A compact holographic optical tweezers instrument

Holographic optical tweezers have found many applications including the construction of complex micron-scale 3D structures and the control of tools and probes for position, force, and viscosity measurement. We have developed a compact, stable, holographic optical tweezers instrument which can be easily transported and is compatible with a wide range of microscopy techniques, making it a valuable tool for collaborative research. The instrument measures approximately 30×30×35 cm and is designed around a custom inverted microscope, incorporating a fibre laser operating at 1070 nm. We designed the control software to be easily accessible for the non-specialist, and have further improved its ease of use with a multi-touch iPad interface. A high-speed camera allows multiple trapped objects to be tracked simultaneously. We demonstrate that the compact instrument is stable to 0.5 nm for a 10 s measurement time by plotting the Allan variance of the measured position of a trapped 2 μm silica bead. We also present a range of objects that have been successfully manipulated

Thermal Conductivity of Tooth Structure, Dental Cements, and Amalgam

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66601/2/10.1177_00220345610400030501.pd

Educational Needs of Community Health Nursing Supervisors

Recent legislative trends toward early hospital dismissal and cost containment have shifted the setting for health care from the hospital to the home. Consequently, community health nursing supervisors are becoming increasingly responsible both for coordinating care for sicker clients with fewer available resources, and for guiding staff nurses who provide high-tech nursing skills in the home. This has resulted in new educational needs for these supervisors. To determine their educational needs and the barriers to implementing their roles, 160 community health nursing supervisors employed by community health nursing agencies in Michigan were surveyed. They reported educational needs related to labor relations, reimbursement procedures, fiscal management, marketing, and computer systems. Several types of educational experiences were found to influence their abilities to handle supervisory responsibilities, including enrollment in an educational program, highest level of education, and selected content areas taught in their formal educational programs. Nursing implications include using the research results to develop educational programs to meet the needs of community health nursing supervisors. Those who are adequately prepared educationally will be better able to provide effective supervision of staff nurses and ultimately, coordinate high-level client home care.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74660/1/j.1525-1446.1989.tb00565.x.pd

Isomeric Poly(benzophenone)s: synthesis of Highly Crystalline Poly(4,4'-benzophenone) and Amorphous Poly(2,5-benzophenone), a Soluble Poly(p-phenylene) Derivative

Nickel-catalyzed polymerization which employs the coupling of isomeric dichlorobenzophenones is described. The polymerization utilizes inexpensive readily available monomers, 4,4-dichlorobenzophenone (4,4'-DCBP) and 2,5-dichlorobenzophenone (2,5-DCBP). The poly(4,4'-benzophenone) can be derivatized to be soluble during the synthesis by the use of a ketimine precursor that is subsequently hydrolyzed to give the target material. The polymerization of 2,5-dichlorobenzophenone yields a soluble derivative of poly(p-phenylene). The resulting polymers were characterized to confirm the composition, molar mass, and thermal properties. The Ni(O) catalyzed route proves to be facile and economically feasible and opens the way to a large variety of heterocyclic and phenyl-based homo- and copolymers

Automatic 3D facial model and texture reconstruction from range scans

This paper presents a fully automatic approach to fitting a generic facial model to detailed range scans of human faces to reconstruct 3D facial models and textures with no manual intervention (such as specifying landmarks). A Scaling Iterative Closest Points (SICP) algorithm is introduced to compute the optimal rigid registrations between the generic model and the range scans with different sizes. And then a new template-fitting method, formulated in an optmization framework of minimizing the physically based elastic energy derived from thin shells, faithfully reconstructs the surfaces and the textures from the range scans and yields dense point correspondences across the reconstructed facial models. Finally, we demonstrate a facial expression transfer method to clone facial expressions from the generic model onto the reconstructed facial models by using the deformation transfer technique

Dielectric anisotropy in the GW space-time method

Excited-state calculations, notably for quasiparticle band structures, are nowadays routinely performed within the GW approximation for the electronic self-energy. Nevertheless, certain numerical approximations and simplifications are still employed in practice to make the computations feasible. An important aspect for periodic systems is the proper treatment of the singularity of the screened Coulomb interaction in reciprocal space, which results from the slow 1/r decay in real space. This must be done without introducing artificial interactions between the quasiparticles and their periodic images in repeated cells, which occur when integrals of the screened Coulomb interaction are discretised in reciprocal space. An adequate treatment of both aspects is crucial for a numerically stable computation of the self-energy. In this article we build on existing schemes for isotropic screening and present an extension for anisotropic systems. We also show how the contributions to the dielectric function arising from the non-local part of the pseudopotentials can be computed efficiently. These improvements are crucial for obtaining a fast convergence with respect to the number of points used for the Brillouin zone integration and prove to be essential to make GW calculations for strongly anisotropic systems, such as slabs or multilayers, efficient. (C) 2006 Elsevier B.V. All rights reserved

The ASCE neutron probe calibration study: overview

A workshop was held at Logan, Utah to gather field information on neutron probe calibration and operation. Several techniques and instruments were compared. This paper serves to establish the background information for the work and describe the overall approaches, conditions, and equipment. Other papers presented at this conference provide detailed procedures and results

The Microhardness of Enamel and Dentin

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68055/2/10.1177_00220345580370041301.pd