High-Efficiency Cut Blasting with Shell Radial Shaped Charge in Laboratory-Scale Blasting

2015 ◽  
Vol 1094 ◽  
pp. 445-450 ◽  
Author(s):  
Wei Chen ◽  
Hong Hao Ma ◽  
Zhao Wu Shen ◽  
De Bao Wang

Due to the inefficiency problem of the cut blasting in rock excavation and rock breaking, a shell radial shaped charge device was proposed based of the ideal of ‘cutting to slotting’ and it was validated through experiments. For this device, the shell materials are used to be shaped materials and multiple shaped ring is designed on the circular tube. It can not only reduce charge quantity but also raise the utilization ratio of explosive energy. After explosion, multiple radial shaped charge jets can be formed along the axial line in sequence and then the surrounding rock mass would be cracked. The crack network will be formed along with the further extension of the fraction under the action of quasi static loading of detonation gas. The shell radial shaped charge device was tested through the cut blasting model experiment. Experimental results show that the utilization ratio of blasting hole nearly approaches 98% with this device. The blasting efficiency and cyclical footage can be improved effectively and the cost of drifting can also be reduced.

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Muhammad Ashar Naveed ◽  
Muhammad Afnan Ansari ◽  
Inki Kim ◽  
Trevon Badloe ◽  
Joohoon Kim ◽  
...  

AbstractHelicity-multiplexed metasurfaces based on symmetric spin–orbit interactions (SOIs) have practical limits because they cannot provide central-symmetric holographic imaging. Asymmetric SOIs can effectively address such limitations, with several exciting applications in various fields ranging from asymmetric data inscription in communications to dual side displays in smart mobile devices. Low-loss dielectric materials provide an excellent platform for realizing such exotic phenomena efficiently. In this paper, we demonstrate an asymmetric SOI-dependent transmission-type metasurface in the visible domain using hydrogenated amorphous silicon (a-Si:H) nanoresonators. The proposed design approach is equipped with an additional degree of freedom in designing bi-directional helicity-multiplexed metasurfaces by breaking the conventional limit imposed by the symmetric SOI in half employment of metasurfaces for one circular handedness. Two on-axis, distinct wavefronts are produced with high transmission efficiencies, demonstrating the concept of asymmetric wavefront generation in two antiparallel directions. Additionally, the CMOS compatibility of a-Si:H makes it a cost-effective alternative to gallium nitride (GaN) and titanium dioxide (TiO2) for visible light. The cost-effective fabrication and simplicity of the proposed design technique provide an excellent candidate for high-efficiency, multifunctional, and chip-integrated demonstration of various phenomena.


Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1105
Author(s):  
Antonio D. Martinez-Perez ◽  
Francisco Aznar ◽  
Guillermo Royo ◽  
Santiago Celma

In the current state of the art, WiFi-alike standards require achieving a high Image Rejection Ratio (IRR) while having low power consumption. Thus, quadrature structures based on passive ring mixers offer an attractive and widely used solution, as they can achieve a high IRR while being a passive block. However, it is not easy for the designer to know when a simple quadrature scheme is enough and when they should aim for a double quadrature structure approach, as the latter can improve the performance at the cost of requiring more area and complexity. This study focuses on the IRR, which crucially depends on the symmetry between the I and Q branches. Non-idealities (component mismatches, parasitics, etc.) will degrade the ideal balance by affecting the mixer and/or following/previous stages. This paper analyses the effect of imbalances, providing the constraints for obtaining a 40 dB IRR in the case of a conversion from a one-hundred-megahertz signal to the five-gigahertz range (upconversion) and vice versa (downconversion) for simple and double quadrature schemes. All simulations were carried out with complete device models from 65 nm standard CMOS technology and also a post-layout Monte Carlo analysis was included for mismatch analysis. The final section includes guidelines to help designers choose the most adequate scheme for each case.


2012 ◽  
Vol 239-240 ◽  
pp. 1522-1527
Author(s):  
Wen Bo Wu ◽  
Yu Fu Jia ◽  
Hong Xing Sun

The bottleneck assignment (BA) and the generalized assignment (GA) problems and their exact solutions are explored in this paper. Firstly, a determinant elimination (DE) method is proposed based on the discussion of the time and space complexity of the enumeration method for both BA and GA problems. The optimization algorithm to the pre-assignment problem is then discussed and the adjusting and transformation to the cost matrix is adopted to reduce the computational complexity of the DE method. Finally, a synthesis method for both BA and GA problems is presented. The numerical experiments are carried out and the results indicate that the proposed method is feasible and of high efficiency.


2011 ◽  
Vol 204-210 ◽  
pp. 1415-1418
Author(s):  
De Jiang Zhang ◽  
Na Na Dong ◽  
Xiao Mei Lin

By studying the conventional algorithm of contour extraction, a new method of contour extraction in blood vessel of brain is proposed based on the MOC maximum optimization cost. First of all, the theory computes the gray differential of the image by conventional differential method to build the cost space. Then, by using dynamic programming theory, the maximum optimization cost curve in the space is extracted to serve as the specific cerebrovascular profile. The experiments show that this method ensures high efficiency in extracting cerebrovascular contour and a high accuracy in positioning cerebrovascular contour, and it diminishes the target image ambiguity caused by noise to improve the anti-interference ability of Contour extraction.


Author(s):  
Hairui Wang ◽  
Chunfang Guo ◽  
Yujie Li ◽  
Yahua Liu ◽  
Minjie Wang ◽  
...  

With the advantage of high adaptability, Miura-origami structure with curvature shows various engineering applications such as a sandwich between two stiff facings with curvature requirements and structural support to form a circular tube. In this research, a forming method of polymer circular tube with single-curved surface origami expressed by five parameters was established and its corresponding theory was solved considering forming rationality in actual manufacturing. The components of circular tube were fabricated by the vacuum forming process and then spliced together. We conducted numerical simulation to analyze the structural performance of the tube with five parameters and shown that these parameters have a great influence on energy absorbed performance. Finally, a male mold of a part with Arc Miura-origami structure was designed and fabricated. The parts with Arc Miura-origami were manufactured using vacuum forming process and then spliced and bonded together into a two-layer tube. This research may provide a method to design and fabricate Miura-origami structure with high efficiency and quality.


2021 ◽  
Vol 61 (2) ◽  
pp. 422
Author(s):  
Polly Mahapatra ◽  
Paris Shahriari

Under the increased pressure of rapidly changing market conditions and disrupting technologies, continuous improvements in efficiency become indispensable for all oil and gas operators. Traditional project management principles in the oil and gas industry employ rigid methods of planning and execution that can sometimes hinder adaptability and a quick response to change. Considering the potential that Agile principles can offer as a solution, the challenge, therefore, is to identify the ideal, hybrid, approach that leverages Agile while incorporating the traditional linear workflow necessitated by the oil and gas industry. This paper seeks to assess pre-existing literature in the application of the Agile principles in the oil and gas industry with a focus on Major Capital Projects (MCPs), backed by the successes experienced as a result of specific pilot projects completed at Chevron’s Australian Business Unit. In particular, this paper will focus on how agility has resulted in improvements to the cost, schedule, teaming and cohesion of MCPs in the early phases as well as key learnings form the pilot agility projects.


2020 ◽  
pp. 38-42
Author(s):  
Galina Veniaminovna Sorokoumova ◽  
Anastasiia Olegovna Bespalova

The article deals with the concept of pedagogical culture of parents, the goals of development of pedagogical culture of parents and methods of formation and improvement of the level of pedagogical culture of parents. The paper focuses on the tasks of interaction between an educational institution and the family in the upbringing of children. Methods of study. To study the possibility of forming a pedagogical culture of parents, we used a questionnaire to survey the needs of parents to interact with the educational institution and the interest of teachers in working with the family, the «Ideas about the ideal parent» method by R. V. Ovcharova, Y.A. Degtyareva, «Family Biofield» inquirer by V. V. Boyko and «Determination of parenting skills» questionnaire by O.L. Zvereva. Results of the study. The article shows the results of the impact of the program, which includes a seminar using the case technology «pedagogical culture of parents» and parent training based on the program «education based on common sense» on the formation of the pedagogical culture of parents. Conclusion. The results of the study proved the possibility of purposeful formation of the pedagogical culture of parents in the educational system of the school and the high efficiency of practice – and personality-oriented methods of such work, and also showed greater competence and awareness among parents and kindergarten teachers in the education of children.


2019 ◽  
Vol 22 (4) ◽  
pp. 329-334
Author(s):  
Noora Saad Faraj Al-Dulaimi ◽  
Samara Saad Faraj Al-Dulaimi

Providing a clean and high quality drinking water to both rural as well as urban areas is a great challenge by itself, adding to it the large volume requirements of such water at high population areas means a very high cost for such industry because mainly of the cost of expensive commercially available adsorbent used in this process. This led inhabitants of the remote and/or rural areas to use less quality water with all its risks and health challenges. In this study, a locally collected rice husk is tested to be used as an alternative adsorbent to the expensive common commercial ones. Parameters like adsorbent dosage, initial concentration of turbidity, and pH level were tested to investigate their effects on the process. Treatment of synthetic turbid water was done after changing these parameters to measure the effect of each parameter alone and the results showed a set of parameters that can be used to achieve high efficiency of turbidity removal. The study concluded that rice husk can be used as a well cheap alternative adsorbent to reduce the river water turbidity due to its availability and low cost with a decent removal efficiency approaching 95%.


2019 ◽  
Vol 2 (1) ◽  
pp. 131
Author(s):  
Rizqi Dwi Prasetyo ◽  
Yosef Cahyo ◽  
Ahmad Ridwan

In industrial areas or densely populated settlements, generally found channels that function besides to drain rainwater as well as to discharge domestic wastewater or dirty water from households. Drainage systems are often the main problem in the occurrence of flooding. It is necessary to analyze how their performance and resistance to flooding in the District of Gandusari, Trenggalek Regency. For analysis of drainage system planning in flood prevention efforts, the authors used the Van-Breun and Mononobe calculation methods to determine the number of incoming water discharge, the ideal dimension of the channel to accommodate the inlet discharge channel, and calculate the cost budget plan (RAB) of the builder. From the analysis, results obtained a cumulative discharge of rainwater, and dirty water entering the drainage amounted to 0.4695 m3 / sec. From the calculation, the ideal dimensions of the drainage can be obtained to be able to accommodate rainwater runoff and dirty water discharge using square channels, where the 1.5 m channel height is all added to the water level of 0.2 m and 0.7 m in width 500 m. While the budget plan for the construction costs is Rp. 794,048,000.00 -Di daerah industri atau pemukiman padat penduduk umumnya ditemukan saluran yang berfungsi selain untuk mengalirkan air hujan juga sekaligus untuk pembuangan air limbah domestik ataupun air kotor dari rumah tangga. System drainase sering menjadi pokok masalah dalam terjadinya banjir, maka perlu di Analisa bagaimana kinerjanya dan ketahanan terhadap banjir di Kecamatan Gandusari Kabupaten Trenggalek. Untuk analisis perencanaan sistem drainase dalam upaya penanggulangan banjir penulis menggunakan metode perhitungan Van-Breun dan Mononobe untuk mengetahui angka debit air yang masuk, dimensi ideal saluran untuk menampung saluran debit air masuk dan menghitung rencana anggaran biaya (RAB) pembangunanya. Dari hasil analisa didapatkan debit komulatif air hujan dan air kotor yang masuk ke drainase sebesar 0.4695 m3/detik. Dari perhitungan didapatkan dimensi saluran drainase yang ideal agar mampu menampung limpasan air hujan dan debit air kotor dengan menggunakan saluran berbentuk persegi, dimana tinggi saluran 1,5 m semuanya ditambahkan dengan tinggi jagaan air sebesar 0,2 m dan lebar 0,7 m dengan panjang 500 m. Sedangkan rencana Anggaran Biaya pembangunannya sebesar Rp. 794.048.000,00,-


Author(s):  
Pranjal Saikia ◽  
Saitanya Kumar Bharadwaj ◽  
Abu Taleb Miah

Vanadium Haloperoxidases (VHPOs) have been used in a variety of biotransformations showing remarkable stereoselectivity and regiospecificity. The high efficiency of the enzyme is influenced by the protein active site and the role of certain amino acids in activation of vanadium(V)-bound peroxide for halide oxidation. The use of natural or recombinant enzymes, or biomimetic vanadium compounds brings up issues regarding the cost of production and reaction conditions. In this chapter, the primary intent is to provide a simple and clear picture of functional mimicking nature of peroxovanadium compounds with haloperoxidases enzymes to the readers. Major emphasis would be given to examine the reactivity of the vanadium haloperoxidases with mechanism.


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