P. Tománek, P. Škarvada, D. Dallaeva, L. Grmela, R. Macků and S. Smith
Monocrystalline silicon is still very interesting material for solar cells fabrication due to its quality and external efficiency. Nevertheless during a tailoring of eligible…
Abstract
Monocrystalline silicon is still very interesting material for solar cells fabrication due to its quality and external efficiency. Nevertheless during a tailoring of eligible silicon wafers, some inhomogeneities or irregularities emerge and provide defects which give trouble to good operation of solar panels. Generally, there are two classes of defects in silicon wafer: material defects due to imperfections or irregularity in crystal structure (point, line, square or volume defects), and defects induced by wafer processing. To avoid a use of damaged cells, macroscopic and microscopic measurement techniques must be applied. In this paper we present a microscopic method combining electrical noise measurements with scanning probe localization of luminous micro-spots defects. The paper brings experimental results showing local electric and optical investigations of defects in etched monocrystalline silicon solar cells and a use of cold field emission tungsten electrode as a local probe for apertureless scanning near-field optical microscope.
Details
Keywords
Adhithya Sreeram and Jayaraman Kathirvelan
Artificial fruit ripening is hazardous to mankind. In the recent past, artificial fruit ripening is increasing gradually due to its commercial benefits. To discriminate the type…
Abstract
Purpose
Artificial fruit ripening is hazardous to mankind. In the recent past, artificial fruit ripening is increasing gradually due to its commercial benefits. To discriminate the type of fruit ripening involved at the vendors’ side, there is a great demand for on-sight ethylene detection in a nondestructive manner. Therefore, this study aims to deal with a comparison of various laboratory and portable methods developed so far with high-performance metrics to identify the ethylene detection at fruit ripening site.
Design/methodology/approach
This paper focuses on various types of technologies proposed up to date in ethylene detection, fabrication methods and signal conditioning circuits for ethylene detection in parts per million and parts per billion levels. The authors have already developed an infrared (IR) sensor to detect ethylene and also developed a lab-based setup belonging to the electrochemical sensing methods to detect ethylene for the fruit ripening application.
Findings
The authors have developed an electrochemical sensor based on multi-walled carbon nanotubes whose performance is relatively higher than the sensors that were previously reported in terms of material, sensitivity and selectivity. For identifying the best sensing technology for optimization of ethylene detection for fruit ripening discrimination process, authors have developed an IR-based ethylene sensor and also semiconducting metal-oxide ethylene sensor which are all compared with literature-based comparable parameters. This review paper mainly focuses on the potential possibilities for developing portable ethylene sensing devices for investigation applications.
Originality/value
The authors have elaborately discussed the new chemical and physical methods of ethylene detection and quantification from their own developed methods and also the key findings of the methods proposed by fellow researchers working on this field. The authors would like to declare that the extensive analysis carried out in this technical survey could be used for developing a cost-effective and high-performance portable ethylene sensing device for fruit ripening and discrimination applications.
Details
Keywords
Shared, dockless micromobility is causing concern across the globe. The phenomenon started with shared bikes and e-bikes. More recently, e-scooters (or electric kickbikes), the…
Abstract
Shared, dockless micromobility is causing concern across the globe. The phenomenon started with shared bikes and e-bikes. More recently, e-scooters (or electric kickbikes), the focus of this chapter, have flooded cities in unprecedented speed and volume – and have caught virtually every city and competent authority off guard. The failure of current regulatory frameworks to address new challenges posed by e-scooters is explored. This chapter first briefly describes major developments of the shared e-scooter market. It then presents rationales for, and to some extent against, e-scooter regulation as well as policy tools available for e-scooter regulation. E-scooters open the door for new and innovative – and potentially efficient – ways to regulate, including geofencing, zoning, mandatory data sharing and mandatory cooperation. Against this backdrop, the chapter discusses regulatory dilemmas, challenges, opportunities and possibilities.
Details
Keywords
On 24 January 2020, France informed WHO of three cases of novel coronavirus, all of whom had travelled from Wuhan, China. These three cases were the first confirmed cases in…
Abstract
On 24 January 2020, France informed WHO of three cases of novel coronavirus, all of whom had travelled from Wuhan, China. These three cases were the first confirmed cases in Europe. By 13 March 2020, Europe had become the epicentre of the pandemic with more reported cases and deaths than the rest of the world combined, apart from the People’s Republic of China. Many European countries like Italy, France and Germany took drastic actions and subsequently announced a lockdown, while other countries like the UK, the Netherlands and Sweden were much more hesitant to introduce such far-reaching safety measures. This chapter provides a literature overview of how the variation in such measures in Europe has ultimately resulted in changes in daily activities and travel behaviour during the pandemic. It focusses on five main themes: (i) reduction in mobility and activities, (ii) spatial-temporal adjustments in out-of-home activities in which people still participated, (iii) modal adjustments especially among people who used to travel by public transport before the pandemic, (iv) new out-of-home activities including new outdoor activities and (v) digital adaptations as several out-of-home activities were replaced by digital activities, with special attention to the experience of teleworking.
Details
Keywords
Laura Burgos, Nora Pece and Silvina Maldonado
The purpose of this study was to establish the degree of ripening of natural goat cheese used as a raw material; to formulate a spreadable processed cheese with creamy…
Abstract
Purpose
The purpose of this study was to establish the degree of ripening of natural goat cheese used as a raw material; to formulate a spreadable processed cheese with creamy consistency; and to determine the level of each process variable.
Design/methodology/approach
Cheeses of various ripening times were selected for the formulation through cluster analysis. The effect of the final moisture was studied using the same proportion of fresh and ripened cheeses in the formulation, and three melting temperatures were tested.
Findings
Goat cheeses ripened for 10, 20 and 40 days were chosen for the formulation of spreadable processed cheese. Final moisture content of 63.0 ± 0.1 per cent was selected (p = 0.0008). Melting temperature at 85.0 ± 0.1°C for 9.0 ± 0.5 min was suitable to homogenize the cheese mass (p = 0.001). The level of variables was validated by changing the proportions of natural goat cheeses selected. Four formulations were obtained with a consistency similar to that of the commercial reference.
Practical implications
Processed cheese is produced by blending shredded natural cheeses of different types and degrees of ripening. The use of ripening goat cheeses as a raw material in processed cheeses contributes to the added value of the local goat milk chain. Goat cheeses have an acid and slightly salty taste and medium to long persistence.
Originality/value
The results of this work can be used by processed cheese manufacturers to better understand the impact of goat cheese ripening on processed cheese quality. The industry can also use these results to introduce the product onto the market and plan their marketing campaign.
Details
Keywords
Vivek Kumar Tiwary, Arunkumar P., Anand S. Deshpande and Nikhil Rangaswamy
Due to intrinsic limitations, fused deposition modelling (FDM) products suffer from the bad surface finish and inaccurate dimensional accuracies restricting its usage in many…
Abstract
Purpose
Due to intrinsic limitations, fused deposition modelling (FDM) products suffer from the bad surface finish and inaccurate dimensional accuracies restricting its usage in many applications. Hence, there is a need for processing polymer patterns before, during and after their productions. This paper aims to highlight the importance of pre- and post-processing treatments on the FDM-based acrylonitrile butadiene styrene patterns improving its surface quality so, that it can be used in rapid investment casting process for making medical implants and other high precision components.
Design/methodology/approach
As a part of pre-processing treatment, the machine parameters affecting the surface quality were identified and optimised using design of experiments. The patterns developed after the first stage of optimisation were given different post-processing treatments, which included vapour smoothening, chemical treatment and sand paper polishing. The results were compared and the best ones were used for making patterns for making medical implants via rapid investment casting technique. The surface quality was checked while the dimensional changes happening during the stages of this hybrid technique were recorded using a three-dimensional optical scanner.
Findings
The surface roughness of the FDM based ABS patterns reduced from 21.63 to 14.40 µm with pre-processing treatments. Chemical treatment (post-processing treatment) turned to be the most suitable technique for reducing the surface roughness further down to 0.30 µm. Medical implants that used these pre- and post-processing treatments gave an average surface roughness of 0.68 µm. Cost and lead time comparisons showed that rapid investment casting technique can be a better method for low volume, customised and with specific requirements.
Originality/value
FDM parts/medical implants produced by rapid investment casting technique suffer from the inferior surface finish and inaccurate dimensional accuracies limiting its applications. A systematic approach to overcome this issue is presented in this research paper. This will directly help the end users and the manufacturers of medical implants, wherein, better surface finish and dimensionally accurate components are expected.
Details
Keywords
Michele Ciotti, Giampaolo Campana and Mattia Mele
This paper aims to present a survey concerning the accuracy of thermoplastic polymeric parts fabricated by additive manufacturing (AM). Based on the scientific literature, the aim…
Abstract
Purpose
This paper aims to present a survey concerning the accuracy of thermoplastic polymeric parts fabricated by additive manufacturing (AM). Based on the scientific literature, the aim is to provide an updated map of trends and gaps in this relevant research field. Several technologies and investigation methods are examined, thus giving an overview and analysis of the growing body of research.
Design/methodology/approach
Permutations of keywords, which concern materials, technologies and the accuracy of thermoplastic polymeric parts fabricated by AM, are used for a systematic search in peer-review databases. The selected articles are screened and ranked to identify those that are more relevant. A bibliometric analysis is performed based on investigated materials and applied technologies of published papers. Finally, each paper is categorised and discussed by considering the implemented research methods.
Findings
The interest in the accuracy of additively manufactured thermoplastics is increasing. The principal sources of inaccuracies are those shrinkages occurring during part solidification. The analysis of the research methods shows a predominance of empirical approaches. Due to the experimental context, those achievements have consequently limited applicability. Analytical and numerical models, which generally require huge computational costs when applied to complex products, are also numerous and are investigated in detail. Several articles deal with artificial intelligence tools and are gaining more and more attention.
Originality/value
The cross-technology survey on the accuracy issue highlights the common critical aspects of thermoplastics transformed by AM. An updated map of the recent research literature is achieved. The analysis shows the advantages and limitations of different research methods in this field, providing an overview of research trends and gaps.
Details
Keywords
Parlad Kumar Garg, Rupinder Singh and IPS Ahuja
The purpose of this paper is to optimize the process parameters to obtain the best dimensional accuracy, surface finish and hardness of the castings produced by using fused…
Abstract
Purpose
The purpose of this paper is to optimize the process parameters to obtain the best dimensional accuracy, surface finish and hardness of the castings produced by using fused deposition modeling (FDM)-based patterns in investment casting (IC).
Design/methodology/approach
In this paper, hip implants have been prepared by using plastic patterns in IC process. Taguchi design of experiments has been used to study the effect of six different input process parameters on the dimensional deviation, surface roughness and hardness of the implants. Analysis of variance has been used to find the effect of each input factor on the output. Multi-objective optimization has been done to find the combined best values of output.
Findings
The results proved that the FDM patterns can be used successfully in IC. A wax coating on the FDM patterns improves the surface finish and dimensional accuracy. The improved dimensional accuracy, surface finish and hardness have been achieved simultaneously through multi-objective optimization.
Research limitations/implications
A thin layer of wax is used on the plastic patterns. The effect of thickness of the layer has not been considered. Further research is needed to study the effect of the thickness of the wax layer.
Practical implications
The results obtained by the study would be helpful in making decisions regarding machining and/or coating on the parts produced by this process.
Originality/value
In this paper, multi-objective optimization of dimensional accuracy, surface roughness and hardness of hybrid investment cast components has been performed.
Details
Keywords
Joachim J. Schouteten, Sara De Pelsmaeker, Joel Juvinal, Sofie Lagast, Koen Dewettinck and Xavier Gellynck
The purpose of this paper is to examine the influence of sensory attributes of milk chocolate on consumers’ emotions and their hedonic ratings using three commercial brands of…
Abstract
Purpose
The purpose of this paper is to examine the influence of sensory attributes of milk chocolate on consumers’ emotions and their hedonic ratings using three commercial brands of milk chocolate.
Design/methodology/approach
Quantitative descriptive analysis by a trained panel (n=8) was performed to obtain the sensory evaluation of the samples. A group of 127 consumers evaluated the samples to indicate their hedonic ratings (nine-point hedonic scale) and emotions (EsSense Profile®).
Findings
The sensory profiles for the three chocolate types showed clear differences. EsSense Profile® methodology revealed that each type of chocolate had a distinct emotional profile. The premium brand was associated with the highest number of positive emotions, whereas the traditional brand was associated with most of the negative emotions (“bored”, “disgusted” and “worried”). The drivers of liking were mainly positive and unclassified emotions. Also, gender differences in emotional profiling were found.
Practical implications
This study illustrates that sensory and emotional measurements can contribute to a better understanding of consumers’ hedonic liking. Moreover, gender differences found in emotional profiling should raise awareness that gender may lead to different emotional profiling. These gender differences are of interest to food companies, for instance, for food product development or marketing purposes.
Originality/value
This study further contributes to the growing literature on emotions. By combining sensory evaluation by a trained panel and emotional profiling by consumers, this paper explores how combining these measurements can contribute to a better understanding of the drivers of liking for milk chocolate.