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For three-dimensional (3D) measurement of object surface and shape by pattern projection systems, we used a hybrid projection system, i.e., a combination of a projection lens and a transmissive freeform to generate an aperiodic sinusoidal fringe pattern. Such a freeform effects a light redistribution, thus leading to an effective and low-loss pattern projection, as it increases the total transmission intensity of the system and has less power dissipation than classical projection systems. In this paper, we present the conception and realization of the measurement setup of a transmissive fringe projection system. We compare the characteristics of the generated intensity distribution with the classical system based on GOBO (GOes Before Optics) projection and show measurement results of different surface shapes, recorded with the new system.

We have developed a 6 dm3-sized optical instrument to characterize the microphysical properties of fine particulate matter or aerosol in the Earth atmosphere from low Earth orbit. Our instrument can provide detailed and worldwide knowledge of aerosol amount, type and properties. This is important for climate and ecosystem science and human health [1, 2]. Therefore, NASA, ESA and the European Commission study the application of aerosol instruments for planned or future missions. We distinguish molecular Rayleigh scattering from aerosol Mie-type scattering by analyzing multi-angle observations of radiance and the polarization state of sun light that is scattered in the Earth atmosphere [3]. We measure across the visible wavelength spectrum and in five distinct viewing angles between-50° and +50°. Such analysis has been traditionally done by rotating polarizers and band-filters in front of an Earth observing wide-angle imager. In contrast, we adopt a means to map the linear polarization state on the spectrum using passive optical components [4]. Thereby we can characterize the full linear polarization state for a scene instantaneously. This improves the polarimetric accuracy, which is critical for aerosol characterization, enabling us to distinguish for example anthropogenic from natural aerosol types. Moreover, the absence of moving parts simplifies the instrument, and makes it more robust and reliable. We have demonstrated this method in an airborne instrument called SPEX airborne [5, 6] in the recent ACEPOL campaign together with a suite of state-of-the art and innovative active and passive aerosol sensors on the NASA ER-2 high-altitude research platform [7]. An earlier report on the SPEX development roadmap was given in [8]. In this contribution we introduce SPEXone, a compact space instrument that has a new telescope that projects the five viewing angles onto a single polarization modulation unit and the subsequent reflective spectrometer. The novel telescope allows the observation of five scenes with one spectrometer, hence the name. We describe the optical layout of the telescope, polarization modulation optics, and spectrometer and discuss the manufacturability and tolerances involved. We will also discuss the modelled instrument performance and show preliminary results from optical breadboards of the telescope and polarization modulation optics. With SPEXone we present a strong and new tool for climate research and air quality monitoring. It can be used to study the effect of atmospheric aerosol on the heating/cooling of the Earth and on air quality. Also, SPEXone can improve the accuracy of satellite measurements of greenhouse gas concentrations and ocean color that rely on molecular absorption of reflected sunlight by providing detailed knowledge of the aerosol properties, required to accurately trace the light path in presence of scattering. SPEXone is developed in a partnership between SRON Netherlands Institute for Space Research and Airbus Defence and Space Netherlands with support from the Netherlands Organisation for Applied Scientific Research (TNO) as a Dutch contribution to the NASA PACE observatory launching in 2022.

We have developed a 6 dm3-sized optical instrument to characterize the microphysical properties of fine particulate matter or aerosol in the Earth atmosphere from low Earth orbit. Our instrument can provide detailed and worldwide knowledge of aerosol amount, type and properties. This is important for climate and ecosystem science and human health [1, 2]. Therefore, NASA, ESA and the European Commission study the application of aerosol instruments for planned or future missions. We distinguish molecular Rayleigh scattering from aerosol Mie-type scattering by analyzing multi-angle observations of radiance and the polarization state of sun light that is scattered in the Earth atmosphere [3]. We measure across the visible wavelength spectrum and in five distinct viewing angles between-50° and +50°. Such analysis has been traditionally done by rotating polarizers and band-filters in front of an Earth observing wide-angle imager. In contrast, we adopt a means to map the linear polarization state on the spectrum using passive optical components [4]. Thereby we can characterize the full linear polarization state for a scene instantaneously. This improves the polarimetric accuracy, which is critical for aerosol characterization, enabling us to distinguish for example anthropogenic from natural aerosol types. Moreover, the absence of moving parts simplifies the instrument, and makes it more robust and reliable. We have demonstrated this method in an airborne instrument called SPEX airborne [5, 6] in the recent ACEPOL campaign together with a suite of state-of-the art and innovative active and passive aerosol sensors on the NASA ER-2 high-altitude research platform [7]. An earlier report on the SPEX development roadmap was given in [8]. In this contribution we introduce SPEXone, a compact space instrument that has a new telescope that projects the five viewing angles onto a single polarization modulation unit and the subsequent reflective spectrometer. The novel telescope allows the observation of five scenes with one spectrometer, hence the name. We describe the optical layout of the telescope, polarization modulation optics, and spectrometer and discuss the manufacturability and tolerances involved. We will also discuss the modelled instrument performance and show preliminary results from optical breadboards of the telescope and polarization modulation optics. With SPEXone we present a strong and new tool for climate research and air quality monitoring. It can be used to study the effect of atmospheric aerosol on the heating/cooling of the Earth and on air quality. Also, SPEXone can improve the accuracy of satellite measurements of greenhouse gas concentrations and ocean color that rely on molecular absorption of reflected sunlight by providing detailed knowledge of the aerosol properties, required to accurately trace the light path in presence of scattering. SPEXone is developed in a partnership between SRON Netherlands Institute for Space Research and Airbus Defence and Space Netherlands with support from the Netherlands Organisation for Applied Scientific Research (TNO) as a Dutch contribution to the NASA PACE observatory launching in 2022.

Matching and retrieval of shapes, both in two and three dimensions, have been a topic of interest to researchers in the field of computer graphics, vision and geometric modeling for at least a decade. In this paper, a shape is assumed to be represented as set of freeform curved boundaries. A prominent approach to matching curved outline is the graph-based approach, where a skeleton is used as a basis for obtaining the graph. In general, graph-matching is a hard problem and the comparison costs increase proportionally with graph size and hence slows down the process. In this paper, the skeleton, and in particular, medial axis of curved boundaries has been used. As opposed to using graph-based matching, statistical-based methods of signatures obtained from the properties of the skeleton have been employed. This enables a faster construction of shape signatures thereby increasing the speed of matching. Moreover, this facilitates the comparison of shapes that may have the presence of holes (inner loops) in it. In addition to the qualitative visualizations of retrieval results, retrieval performance by calculating quantitative statistics parameters typically used in shape matching is also discussed.� 2012 CAD Solutions, LLC.

Bounding hulls, such as convex hulls, have been shown to be useful in many application areas. ?-hull, a generalization of convex hull, has been predominantly employed in reconstruction. Other hulls such as concave hull, which generates nonconvex polygons poly hull, r-shape and s-shape etc. have also been shown to be useful. Most algorithms for bounding hulls deal with point-set as input. Recently, we approached the question of bounding hull to a set of close planar freeform curves and proposed an algorithm for concave hull by defining it (definition was lacking even for a point-set). In this paper, we extend it to concave hull of a set of freeform closed surfaces in R 3 of genus 0. Surfaces used are represented as NURBS (non-uniform rational B-splines). The concept of concave hull is then extended for genus &gt, 0 and showed that the hull will consists of lower dimensional elements and topological disks. Based on this observation, a conjecture is proposed for elements in the concave hull of freeform closed objects in n dimensions. � 2012 CAD Solutions, LLC.

As a novel computer-aided materials additive manufacturing process, the freeform laser consolidation (LC) can directly produce functional shapes (features or structures) through a "layer-upon-layer" deposition. In this research, LC processability of both H13 and CPM 9V tool steels and their mechanical performance thus obtained were investigated. Both laser-consolidated tool steels were metallurgically sound with no crack, exhibiting layer-wise refined solidified structures with dominated martensite and small amount of retained austenite, as well as composition-dependent carbides. Laser-consolidated H13 could outperform its wrought counterpart mechanically as measured by tensile strength/strain, and bonding strength as well as sliding wear resistance; laser-consolidated CPM 9V could provide excellent sliding wear resistance superior to the conventional widely used tool steel (such as wrought D2). These unique microstructures and mechanical properties could be tailored for niche applications in additive manufacturing of tools, molds, and dies. © 2013 Her Majesty the Queen in Right of Canada.

Background: Calnuc is a multidomain Ca2+-binding protein with many interacting partners but whose function is still elusive. Results: Calnuc is a serine protease with its active site catalytic triad present in the C-terminal domain. Conclusion: The serine protease activity of calnuc is allosterically regulated by Zn2-binding and its interaction with G protein? subunit. Significance: Novel proteolytic function of calnuc will have vital implications in its physiological role. The functions of calnuc, a novel Ca 2+-binding protein with multiple structural domains and diverse interacting partners, are yet unknown. We demonstrate unknown facets of calnuc, which is a serine protease in which Ser-378 of GXSXG motif, Asp-328 of DTG motif, and His-339 form the "catalytic triad," locating the enzyme active site in the C-terminal region. Analogous to the active site of Zn2 carboxypeptidases, calnuc has two high affinity (Kd= 20 nM), well conserved Zn2-binding sites near its N terminus, although it is inactive as a peptidase. Zn2 binding allosterically and negatively regulates the serine protease activity of calnuc, inhibition being caused by an "open to close" change in its conformation not seen upon Ca2+ binding. Most strikingly, interaction with G protein? subunit completely inhibits the enzymatic activity of calnuc. We thus illustrate that G proteins and Zn2 act as two "keys" that control enzymatic activity of calnuc, arresting it in "locked" state. Calnuc, therefore, exists dynamically in two different forms, (i) as a Ca2+-binding protein in Zn2-bound form and (ii) as a protease in Zn2-free form, commissioning it to perform multiple functions. � 2013 by The American Society for Biochemistry and Molecular Biology, Inc.

In this work, we describe the use of a composite material made of a renewable source and metallic nanoparticles for biosensing applications. NCC is a product isolated from natural cellulose fibers, which is of approx. 100 nm long and 10 nm wide in size. We augmented the surface area and chemical affinity of NCC by optimally dressing it with gold nanoparticles (AuNP). The deposition of AuNP on NCC was controlled by using cationic Polyethylenimine (PEI). AuNPs were thio-funtionalized prior to enzyme immobilization and the enzyme (glucose oxidase) was conjugated on the composite by carbodiimide (EDC)/NHS coupling. Using UV-visible and fluorescence spectroscopy in the presence of a specific substrate we monitored the activity of the immobilized enzymes, and its efficiency was compared with that of the enzyme in free form. Our results using FT-IR and SEM show that thiol-AuNPs were attached to the surface of NCC. The enzymes activity were measured and quantified using different kit assays and proved that the enzymes were attached to the support and maintained their activity., Nanotech Conference and Expo 2012, June 18-21, 2012, Santa Clara, CA, USA

This work presents the Continuous Wave (CW) laser crystallization of thin amorphous silicon (a-Si) films deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) and by Electron Beam Evaporation (EBE) on low cost glass substrate. The films are characterized by Elastic Recoil Detection Analysis (ERDA) and by Fourier-Transform Infrared (FTIR) spectroscopy to evaluate the hydrogen content. Analysis shows that the PECVD films contain a high hydrogen concentration (∼10 at.%) while the EBE films are almost hydrogen-free. It is found that the hydrogen is in a bonding configuration with the a-Si network and in a free form, requiring a long thermal annealing for exodiffusion before the laser treatment to avoid explosive effusion. The CW laser crystallization process of the amorphous silicon films was operated in liquid phase regime. We show by Electron Backscatter Diffraction (EBSD) that polysilicon films with large grains can be obtained with EBE as well as for the PECVD amorphous silicon provided that for the latest the hydrogen content is lower than 2 at.%. © 2012 Elsevier B.V.

The breakthrough of freeform optics is limited by manufacturing and metrology technology. However, today's manufacturing machines like polishing robots and diamond turning machines are accurate enough to produce good surface quality, so the question is how accurate can a freeform be produced. To investigate how accurate freeform optics can be diamond turned, measurable freeforms (e.g. an "off-axis" sphere) were diamond turned and they were compared to there on-axis equivalents. The results of this study are described in this paper. Furthermore, an overview of the accuracies of freeform optics that TNO diamond turned are presented. An indication of freeform accuracy for diamond turned optics is derived from this, which can be used for optical designers as a guideline in their design work. © 2009 SPIE.

The breakthrough of freeform optics is limited by manufacturing and metrology technology. However, today's manufacturing machines like polishing robots and diamond turning machines are accurate enough to produce good surface quality, so the question is how accurate can a freeform be produced. To investigate how accurate freeform optics can be diamond turned, measurable freeforms (e.g. an "off-axis" sphere) were diamond turned and they were compared to there on-axis equivalents. The results of this study are described in this paper. Furthermore, an overview of the accuracies of freeform optics that TNO diamond turned are presented. An indication of freeform accuracy for diamond turned optics is derived from this, which can be used for optical designers as a guideline in their design work. © 2009 SPIE.