Applying uses and gratifications theory (UGT) and social capital theory, our study examined users of four social networking sites (SNSs) (Facebook, Twitter, Instagram, and Snapchat), and their ...influence on online bridging and bonding social capital. Results (N = 297) found that Twitter users had the highest bridging social capital, followed by Instagram, Facebook, and Snapchat, while Snapchat users had the highest bonding social capital, followed by Facebook, Instagram, and Twitter. SNS intensity, trust, tie strength, homophily, privacy concerns, introversion, and attention to social comparison were also found to moderate the relationship between SNS use and online bridging and bonding social capital.
•Uses and gratification theory (UGT) was applied to explain social networking site usage.•Facebook, Twitter, Instagram, and Snapchat influence bridging/bonding social capital.•SNS intensity, tie strength, privacy, introversion, and social comparison are moderators.
Most traditional research on mergers and acquisitions tends to focus on the role of similarity in explaining acquisition performance. While scholars have recently begun to examine acquisition ...complementarity, there is still little evidence concerning how complementarity influences acquisition performance. Further, previous research has not drawn the connections between related contexts and the potential benefits from complementarity. In this article, we move the study of acquisition complementarity forward by investigating the effects of strategic and market complementarity on acquisition performance in the context of related horizontal acquisitions. We also propose that two key attributes of acquirers--strategic focus and out-of-market acquisition experience--will moderate this relationship. We investigate our research questions in the context of all 2,204 acquisitions made by publicly traded U.S. commercial banks during the 12-year period from 1989 to 2001. Our findings are generally supportive, suggesting complementarity is an important antecedent of acquisition performance, and raising important issues on the nature of acquisition research in general.
Most PET bottles used as beverage containers become waste after their usage, causing environmental problems. To address this issue, a method to recycle wasted PET bottles is presented, in which short ...fibers made from recycled PET are used within structural concrete. To verify the performance capacity of recycled PET fiber reinforced concrete, it was compared with that of polypropylene (PP) fiber reinforced concrete for fiber volume fractions of 0.5%, 0.75%, and 1.0%. Appropriate tests were performed to measure material properties such as compressive strength, elastic modulus, and restrained drying shrinkage strain. Flexural tests were performed to measure the strength and ductility capacities of reinforced concrete (RC) members cast with recycled PET fiber reinforced concrete. The results show that compressive strength and elastic modulus both decreased as fiber volume fraction increased. Cracking due to drying shrinkage was delayed in the PET fiber reinforced concrete specimens, compared to such cracking in non-reinforced specimens without fiber reinforcement (NF), which indicates crack controlling and bridging characteristics of the recycled PET fibers. Regarding structural member performance, ultimate strength and relative ductility of PET fiber reinforced RC beams are significantly larger than those of companion specimens without fiber reinforcement.
•Pore distribution in the interlayer analyzed using X-ray Computed Tomography.•Relationship between pore fraction and position of tensile bond fracture determined.•Tensile bond strength of 6.27% of ...compressive strength obtained.•Weakest layer occurred when tensile stress is perpendicular to printing direction.
Recently, researches on additive manufacturing (AM) method have been actively carried out as the latest technique for building concrete structures in the construction field. It is known that the additive manufacturing method, also called 3D printing technique, is a method of constructing a structure by printing layers, and the adhesion strength in the interlayer between the layers plays a dominant role in the performance of the structure. In this study, we focused on the formation of interlayer of concrete structure built using additive manufacturing method. In this study, the position of the interlayer was analyzed using the computed tomography (CT) method and the correlation between porosity and tensile bond strength in the analyzed interlayer was tried. As a result of the CT analysis of 13 specimens extracted from the printed specimens, it was confirmed that the porosity was formed high in the interlayer. The porosity of the interlayer was at least 2.15% and 6.66% higher than the average porosity. After analyzing the porosity by CT, the tensile bond strength of the specimens was measured to confirm the tensile bond strength and location of the fracture surface. Tensile bond strengths were 2.58–3.77 MPa with an average of 2.80 MPa using 10 specimens. It was confirmed that all of the fracture surfaces occurred along the interlayer. It was confirmed that there was no correlation between the tensile bond strength and porosity of the test specimens used in this study. Six of the ten specimens failed in the other interlayer, but four specimens failed in the interlayer with the highest porosity. As a result of analysis of the fracture surfaces of six specimens without fracture at the highest porosity, the porosity at the fracture surface was 5.73–9.18%, which was higher by 0.6–3.3% than the average porosity. However, defects occurred during layer output were confirmed from the failure of six specimens. Through this study, we confirmed that the interlayer is the weakest when tensile stress is applied in the perpendicular direction of printing, and that it is necessary to review the defects when applying the printing method.
Adaptation requires genetic variation, but founder populations are generally genetically depleted. Here we sequence two populations of an inbred ant that diverge in phenotype to determine how ...variability is generated. Cardiocondyla obscurior has the smallest of the sequenced ant genomes and its structure suggests a fundamental role of transposable elements (TEs) in adaptive evolution. Accumulations of TEs (TE islands) comprising 7.18% of the genome evolve faster than other regions with regard to single-nucleotide variants, gene/exon duplications and deletions and gene homology. A non-random distribution of gene families, larvae/adult specific gene expression and signs of differential methylation in TE islands indicate intragenomic differences in regulation, evolutionary rates and coalescent effective population size. Our study reveals a tripartite interplay between TEs, life history and adaptation in an invasive species.
Insulating concrete is a type of concrete that is designed to reduce thermal conductivity. Insulating concrete contains numerous voids that play an important role in reducing heat conduction. ...Therefore, appropriate nondestructive methods are required to examine the spatial distribution of voids and constituents in a concrete specimen. In this study, an insulating concrete specimen containing hollow glass beads to increase the insulating effect is adopted. Then, micro computed tomography (CT) is used to investigate the spatial distribution of the voids in this specimen. By using a micro CT device, a series of cross-sectional images of the specimen at micrometer-order pixel size are generated by X-rays. To quantitatively describe the spatial distribution of voids in the specimen, probability functions such as two-point correlation, lineal-path, and two-point cluster functions are adopted. In addition, the thermal conductivity of the specimen is evaluated using finite element simulation. The results clarify the insulating effect of glass beads on the concrete specimen and reveal a strong relationship between the probabilistic characteristics of the void distribution and the material responses of insulating concrete.
This paper argues that two different types of a firm's own extreme performance experiences—success and recovery—and their interactions can generate survival-enhancing learning. Although these types ...of experience often represent valuable sources of useful learning, several important learning challenges arise when a firm has extremely limited prior experience of the same type. Thus, we theorize that a certain threshold of a given type of experience is required before each type of experience becomes valuable, with low levels of experience harming the organization. Furthermore, we propose that success and recovery experience will interact to enhance each other's value. These conditions can help overcome learning challenges such as superstitious learning or learning from small samples. We investigate our ideas using a sample of the U.S. commercial banks founded between 1984 and 1998. Our results indicate that both success and recovery experience of a firm generate survival-enhancing learning, but only after a certain level of experience is reached. Furthermore, success and recovery experience enhance each other's learning value, consistent with the theories that emphasize the importance of richer and contrasting experience in providing useful knowledge. Our framework advances organizational learning theory by presenting a contingent model of the impact of success and recovery experience and their interaction.
This study delved into the integration of carbon nanotubes (CNTs) in Ultra-High Performance Concrete (UHPC), exploring aspects such as mechanical properties, microstructure analysis, accelerated ...chloride penetration, and life service prediction. A dispersed CNT solution (0.025 to 0.075 wt%) was employed, along with a superplasticizer, to ensure high flowability in the UHPC slurry. In addition, the combination of high-strength functional artificial lightweight aggregate (ALA) and micro hollow spheres (MHS) was utilized as a replacement for fine aggregate to not only reduce the weight of the concrete but also to increase its mechanical performance. Experimental findings unveiled that an increased concentration of CNT in CNT1 (0.025%) and CNT2 (0.05%) blends led to a marginal improvement in compressive strength compared to the control mix. Conversely, the CNT3 (0.075%) mixture exhibited a reduction in compressive strength with a rising CNT content as an admixture. SEM analysis depicted that the heightened concentration of CNTs as an admixture induced the formation of nanoscale bridges within the concrete matrix. Ponding test results indicated that, for all samples, the effective chloride transport coefficient remained below the standard limitation of 1.00 × 10−12 m2/s, signifying acceptable performance in the ponding test for all samples. The life service prediction outcomes affirmed that, across various environmental scenarios, CNT1 and CNT2 mixtures consistently demonstrated superior performance compared to all other mixtures.
In this paper we draw on work in behavioral learning theory and risk taking to examine whether firms desperate for growth overpay for acquisitions, and we develop a theory of desperation in the ...context of growth. We suggest two key drivers of such desperation: (1) when a firm's organic growth is low, paying handsomely for acquisitions may be one of the few options for growth, and (2) when a firm becomes dependent on acquisitions for continuing growth, it is vulnerable to overpaying for acquisitions. Although pressures to grow via acquisition can be intense, we also test whether the benefits of acquisition experience— from both acquirers and their advisors— help to prevent overpayment caused by desperation. We test these ideas in a sample of firms in the banking industry between 1994 and 2005. Consistent with this theory of desperation, our results showed that firms desperate for growth are more likely to pay high acquisition premiums. Our findings on the moderating role of acquisition experience showed that advisors' acquisition experience is more helpful than acquirers' own acquisition experience in preventing desperate acquirers from overpaying for a target.*
We examine whether organizations vicariously learn from near-failures and failures of others. We propose that the impact of such failure-related experience depends on the geographic market and ...industry origin of the experience. Our findings indicate that the local failure-related experience of both banks and thrifts have higher survival-enhancing learning value for banks than nonlocal experience, supporting the value of accessibility and applicability for useful learning. Bank near-failure experience had more value than bank failure experience, but thrift failure and near-failure experience had equivalent impact, suggesting that the learning impact of types of failure-related experience varies with its industry origin.
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