Oklahoma State University–Stillwater

About: Oklahoma State University–Stillwater is a education organization based out in Stillwater, Oklahoma, United States. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 18267 authors who have published 36743 publications receiving 1107500 citations. The organization is also known as: Oklahoma State University & OKState.

Chemical, Physical, and Mechanical Characterization of Isocyanate Cross-linked Amine-Modified Silica Aerogels

Abstract: We describe a new mechanically strong lightweight porous composite material obtained by encapsulating the skeletal framework of amine-modified silica aerogels with polyurea. The conformal polymer coating preserves the mesoporous structure of the underlying silica framework and the thermal conductivity remains low at 0.041 plus or minus 0.001 W m(sup -1 K(sup -1). The potential of the new cross-linked silica aerogels for load-carrying applications was determined through characterization of their mechanical behavior under compression, three-point bending, and dynamic mechanical analysis (DMA). A primary glass transition temperature of 130 C was identified through DMA. At room temperature, results indicate a hyperfoam behavior where in compression cross-linked aerogels are linearly elastic under small strains (less than 4%) and then exhibit yield behavior (until 40% strain), followed by densification and inelastic hardening. At room temperature the compressive Young's modulus and the Poisson's ratio were determined to be 129 plus or minus 8 MPa and 0.18, respectively, while the strain at ultimate failure is 77% and the average specific compressive stress at ultimate failure is 3.89 x 10(exp 5) N m kg(sup -1). The specific flexural strength is 2.16 x 10(exp 4) N m kg(sup -1). Effects on the compressive behavior of strain rate and low temperature were also evaluated.

A Homoeotic Mutant of Arabidopsis thaliana with Leafy Cotyledons.

Abstract: Cotyledons are specialized leaves produced during plant embryogenesis. Cotyledons and leaves typically differ in morphology, ultrastructure, and patterns of gene expression. The leafy cotyledon (Iec) mutant of Arabidopsis thaliana fails to maintain this distinction between embryonic and vegetative patterns of plant development. Mutant embryos are phenotypically abnormal, occasionally viviparous, and intolerant of desiccation. Mutant cotyledons produce trichomes characteristic of leaves, lack embryo-specific protein bodies, and exhibit a vascular pattern intermediate between that of leaves and cotyledons. These results suggest that lec cotyledons are partially transformed into leaves and that the wild-type gene (LEC) functions to activate a wide range of embryo-specific pathways in higher plants.

The Internet of Things: Review and theoretical framework

Abstract: The Internet of Things (IoT) global arena is massive and growing exponentially. Those in the emerging digital world have recently witnessed the proliferation and impact of IoT-enabled devices. The IoT has provided new opportunities in the technology arena while bringing several challenges to an increased level of concern. This research has both practical and theoretical impetus since IoT is still in its infancy, and yet it is considered by many as the most important technology initiative of today. This study includes a systematic review and synthesis of IoT related literature and the development of a theoretical framework and conceptual model. The review of the literature reveals that the number of applications that make use of the IoT has increased dramatically and spans areas from business and manufacturing to home, health care, and knowledge management. Although IoT can create invaluable data in every industry, it does not occur without its challenges. The theoretical framework developed identifies IoT priority areas and challenges, providing a guide for those leading IoT initiatives and revealing opportunities for future IoT research.

Asymptotic Optimality of Fisher's Method of Combining Independent Tests

Abstract: Four methods of combining independent tests of hypothesis are compared via exact Bahadur relative efficiency. The methods considered are Fisher's method, the mean of the normal transforms of the significance levels, the maximum significance level, and the minimum significance level. None of these is uniformly more powerful than the others, but, according to Bahadur efficiency, Fisher's method is the most efficient of the four. In some cases, Fisher's method is most efficient of all tests based on the data, but this is not generally true.