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1 – 10 of 311Bo You and Qi Si Wang
The purpose of this paper is to investigate the distribution characteristics of airflow in mine ventilation suits with different pipeline structures when the human body is bent at…
Abstract
Purpose
The purpose of this paper is to investigate the distribution characteristics of airflow in mine ventilation suits with different pipeline structures when the human body is bent at various angles. On this basis, the stress points are extracted to investigate the pressure variation of a ventilation suit under different ventilation rates and pipeline structures.
Design/methodology/approach
Based on the three-dimensional human body scanner, portable pressure test and other instruments, a human experiment was conducted in an artificial cabin. The study analyzed and compared the distribution characteristics of clearance under three different pipeline structures, as well as the pressure variation of the ventilation suit.
Findings
The study found that the clearance in front of two pipeline structures gradually increased in size as the degree of bending increased, and there was minimal clearance in the chest and back. The longitudinal structure exhibits a significant decrease in clearance compared to the spiral structure. The pressure value of the spiral pipeline structure with the same ventilation volume is low, followed by the transverse structure, while the longitudinal structure has the highest pressure value. The increase in clothing pressure value of a spiral pipeline structured ventilation suit with varying ventilation volumes is minimal.
Originality/value
The ventilation suit has a promising future as a type of personal protective equipment for mitigating heat damage in mines. It is of great value to study the pipeline structure of the ventilation suit for human comfort.
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Su Yong and Gong Wu-Qi
Abnormal vibrations often occur in the liquid oxygen kerosene transmission pipelines of rocket engines, which seriously threaten their safety. Improper handling can result in…
Abstract
Purpose
Abnormal vibrations often occur in the liquid oxygen kerosene transmission pipelines of rocket engines, which seriously threaten their safety. Improper handling can result in failed rocket launches and significant economic losses. Therefore, this paper aims to examine vibrations in transmission pipelines.
Design/methodology/approach
In this study, a three-dimensional high-pressure pipeline model composed of corrugated pipes, multi-section bent pipes, and other auxiliary structures was established. The fluid–solid coupling method was used to analyse vibration characteristics of the pipeline under various external excitations. The simulation results were visualised using MATLAB, and their validity was verified via a thermal test.
Findings
In this study, the vibration mechanism of a complex high-pressure pipeline was examined via a visualisation method. The results showed that the low-frequency vibration of the pipe was caused by fluid self-excited pressure pulsation, whereas the vibration of the engine system caused a high-frequency vibration of the pipeline. The excitation of external pressure pulses did not significantly affect the vibrations of the pipelines. The visualisation results indicated that the severe vibration position of the pipeline thermal test is mainly concentrated between the inlet and outlet and between the two bellows.
Practical implications
The results of this study aid in understanding the causes of abnormal vibrations in rocket engine pipelines.
Originality/value
The causes of different vibration frequencies in the complex pipelines of rocket engines and the propagation characteristics of external vibration excitation were obtained.
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Keywords
Britto Pari J., Mariammal K. and Vaithiyanathan D.
Filter design plays an essential role in most communication standards. The essential element of the software-defined radio is a channelizer that comprises several channel filters…
Abstract
Purpose
Filter design plays an essential role in most communication standards. The essential element of the software-defined radio is a channelizer that comprises several channel filters. Designing filters with lower complexity, minimized area and enhanced speed is a demanding task in currently prevailing communication standards. This study aims to propose an efficient reconfigurable residue number system (RNS)-based multiply-accumulate (MAC) channel filter for software radio receivers.
Design/methodology/approach
RNS-based pipelined MAC module for the realization of channel finite impulse response (FIR) filter architecture is considered in this work. Further, the use of a single adder and single multiplier for realizing the filter architecture regardless of the number of taps offers effective resource sharing. This design provides significant improvement in speed of operation as well as a reduction in area complexity.
Findings
In this paper, two major tasks have been considered: first, the RNS number conversion is performed in which the integer is converted into several residues. These residues are processed in parallel and are applied to the MAC-FIR filter architecture. Second, the MAC filter architecture involves pipelining, which enhances the speed of operation to a significant extent. Also, the time-sharing-based design incorporates a single partial product-based shift and add multiplier and single adder, which provide a low complex design. The results show that the proposed 16-tap RNS-based pipelined MAC sub-filter achieves significant improvement in speed as well as 89.87% area optimization when examined with the conventional RNS-based FIR filter structure.
Originality/value
The proposed MAC-FIR filter architecture provides good performance in terms of complexity and speed of operation because of the use of the RNS scheme with pipelining and partial product-based shift and adds multiplier and single adder when examining with the conventional designs. The reported architecture can be used in software radios.
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Europe is increasingly interested in accessing large Turkmen gas reserves, potentially via Turkey, which has reached agreements with Turkmenistan on possible swap deals via Iran…
Details
DOI: 10.1108/OXAN-DB286656
ISSN: 2633-304X
Keywords
Geographic
Topical
Russia’s gas export strategy is predicated on the rapid growth of liquefied natural gas (LNG) exports. Following the collapse of pipeline gas sales to Europe, Russia’s plans to…
Details
DOI: 10.1108/OXAN-DB286171
ISSN: 2633-304X
Keywords
Geographic
Topical
This episode could have a significant impact on South Sudan's government, which derives almost 90% of its revenue from oil.
Details
DOI: 10.1108/OXAN-DB286085
ISSN: 2633-304X
Keywords
Geographic
Topical
Anastasios Chrysochoou, Dimitris Zissis, Konstantinos Chalvatzis and Kostas Andriosopoulos
The purpose of this study is to investigate the impact of the construction and operation of underground gas storage (UGS) facilities, under the prism of the recent rise in energy…
Abstract
Purpose
The purpose of this study is to investigate the impact of the construction and operation of underground gas storage (UGS) facilities, under the prism of the recent rise in energy prices. The focus is on developing energy markets interconnected with gas producers through pipelines and has access to liquefied natural gas (LNG) facilities in parallel.
Design/methodology/approach
Through a focal market in Europe, the authors estimate the economic value for both stakeholders and consumers by introducing a methodology, appropriately adjusted to the specificities of the domestic energy market. The Transmission System Operator, the Energy Market Regulator, the Energy Exchange and Eurostat are the main data sources for our calculations and conclusions.
Findings
The authors investigate the perspectives of UGS facilities, identifying financial challenges considering specific energy market conditions which are barriers to new storage facilities. Nevertheless, the energy price rocketing coupled with the security of gas supply issues, which arose in autumn 2021 and were continuing in 2022 due to the Russia–Ukraine crisis, highlight that gas storage remains, at least for the midterm, at the core of European priorities.
Originality/value
The paper emphasizes on developing markets toward green transition, proposing tangible policy recommendations regarding gas storage. A new methodological approach is proposed, appropriate to quantify the economic value of UGSs in such markets. Last, a mix of energy policy options is suggested which include regulatory reforms, support schemes and new energy infrastructures that could make the gas storage investments economically viable.
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Omotayo Farai, Nicole Metje, Carl Anthony, Ali Sadeghioon and David Chapman
Wireless sensor networks (WSN), as a solution for buried water pipe monitoring, face a new set of challenges compared to traditional application for above-ground infrastructure…
Abstract
Purpose
Wireless sensor networks (WSN), as a solution for buried water pipe monitoring, face a new set of challenges compared to traditional application for above-ground infrastructure monitoring. One of the main challenges for underground WSN deployment is the limited range (less than 3 m) at which reliable wireless underground communication can be achieved using radio signal propagation through the soil. To overcome this challenge, the purpose of this paper is to investigate a new approach for wireless underground communication using acoustic signal propagation along a buried water pipe.
Design/methodology/approach
An acoustic communication system was developed based on the requirements of low cost (tens of pounds at most), low power supply capacity (in the order of 1 W-h) and miniature (centimetre scale) size for a wireless communication node. The developed system was further tested along a buried steel pipe in poorly graded SAND and a buried medium density polyethylene (MDPE) pipe in well graded SAND.
Findings
With predicted acoustic attenuation of 1.3 dB/m and 2.1 dB/m along the buried steel and MDPE pipes, respectively, reliable acoustic communication is possible up to 17 m for the buried steel pipe and 11 m for the buried MDPE pipe.
Research limitations/implications
Although an important first step, more research is needed to validate the acoustic communication system along a wider water distribution pipe network.
Originality/value
This paper shows the possibility of achieving reliable wireless underground communication along a buried water pipe (especially non-metallic material ones) using low-frequency acoustic propagation along the pipe wall.
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Karen M. Peesker, Lynette J. Ryals and Peter D. Kerr
The digital transformation is dramatically changing the business-to-business (B2B) sales environment, challenging long-standing views regarding the critical competencies required…
Abstract
Purpose
The digital transformation is dramatically changing the business-to-business (B2B) sales environment, challenging long-standing views regarding the critical competencies required of salespeople. This paper aims to explore the personal traits associated with sales performance in a digital selling environment.
Design/methodology/approach
Using template analysis, the researchers captured and coded over 21 h of in-depth, semi-structured interviews with senior sales leaders from various industry sectors, exploring their perceptions of the personal traits now required of B2B salespeople in the digital landscape.
Findings
The research identifies three high-level trait types critical to sales success within a digital selling environment: “analytical curiosity” – the natural motivation and ability to gather and synthesize sales-related knowledge, “empathetic citizenship” – the ability to establish initial rapport while building long-term trust and “disciplined drive” – the exertion of selling effort in a highly focused and methodical manner across all stages of the sales process.
Research limitations/implications
The present data came from interviews with sales leaders in Canada. A more global sample may lead to additional insights. Moreover, the sample was drawn from long-cycle B2B sales environments; conclusions may differ for short-cycle or business-to-consumer markets.
Practical implications
This paper presents a framework for hiring and developing salespeople in the digital sales environment, identifying personal trait types that sales leaders should look for when hiring: analytical curiosity, empathetic citizenship and disciplined drive. The paper identifies how these trait types influence sales success, suggesting that sales leaders could coach and educate their teams to make the best use of them.
Originality/value
This paper presents a conceptual framework for hiring in the digital sales environment and introduces the trait of analytical curiosity not previously discussed in the literature.
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Keywords
Zhen Li, Jianqing Han, Mingrui Zhao, Yongbo Zhang, Yanzhe Wang, Cong Zhang and Lin Chang
This study aims to design and validate a theoretical model for capacitive imaging (CI) sensors that incorporates the interelectrode shielding and surrounding shielding electrodes…
Abstract
Purpose
This study aims to design and validate a theoretical model for capacitive imaging (CI) sensors that incorporates the interelectrode shielding and surrounding shielding electrodes. Through experimental verification, the effectiveness of the theoretical model in evaluating CI sensors equipped with shielding electrodes has been demonstrated.
Design/methodology/approach
The study begins by incorporating the interelectrode shielding and surrounding shielding electrodes of CI sensors into the theoretical model. A method for deriving the semianalytical model is proposed, using the renormalization group method and physical model. Based on random geometric parameters of CI sensors, capacitance values are calculated using both simulation models and theoretical models. Three different types of CI sensors with varying geometric parameters are designed and manufactured for experimental testing.
Findings
The study’s results indicate that the errors of the semianalytical model for the CI sensor are predominantly below 5%, with all errors falling below 10%. This suggests that the semianalytical model, derived using the renormalization group method, effectively evaluates CI sensors equipped with shielding electrodes. The experimental results demonstrate the efficacy of the theoretical model in accurately predicting the capacitance values of the CI sensors.
Originality/value
The theoretical model of CI sensors is described by incorporating the interelectrode shielding and surrounding shielding electrodes into the model. This comprehensive approach allows for a more accurate evaluation of the detecting capability of CI sensors, as well as optimization of their performance.
Details