Effect of Manual Grinding Operations on Surface Integrity

AbstractManual grinding operations are influenced by a number of variants such as a worker's posture and motion, in addition to the general parameters affecting automated grinding processes, for example, tool speed and feed rate. Moreover, dry cutting conditions and poor control of the machining process can negatively influence chip formation and part quality in terms of roughness, microhardness, microstructure, etc. The goal of this work is to analyze the processing energy, resulting surface integrity, and prospective part performance, considering the above-mentioned variants, with the aim to give a detailed insight into manual grinding processes and fill the existing knowledge gaps. For this paper, we have limited our subject to one and thus have not studied the effect of worker's skills involved in manual grinding

Development of Desktop Multipurpose Grinding Machine for Educational Purposes

AbstractGiven the growing popularity of the maker movement, it is proposed that affordable machine tools may be desirable for both teaching purposes in universities and high schools and use at home by Do It Yourself enthusiasts. For the concept to become a reality, it is necessary that the machine tool can be easily assembled and disassembled by an end-user (e.g. student or hobbyist) and can adapt to changing projects or machining requirements. In this paper the concept and initial development of such a desktop multipurpose machine tool is reported. Through the use of modular robot modules, it is demonstrated that a machine can be converted from an outer diameter grinding to freeform grinding configuration in approximately 15minutes. The initial prototype machine will be used to demonstrate concepts such as miniaturization, multi-functionality, and re-configurability for machine tools to undergraduate and high school students

Data on ADME parameters of bisphenol A and its metabolites for use in physiologically based pharmacokinetic modelling

The paper presents the collection of physicochemical parameters of bisphenol A (BPA) and its sulfate (BPAS) and glucuronide (BPAG) conjugates, accompanied by data characterizing their absorption, distribution, metabolism and excretion (ADME) behavior following oral administration of BPA. The data were collected from open literature sources and publicly available databases. Additionally, data calculated by using the MarvinSketch 18.30.0 software or predicted by relevant QSAR models built in Simcyp® Simulator were also used. All data were analysed and are fit for purpose if necessary to ensure a reliable prediction of pharmacokinetics of BPA and its conjugates. The data selection process and reasoning for fitting is provided to allow critical assessment and to ensure data transparency. Finally, the sensitivity analysis was performed to assess the influence of the selected parameters on the PBPK model predictions

Direct deposit of catalyst on the membrane of direct feed fuel cells

An improved direct liquid-feed fuel cell having a solid membrane electrolyte for electrochemical reactions of an organic fuel. Catalyst utilization and catalyst/membrane interface improvements are disclosed. Specifically, the catalyst layer is applied directly onto the membrane electrolyte

Aesthetics and Gloss of Ground Surfaces: A Review on Measurement and Generation

Visual appearance of an object significantly influences a consumer's choice and largely controls the market economy. The perceived quality of products is governed by surface's optical properties (reflection, refraction, etc.), geometrical properties (roughness, waviness, etc.), and chemical properties (oxide layer formation, thermal variation, etc.). Surface shininess attracts researchers from many different disciplines, in particular manufacturing, metrology, psychology, physiology, and computer science. Unfortunately, there are still huge knowledge gaps on characterizing and appraising shiny surfaces in a reproducible way. This paper introduces the main definitions and physics of shininess and gloss, methods of gloss sensing, and relates these definitions and methods to surface generation by grinding. Automated gloss measurement is difficult in particular for free-form surfaces, and optical quality is still often evaluated by human workers. Gloss models are often based on the bidirectional reflection distribution function (BRDF) of the surface, but the models are commonly not connected with the manufacturing process. This study proposes to consider the geometrical features (defects, waviness, lay, and roughness) of metal surfaces as well as the physical and chemical features (grain structure and microlayers) to understand surface appearance and manufacturing in a holistic way. Preliminary tests show that 2D roughness measurements are not connected well with measured gloss units (GUs) and subjective, perceived quality. More fundamental research on the generation and measurement of surface appearance is needed and would benefit many industries

Assoziative Zuordnung und Suche von Wissen in einer thematisch strukturierten Wissensbasis

Gängler B, Greten M, Linke T, Wachsmuth I. Assoziative Zuordnung und Suche von Wissen in einer thematisch strukturierten Wissensbasis. MOSYS Report. Vol 11.; 1992.Von einer thematischen Strukturierung der Wissensbasis sind zwei Funktionen eines sprachverstehenden Systems betroffen: Bei der Wissensakquisition aus Texten können die gegebenen Fakten dem geeigneten Teil der Wissensbasis zugeordnet werden; für die Bearbeitung von Anfragen kann die Suche auf thematisch eingeschränkte Teilbereiche der Wissensbasis fokussiert werden. In beiden Fällen muß vom System der für die zu bearbeitenden Texte (und Anfragen) relevante Wissensbasis-Ausschnitt erkannt werden. In dem vorliegenden Papier werden erste Versuche mit einem subsymbolischen Klassifizierungsmodul beschrieben, das Texte aufgrund wortbezogener Merkmale Teilbereichen einer strukturierten Wissensbasis thematisch zuordnet. Ausgangspunkt war die Annahme, daß das Vokabular faktenübermittelnder Informationstexte kumulativ auf den in einem Text angesprochenen Weltausschnitt hinweist. Verschiedene Typen künstlicher neuronaler Netze wurden in einer Lernphase mit vorbereiteten Paaren von textspezifischen Merkmalskombinationen und assoziierten Wissensbereichen trainiert. In Tests mit neuen Texten wurden von einem derart trainierten Backpropagation-Netzwerk in den meisten Fällen plausible Bereichszuordnungen vorgeschlagen

Implementing an Insect Brain Computational Circuit Using III–V Nanowire Components in a Single Shared Waveguide Optical Network

Recent developments in photonics include efficient nanoscale optoelectronic components and novel methods for sub-wavelength light manipulation. Here, we explore the potential offered by such devices as a substrate for neuromorphic computing. We propose an artificial neural network in which the weighted connectivity between nodes is achieved by emitting and receiving overlapping light signals inside a shared quasi 2D waveguide. This decreases the circuit footprint by at least an order of magnitude compared to existing optical solutions. The reception, evaluation and emission of the optical signals are performed by a neuron-like node constructed from known, highly efficient III-V nanowire optoelectronics. This minimizes power consumption of the network. To demonstrate the concept, we build a computational model based on an anatomically correct, functioning model of the central-complex navigation circuit of the insect brain. We simulate in detail the optical and electronic parts required to reproduce the connectivity of the central part of this network, using experimentally derived parameters. The results are used as input in the full model and we demonstrate that the functionality is preserved. Our approach points to a general method for drastically reducing the footprint and improving power efficiency of optoelectronic neural networks, leveraging the superior speed and energy efficiency of light as a carrier of information.Comment: 28 pages, 6 figures; supplementary information 15 pages, 8 figure