Application of lean six sigma business practices to an Air Purifying Respirator process

Chemical and metallurgical operations involving hazardous materials (plutonium, other nuclear materials, beryllium, and corrosive liquids) account for most activities performed at nuclear research facilities. When engineering controls are not feasible, excursions of these contaminants into the operator's breathing zone are prevented through the use of personal protective equipment, including Air Purifying Respirators (APRs). Lean Manufacturing and Six Sigma (LSS) business practices effectively improve the APR process. Designing the APR process management system increases effectiveness, while adopting streamlined and cost effective activities that meet nuclear research worker needs. This paper discusses the application of LSS business practices to an APR process and demonstrates how management uses the results to make decisions.     

A comparison of spherical and cylindrical microparticles composed of nanoparticles for pulmonary application

Nano-embedded microparticles represent promising carrier systems to tackle the challenges of nanoparticle delivery into the lungs by inhalation. While spray drying is widely used for the incorporation of nanoparticles into microparticles, the template-assisted technique is a novel method to prepare aspherical, cylindrical microparticles composed of nanoparticles. In this work, both techniques were applied to produce both spherical and cylindrical nano-embedded microparticles. For both geometries particles consisting of gelatin nanoparticles, mannitol and leucine were prepared in three different sizes each. Cylindrical microparticles could be prepared with defined dimensions and narrow size distributions, allowing to target a wide range of aerodynamic diameters. The size of spherical microparticles was influenced by the spraying feed concentration, yielding only small differences in geometric and aerodynamic diameters and broad particle size distributions. Regarding the redispersibility of the nano-embedded microparticles, spherical particles showed better disintegration behavior and higher nanoparticle release in comparison to cylindrical particles upon contact with water. The template-assisted technique yielded higher nanoparticle content in contrast to spray drying. In summary, cylindrical particles represent a promising drug delivery system with high potential for later application. However, further improvements in the preparation method are required to enable higher yields and a possible later scale-up.

Copyright © 2018 American Association for Aerosol Research     

Goal consensus and collaboration.

This article updates our previous article in this journal (Tryon & Winograd, 2001) by examining via meta-analyses results of recent studies, published from 2000 through 2009, that relate goal consensus and collaboration to treatment outcome. Specifically, 15 studies with a total sample size of 1,302 yielded a goal consensus-psychotherapy outcome effect size of .34 (SD = .19, p SD = .17, p     

Analytic techniques in the interpretation of the Luria-Nebraska Neuropsychological Battery.

The use of the Luria-Nebraska Neuropsychological Battery meets clinical needs and provides for continued research, but should not prevent the clinician from using qualitative data when appropriate. A review of the theoretical basis of the Luria-Nebraska Battery, including reasons for use of a standardized battery and the construction of the scales, is included. The article also presents a brief example of a Luria-Nebraska interpretation using the case of a 60-yr-old male displaying fluent aphasic deficits, who was examined by D. C. Delis and E. Kaplan (see record 1982-08842-001). (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Targeted synthesis and environmental applications of oxide nanomaterials

Oxide nanomaterials are indispensable building blocks for a future nanotechnology, because they offer an infinite variety of structural motifs that lead to their widespread technical application. Therefore, flexible and tunable preparative strategies are required to convert this large family of materials onto the nanoscale. Although hydrothermal syntheses have proven especially suitable for this purpose, their reaction pathways and mechanisms often remain unknown so that they can be difficult to control. In the following, we summarize our comprehensive approach towards nanostructured functional oxides that is based on synthetic parameter optimizations, mechanistic in situ investigations and the characterization of environmentally relevant properties, e.g. in photocatalysis or sensor technology. The connection between preparative morphology control and the resulting materials properties is demonstrated for selected tungstate systems and bismuth-containing oxides. Furthermore, different methods for the in situ monitoring of hydrothermal processes are discussed.     

How to Evaluate and Manipulate Charge Transfer and Photocatalytic Response at Hybrid Nanocarbon–Metal Oxide Interfaces

Nanocarbon–metal oxide hybrids are among the most promising functional materials in many cutting‐edge environmental and energy applications where efficient charge separation and extraction are keys to success. The next level of hybrid structures will be achieved once one learns how to control and tune charge/energy transfer processes at the interfaces. However, little is yet known about the nature and extent of these interfacial dynamics in nanocarbon hybrids. Here a model is designed in which ultrathin dielectric layers (Al₂O₃, ZrO₂) between the hybrid's components (ZnO, TiO₂) and carbon nanotubes allow for evaluating and tuning of interfacial charge transfer over an unusually long distance of at least 50 nm. Surprisingly, the transfer efficiency correlates linearly with the barrier layer thickness, indicating that electron conduction through the barrier layer constitutes the rate‐limiting step. It is also demonstrated that the charge transfer efficiency can be tuned by the type of interlayer and its degree of crystallinity, thus controlling the hybrid's performance in the photocatalytic production of hydrogen. It is believed that this model system will help to understand and decipher the fundamentals regarding interfacial charge and energy transfer in nanocarbon hybrids with the aim to further advance these hybrid structures for a wide range of energy applications.     

Carbodiimide cross-linking counteracts the detrimental effects of gamma irradiation on the physical properties of collagen-hyaluronan sponges

Collagen-based scaffolds are extensively used in biomaterials and tissue engineering applications. These scaffolds have shown great biocompatibility and versatility, but their relatively low mechanical properties may limit use in orthopaedic load-bearing applications. Moreover, terminal sterilization with gamma irradiation, as is commonly performed with commercial devices, presents concerns over structural integrity and enzymatic stability. Therefore, the goal of this study was to test the hypothesis that EDC/NHS cross-linking (10?mM/5?mM) can protect collagen-hyaluronan sponges from the damaging effects of gamma irradiation. Specifically, we evaluated compressive and tensile mechanical properties, enzymatic stability, porosity and pore size, and swelling ratio. Ultimate tensile strength and elastic modulus exhibited increases (168.5 and 245.8%, respectively) following irradiation, and exhibited over tenfold increases (1049.2 and 1270.6%, respectively) following cross-linking. Irradiation affected pore size (38.4% decrease), but cross-linking prior to irradiation resulted in only a 17.8% decrease. Cross-linking also showed an offsetting effect on the equilibrium modulus, enzymatic stability, and swelling ratio of sponges. These results suggest that carbodiimide cross-linking of collagen-hyaluronan sponges can mitigate the structural damage typically experienced during gamma irradiation, warranting their use in tissue engineering applications.

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Sorption and Reaction of Biomass Derived HC Blends and Their Constituents on a Commercial Pt–Pd/Al2O3 Oxidation Catalyst

Catalysis Letters - Within the Research Cluster of Excellence “The Fuel Science Center” at RWTH Aachen University, the production and application of new fuels from bio-based carbon...     

Effect of enzymatic cross-linking of β-casein on proteolysis by pepsin

Food texture has a significant influence on the sensation of satiety. The digestibility of a protein matrix can be decreased by e.g. disulfide cross-links during heating, but the structure and properties of a single protein molecule can also be modified by cross-linking enzymes. In this study the effects of cross-linking of β-casein by fungal Trichoderma reesei tyrosinase (TrTyr) and bacterial Streptoverticillium mobaraense transglutaminase (Tgase) on digestibility by proteolytic pepsin were investigated by different methods. The enzymatic reaction conditions were selected in such a way that high and low molecular mass cross-linked β-casein polymers were formed. SDS-PAGE (sodium dodecyl sulphate-polyacrylamide gel electrophoresis) was used to analyze the pH stability of the cross-linked β-casein in acidic solution mimicking gastric conditions typically present during proteolytic digestion. In order to monitor the extent of pepsin digestion, the proteolytic process was halted at specific time points and aliquots of the reaction mixtures were subjected to SDS-PAGE, size-exclusion chromatography (SEC) and matrix-assisted laser desorption ionization-time of flight mass spectrometric (MALDI-TOF MS) analyses in order to evaluate sizes and quantities of the digested protein fragments. A pH-stat method was used to determine the degree of hydrolysis (DH) of the enzymatically cross-linked β-casein. The results demonstrated that enzymatically cross-linked β-casein was stable under acidic conditions and was more resistant to pepsin digestion when compared to non cross-linked β-casein. The research results will have high impact on the development of novel food structures with improved properties such as good satiety, controlled energy intake and digestibility.