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[Objective] The aim was to improve the genetic property of peppers, the mutant population of Capsicum annuum L cultivar "6421" was constructed. [Method] The seeds of "6421" were treated with 0.2% to 1.2% ethyl methane sulfonate to identified LD50, and then 10 000 LD50 of treated seeds were sowed to construct mutant population. The agronomic characters and genetic regularity of dwarf mutants in M4 generation were analyzed. [Result] Our results showed that GR and SSR were 45.2% and 40.2% respectively at 1.0% EMS, close to LD50 with Gl (17.6) and seed VI (19.7) being half of that of control; 562 M4 mutants were identified in 2015, and the mutation could be characterized according 11 major categories and 32 subcategories; Simultaneously, we found that plant height, plant width, diameter of main-stem, length of main-stem, the number of main-stem nodes and branch of lines E29, E58, E142 and E312 were all significantly different from that of the control. The mutation of lines E29, E58 and E312 was all controlled by a single recessive gene. [Conclusion] The study first created a pepper mutant population, which provides not only the germplasm resources for further breeding but also direct and effective materials for genomic study of the pepper. [ABSTRACT FROM AUTHOR]

Abstract-This paper presents a latchable phase-change microvalve with integrated microheaters, which is suitable for labon-a-chip systems where minimal energy consumption is desired. The microvalve exploits low-melting-point paraffin wax, whose solid-liquid phase changes allow switching of fluid flow through deformable microchannel ceiling. Switching is initiated by melting of paraffin through an integrated microheater, with an additional pneumatic pressure used for the open-to-close switching. The valve consumes energy only during initiation of valve switching. When paraffin solidifies, the switched state is maintained passively. The microvalve was fabricated from polydimethylsiloxane through multilayer soft lithography techniques. Experiments show that the valve can switch flow within 4-8 s due to the small thermal mass and localized melting of paraffin wax; when closed, the valve can passively withstand an inlet pressure over 50 kPa without leakage. Time response of the valve can be further improved with improved heater and wax chamber designs, while the latching ability can be improved by optimizing the wax chamber/membrane design. Compared to existing latchable phase-change valves, the microvalve has no risk of cross-contamination. In addition, the improved sealing offered by the compliant membrane makes the valve robust and flexible in operation, allowing large ranges of initiation pressure from various actuation schemes. [ABSTRACT FROM AUTHOR]

Purpose - The goal of this review paper is to provide information on several commonly used thermography techniques in semiconductor and micro-device industry and research today. Design/methodology/approach - The temperature imaging or mapping techniques include thin coating methods such as liquid crystal thermography and fluorescence microthermography, contact mechanical methods such as scanning thermal microscopy, and optical techniques such as infrared microscopy and thermoreflectance. Their principles, characteristics and applications are discussed. Findings - Thermal issues play an important part in optimizing the performance and reliability of high-frequency and high-packing density electronic circuits. To improve the performance and reliability of microelectronic devices and also to validate thermal models, accurate knowledge of local temperatures and thermal properties is required. Originality/value - The paper provides readers, especially technical engineers in industry, a general knowledge of several commonly used thermography techniques in the semiconductor and micro-device industries. [ABSTRACT FROM AUTHOR]

This paper presents a self-adaptive microfluidic variable resistor that accomplishes passive control of liquid flows by exploiting the large compliance of elastomeric polymers such as polydimethylsiloxane. The device features a compliant microstructure embedded in a microchannel that consists of a flexible thin flap and a stiff stopper located in close proximity. The shape and size of the gap between the flap and stopper vary with the applied pressure, resulting in small resistance with respect to forward flow and large resistance with respect to reverse flow. The variable flow resistor shows an interesting diode behavior because its flow resistance is drastically different for different directions of applied pressures and is self-adaptive in the sense that its flow resistance varies with reverse pressure in such a way that the resulting flow rate remains a constant. That is, the flow resistor can be used as a check valve and, more importantly, a passive flow regulator. Prototype devices have demonstrated regulation of nearly constant water flow rates from 0.21 to 1.2 ml/min, with variations less than 3%, under driving pressures that vary significantly from 100 to over 200 kPa. Three-dimensional fluid-structure interaction simulations have been performed to investigate the interactions between the fluid flow and flap deflection. The simulation results agree with the experimental data and provide insight into the device characteristics. Based on its single-layer planar configuration, passive operation over a large pressure range, and use of a flexible and inexpensive polymer, this self-adaptive variable flow resistor is well suited to flow control in lab-on-a-chip systems. [ABSTRACT FROM AUTHOR]

This paper presents lumped-parameter simulation of dynamic characteristics of peristaltic micropumps. The pump consists of three pumping cells connected in series, each of which is equipped with a compliant diaphragm that is electrostatically actuated in a peristaltic sequence to mobilize the fluid. Diaphragm motion in each pumping cell is first represented by an effective spring subjected to hydrodynamic and electrostatic forces. These cell representations are then used to construct a system-level model for the entire pump, which accounts for both cell- and pump-level interactions of fluid flow and diaphragm vibration. As the model is based on first principles, it can be evaluated directly from the device's geometry, material properties and operating parameters without using any experimentally identified parameters. Applied to an existing pump, the model correctly predicts trends observed in experiments. The model is then used to perform a systematic analysis of the impact of geometry, materials and pump loading on device performance, demonstrating its utility as an efficient tool for peristaltic micropump design. [ABSTRACT FROM AUTHOR]