A New Direction in Microfluidics: Printed Porous Materials

In this work, the feasibility of a novel direction for microfluidics is studied by demonstrating a set of new methods to fabricate microfluidic systems. Similarly to microfluidic paper-based analytical devices, porous materials are being used. However, alternative porous materials and different printing methods are used here to give the material the necessary pattern to act as a microfluidic system. In this work, microfluidic systems were produced by the following three separate methods: (1) by curing a porous monolithic polymer sheet into a necessary pattern with photolithography, (2) by screen printing silica gel particles with gypsum, and (3) by dispensing silica gel particles with polyvinyl acetate binder using a modified 3D printer. Different parameters of the printed chips were determined (strength of the printed material, printing accuracy, printed material height, wetting characteristics, repeatability) to evaluate whether the printed chips were suitable for use in microfluidics. All three approaches were found to be suitable, and therefore the novel approach to microfluidics was successfully demonstrated.

Dehumidification Analysis of Rotary Solid Desiccant Wheel & Packed Bed System

Moisture transport is one of the major challenges in desiccant dehumidification. The transfer of moisture basically involves transfer of heat between moist air and desiccant particles as well as the mass transferal of moisture between moist air and desiccant particles. Type of desiccant dehumidification analysis is heating with dehumidification. Warmth move between sodden air and desiccants likewise gains consideration since temperature appropriation significantly influences the mass exchange execution through desiccant isotherms. The warmth and mass exchange between a clammy air stream and desiccant particles is dissected. Surface dissemination is noticed to overwhelm mass exchange within the silica gel particles. Here in this paper, we have compared the three diffusion coefficients Ordinary, Knudson and surface diffusion both for packed bed system and rotary desiccant system. Also, two models of move coefficients are introduced here and analyzed. Pseudo gas side controlled model usages an observational gas side mass exchange coefficient to represent dissemination opposition on strong side. Solid side resistance model settles the dissemination condition and is the finest exact as far as move coefficients. Notwithstanding, it makes examination considerably more clear.

FABRICATION OF GRANULAR HUMIDITY INDICATOR

This work presents the fabrication of the granular humidity indicator for the monitor of the relative moisture in the outdoor environment or in the enclosed areas such as bags, containers, enclosed rooms, boxes which are used for the storage of the weapons and military equipment, food preservation, seed storage in agriculture, controlling fermentation process as well as the plants growing process, etc. Moisture indicator was fabricated from cobalt chloride, desiccant, color-stabilizing agents, and silica gel particles. The obtained indicator can measure the relative humidity in the range of 30 to 70 based on the color changing from the indicator.

Water Resistant Self-Extinguishing Low Frequency Soundproofing Polyvinylpyrrolidone Based Electrospun Blankets

This paper shows that an eco-friendly electrospinning process allows us to produce water resistant sound absorbers with reduced thickness and excellent sound-absorption properties in the low and medium frequency range (250–1600 Hz) for which which human sensitivity is high and traditional materials struggle to match, that also pass the fire tests which are mandatory in many engineering areas. The structure and composition were studied through Scanning Electron Microscopy (SEM), Fourier Transform InfraRed (FTIR) Spectroscopy and ThermoGravimetric Analysis (TGA). The density, porosity and flow resistivity were measured. Preliminary investigation of the thermal conductivity through Differential Scanning Calorimetry (DSC) shows that they have perspectives also for thermal insulation. The experimental results indicate that the achievements are to be ascribed to the chemical nature of Polyvinylpyrrolidone (PVP). PVP is, in fact, a polymeric lactam with a side polar group that may be easily released by a thermooxidative process. The side polar groups allow for using ethanol for electrospinning than relying on a good dispersion of silica gel particles. The silica particles dimensionally stabilize the mats upon thermal treatments and confer water resistance while strongly contributing to the self-extinguishing property of the materials.

Investigation on methane hydrate formation in silica gel particles below the freezing point

Herein, methane hydrate formation in silica gel was studied in the temperature and pressure range of 253.1–268.1 K and 4.0–6.0 MPa, respectively.