White lighting, an assessment of different organic, hybrid, non-conventional and theoretical methods

During the last two decades, worldwide economic growth has highlighted the issue of new and more efficient lighting technologies. The swift development of new and high performing inorganic and organic emissive materials has brought to the market competitive and efficient solid state lighting (SSL) devices with promising performance features and efficiencies well beyond those of traditional artificial lighting. They are predicted to become the next generation of general illumination systems and researchers are working worldwide in order to improve device properties, cost and environmental impact of these technologies. The principal aim of this work is to develop new emissive materials that can be employed for lighting applications using different expedients. Furthermore, in order to do this, a deep understanding of the electronic processes and of the molecular interactions that are behind their properties is desired. In the first chapter, the fundamentals of organic electronic materials, with a particular focus on OLEDs, are described. The principles that are behind the production of white light using organic materials are discussed, with practical examples able to summarise the state of the art technologies explored currently.In the second chapter, novel emissive materials based on the under explored bis-benzothiadiazole (bBT) unit are presented. These have been successfully incorporated as down converters in simple hybrid inorganic-organic white LEDs and their performance studied. In chapter 3, four OLED devices that employ a novel benzothiadiazole (BT) derivative molecule as the single emissive layer are presented. The performances of the devices depended on the architecture chosen, and they achieved colour qualities similar to those of commercial fluorescent tubes. In chapter 4, a new way to make highly emissive materials has been explored, with two metal-organic frameworks (MOFs) and four porous organic polymers (POPs) synthesised and characterised. Finally, the role of non-covalent interactions in dictating constricted geometries have been explored in a novel class of 4,8-benzobisthiazole (BBT) materials in chapter 5.During the last two decades, worldwide economic growth has highlighted the issue of new and more efficient lighting technologies. The swift development of new and high performing inorganic and organic emissive materials has brought to the market competitive and efficient solid state lighting (SSL) devices with promising performance features and efficiencies well beyond those of traditional artificial lighting. They are predicted to become the next generation of general illumination systems and researchers are working worldwide in order to improve device properties, cost and environmental impact of these technologies. The principal aim of this work is to develop new emissive materials that can be employed for lighting applications using different expedients. Furthermore, in order to do this, a deep understanding of the electronic processes and of the molecular interactions that are behind their properties is desired. In the first chapter, the fundamentals of organic electronic materials, with a particular focus on OLEDs, are described. The principles that are behind the production of white light using organic materials are discussed, with practical examples able to summarise the state of the art technologies explored currently.In the second chapter, novel emissive materials based on the under explored bis-benzothiadiazole (bBT) unit are presented. These have been successfully incorporated as down converters in simple hybrid inorganic-organic white LEDs and their performance studied. In chapter 3, four OLED devices that employ a novel benzothiadiazole (BT) derivative molecule as the single emissive layer are presented. The performances of the devices depended on the architecture chosen, and they achieved colour qualities similar to those of commercial fluorescent tubes. In chapter 4, a new way to make highly emissive materials has been explored, with two metal-organic frameworks (MOFs) and four porous organic polymers (POPs) synthesised and characterised. Finally, the role of non-covalent interactions in dictating constricted geometries have been explored in a novel class of 4,8-benzobisthiazole (BBT) materials in chapter 5

The nature of corporate entrepreneurship: theoretical and empirical insights

This thesis consists of three essays linked to each other by perspectives of entrepreneurship, openness, and innovation, through which I sought to give an answer to a specific research question. Starting from the premise that corporate entrepreneurship should be understood as a renewal process of the existing organization that is aimed at maintaining and improving the competitive potential of a company in its environment, I have developed my research in order to give an answer to the following question: how does the evolution of the relationship between a company and external agents effect the inclination of the first one to innovate? According to this premise, in the first essay I analyzed the conceptual structure of corporate entrepreneurship in order to discover the core themes and limitations. In the second essay, according to results that emerged from the previous research, I have delivered a theoretical framework aimed to fulfill the limitations that emerged. In the third and last essay, I sought to demonstrate empirically the theoretical results that emerged in the previous essays, analyzing how relationships with external agents could affect the strategic innovation of a company. More specifically, the first essay aimed to reveal the conceptual structure map of the corporate entrepreneurship research field during the period 1992-2015. By adopting a co-word analysis approach and following the most rigorous methodological prescriptions, 43 main concepts were detected by filtering the co-occurrence of 654 normalized author’s keywords extracted from the Scopus database. Cluster analysis and multidimensional scaling (MDS) were applied in order to gather and detect the concepts’ positioning, densities, distances, and gaps cartography. Based on these multivariate analyses, the following conclusions can be drawn: (i) the five main keyword groups of concepts are located in three areas: central, semi-peripheral and peripheral; (ii) innovation and strategy related concepts are central in the field; (iii) entrepreneurial leverages and entrepreneurialism focused on SME’s concepts are semiperipheral; (iv) organizational concepts related to learning and absorptive capacity, culture, human resources and cognition are largely decentralized and represent the emerging, hidden or peripheral topics. The second essay deals with the collaborative nature of corporate entrepreneurship and deepens the limitations that emerged from the previous analysis. In particular, the starting point has been the perspective that collaborative innovation with customers or external agents is increasingly important for the development of company innovation processes. Despite this critical role, how a customer’s collaborative relationship with a firm can be used to manage the innovation processes has received relatively little attention in the current corporate entrepreneurship literature. This analysis aims to reveal a theoretical framework that helps to fill a specific gap that has emerged in previous studies in this field, offering a theory of innovation that links this field of study with value co-creation and open innovation. By adopting a bibliometric analysis approach and following the most rigorous methodological prescriptions, the main concepts have been detected by the literature review of each field of study and a frequency of keywords analysis has been applied. Based on these analyses, the essay is divided into two studies. The first study provides a review of the literature from three existing fields of studies: corporate entrepreneurship, value co-creation, and open innovation, placing emphasis on how companies engage in collaborative innovation with external agents. The second study, using a multiple qualitative case study, shows how companies’ innovations are shaped by relationships with customers. The goal of the last essay is to demonstrate empirically the results that emerged in the previous essays in the field of companies’ openness. Since the last century, the increasing adoption of more open approaches to innovation has required firms to revise their traditional views of strategy. However, relatively little is known about how managers can go about achieving this transformation, and how—and to what extent—strategy should be adapted. This study, using a grounded-theory approach, investigates how and why forms of open strategy occur as a result of open innovation approaches. In particular, we identify the key dimensions that underpin open strategy. We discuss them in terms of innovation strategy, business complementarities, strategic fit and bidirectional communication. We also identify three different possible levels of open strategy: corporate, functional and business area. The results of our analysis: (i) highlight that the open innovation approach is a starting point for the process of open strategy, (ii) show to what extent an open innovation approach tends to influence and shape the strategy of a firm, and (iii) provide researchers with a framework that seeks to explain the key dimensions of open strategy

Diversity of Expertise is Key to Scientific Impact: a Large-Scale Analysis in the Field of Computer Science

Understanding the relationship between the composition of a research team and the potential impact of their research papers is crucial as it can steer the development of new science policies for improving the research enterprise. Numerous studies assess how the characteristics and diversity of research teams can influence their performance across several dimensions: ethnicity, internationality, size, and others. In this paper, we explore the impact of diversity in terms of the authors' expertise. To this purpose, we retrieved 114K papers in the field of Computer Science and analysed how the diversity of research fields within a research team relates to the number of citations their papers received in the upcoming 5 years. The results show that two different metrics we defined, reflecting the diversity of expertise, are significantly associated with the number of citations. This suggests that, at least in Computer Science, diversity of expertise is key to scientific impact.Comment: This paper has been accepted for presentation at STI2023 (https://www.sti2023.org/). It will be presented on September 202

The AIDA Dashboard: Analysing Conferences with Semantic Technologies

Scientific conferences play a crucial role in the field of Computer Science by promoting the cross-pollination of ideas and technologies, fostering new collaborations, shaping scientific communities, and connecting research efforts from academia and industry. However, current systems for analysing research data do not provide a good representation of conferences. Specifically, these solutions do not allow to track research trends, to compare conferences in similar fields, and to analyse the involvement of industrial sectors. In order to address these limitations, we developed the AIDA Dashboard, a tool for exploring and making sense of scientific conferences which integrates statistical analysis, semantic technologies, and visual analytics

Integrating Knowledge Graphs for Comparing the Scientific Output of Academia and Industry

Analysing the relationship between academia and industry allows us to understand how the knowledge produced by the universities is being adopted and enriched by the industrial sector, and ultimately affects society through the release of relevant products and services. In this paper, we present a preliminary approach to assess and compare the research outputs of academia and industry. This solution integrates data from several knowledge graphs describing scientific articles (Microsoft Academics Graph), research topics (Computer Science Ontology), organizations (Global Research Identifier Database), and types of industry (DBpedia). We focus on the Semantic Web as exemplary field and report several insights regarding the different behaviours of academia and industry, and the types of industries most active in this field

The role of structural and electronic factors in shaping the ambipolar properties of donor-acceptor polymers of thiophene and benzothiadiazole

The influence of different thiophene donor units on electrochemical and spectroscopic properties of benzothiadiazole based donor–acceptor π-conjugated organic materials is studied. Two different structure modification vectors of the donor units are being considered – one addressing the intermolecular interactions through off-conjugation side chain architecture, and the other focusing on intramolecular interactions tuned by in-conjugation substituents. Electrochemical and simultaneous in situ EPR-UV-Vis-NIR spectroelectrochemical studies of the oxidative (p-) and reductive (n-) doping processes, which are responsible for the optoelectronic properties of these materials, revealed their disparate course and dissimilar effects of redox reactions of the conjugated π-bond. While p-doping prevalent species were found to comprise intensively interacting spin bearing and spinless charge carriers, the n-doping state was found to involve only one type of negatively charged carrier, with spin carrying species being selectively generated at due cathodic potentials. No spin pairing of these negative polarons was observed with their increasing population behaving like a collection of localised charge carriers. Qualitative and quantitative comparisons between the p- and n-doping carrier populations provided independent support for the spin pairing phenomena of positive charge carriers. Steric effects of varying alkyl side chain substitution have demonstrated predominant impact on the electrochemical properties of investigated polymers, and, thereto related, stability of n-doped state, while mesomeric effects of different 3,4-ethylenechalcogenide thiophene functionalities have been found to shape the energy level related spectral properties of these polymers, with particular reference to p-doping induced charged states. These findings provide new insights into the factors requiring attention during structure tailoring of donor–acceptor assemblies for organic optoelectronic applications

Effective Surgical Management of a Large Serous Ovarian Cyst in a Morbidly Obese Middle-Aged Woman: A Case Study and Literature Review

Background: In contemporary gynecological practice, encountering giant ovarian tumors is a rarity. While most are benign and of the mucinous subtype, the borderline variant only accounts for approximately 10% of these cases. This paper addresses the paucity of information about this specific subtype, emphasizing critical elements of managing borderline tumors that can pose life-threatening complications. Additionally, a review of other documented cases of the borderline variant in the literature is also included to foster a deeper understanding of this uncommon condition. Case Report: We present the multidisciplinary management of a 52-year-old symptomatic woman with a giant serous borderline ovarian tumor. Preoperative assessment showed a multiloculated pelvic-abdominal cyst responsible for compression of the bowel and retroperitoneal organs, and dyspnea. All tumor markers were negative. Together with anesthesiologists and interventional cardiologists, we decided to perform a controlled drainage of the cyst of the tumor, to prevent hemodynamic instability. Subsequent total extrafascial hysterectomy, contralateral salpingo-oophorectomy, and abdominal wall reconstruction, followed by admission to the intensive care unit, were also conducted by the multidisciplinary team. During the postoperative period, the patient experienced a cardiopulmonary arrest and acute renal failure, which were managed by dialysis. After discharge, the patient underwent oncologic followup, and after 2 years, she was found to be completely recovered and disease free. Conclusions: Intraoperative controlled drainage of Giant ovarian tumor fluid, planned by a multidisciplinary management team, constitutes a valid and safe alternative to the popular choice of “en bloc” tumor resection. This approach avoids rapid changes in body circulation, which are responsible for intraoperative and postoperative severe complications

To bend or not to bend – are heteroatom interactions within conjugated molecules effective in dictating conformation and planarity?

We consider the roles of heteroatoms (mainly nitrogen, the halogens and the chalcogens) in dictating the conformation of linear conjugated molecules and polymers through non-covalent intramolecular interactions. Whilst hydrogen bonding is a competitive and sometimes more influential interaction, we provide unambiguous evidence that heteroatoms are able to determine the conformation of such materials with reasonable predictability

AIDA: a Knowledge Graph about Research Dynamics in Academia and Industry

Academia and industry share a complex, multifaceted, and symbiotic relationship. Analysing the knowledge flow between them, understanding which directions have the biggest potential, and discovering the best strategies to harmonise their efforts is a critical task for several stakeholders. Research publications and patents are an ideal medium to analyze this space, but current datasets of scholarly data cannot be used for such a purpose since they lack a high-quality characterization of the relevant research topics and industrial sectors. In this paper, we introduce the Academia/Industry DynAmics (AIDA) Knowledge Graph, which describes 21M publications and 8M patents according to the research topics drawn from the Computer Science Ontology. 5.1M publications and 5.6M patents are further characterized according to the type of the author’s affiliations and 66 industrial sectors from the proposed Industrial Sectors Ontology (INDUSO). AIDA was generated by an automatic pipeline that integrates data from Microsoft Academic Graph, Dimensions, DBpedia, the Computer Science Ontology, and the Global Research Identifier Database. It is publicly available under CC BY 4.0 and can be downloaded as a dump or queried via a triplestore. We evaluated the different parts of the generation pipeline on a manually crafted gold standard yielding competitive results

An ambipolar BODIPY derivative for a white exciplex OLED and cholesteric liquid crystal laser toward multifunctional devices

A new interface engineering method is demonstrated for the preparation of an efficient white organic light-emitting diode (WOLED) by embedding an ultrathin layer of the novel ambipolar red emissive compound 4,4-difluoro-2,6-di(4-hexylthiopen-2-yl)-1,3,5,7,8-pentamethyl-4-bora-3a,4a-diaza-s-indacene (bThBODIPY) in the exciplex formation region. The compound shows a hole and electron mobility of 3.3 × 10–4 and 2 × 10–4 cm2 V–1 s–1, respectively, at electric fields higher than 5.3 × 105 V cm–1. The resulting WOLED exhibited a maximum luminance of 6579 cd m–2 with CIE 1931 color coordinates (0.39; 0.35). The bThBODIPY dye is also demonstrated to be an effective laser dye for a cholesteric liquid crystal (ChLC) laser. New construction of the ChLC laser, by which a flat capillary with an optically isotropic dye solution is sandwiched between two dye-free ChLC cells, provides photonic lasing at a wavelength well matched with that of a dye-doped planar ChLC cell