Search results

During the construction process of the China Railway Track System (CRTS) I type filling layer, the nonwoven fabric bags have been used as grouting templates for cement asphalt (CA) emulsified mortar. The porous structure of nonwoven fabrics endowed the templates with breathability and water permeability. The standard requires that the volume expansion rate of CA mortar must be controlled within 1%–3%, which can generate expansion pressure to ensure that the cavities under track slabs are filled fully. However, the expansion pressure caused some of the water to seep out from the periphery of the filling bag, and it would affect the actual mix proportion of CA mortar. The differences in physical and mechanical properties between the CA mortar under track slabs and the CA mortar formed in the laboratory were studied in this paper. The relevant results could provide important methods for the research of filling layer materials for CRTS I type and other types of ballastless tracks in China.

During the inspection of filling layer, the samples of CA mortar from different working conditions and raw materials were taken by uncovering the track slabs and drilling cores. The physical and mechanical properties of CA mortar under the filling layer of the slab were systematically analyzed by testing the electrical flux, compressive strength and density of mortar in different parts of the filling layer.

In this paper, the electric flux, the physical properties and mechanical properties of different parts of CA mortar under the track slab were investigated. The results showed that the density, electric flux and compressive strength of CA mortar were affected by the composition of raw materials for dry powders and different parts of the filling layer. In addition, the electrical flux of CA mortar gradually decreased within 90 days’ age. The electrical flux of samples with the thickness of 54 mm was lower than 500 C. Therefore, the impermeability and durability of CA mortar could be improved by increasing the thickness of filling layer. Besides, the results showed that the compressive strength of CA mortar increased, while the density and electric flux decreased gradually, with the prolongation of hardening time.

During 90 days' age, the electrical flux of the CA mortar gradually decreased with the increase of specimen thickness and the electrical flux of the specimens with the thickness of 54 mm was lower than 500 C. The impermeability and durability of the CA mortar could be improved by increasing the thickness of filling layer. The proposed method can provide reference for the further development and improvement of CRTS I and CRTS II type ballastless track in China.

This paper is devoted to prepare micro-cone structure with variable cross-section size by Stereo Lithography Appearance (SLA)-based 3D additive manufacturing technology. It is mainly focused on analyzing the forming mechanism of equipment and factors affecting the forming quality and accuracy, investigating the influence of forming process parameters on the printing quality and optimization of the printing quality. This study is expected to provide a µ-SLA surface preparation technology and process parameters selection with low cost, high precision and short preparation period for microstructure forming.

The µ-SLA process is optimized based on the variable cross-section micro-cone structure printing. Multi-index analysis method was used to analyze the influence of process parameters. The process parameter influencing order is determined and validated with flawless micro array structure.

After the optimization analysis of the top diameter size, the bottom diameter size and the overall height, the influence order of the printing process parameters on the quality of the micro-cone forming is: exposure time (B), print layer thickness (A) and number of vibrations (C). The optimal scheme is A1B3C1, that is, the layer thickness of 5 µm, the exposure time of 3000 ms and the vibration of 64x. At this time, the cone structure with the bottom diameter of 50 µm and the cone angle of 5° could obtain a better surface structure.

This study is expected to provide a µ-SLA surface preparation technology and process parameters selection with low cost, high precision and short preparation period for microstructure forming.

Unconventional machining processes, particularly ultrasonic vibration cutting (UVC), can overcome such technical bottlenecks. However, the precise mechanism through which UVC affects the in-service functional performance of advanced aerospace materials remains obscure. This limits their industrial application and requires a deeper understanding.

The surface integrity and in-service functional performance of advanced aerospace materials are important guarantees for safety and stability in the aerospace industry. For advanced aerospace materials, which are difficult-to-machine, conventional machining processes cannot meet the requirements of high in-service functional performance owing to rapid tool wear, low processing efficiency and high cutting forces and temperatures in the cutting area during machining.

To address this literature gap, this study is focused on the quantitative evaluation of the in-service functional performance (fatigue performance, wear resistance and corrosion resistance) of advanced aerospace materials. First, the characteristics and usage background of advanced aerospace materials are elaborated in detail. Second, the improved effect of UVC on in-service functional performance is summarized. We have also explored the unique advantages of UVC during the processing of advanced aerospace materials. Finally, in response to some of the limitations of UVC, future development directions are proposed, including improvements in ultrasound systems, upgrades in ultrasound processing objects and theoretical breakthroughs in in-service functional performance.

This study provides insights into the optimization of machining processes to improve the in-service functional performance of advanced aviation materials, particularly the use of UVC and its unique process advantages.

Particles bed binding by selective cement activation (SCA) method is a computer-aided manufacturing (CAM) technique used to produce cementitious elements. A computer-aided design file is sliced to generate G-codes before printing. This paper aims to study the effect of key input parameters for slicer software on the final properties of printed products.

The one factor at a time (OFAT) methodology is used to investigate the impact of selected parameters on the final properties of printed specimens, and the causes for the variations in outcomes of each variable are discussed.

Finer aggregates can generate a more compact layer, resulting in a denser product with higher strength. Fluid pressure is directly determined by voxel rate (r_V); however, high pressures enable better fluid penetration control for fortified products; for extreme r_Vs, residual voids in the interfaces between successive layers and single-line primitives impair mechanical strength. It was understood that printhead movement along the orientation of the parts in the powder bed improved the mechanical properties.

The design of experiment (DOE) method assesses the influence of process parameters on various input printing variables at the same time. As the resources are limited, a fractional factorial plan is carried out on a subset of a full factorial design; hence, providing physical interpretation behind changes in each factor is difficult. OFAT aids in analyzing the effect of a change in one factor on output while all other parameters are kept constant. The results assist engineers in properly considering the influence of variable variations for future DOE designs.

Polymer laser powder bed fusion (PBF-LB/P) is an additive manufacturing technology that is sustainable due to the possibility of recycling the powder multiple times and allowing the fabrication of gears without the aid of support structures and subsequent assembly. However, there are constraints in the process that negatively affect its adoption compared to other additive technologies such as material extrusion to produce gears. This study aims to demonstrate that it is possible to overcome the problems due to the physics of the process to produce accurate mechanism.

Technological aspects such as orientation, wheel-shaft thicknesses and degree of powder recycling were examined. Furthermore, the evolving tooth profile was considered as a design parameter to provide a manufacturability map of gear-based mechanisms.

Results show that there are some differences in the functioning of the gear depending on the type of powder used, 100% virgin or 50% virgin and 50% recycled for five cycles. The application of a groove on a gear produced with 100% virgin powder allows the mechanism to be easily unlocked regardless of the orientation and wheel-shaft thicknesses. The application of a specific evolutionary profile independent of the diameter of the reference circle on vertically oriented gears guarantees rotation continuity while preserving the functionality of the assembled mechanism.

In the literature, there are various studies on material aging and reuse in the PBF-LB/P process, mainly focused on the powder deterioration mechanism, powder fluidity, microstructure and mechanical properties of the parts and process parameters. This study, instead, was focused on the functioning of gears, which represent one of the applications in which this technology can have great success, by analyzing the two main effects that can compromise it: recycled powder and vertical orientation during construction.

The aim of the present study is to shed light on the role of legal practitioners, namely, lawyers and notaries, in the fight against money laundering: Are they considered as facilitators or obstacles against money laundering? How does the global and the EU legal framework deal with the legal professionals?

The research follows a deductive approach attempting to respond to questions such as: How do the lawyers’ and notaries’ societies react in front of the anti-money laundering measures that concern them and why? What are the discrepancies between the lawyers’ professional secrecy and the obligations that EU anti-money laundering legislation assigns them?

This study disclosures the response of the European union and international legal and regulatory framework as well as the reflexes of the international and European legal professionals’ associations to this danger. It also demonstrates the reaction of lawyers against European union anti-money laundering legislation, to the point that it limits not only the confidentiality principle but also the position of the European judicial systems to the contradiction between this principle and the lawyers’ obligation to report their suspicions to the authorities.

To fulfil the study goals, it was necessary to overcome some obstacles, like the limitation of existing sources. Indeed, transnational empirical research considering the professionals who facilitate money laundering is narrow. Besides, policymakers and academics only recently expressed more interest in money laundering and its facilitators.

This paper fulfils an identified need to study the legal professionals’ role not only in money laundering practices but also in anti-money laundering policies.

This paper presents an experimental investigation in establishing the relationship between FDM process parameters and tensile strength of polycarbonate (PC) samples using the I-Optimal design.

I-optimal design methodology is used to plan the experiments by means of Minitab-17.1 software. Samples are manufactured using Stratsys FDM 400mc and tested as per ISO standards. Additionally, an artificial neural network model was developed and compared to the regression model in order to select an appropriate model for optimisation. Finally, the genetic algorithm (GA) solver is executed for improvement of tensile strength of FDM built PC components.

This study demonstrates that the selected process parameters (raster angle, raster to raster air gap, build orientation about Y axis and the number of contours) had significant effect on tensile strength with raster angle being the most influential factor. Increasing the build orientation about Y axis produced specimens with compact structures that resulted in improved fracture resistance.

The fitted regression model has a p-value less than 0.05 which suggests that the model terms significantly represent the tensile strength of PC samples. Further, from the normal probability plot it was found that the residuals follow a straight line, thus the developed model provides adequate predictions. Furthermore, from the validation runs, a close agreement between the predicted and actual values was seen along the reference line which further supports satisfactory model predictions.

This study successfully investigated the effects of the selected process parameters - raster angle, raster to raster air gap, build orientation about Y axis and the number of contours - on tensile strength of PC samples utilising the I-optimal design and ANOVA. In addition, for prediction of the part strength, regression and ANN models were developed. The selected ANN model was optimised using the GA-solver for determination of optimal parameter settings.

The proposed ANN-GA approach is more appropriate to establish the non-linear relationship between the selected process parameters and tensile strength. Further, the proposed ANN-GA methodology can assist in manufacture of various industrial products with Nylon, polyethylene terephthalate glycol (PETG) and PET as new 3DP materials.

Shadow banks or non-bank financial intermediaries (NBFIs) are facilitators of credit, especially in emerging market economies (EMEs). However, there are certain risks associated with them, such as their unchecked leverage and interconnectedness with the rest of the financial system. In light of this, the present study analyses the impact of the growth of shadow banks on the stability of the banking sector and the overall stability of the financial system. The authors further examine the effect of the growth of finance companies (a type of NBFIs) on financial stability.

The study employs data of 11 EMEs (monitored by the Financial Stability Board (FSB)) for the period 2002–2020 to examine the above relationships. Panel-corrected standard errors method and Driscoll–Kray standard error estimation are deployed to conduct the analysis.

The results signify that the growth of the shadow banking sector and the growth of lending to the shadow banking sector are negatively associated with the stability of the banking sector and increases the vulnerability of the financial system (overall instability). This implies that the higher the growth of the shadow banks, the higher the financial fragility. Finance companies are also found to negatively affect financial stability. These findings are validated by different estimation methods and point out the risks posed by the NBFI sector.

The extant study builds a composite index (Financial Vulnerability Index (FVI)) to measure financial stability; thus, the findings contribute to the evolving literature on shadow banks.

This paper explores the historical aspects of customer due diligence and related anti-money laundering measures in South Africa. Customer due diligence measures are usually employed to ensure that financial institutions know their customers well by assessing them against the possible risks they might pose such as fraud, money laundering, Ponzi schemes and terrorist financing. Accordingly, customer due diligence measures enable banks and other financial institutions to assess their customers before they conclude any transactions with them. Customer due diligence measures that are utilised in South Africa include identification and verification of customer identity, keeping records of transactions concluded between customers and financial institutions, ongoing monitoring of customer account activities, reporting unusual and suspicious transactions and risk assessment programmes. The Financial Intelligence Centre Act 38 of 2001 (FICA) as amended by the Financial Intelligence Centre Amendment Act 1 of 2017 (Amendment Act) is the primary statute that provides for the adoption and use of customer due diligence measures to detect and combat money laundering in South Africa. Prior to the enactment of the FICA, several other statutes were enacted in a bid to prohibit money laundering in South Africa. Against this background, the article provides a historical overview analysis of these statutes to, inter alia, explore their adequacy and examine whether they consistently complied with the Financial Action Task Force Recommendations on the regulation of money laundering.

The paper provides an overview analysis of the historical aspects of the regulation and use of customer due diligence to combat money laundering in South Africa. In this regard, a qualitative research method as well as the doctrinal research method are used.

It is hoped that policymakers and other relevant persons will adopt the recommendations provided in the paper to enhance the curbing of money laundering in South Africa.

The paper does not provide empirical research.

The paper is useful to all policymakers, lawyers, law students and regulatory bodies, especially, in South Africa.

The paper advocates for the use of customer due diligence measures to curb money laundering in the South African financial markets and financial institutions.

The paper is original research on the South African anti-money laundering regime and the use of customer due diligence measures to curb money laundering in South Africa.

Banditry and terrorism constitute serious security risks in Nigeria. This follows the fact that Nigeria is rated as one of the leading states in the world that is plagued by terrorism. Terrorists and bandits usually embark on predicate crimes such as kidnapping, smuggling, narcotics trade, and similar trades to finance their terrorist enterprises in Nigeria. The funds realized by criminals from nefarious sources such as sales of narcotics and ransom from kidnapping are usually laundered to make their criminal enterprises self-sustaining. Thus, all “dirty” money is laundered so as not to attract the attention of law enforcement agents. The funds realized through receipt of ransom from kidnapping, smuggling or funds from sponsors are laundered through channels such as bureau de change, which are difficult to monitor by the Nigerian authorities due, in part, to flaws and loopholes in the current anti-money laundering and anti-terrorist laws. This paper aims to adopt a doctrinal and qualitative desktop research methodology. In this regard, the current anti-money laundering and anti-terrorist laws are discussed to explore possible measures that could be adopted to remedy the flaws and loopholes in such laws and combat money laundering and financing of terrorism in Nigeria.

The article analyses the regulation and combating of money laundering and terrorist financing activities in Nigeria. In this regard, a doctrinal and qualitative research method is used to explore the flaws in the Nigerian anti-money laundering laws so as to recommend possible remedies in respect thereof.

It is hoped that policymakers and other relevant persons will use the recommendations provided in this article to enhance the curbing of money laundering and terrorist financing activities in Nigeria.

The article is not based on empirical research.

This study is important and vital to all policymakers, lawyers, law students and regulatory bodies in Nigeria and other countries globally.

The study seeks to curb money laundering and terrorist financing activities in Nigeria.

The study is based on original research which is focused on the regulation and combating of money laundering and terrorist financing activities in Nigeria.