Analytical and bioanalytical chemistry, 2015 Nov., v. 407, no. 29, p. 8735-8743.
chemical analysis, equipment design, mass spectrometry, and equipment performance
A fast and straightforward method to prototype microfluidic chip systems for dead-volume-free hyphenation to electrospray-ionisation mass spectrometry is presented. The developed approach based on liquid-phase lithography provides an inexpensive and reliable access to microfluidic chips for MS coupling which can be manufactured in any laboratory with low technical demands. The rapid prototyping approach enables the seamless integration of capillaries serving as electrospray emitters with negligible dead volume. The high versatility of the presented prototyping method and the applicability of a variety of chip-based devices in different fields of lab-on-a-chip technology are established for analytical separations by means of chip-electrochromatography–MS and for continuous-flow synthesis using microreactor technology with MS detection.
Includes references The main objective of this study was to model and simulate a reduced three-dimensional (3D) model for designing the driving system of an automatic vacuum packer. The 3D reduced model consisted of a pressing board sub-model, a taping sub-model, and a vibrating board sub-model. The reduced 3D model was parameterised using the variable of pouch thickness. The sub-models were driven by three virtual motors. To fulfil the required processing capacity of 6 pouches min-1 (pouch size of 45 cm by 35 cm; 5 kg-1 pouch) of the vacuum packer, three rotational motions for the motors were properly designed. When sub-models were driven according to the developed motions, the rated powers of the motors were estimated to be 100, 25, and 90 W, respectively. A real prototype of the vacuum packer was manufactured and controlled according to the developed motions to validate the simulation results. The motors determined by simulating the reduced 3D model drove the three units of the real prototype successfully. The developed motions of the motors satisfied the required operating sequences of the vacuum packer with a processing capacity of 6.7 pouches min-1. Vacuum-packaging tests showed that the success rate of the vacuum packer was 92.6%.
Biosystems engineering, 2010 Aug., v. 106, issue 4, p. 352-366.
global sensitivity measure, single axle grain cart dynamic system model, carts, equipment design, tractors, axles, dynamic models, velocity, and equipment performance
Includes references Tractor and towed implement system models have become increasingly important for model-based guidance controller design, virtual prototyping, and operator-and-hardware-in-loop simulation. Various tractor and towed implement models have been proposed in the literature which contain uncertain or time-varying parameters. Sensitivity analysis was used to identify the effect of system parameter uncertainty/variation on system responses and to identify the most critical parameters of the lateral dynamics model for a tractor and single axle grain cart system. Both local and global sensitivity analyses were performed with respect to three tyre cornering stiffness parameters, three tyre relaxation length parameters, and two implement inertial parameters. Overall, the system was most sensitive to the tyre cornering stiffness parameters and least sensitive to the implement inertial parameters. In general, the uncertainty in the input parameters and the system output responses were related in a non-linear fashion. With the nominal parameter values for a Mechanical Front Wheel Drive (MFWD) tractor, a single axle grain cart, and maize stubble surface conditions, a 10% uncertainty in cornering stiffness parameters caused a 2% average uncertainty in the system responses whereas a 50% uncertainty in cornering stiffness parameters caused a 20% average uncertainty at 4.5 m s−1 forward velocity. If a 5% average uncertainty in system responses is acceptable, the cornering stiffness parameters must be estimated within 25% of actual/nominal values. The output uncertainty increased as the forward velocity was increased.