bluuebunny/crossref_metadata_2025 huggingface dataset:
Pre-training competencies and the productivity of apprentices
Authors: Jansen Anika , Pfeifer Harald Ulrich
Published: March 2017

Purpose

The purpose of this paper is to investigate the relationship between pre-training competencies of apprentices and their productivity at the workplace.

Design/methodology/approach

For the analysis, the authors use firm-level data on apprentices’ oral and writing competencies and competencies in basic mathematics, information technology and problem solving. The authors regress the apprentices’ productivity on these school competencies and include a number of firm and apprentice-specific control variables. By reducing the authors’ data set to firms that only have one apprentice the authors transform the firm-level data into quasi individual-level data.

Findings

The main findings are that not all competencies are equally related to productivity. Problem-solving competencies followed by oral and writing competencies show the strongest relation to the productive potential of apprentices. IT competencies are also positively but weakly related to the apprentices’ productivity. In contrast, higher levels of basic mathematical competencies leave productivity levels largely unchanged. Differentiating between occupational groups, the authors find that the positive relation between the competencies and productivity predominantly exists in commercial occupations rather than in industrial and technical occupations.

Practical implications

The results show that better school competencies are associated with a higher productivity of apprentices, which in turn lowers the firms’ training costs. From a policy perspective, this finding is important because it implies that, by improving the apprentices’ competencies, the firms’ willingness to participate in the apprenticeship system can be increased. Moreover, the results are important for training firms because they show on which competencies firms should focus in their recruitment decision.

Originality/value

The paper studies for the first time the relation between pre-training competencies and productivity of apprentices at the working place. A practical implication from the authors’ analysis is that it could be useful to implement tools measuring the problem solving and oral and writing competencies of apprenticeship applicants in the process of recruitment.
Product and service innovation and discontinuation in manufacturing and service firms in Europe
Authors: Crowley Frank
Published: March 2017

Purpose

The purpose of this paper is to explore product/service innovation and discontinuation using the firm as a unit of analysis. A key objective of the paper is to compare the results between manufacturing and service firms.

Design/methodology/approach

A two-step production function approach is employed to examine first, a firm’s decision to innovate and second, a firm’s decision to discontinue products/services.

Findings

The results indicate that the factors affecting product innovation and discontinuation are similar for manufacturing and service firms, where innovation was significant for product/service discontinuation and process innovation was found to be important for innovations. Similarly, monopoly power was important for innovation in both industry types. However, there were also some underlying differences, particularly in relation to firm age and economic geography effects.

Practical implications

The conclusion of the paper is that it is not appropriate to assume that the process of product innovation and discontinuation will be identical across industry types.

Originality/value

This study is the first study in the literature that examines product/service discontinuation at the firm level and the relationship between innovation and product/service discontinuation using the firm as a unit of analysis. This study further adds to the under-researched (relative to manufacturing studies) area of service innovation.
Open innovation in SMEs
Authors: Henttonen Kaisa , Lehtimäki Hanna
Published: March 2017

Purpose

This study examines how technology-intensive small- and medium-sized enterprises (SMEs) engage in open innovation. The purpose of this paper is to add to the literature on open innovation in SMEs, which has received considerably less attention than open innovation in large companies. Also, the study adds on the literature on open innovation in the commercialization phase.

Design/methodology/approach

A multiple case study of 13 technology-intensive SMEs in forestry sector was conducted. The forestry sector in Finland was chosen as a target context, there were many innovative pioneering SMEs operating in the industry and because the sector was going through significant changes.

Findings

Three multi-firm collaboration modes in the commercialization phase were identified: networks with a lead partner, equal partnership, and partnership for external technology commercialization. The study shows that in SMEs, open innovation is used for commercialization rather than research and development. The main conclusion of the study is that the mode of collaboration in commercialization is determined by the core competence of the firm and the strategy for open innovation.

Practical implications

The study results imply that SMEs benefit from opening up their innovation process in the commercialization phase. The firms in this study employed a blend of strategies that capitalized on their internal strengths. They collaborated actively with external firms and outsourced from specialists. This way they were able to compensate for their internal weaknesses and gain competitive advantage.

Originality/value

The study extends our understanding of open innovation by providing a detailed analysis of how open innovation takes place in the commercialization phase of innovation process. Also, the study extends understanding of the strategic use of open innovation in SMEs by showing how SMEs balance the risk of losing their competitive advantage built on innovation and the benefit of creating a broader competence base with partnerships.
Sales nationality and debt financing impact on firm’s performance and risk
Authors: Khasawneh Ahmad Y. , Dasouqi Qais A.
Published: March 2017

Purpose

The purpose of this paper is to examine the impact of debt financing on both performance and systematic risk in Amman Stock Exchange listed firms. The authors focus the study to analyze the differences between services and industrial firms in one sense and the differences between international and domestic firms in the other sense, as the study depends on the geographical distribution of sales to classify the nationality of firms.

Design/methodology/approach

The study sample includes all listed Jordanian firms in Amman Stock Exchange from 2005 to 2013 for both industrial and services sectors. Using panel data techniques, fixed effects regression with modified Driscoll-Kraay standard error as a remedy for heteroscedasticity problem is employed.

Findings

The results show that there is a significant negative impact of debt financing on the firm’s performance, where the sector and the sales nationality play an important role. Moreover, the results indicate that there is a significant positive impact of debt financing on the firm’s systematic risk. Taking the sector and sales nationality into consideration, the authors find that the debt financing has no significant impact on the systematic risk of services firms and domestic firms. Additionally, the findings indicate that services firms and international firms are, on average, more riskier than industrial firms and domestic firms, respectively.

Originality/value

The paper provides a visibility on the comparison between international and local firms in Jordan in terms of the impact of debt financing on the financial performance and systematic risk in one research.
The MED scale: regional variation in values and beliefs, evidence from Italy
Authors: Petruzzellis Luca , Samuel Craig C. , Palumbo Ada
Published: March 2017

Purpose

The purpose of this paper is to provide a measurement scale that captures elements of Mediterranean identity.

Design/methodology/approach

A scale was developed from items drawn from existing scales and from a qualitative study that examined how respondents viewed their national identity as well as the concept of a Mediterranean identity. The literature pertaining to Mediterranean identity, culture and the influence of contextual factors on its development were reviewed. The scale revealed four dimensions of Mediterranean identity: traditions, relationships, ethnocentrism and a bond with the Sea.

Findings

The scale successfully discriminated between those living by the Sea and those living inland. At the same time, it did not differentiate between respondents living in the north from those living in the south. The study suggests that context, specifically proximity to the Sea, helps shape some of the regional variation in values and beliefs.

Research limitations/implications

The geographic composition of the sample limits the generalizability of the results. A sample across additional countries would provide greater confidence in the results, although much of the theoretical work on Mediterranean thinking has focused on Italy. Further, it was desirable to keep as many factors as possible constant to limit extraneous variation. Inclusion of respondents from countries with different levels of wealth, religious and political ideologies would likely uncover additional facets of Mediterranean identity.

Practical implications

The results have broader implications for identifying transnational segments that may exist around the Mediterranean. A key implication relates to the extent that similar values and beliefs appear to be associated with proximity to the Mediterranean Sea. It also highlights the importance of considering contextual factors when developing an understanding of consumer behavior.

Originality/value

Mediterranean identity has been examined conceptually, but a systematic means to measure is lacking. The essence of Mediterranean thinking embodies the importance individuals place on adhering to traditions, the value they attach to personal relationship, a certain degree of ethnocentricism, and of course the bond with the Sea. The results also suggest that differences that have been attributed to a north/south divide, needs to be reexamined.
Impacts of changing weather patterns on smallholder well-being
Authors: Ali Akhter , Rahut Dil Bahadur , Mottaleb Khondoker Abdul , Erenstein Olaf
Published: March 2017

Purpose

This paper aims to assesses impacts of perceived weather changes (i.e. temperature, wind and rainfall) at the farm household level on income, poverty, wheat yield and use of timber and non-timber forest products in Pakistan’s Himalayan region. Mountains are fragile ecosystems – particularly for farming and in the context of climate change. Yet for many such geographies, there is limited empirical understanding of the potential impacts of climate change.

Design/methodology/approach

It uses a comprehensive field survey of 500 farmers from the Gilgit-Baltistan territory (comprising seven districts Ghizer, Gilgit, Diamer, Astore, Skardu, Ghance and Hunza-Nagar). A multivariate probit model first assesses the factors associated with perceived weather changes by farm households and a propensity score matching (PSM) approach then estimates the impacts of the perceived changes in temperature, wind and rainfall.

Findings

The empirical results show that an overwhelming majority of the farmers experience climate change, which primarily has adverse impacts on household income, poverty levels and wheat yields and increases dependence on both timber and non-timber forest products.

Originality/value

This paper contributes to the scanty literature on the climate change in the Himalayan region of Pakistan.
Building climate change resilience through adaptation in smallholder farming systems in semi-arid Zimbabwe
Authors: Jiri Obert , Mafongoya Paramu L. , Chivenge Pauline
Published: March 2017

Purpose

This study aimed to determine factors that increase resilience and cause smallholder farmers to adapt better to climate change and vulnerability.

Design/methodology/approach

In this study, the authors used the vulnerability to resilience model and binary logit model to analyse the factors influencing household decisions to adapt.

Findings

Households with increased access to climate information through extension services were likely to have better adaptation abilities. It was also shown that younger farmers were likely to adapt to climate change given their flexibility to adopt new techniques and their access and use of modern information and technology. Larger households were found to have higher probability of adapting as most adaptation strategies are labour intensive. Household’s possession of livestock and access to credit significantly enhanced adaptation. However, households with higher farm income have lesser incentives to adapt to because their current farming practices might already be optimum.

Research limitations/implications

Given that most of the smallholder farmers are vulnerable, such as women-headed households and the elderly, who are labour constrained, there is need for research and development of labour saving technologies to increase resilience to climate change and vulnerability.

Originality/value

These findings underscore the importance of enabling farmer access to information and better technologies which enable them to increase adaptive capacity and resilience.
Determinants of house buyers’ expected holding periods in boom and bust markets in California
Authors: Chernobai Ekaterina , Hossain Tarique
Published: March 2017

Purpose

This study aims to investigate the determinants of homeowners’ planned holding periods. Real estate market is known for displaying buying and selling behavior that does not conform to traditional economic theories such as rational expectation or expected utility. Mounting evidence of anomalous observations appear to be supported by other theories, such as prospect theory, which in particular helps explain the disposition effect – sellers are too quick to sell when prices are climbing and hold on to properties longer when prices are plummeting. While this evidence is widely documented in housing studies based on data on realized holding periods (i.e.ex post), this study explores factors that may motivate homeowners to alter their expected holding horizons (i.e.ex ante) to form new preferred holding periods that may be shorter or longer than those planned during house search.

Design/methodology/approach

The empirical study uses data collected from two cross-section surveys of recent homebuyers in rising and declining housing markets in Southern California in 2004-2005 and 2007-2008, respectively.

Findings

The empirical results demonstrate that in addition to the financial characteristics of the recent homebuyer, the characteristics of the buying experience – non-monetary, such as the realized search duration, and monetary, such as perception of negative or positive premium paid for the house relative to its market value – have a statistically significant effect on the holding horizon revision. The data strongly indicate that the perception of having overpaid increases the likelihood of upward revision of the original holding horizon. This effect is stronger in the declining than in the rising market – a crucial finding that mirrors the disposition effect.

Originality/value

This study sheds new light on what may contribute to the disposition effect in housing markets that has not yet been investigated in past literature. The novel approach here is to look at how different house price environments may affect homeowners’ holding periodsex antewhen they begin, rather thanex postwhen already realized.
Total Interpretive Structural Modeling (TISM): approach and application
Authors: Jena J. , Sidharth Sumati , Thakur Lakshman S. , Kumar Pathak Devendra , Pandey V.C.
Published: March 2017

Purpose

The purpose of this paper is to elucidate the methodology of total interpretive structural modeling (TISM) in order to provide interpretation for direct as well as significant transitive linkages in a directed graph.

Design/methodology/approach

This study begins by unfolding the concepts and advantages of TISM. The step-by-step methodology of TISM is exemplified by employing it to analyze the mutual dependence among inhibitors of smartphone manufacturing ecosystem development (SMED). Cross-impact matrix multiplication applied to the classification analysis is also performed to graphically represent these inhibitors based on their driving power and dependence.

Findings

This study highlights the significance of TISM over conventional interpretive structural modeling (ISM). The inhibitors of SMED are explored by reviewing existing literature and obtaining experts’ opinions. TISM is employed to classify these inhibitors in order to devise a five-level hierarchical structure based on their driving power and dependence.

Practical implications

This study facilitates decision makers to take required actions to mitigate these inhibitors. Inhibitors (with strong driving power), which occupy the bottom level in the TISM hierarchy, require more attention from top management and effective monitoring of these inhibitors can assist in achieving the organizations’ goals.

Originality/value

By unfolding the benefits of TISM over ISM, this study is an endeavor to develop insights toward utilization of TISM for modeling inhibitors of SMED. This paper elaborates step-by-step procedure to perform TISM and hence makes it simple for researchers to understand its concepts. To the best of the authors’ knowledge, this is the first study that analyzes the inhibitors of SMED by utilizing TISM approach.
Photovoice: a creative method to engage library user community
Authors: Luo Lili
Published: March 2017

Purpose

The purpose of this paper is to generate awareness of and interest in the photovoice method, and help librarians to be more creative in examining user needs, perceptions and behavior and be more effective in conducting outreach to user communities.

Design/methodology/approach

Photovice is a qualitative method that combines visuals and narratives in exploring community issues. This paper reviews the photovoice method and discusses its implications in engaging library user communities.

Findings

Photovoice is rarely used in library research and practice and only three published studies reported the use of this method. The three studies were reviewed in this paper to offer ideas regarding the potential application of this method in the library profession.

Originality/value

This paper provides an overview of an innovative method and contributes new ideas to library outreach and user engagement.
A nostalgic look back at library hi tech(nology)
Authors: Matthews Joe
Published: March 2017

Purpose

The purpose of this paper is to reflect on the history of information technology and computers in libraries over the last 50 years.

Design/methodology/approach

This paper represents a personal perspective and reflects the views and opinions of the author. It is not intended to be an authoritative reporting of this history.

Findings

This paper suggests that libraries were generally too shortsighted in their application of information technology and computing and submits that there are significant challenges facing libraries today.

Research limitations/implications

No research was conducted.

Practical implications

The author identifies several issues that libraries must confront in order that the automated systems being implemented add value for staff members but most importantly for users of library systems and services.

Social implications

The paper suggests that libraries are facing a number of challenges based on a historical review of how libraries have adopted and adapted to information technology over the past 50 years.

Originality/value

This paper, due to its personal perspective, reflects an original viewpoint.
Personal digital archiving: an analysis of URLs in the .edu domain
Authors: Moulaison Sandy Heather , Corrado Edward M. , Ivester Brandi B.
Published: March 2017

Purpose

The purpose of this paper is to consider personal digital archiving (PDA) from an academic perspective. Although elements of research data management and personal information management are relevant, it is unclear what is available on university websites supporting PDA. The following question guided the research: where is “PDA” content housed in the top-level .edu domain and what is the format and nature of the content made available?

Design/methodology/approach

This descriptive study analyzed Google hits yielded by searching “PDA” within the .edu domain. Results were analyzed to determine where content was housed and its format and nature. Placement in the domain, delivery methods, topics, and the nature of the most highly ranking Uniform Resource Locators (URLs) were analyzed.

Findings

In the academy, PDA is not exclusively of interest in libraries; not quite half of the .edu URLs (45 percent) pointed to a library site. Scholarly papers were the most returned content, followed by blogs and conferences information. Closer analysis of the top 20 URLs showed that libraries are popular and papers, and blogs continue to be dominant.

Research limitations/implications

The results suggest good PDA practices and recommendations are evolving. Academic librarians should examine these practices, refine them, and make them available and discoverable on the web.

Originality/value

This is the first paper, to the knowledge, to consider PDA content from the perspective of universities and university libraries.
The medium-term prospects for long-term storage systems
Authors: Rosenthal David Stuart Holmes
Published: March 2017

Purpose

Increasingly, the content that libraries collect is no longer on paper, a long-lived, medium whose technology changes very slowly and with which they have centuries of experience. Instead, it is stored on relatively short-lived digital media whose technology appears to change rapidly and with which they have little history. The paper aims to discuss this issue.

Design/methodology/approach

The storage media industry is highly competitive and is currently evolving rapidly as flash, a solid state medium, displaces spinning disk from many applications. Long-term archival storage is a small part of the total storage market. It typically re-uses media and systems intended for more general bulk storage.

Findings

What are the medium-term prospects for change in this market?

Originality/value

Much of this material has appeared in blog posts and talks aimed at storage experts, such as the recent DARPA workshop on future of storage. It is presented here for a librarian audience with the necessary additional exposition and background.
Disruption be my guide
Authors: O’Connor Steve , Smith Ian , Afzal Waseem
Published: March 2017

Purpose

The skill set required to be a professional in any profession is inherent in the qualifications required for entrance to that profession. The ability to demonstrate leadership in the middle to upper echelons of that profession is demonstrably different. The School of Information Studies at the Charles Sturt University in Wagga Wagga Australia sought to explore what a postgraduate qualification in the leadership of the profession might look like and what the demand for such a qualification might be. The purpose of this paper is to detail that research effort and the outcomes.

Design/methodology/approach

The study undertook a number of different approaches including engaging in networks of professional colleagues globally and a series of focus groups in Brisbane, Sydney and Melbourne. The outcomes were analyzed in terms of the expectations of what a new degree might contain as well as the enrollment prospects for such a degree.

Findings

There was a strong ground-swell of support for a new degree of Masters of Information Leadership. The combination of subjects from the LIS environment together with subjects from a MBA environment was strongly endorsed. These areas of interest were documented in the paper along with recommendations.

Research limitations/implications

There is a fertile ground for research here in two ways. First, there is much scope for the examination of the course requirements and how they sit in a future work environment. This is especially the case where there is a convergence of the interests of the galleries, libraries, archives and museums sectors. Second, there is much to be done as the authors look at leadership skills sets for future information environments which are highly speculative.

Practical implications

This study has produced a set of requirements for a new Masters of Information Leadership. It is a very useful set of requirements to base future studies. There was also a very strong requirement for real life aspects to such a course rather than theoretical exercises as has been the current academic practice.

Originality/value

This study is quite original as it sought to engage practitioners in different areas and sectors in Australia aiming to ensure that the resulting academic program was closely aligned with practitioner need.
Design and experimental study on the freeform fabrication with polymer melt droplet deposition
Authors: Chi Baihong , Jiao Zhiwei , Yang Weimin
Published: March 2017

Purpose

3D printing based on additive manufacturing has advantages in manufacturing products with high geometrical complexity. However, there are many limitations to print plastic products with the existing commercial 3D printers. The polymer materials processing industry needs new devices which can satisfy the trend of processing individual units and small batch sizes of plastic parts.

Design/methodology/approach

In this study, a freeform fabrication system with the method of polymer melt droplet deposition is proposed. The performance of this system under different conditions was studied by changing the operating parameters. Furthermore, the dimensional uniformity of droplets and their deposition process are analyzed, and a plastic sample was fabricated with this system as an example.

Findings

The results show a clear correlation between the processing parameters and the droplet diameter. In the experiment for examining the dimensional uniformity of the droplet, the droplets become spindles, and there appears a melt filament between the droplets. The variation of the droplet’s diameters is within 5 per cent. Furthermore, a successfully processed rectangular plastic sample verified the feasibility of this technology for the printing of plastic products.

Originality/value

A freeform fabrication system with polymer melt droplet deposition is proposed, which can process a wide variety of materials in the form of standard granulates like injection molding or extrusion. Based on the principle of droplet deposition, multi-component or colorful materials can be printed.
Effects of 3D-bioplotted polycaprolactone scaffold geometry on human adipose-derived stem cell viability and proliferation
Authors: Mehendale Saahil V. , Mellor Liliana F. , Taylor Michael A. , Loboa Elizabeth G. , Shirwaiker Rohan A.
Published: March 2017

Purpose

This study aims to investigate the effect of three-dimensional (3D)- bioplotted polycaprolactone (PCL) scaffold geometry on the biological and mechanical characteristics of human adipose-derived stem cell (hASC) seeded constructs.

Design/methodology/approach

Four 3D-bioplotted scaffold disc designs (Ø14.5 × 2 mm) with two levels of strand–pore feature sizes and two strand laydown patterns (0°/90° or 0°/120°/240°) were evaluated for hASC viability, proliferation and construct compressive stiffness after 14 days of in vitro cell culture.

Findings

Scaffolds with the highest porosity (smaller strand–pore size in 0°/120°/240°) yielded the highest hASC proliferation and viability. Further testing of this design in a 6-mm thick configuration showed that cells were able to penetrate and proliferate throughout the scaffold thickness. The design with the lowest porosity (larger strand–pore size in 0°/90°) had the highest compression modulus after 14 days of culture, but resulted in the lowest hASC viability. The strand laydown pattern by itself did not influence the compression modulus of scaffolds. The 14-day cell culture also did not cause significant changes in compressive properties in any of the four designs.

Originality/value

hASC hold great potential for musculoskeletal tissue engineering applications because of their relative ease of harvest, abundance and differentiation abilities. This study reports on the effects of 3D-bioplotted scaffold geometry on mechanical and biological characteristics of hASC-seeded PCL constructs. The results provide the basis for future studies which will use this optimal scaffold design to develop constructs for hASC-based osteochondral tissue engineering applications.
Healing simulation for bond strength prediction of FDM
Authors: Coogan Timothy J. , Kazmer David O.
Published: March 2017

Purpose

The purpose of this paper is to present a diffusion-controlled healing model for predicting fused deposition modeling (FDM) bond strength between layers (z-axis strength).

Design/methodology/approach

Diffusion across layers of an FDM part was predicted based on a one-dimensional transient heat analysis of the interlayer interface using a temperature-dependent diffusion model determined from rheological data. Integrating the diffusion coefficient across the temperature history with respect to time provided the total diffusion used to predict the bond strength, which was compared to the measured bond strength of hollow acrylonitrile butadiene styr (ABS) boxes printed at various processing conditions.

Findings

The simulated bond strengths predicted the measured bond strengths with a coefficient of determination of 0.795. The total diffusion between FDM layers was shown to be a strong determinant of bond strength and can be similarly applied for other materials.

Research limitations/implications

Results and analysis from this paper should be used to accurately model and predict bond strength. Such models are useful for FDM part design and process control.

Originality/value

This paper is the first work that has predicted the amount of polymer diffusion that occurs across FDM layers during the printing process, using only rheological material properties and processing parameters.
Pre and post processing techniques to improve surface characteristics of FDM parts: a state of art review and future applications
Authors: Chohan Jasgurpreet Singh , Singh Rupinder
Published: March 2017

Purpose

The purpose of this paper is to review the various pre-processing and post-processing approaches used to ameliorate the surface characteristics of fused deposition modelling (FDM)-based acrylonitrile butadiene styrene (ABS) prototypes. FDM being simple and versatile additive manufacturing technique has a calibre to comply with present need of tailor-made and cost-effective products with low cycle time. But the poor surface finish and dimensional accuracy are the primary hurdles ahead the implementation of FDM for rapid casting and tooling applications.

Design/methodology/approach

The consequences and scope of FDM pre-processing and post-processing parameters have been studied independently. The comprehensive study includes dominance, limitations, validity and reach of various techniques embraced to improve surface characteristics of ABS parts. The replicas of hip implant are fabricated by maintaining the optimum pre-processing parameters as reviewed, and a case study has been executed to evaluate the capability of vapour smoothing process to enhance surface finish.

Findings

The pre-processing techniques are quite deficient when different geometries are required to be manufactured within limited time and required range of surface finish and accuracy. The post-processing techniques of surface finishing, being effective disturbs the dimensional stability and mechanical strength of parts thus incapacitates them for specific applications. The major challenge for FDM is the development of precise, automatic and controlled mass finishing techniques with low cost and time.

Research limitations/implications

The research assessed the feasibility of vapour smoothing technique for surface finishing which can make consistent castings of customized implants at low cost and shorter lead times.

Originality/value

The extensive research regarding surface finish and dimensional accuracy of FDM parts has been collected, and inferences made by study have been used to fabricate replicas to further examine advanced finishing technique of vapour smoothing.
Inkjet and inkjet-based 3D printing: connecting fluid properties and printing performance
Authors: Guo Yang , Patanwala Huseini S. , Bognet Brice , Ma Anson W.K.
Published: March 2017

Purpose

This paper aims to summarize the latest developments both in terms of theoretical understanding and experimental techniques related to inkjet fluids. The purpose is to provide practitioners a self-contained review of how the performance of inkjet and inkjet-based three-dimensional (3D) printing is fundamentally influenced by the properties of inkjet fluids.

Design/methodology/approach

This paper is written for practitioners who may not be familiar with the underlying physics of inkjet printing. The paper thus begins with a brief review of basic concepts in inkjet fluid characterization and the relevant dimensionless groups. Then, how drop impact and contact angle affect the footprint and resolution of inkjet printing is reviewed, especially onto powder and fabrics that are relevant to 3D printing and flexible electronics applications. A future outlook is given at the end of this review paper.

Findings

The jettability of Newtonian fluids is well-studied and has been generalized using a dimensionless Ohnesorge number. However, the inclusion of various functional materials may modify the ink fluid properties, leading to non-Newtonian behavior, such as shear thinning and elasticity. This paper discusses the current understanding of common inkjet fluids, such as particle suspensions, shear-thinning fluids and viscoelastic fluids.

Originality/value

A number of excellent review papers on the applications of inkjet and inkjet-based 3D printing already exist. This paper focuses on highlighting the current scientific understanding and possible future directions.
Processability of pure Zn and pure Fe by SLM for biodegradable metallic implant manufacturing
Authors: Montani Marco , Demir Ali Gökhan , Mostaed Ehsan , Vedani Maurizio , Previtali Barbara
Published: March 2017

Purpose

This paper aims to investigate the processability by selective laser melting (SLM) of materials of potential interest for innovative biodegradable implants, pure Fe and pure Zn. The processability of these materials is evaluated with a more established counterpart in permanent implants, stainless steel. In particular, the processing conditions were studied to reduce porosity due to incomplete fusion of the powder.

Design/methodology/approach

In the first phase of the experiments, SLM of AISI 316L was studied through design of experiments method. The study was used to identify the significant parameters in the experimental range and estimate the fluence ranges for pure Fe and pure Zn using the lumped heat capacity model. In the second phase, SLM of pure Fe and pure Zn were studied using estimated fluence ranges. In the final phase, best conditions were characterized for mechanical properties.

Findings

The results showed that complete melting of AISI 316L and pure Fe could be readily achieved, whereas laser melting generated a foam-like porous structure in Zn samples. The mechanical properties of laser melt implant materials were compared to as-cast and rolled counterparts. Laser melted AISI 316L showed superior mechanical performance compared to as-cast and rolled material, whereas Fe showed mechanical performance similar to rolled mild steel. Despite 12 per cent apparent porosity, laser melted Zn exhibited superior mechanical properties compared to as-cast and wrought material because of reduced grain size.

Originality/value

The paper provides key processing knowledge on the SLM processability of new biodegradable metals, namely, pure Fe, which has been studied sparingly, and pure Zn, on which no previous work is available. The results prefigure the production of new biodegradable metallic implants with superior mechanical properties compared to their polymeric counterparts and with improved degradation rates compared to magnesium alloys, the reference material for biodegradable metals.
Rapid prototyping assisted fabrication of customized surgical guides in mandibular distraction osteogenesis: a case report
Authors: Dahake Sandeep W. , Kuthe Abhaykumar M. , Chawla Jitendra , Mawale Mahesh B.
Published: March 2017

Purpose

The purpose of this paper is to develop a workflow for design and fabrication of customized surgical guides (CSGs) for placement of the bidirectional extraoral distraction instruments (EDIs) in bilateral mandibular distraction osteogenesis (MDO) surgery to treat the bilateral temporomandibular joint ankylosis with zero mouth opening.

Design/methodology/approach

The comprehensive workflow consists of six steps: medical imaging; virtual surgical planning (VSP); computer aided design; rapid prototyping (RP); functional testing of CSGs and mock surgery; and clinical application. Fused deposition modeling, an RP process was used to fabricate CSGs in acrylonitrile butadiene styrene material. Finally, mandibular reconstruction with MDO was performed successfully using RP-assisted CSGs.

Findings

Design and development of CSGs prior to the actual MDO surgery improves accuracy, reduces operation time and decreases patient morbidity, hence improving the quality of surgery. Manufacturing of CSG is easy using RP to transfer VSP into the actual surgery.

Originality/value

This study describes an RP-assisted CSGs fabrication for exact finding of both; osteotomy site and drilling location to fix EDI’s pins accurately in the mandible; for accurate osteotomy and placement of the bidirectional EDIs in MDO surgery to achieve accurate distraction.
Direct selective laser sintering and melting of ceramics: a review
Authors: Sing Swee Leong , Yeong Wai Yee , Wiria Florencia Edith , Tay Bee Yen , Zhao Ziqiang , Zhao Lin , Tian Zhiling , Yang Shoufeng
Published: March 2017

Purpose

This paper aims to provide a review on the process of additive manufacturing of ceramic materials, focusing on partial and full melting of ceramic powder by a high-energy laser beam without the use of binders.

Design/methodology/approach

Selective laser sintering or melting (SLS/SLM) techniques are first introduced, followed by analysis of results from silica (SiO2), zirconia (ZrO2) and ceramic-reinforced metal matrix composites processed by direct laser sintering and melting.

Findings

At the current state of technology, it is still a challenge to fabricate dense ceramic components directly using SLS/SLM. Critical challenges encountered during direct laser melting of ceramic will be discussed, including deposition of ceramic powder layer, interaction between laser and powder particles, dynamic melting and consolidation mechanism of the process and the presence of residual stresses in ceramics processed via SLS/SLM.

Originality/value

Despite the challenges, SLS/SLM still has the potential in fabrication of ceramics. Additional research is needed to understand and establish the optimal interaction between the laser beam and ceramic powder bed for full density part fabrication. Looking into the future, other melting-based techniques for ceramic and composites are presented, along with their potential applications.
Economic crises and the nationalisation of politics
Authors: JURADO IGNACIO , LEÓN SANDRA
Published: March 2017

The literature on party system nationalisation has yet to provide a better understanding of the impact of short‐term factors upon the nationalisation of politics. This article helps to fill this literature gap by analysing the effect of economic conditions on party system nationalisation. The argument is that economic crises will decrease levels of nationalisation by amplifying territorial variation in preferences for redistribution, limiting political parties’ capacity to coordinate divergent interests across districts and triggering the emergence of new political forces. Data on 47 countries for the 1960–2011 period confirm this hypothesis and show that lower economic growth during the years prior to the election is associated with a decrease in levels of party system nationalisation in the next election. The result is robust to variation in the specification of the econometric model and to the use of different measures of nationalisation. Results also show that federal institutions increase the impact of economic conditions on the nationalisation of politics, whereas any moderating effect of electoral system proportionality on the economy is not found.
Women's rights in democratic transitions: A global sequence analysis, 1900–2012
Authors: WANG YI‐TING , LINDENFORS PATRIK , SUNDSTRÖM AKSEL , JANSSON FREDRIK , PAXTON PAMELA , LINDBERG STAFFAN I.
Published: March 2017

What determines countries’ successful transition to democracy? This article explores the impact of granting civil rights in authoritarian regimes and especially the gendered aspect of this process. It argues that both men's and women's liberal rights are essential conditions for democratisation to take place: providing both women and men rights reduces an inequality that affects half of the population, thus increasing the costs of repression and enabling the formation of women's organising – historically important to spark protests in initial phases of democratisation. This argument is tested empirically using data that cover 173 countries over the years 1900–2012 and contain more nuanced measures than commonly used. Through novel sequence analysis methods, the results suggest that in order to gain electoral democracy a country first needs to furnish civil liberties to both women and men.
Evaluating the Slope‐Area Method to Accurately Identify Stream Channel Heads in Three Physiographic Regions
Authors: Avcioglu Burak , Anderson Christopher J. , Kalin Latif
Published: March 2017

Estimation of stream channel heads is an important task since ephemeral channels play a significant role in the transport of sediment and materials to perennial streams. The slope‐area method utilizes digital elevation model (DEM) and related information to develop slope‐area threshold relationships used to estimate the position of channel heads in the watershed. A total of 162 stream channel heads were mapped across the three physiographic regions of Alabama, including the Southwestern Appalachians (51), Piedmont/Ridge and Valley (61), and Coastal Plains (51). Using Geographic Information System and DEM, the local slope and drainage area for each mapped channel head was calculated and region‐specific models were developed and evaluated. Results demonstrated the local slope and drainage area had an inverse and strong correlation in the Piedmont/Ridge and Valley region (r2 = 0.71) and the Southwestern Appalachian region (r2 = 0.61). Among three physiographic regions, the weakest correlation was observed in the Coastal Plain region (r2 = 0.45). By comparing the locations of modeled channel heads to those located in the field, calculated reliability and sensitivity indices indicated model accuracy and reliance were weak to moderate. However, the slope‐area method helped define the upstream boundaries of a more detailed channel network than that derived from the 1:24,000‐scale National Hydrography Dataset, which is commonly used for planning and regulatory purposes.
Relationship between dietary carbohydrates intake and circulating sex hormone‐binding globulin levels in postmenopausal women
Authors: Huang Mengna , Liu Jinjie , Lin Xiaochen , Goto Atsushi , Song Yiqing , Tinker Lesley F. , Chan Kei‐hang Katie , Liu Simin
Published: March 2017

Background

Low circulating levels of sex hormone‐binding globulin (SHBG) have been shown to be a direct and strong risk factor for type 2 diabetes, cardiovascular diseases, and hormone‐dependent cancers, although the relationship between various aspects of dietary carbohydrates and SHBG levels remains unexplored in population studies.

Methods

Among postmenopausal women with available SHBG measurements at baseline (n = 11 159) in the Women's Health Initiative, a comprehensive assessment was conducted of total dietary carbohydrates, glycemic load (GL), glycemic index (GI), fiber, sugar, and various carbohydrate‐abundant foods in relation to circulating SHBG levels using multiple linear regressions adjusting for potential covariates. Linear trend was tested across quartiles of dietary variables. Benjamini and Hochberg's procedure was used to calculate the false discovery rate for multiple comparisons.

Results

Higher dietary GL and GI (both based on total and available carbohydrates) and a higher intake of sugar and sugar‐sweetened beverages were associated with lower circulating SHBG concentrations (all P
trend < 0.05; Q
‐values = 0.04,0.01, 0.07, 0.10, 0.01, and <0.0001, respectively). In contrast, women with a greater intake of dietary fiber tended to have elevated SHBG levels (P
trend = 0.01, Q
‐value = 0.04). There was no significant association between total carbohydrates or other carbohydrate‐abundant foods and SHBG concentrations.

Conclusions

The findings suggest that low GL or GI diets with low sugar and high fiber content may be associated with higher serum SHBG concentrations among postmenopausal women. Future studies investigating whether lower GL or GI diets increase SHBG concentrations are warranted.
New approach shows no association between maternal milk fatty acid composition and childhood wheeze or asthma
Authors: Logan C. A. , Brandt S. , Wabitsch M. , Brenner H. , Wiens F. , Stahl B. , Marosvölgyi T. , Decsi T. , Rothenbacher D. , Genuneit J.
Published: March 2017

Background

Previous observational studies have implied breastmilk fatty acid composition may play a role in the development of atopic eczema or atopic sensitization in breastfed infants and toddlers. However, studies investigating associations with wheeze and asthma in later childhood are scarce and did not account for inherent correlation of compositional data. Our aim was to explore the association of maternal milk fatty acid composition with childhood wheezing phenotypes and asthma up to age 13 years using a new statistical approach.

Methods

Breastmilk was collected 6 weeks and 6 months postdelivery in the Ulm Birth Cohort Study (n=720 and n=454, respectively). Concentrations of 28 fatty acids were measured by high‐resolution capillary gas‐liquid chromatography. To control for constant‐sum constraint, concentration data were transformed using the centered log ratio method. Compositional biplots and correlation matrices were used to group centered log ratio transformed fatty acids. Adjusted risk ratios with parent‐reported wheezing phenotypes and doctor‐diagnosed asthma were computed using a modified Poisson regression.

Results

We observed no straightforward evidence of associations between overall breastmilk fatty acid composition and specific wheeze phenotypes or doctor‐diagnosed asthma.

Conclusion

Using appropriate statistical methodology, we report null associations. These findings may partly be attributable to several cohort‐specific factors associated with breastfeeding and breastmilk collection. Further studies could improve on ours by analyzing samples of breastmilk and formula and by including all children for whom these are exclusively or together the major source of fatty acids in the first months of life.