What drives the valuation of entrepreneurial ventures? A map to navigate the literature and research directions

The drivers of the valuations of entrepreneurial ventures are an important issue in entrepreneurial finance, but related research is fragmented. The theoretical perspectives and the drivers highlighted by previous studies differ based on the financial milestones during a venture's lifecycle in which the valuation is performed (e.g., venture capital investments, initial public offerings, acquisitions). The introduction of new digital financing channels (e.g., crowdfunding, initial coin offerings) that allow retail investors to directly invest in entrepreneurial ventures challenge our understanding of the drivers of valuation. This change has also increased the diversity in the sequence of financial milestones that ventures go through, with important implications for valuation. We conduct a systematic literature review and develop a map highlighting how and why the drivers of venture valuations and their underlying theoretical lenses vary across the different milestones that ventures go through. The map allows us to outline new promising avenues for future research.Plain English Summary In this paper, we conduct a systematic literature review on entrepreneurial ventures' valuation drivers and their underlying theoretical lenses, highlighting how and why they vary along firms' life cycle. The valuation of entrepreneurial ventures is a challenging task for practitioners and a relevant issue that attracts the attention of scholars in entrepreneurship, finance, management, and economics. The literature on the topic is highly fragmented. Indeed, the context in which venture valuations are observed (e.g., in private deals or public offerings) differs across different financial milestones. The introduction of new digital financing channels (e.g., crowdfunding, initial coin offerings) and the increased diversity in the sequence of financial milestones that ventures go through further challenge our understanding of valuation drivers. This study is primarily aimed at scholars, offering them a map to create order in what we know about the drivers of entrepreneurial venture valuations and indicating promising avenues for future research

Alkali-activation of marble sludge: Influence of curing conditions and waste glass addition

The use of marble sludge as precursor for new alkali activated materials was assessed studying three different curing conditions (air, humid and water immersion, respectively), after an initial curing at 60 °C for 24 h, and two glass powder fractions additions (2.5 and 5.0 vol%). Microstructural, physical (drying shrinkage, Fourier transform-infrared (FT-IR) spectroscopy, X-ray spectroscopy (XPS)), thermal (differential thermal analysis – thermogravimetric analysis, DTA-TGA) and mechanical (flexural and compressive strength) properties were investigated. Air curing was the most favourable atmosphere for mechanical properties development because it promotes Si-O-Si polymerization and gel densification, as demonstrated by FT-IR and FE-SEM observations, respectively. Satisfactory mechanical properties were achieved (18 MPa and 45 MPa, for flexural and compressive strength, respectively) in particular for glass containing mixtures. Moreover, glass powder addition significantly reduced drying shrinkage of air-cured samples because it operated as a rigid aggregate in the matrix and strengthened the formed gel

Architecture framework of IoT-based food and farm systems: A multiple case study

The Internet of Things (IoT) is expected to be a real game changer in food and farming. However, an important challenge for large-scale uptake of IoT is to deal with the huge heterogeneity of this domain. This paper develops and applies an architecture framework for modelling IoT-based systems in the agriculture and food domain. The framework comprises a coherent set of architectural viewpoints and a guideline to use these viewpoints to model architectures of individual IoT-based systems. The framework is validated in a multiple case study of the European IoF2020 project, including different agricultural sub sectors, conventional and organic farming, early adopters and early majority farmers, and different supply chain roles. The framework provides a valuable help to model, in a timely, punctual and coherent way, the architecture of IoT-based systems of this diverse set of use cases. Moreover, it serves as a common language for aligning system architectures and enabling reuse of architectural knowledge among multiple autonomous IoT-based systems in agriculture and food

Stratigraphic reconstruction of the Víti breccia at Krafla volcano (Iceland): insights into pre-eruptive conditions priming explosive eruptions in geothermal areas

Krafla central volcano in Iceland has experienced numerous basaltic fissure eruptions through its history, the most recent examples being the Mývatn (1724‒1729) and Krafla Fires (1975-1984). The Mývatn Fires opened with a steam-driven eruption that produced the Víti crater. A magmatic intrusion has been inferred as the trigger perturbing the geothermal field hosting Víti, but the cause(s) of the explosive response remain uncertain. Here, we present a detailed stratigraphic reconstruction of the breccia erupted from Víti crater, characterize the lithologies involved in the explosions, reconstruct the pre-eruptive setting, fingerprint the eruption trigger and source depth, and reveal the eruption mechanisms. Our results suggest that the Víti eruption can be classified as a magmatic-hydrothermal type and that it was a complex event with three eruption phases. The injection of rhyolite below a pre-existing convecting hydrothermal system likely triggered the Víti eruption. Heating and pressurization of shallow geothermal fluid initiated disruption of a scoria cone \textquotedblcap\textquotedbl via an initial series of small explosions involving a pre-existing altered weak zone, with ejection of fragments from at least 60-m depth. This event was superseded by larger, broader, and dominantly shallow explosions (\~ 200~m depth) driven by decompression of hydrothermal fluids within highly porous, poorly compacted tuffaceous hyaloclastite. This second phase was triggered when pressurized fluids broke through the scoria cone complex \textquotedblcap\textquotedbl. At the same time, deep-rooted explosions (\~ 1-km depth) began to feed the eruption with large inputs of fragmented rhyolitic juvenile and host rock from a deeper zone. Shallow explosions enlarging the crater dominated the final phase. Our results indicate that at Krafla, as in similar geological contexts, shallow and thin hyaloclastite sequences hosting hot geothermal fluids and capped by low-permeability lithologies (e.g. altered scoria cone complex and/or massive, thick lava flow sequence) are susceptible to explosive failure in the case of shallow magmatic intrusion(s). Supplementary Information The online version contains supplementary material available at 10.1007/s00445-021-01502-y

Multifunctional peri-urban agriculture: Some ecosystem services of a sustainable olive grove

This study reports the influence of a sustainable management model which entails the recycling of urban wastewater and distribution by drip irrigation, recycling of polygenic carbon sources internal to the olive orchard (cover crops, pruning material) on yield, soil water holding capacity, soil biodiversity. Sustainable management practices were applied for a 15-year period in a 2-ha olive orchard located in an hilly peri-urban zone of southern Italy, where olive tree represents the dominant crop and has a key role inside the traditional landscape. A comparison between sustainable and conventional management (soil tillage, burning of the pruning residues, mineral fertilization, empirical irrigation) was carried out. This study suggests some guidelines of a sustainable management of peri-urban olive groves, with benefits to the whole agro-ecosystem stability and to the near town, recognizing the multifunctional role of agriculture that enhances the creation of synergies between urban and rural areas

Digital light processing stereolithography of zirconia ceramics: Slurry elaboration and orientation-reliant mechanical properties

Digital Light Processing (DLP) is a promising technique for the preparation of ceramic parts with complex shapes and high accuracy. In this study, 3 mol% yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) UV-curable slurries were prepared and printed via DLP. Two different solid loadings (40.5 and 43.6 vol%, respectively) and printing directions were investigated to assess the influence of these parameters on physical and mechanical properties of the sintered parts. Zirconia samples were sintered at 1550 °C for 1 h, achieving a very high relative density (99.2%TD), regardless of solid loading and printing direction. FE-SEM micrographs shown a homogeneous and defect-free cross section with an average grains size of 0.56 ± 0.19 µm. Finally, mechanical properties were influenced by printing direction and zirconia vol%. Indeed, the composition with the higher solid loading (i.e. 43.6 vol%) had the highest three-point flexural strength (751 ± 83 MPa) when tested perpendicular to the printing plane

Calibration of the Thermal Infrared Sensor on the Landsat Data Continuity Mission

The Landsat series of satellites provides the longest running continuous data set of moderate-spatial-resolution imagery beginning with the launch of Landsat 1 in 1972 and continuing with the 1999 launch of Landsat 7 and current operation of Landsats 5 and 7. The Landsat Data Continuity Mission (LDCM) will continue this program into a fourth decade providing data that are keys to understanding changes in land-use changes and resource management. LDCM consists of a two-sensor platform comprised of the Operational Land Imager (OLI) and Thermal Infrared Sensors (TIRS). A description of the applications and design of the TIRS instrument is given as well as the plans for calibration and characterization. Included are early results from preflight calibration and a description of the inflight validation

Indocyanine green (ICG) fluorescent cholangiography during laparoscopic cholecystectomy using RUBINA™ technology: preliminary experience in two pediatric surgery centers

Background: Recently, we reported the feasibility of indocyanine green (ICG) near-infrared fluorescence (NIRF) imaging to identify extrahepatic biliary anatomy during laparoscopic cholecystectomy (LC) in pediatric patients. This paper aimed to describe the use of a new technology, RUBINA™, to perform intra-operative ICG fluorescent cholangiography (FC) in pediatric LC. Methods: During the last year, ICG-FC was performed during LC using the new technology RUBINA™ in two pediatric surgery units. The ICG dosage was 0.35 mg/Kg and the median timing of administration was 15.6 h prior to surgery. Patient baseline, intra-operative details, rate of biliary anatomy identification, utilization ease, and surgical outcomes were assessed. Results: Thirteen patients (11 girls), with median age at surgery of 12.9 years, underwent LC using the new RUBINA™ technology. Six patients (46.1%) had associated comorbidities and five (38.5%) were practicing drug therapy. Pre-operative workup included ultrasound (n = 13) and cholangio-MRI (n = 5), excluding biliary and/or vascular anatomical anomalies. One patient needed conversion to open surgery and was excluded from the study. The median operative time was 96.9 min (range 55–180). Technical failure of intra-operative ICG-NIRF visualization occurred in 2/12 patients (16.7%). In the other cases, ICG-NIRF allowed to identify biliary/vascular anatomic anomalies in 4/12 (33.3%), including Moynihan's hump of the right hepatic artery (n = 1), supravescicular bile duct (n = 1), and short cystic duct (n = 2). No allergic or adverse reactions to ICG, post-operative complications, or reoperations were reported. Conclusion: Our preliminary experience suggested that the new RUBINA™ technology was very effective to perform ICG-FC during LC in pediatric patients. The advantages of this technology include the possibility to overlay the ICG-NIRF data onto the standard white light image and provide surgeons a constant fluorescence imaging of the target anatomy to assess position of critical biliary structures or presence of anatomical anomalies and safely perform the operation