Iowa State University

About: Iowa State University is a education organization based out in Ames, Iowa, United States. It is known for research contribution in the topics: Population & Gene. The organization has 50151 authors who have published 107716 publications receiving 3355909 citations. The organization is also known as: Iowa State University of Science and Technology & Iowa State College.

An Empirically Derived Framework of Global Supply Resiliency

Abstract: In today’s global business environment, supply chains have increased in both length and complexity. This increase in length and complexity coupled with a focus on improving efficiency, such as lean manufacturing practices, may lead to higher levels of supply chain risk where the likelihood of a disruption severely impacting supply chain performance increases. Resilient supply chains have been touted as a means to reduce the likelihood and severity of supply chain disruptions. However, there is little empirical evidence relative to the factors that contribute to or detract from supply resiliency. Using systems theory and the resource-based view of the firm as the theoretical underpinnings, this study provides an in-depth systematic investigation of supply resiliency. Adopting a theory-building approach based on a multi-industry empirical investigation, this study derives empirical generalizations linking 19 supply chain characteristics to supply resiliency. The study culminates in a framework that could be used to assess the level of resiliency in a supply base. Building on this framework, the study also provides a supply resiliency matrix that can be utilized to classify supply chains, or supply chains segments according to the level of resiliency realized. This article concludes by proposing several future research directions and issues that may be investigated in more detail.

Contamination of water resources by pathogenic bacteria

Abstract: Water-borne pathogen contamination in water resources and related diseases are a major water quality concern throughout the world. Increasing interest in controlling water-borne pathogens in water resources evidenced by a large number of recent publications clearly attests to the need for studies that synthesize knowledge from multiple fields covering comparative aspects of pathogen contamination, and unify them in a single place in order to present and address the problem as a whole. Providing a broader perceptive of pathogen contamination in freshwater (rivers, lakes, reservoirs, groundwater) and saline water (estuaries and coastal waters) resources, this review paper attempts to develop the first comprehensive single source of existing information on pathogen contamination in multiple types of water resources. In addition, a comprehensive discussion describes the challenges associated with using indicator organisms. Potential impacts of water resources development on pathogen contamination as well as challenges that lie ahead for addressing pathogen contamination are also discussed.

Magnetization and transport currents in thin superconducting films.

Abstract: The critical-state behavior of an infinitely long type-II superconducting thin-film strip is theoretically analyzed for an arbitrary sequence of applied transport currents and perpendicular magnetic fields. Included are solutions for applied field only, transport current only, transport current applied to a sample initially in the remanent critical state, ac applied field, ac transport current, and simultaneously applied field and transport current. The results are compared side by side with corresponding solutions for the more famililar slab geometry; there are striking differences in behavior.

Spectroscopic evidence for a type II Weyl semimetallic state in MoTe2

Abstract: In a type I Dirac or Weyl semimetal, the low-energy states are squeezed to a single point in momentum space when the chemical potential μ is tuned precisely to the Dirac/Weyl point. Recently, a type II Weyl semimetal was predicted to exist, where the Weyl states connect hole and electron bands, separated by an indirect gap. This leads to unusual energy states, where hole and electron pockets touch at the Weyl point. Here we present the discovery of a type II topological Weyl semimetal state in pure MoTe2, where two sets of Weyl points (, ) exist at the touching points of electron and hole pockets and are located at different binding energies above EF. Using angle-resolved photoemission spectroscopy, modelling, density functional theory and calculations of Berry curvature, we identify the Weyl points and demonstrate that they are connected by different sets of Fermi arcs for each of the two surface terminations. We also find new surface 'track states' that form closed loops and are unique to type II Weyl semimetals. This material provides an exciting, new platform to study the properties of Weyl fermions.

Transforming online teaching practice: critical analysis of the literature on the roles and competencies of online teachers

Abstract: Understanding what is lacking in the online teaching literature is critical to helping researchers and practitioners develop programs and support mechanisms for online teachers in higher education. This review formulates a critique of the standards- and competency-driven vision of online teaching from the perspective of transformative learning theory, in order to offer an alternative exploration of the professional development of online teachers as adult learners. The results indicate that while research about online teacher roles and competencies guides the development of teacher preparation and training programs, it lacks in terms of addressing the issues of empowerment of online teachers, promoting critical reflection, and integrating technology into pedagogical inquiry. An alternative perspective is suggested that considers teachers as adult learners who continuously transform their meaning of structures related to online teaching through a continuous process of critical reflection and action.