundamental characteristics of this innovative technique. Results indicate that the sequential laser-mechanical micro-drilling approach mitigates the drawbacks associated with laser-drilled holes, leading to reduced burr size, decreased machining time, and increased tool life when compared to conventional mechanical drilling methods. This advancement holds promise for enhancing precision and efficiency in aerospace applications, paving the way for improved manufacturing processes in the aerospace industry.