Influence of Printing Technique and Printing Conditions on Prints Recycling Efficiency and Effluents Quality

The aim of this work was to determine the influence of the conventional offset printing technique and digital electrophotography printing with liquid toner (LEP) on some optical properties of recycled fibres. A series of LEP prints was made with the variation of the negative voltage of the developing drum (−200 V, −280 V, −350 V, and −430 V) after calibration of the machine and achieving standard densitometry values. Besides deinkability aspects, the quality of wastewater effluents after process of prints recycling was observed in order to make a conclusion regarding how different printing techniques, conditions in printing process, and different types of inks can affect the wastewater effluents. Results of image analysis showed that by increasing the negative voltage of developing drum in LEP printing technique, the formation of large ink particles on handsheet from recycled pulp increases. Depending on the size of the negative voltage of the developing drum, under the same experimental conditions, handsheets made from LEP recycled fibres have lower whiteness gain, brightness gain, and ΔERIC of handsheets compared to those made from the offset prints. In addition, a certain correlation was found between IEERIC (ink elimination), chemical oxygen demand (COD), and total organic carbon (TOC) of wastewater effluents after recycling of LEP prints and offset prints as well. Organic water pollution parameters (COD and TOC) showed higher values in wastewater after recycling of offset prints compared to recycling of LEP prints.

Flexible Nonvolatile Bioresistive Random Access Memory with an Adjustable Memory Mode Capable of Realizing Logic Functions

In this study, a flexible bioresistive memory with an aluminum/tussah hemolymph/indium tin oxide/polyethylene terephthalate structure is fabricated by using a natural biological material, tussah hemolymph (TH), as the active layer. When different compliance currents (Icc) are applied to the device, it exhibits different resistance characteristics. When 1 mA is applied in the positive voltage range and 100 mA is applied in the negative voltage range, the device exhibits bipolar resistive switching behavior. Additionally, when 1 mA is applied in both the positive- and negative-voltage ranges, the device exhibits write-once-read-many-times (WORM) characteristics. The device has good endurance, with a retention time exceeding 104 s. After 104 bending cycles, the electrical characteristics remain constant. This memory device can be applied for “AND” and “OR” logic operations in programmable logic circuits. The prepared flexible and transparent biomemristor made of pure natural TH provides a promising new approach for realizing environmentally friendly and biocompatible flexible memory, nerve synapses, and wearable electronic devices.

A counterintuitive method for slowing down an analyte in a nanopore and its application to polymer sequencing

A major obstacle in nanopore-based polymer sequencing and analysis is the high speed of translocation of an analyte (nucleotide, DNA, amino acid (AA), peptide) through the pore; it currently exceeds available detector bandwidth. Except for one method that uses an enzyme motor to sequence DNA, attempts to resolve the problem satisfactorily have been unsuccessful. Here a counterintuitive method based on reversing the pore voltage and/or increasing the mobility of some analytes is described. A simplified Fokker-Planck model shows increases in translocation times of 10s of ms for single nucleotides and AAs. More realistic simulations show that a bi-level positive-negative voltage profile can trap an analyte inside the pore for ∼1 ms and thereby enable detection of the four nucleotides and 20 proteinogenic AAs with a low bandwidth. While the bi-level voltage profile also reduces the ionic pore current, other methods, such as optical, that do not depend on ionic current blockades to detect an analyte, can take advantage of the slowdown method given here. This is a potentially viable solution to a problem that has prevented nanopore-based polymer sequencing methods from realizing their full potential.