Manufacturing method and performance assessment for variable lead vacuum rotors

In recent years variable lead rotors have been produced, mainly for vacuum applications, involving a multiple pass manufacturing process which is necessarily time-consuming. A faster method of manufacturing such rotors uses a full profiled disc-type milling or grinding tool but involves clearance variations along the length. These effects have been assessed by computer modelling to quantify any disadvantages. The results indicate that the effects on performance are negligible and the profiled disk tool process is suitable for such components

Achieving workplace inclusiveness by using ergonomics risk assessment

Traditional manufacturing work practices do not consider human variability issues during the design process. However, most manual assembly activities demand high levels of repetition and speed without compromising product quality and work productivity. Individual factors including age, gender, skill, experience and anthropometry cause variations in task strategies that lead to variations in individual and organizational work performance. The ergonomics-based risk assessment methods OWAS, REBA and RULA have been used to evaluate risk levels associated with working methods. This paper discusses the need for these methods to understand and highlight the key issues generated by these variations with the objective of minimizing these variations. Methods that can be used to promote working strategies that minimize the level of risk are described. The proposed research method potentially reduces work-related musculoskeletal disorders, injuries, pain, and promotes safe, healthy, productive and more inclusive working strategies suitable for a diverse working population

Determinants of new firm formation in Japan: A comparison of the manufacturing and service sectors

This paper analyzes the determinants of regional variations in new firm formation by industry, using the data of 47 prefectures in Japan. The results of this paper reveal the following evidences: (1) market access is the factor that promotes new firm formation in all industries, though the impact on new firm formation is greater in the service sectors than in the manufacturing sectors (2) the industrial agglomeration contributes to stimulating new firm formation in the manufacturing sectors and (3) while average wage is an important factor in the manufacturing sectors, it is not significant in the service sectors.

Does agricultural growth have a causal effect on manufacturing growth?

Though the role of agricultural growth for manufacturing growth has been at the center of the discourse on economic development, empirically identifying the causal effect of agricultural growth on manufacturing growth has remained illusive for the correlation between the two doesn't necessarily imply causality. This paper attempts to overcome the identification problem. Since agriculture is heavily dependent on the weather, random weather variations are used as instruments to identify the causal impact of agricultural growth on manufacturing growth. Results show that agricultural growth has a significant positive impact on manufacturing growth. The impact is higher the higher is agriculture's share in the economy (as measured by GDP and employment share). For example, in an economy with 50% of agricultural GDP, a 1% increase in agricultural output increases manufacturing output by about 1%.Agricultural Growth, Manufacturing Growth, Instrumental variable., Community/Rural/Urban Development, International Development, O14, O25, Q10,

Design of domestic photovoltaics manufacturing systems under global constraints and uncertainty

As global political discourse is taking place where the need for a cleaner energy mix is constantly highlighted, manufacturing strategies are becoming more relevant. Thus, the photovoltaics system design is a crucial aspect related with the overall sustainability. In fact, various countries are considering the potential to locally manufacture different elements of the photovoltaics (PV) value chain and the strategies to incentivize a local manufacturing base. This paper develops a mathematical programming approach for the optimal design of a PV manufacturing value chain considering diverse criteria linked to economic and environmental performance such as minimum sustainable price, transportation capacity, among others, and considering uncertainty. In addition, the proposed methodology involves the dependence over time of supply chain variables and economic parameters such as inflation, electricity cost, and weighted average cost of capital, to determine the manufacturing system topology under uncertain conditions. Our results highlight the importance of planning models to develop markets policies related to supply chains, production level changes and imposed tariffs all while involving uncertainty in economic parameters, which is an improvement compared to planning models that use deterministic formulations. Finally, the proposed methodology and results can encourage decision-making considering probable variations in different parameters

Image Transformations and Printing of Plaster Layers in Spiral Growth Manufacturing

Spiral growth manufacturing (SGM) is a high speed rapid manufacturing technique in which objects are built up, layer by layer, by simultaneously depositing, levelling and selectively consolidating thin powder layers onto a rotating build platform. The size and position of the jetted droplets are mapped by the position and greyscale level of pixels within an 8 bit greyscale bitmap image. This paper reports on the development of software in which mathematical algorithms apply geometric transformations to images in preparation for printing onto a rotating substrate. In support of this work, dimensional accuracy measurements of printed images and methods to correct radial print density variations are reported. The accuracy of printed images were found to be within ±0.2mm of their predicted size. The experimental work is briefly extended to the direct printing of plaster layers, formed by mixing two reactive ink solutions.Mechanical Engineerin

The Effects of Variable Capital Utilization on the Measurement and Properties of Sectoral Productivity: Some International Evidence

This paper explores how accounting for variations in factor utilization rates alters the empirical characteristics of productivity residuals in the United States and Canada. Using data on 19 manufacturing industries, we study the behavior of productivity using three proxies for capital services. We find that adjusting for cyclical movements in capital utilization alters many of the empirical characteristics of productivity, both within and across countries.

Performance of a novel wafer scale CMOS active pixel sensor for bio-medical imaging

Recently CMOS Active Pixels Sensors (APSs) have become a valuable alternative to amorphous Silicon and Selenium Flat Panel Imagers (FPIs) in bio-medical imaging applications. CMOS APSs can now be scaled up to the standard 20 cm diameter wafer size by means of a reticle stitching block process. However despite wafer scale CMOS APS being monolithic, sources of non-uniformity of response and regional variations can persist representing a significant challenge for wafer scale sensor response. Non-uniformity of stitched sensors can arise from a number of factors related to the manufacturing process, including variation of amplification, variation between readout components, wafer defects and process variations across the wafer due to manufacturing processes. This paper reports on an investigation into the spatial non-uniformity and regional variations of a wafer scale stitched CMOS APS. For the first time a per-pixel analysis of the electro-optical performance of a wafer CMOS APS is presented, to address inhomogeneity issues arising from the stitching techniques used to manufacture wafer scale sensors. A complete model of the signal generation in the pixel array has been provided and proved capable of accounting for noise and gain variations across the pixel array. This novel analysis leads to readout noise and conversion gain being evaluated at pixel level, stitching block level and in regions of interest, resulting in a coefficient of variation ≤ 1.9%. The uniformity of the image quality performance has been further investigated in a typical X-ray application, i.e. mammography, showing a uniformity in terms of CNR among the highest when compared with mammography detectors commonly used in clinical practise. Finally, in order to compare the detection capability of this novel APS with the currently used technology (i.e. FPIs), theoretical evaluation of the Detection Quantum Efficiency (DQE) at zero-frequency has been performed, resulting in a higher DQE for this detector compared to FPIs. Optical characterization, X-ray contrast measurements and theoretical DQE evaluation suggest that a trade off can be found between the need of a large imaging area and the requirement of a uniform imaging performance, making the DynAMITe large area CMOS APS suitable for a range of bio-medical applications

Early detection of capping risk in pharmaceutical compacts

Capping is a common mechanical defect in tablet manufacturing, exhibited during or after the compression process. Predicting tablet capping in terms of process variables (e.g. compaction pressure and speed) and formulation properties is essential in pharmaceutical industry. In current work, a non-destructive contact ultrasonic approach for detecting capping risk in the pharmaceutical compacts prepared under various compression forces and speeds is presented. It is shown that the extracted mechanical properties can be used as early indicators for invisible capping (prior to visible damage). Based on the analysis of X-ray cross-section images and a large set of waveform data, it is demonstrated that the mechanical properties and acoustic wave propagation characteristics is significantly modulated by the tablet’s internal cracks and capping at higher compaction speeds and pressures. In addition, the experimentally extracted properties were correlated to the directly-measured porosity and tensile strength of compacts of Pearlitol®, Anhydrous Mannitol and LubriTose® Mannitol, produced at two compaction speeds and at three pressure levels. The effect compaction speed and pressure on the porosity and tensile strength of the resulting compacts is quantified, and related to the compact acoustic characteristics and mechanical properties. The detailed experimental approach and reported wave propagation data could find key applications in determining the bounds of manufacturing design spaces in the development phase, predicting capping during (continuous) tablet manufacturing, as well as online monitoring of tablet mechanical integrity and reducing batch-to-batch end-product quality variations