Machine learning for fiber nonlinearity mitigation in long-haul coherent optical transmission systems

Fiber nonlinearities from Kerr effect are considered as major constraints for enhancing the transmission capacity in current optical transmission systems. Digital nonlinearity compensation techniques such as digital backpropagation can perform well but require high computing resources. Machine learning can provide a low complexity capability especially for high-dimensional classification problems. Recently several supervised and unsupervised machine learning techniques have been investigated in the field of fiber nonlinearity mitigation. This paper offers a brief review of the principles, performance and complexity of these machine learning approaches in the application of nonlinearity mitigation

Development of microcantilever sensors for cell studies

Micro- and nano- electromechanical devices such as microcantilevers have paved the way for a large variety of new possibilities, such as the rapid diagnosis of diseases and a high throughput platform for drug discovery. Conventional cell assay methods rely on the addition of reagents, disrupting the measurement, therefore providing only the endpoint data of the cell growth experiment. In addition, these methods are typically slow to provide results and time and cost consuming. Therefore, microcantilever sensors are a great platform to conduct cell culturing experiments for cell culture, viability, proliferation, and cytotoxicity monitoring, providing advantages such as being able to monitor cell kinetics in real time without requiring external reagents, in addition to being low cost and fast, which conventional cell assay methods are unable to provide. This work aims to develop and test different types of microcantilever biosensors for the detection and monitoring of cell proliferation. This approach will overcome many of the current challenges facing microcantilever biosensors, including but not limited to achieving characteristics such as being low cost, rapid, easy to use, highly sensitive, label-free, multiplexed arrays, etc. Microcantilever sensor platforms utilizing both a single and scanning optical beam detection methods were developed and incorporated aspects such as temperature control, calibration, and readout schemes. Arrays of up to 16 or 32 microcantilever sensors can be simultaneously measured with integrated microfluidic channels. The effectiveness of these cantilever platforms are demonstrated through multiple studies, including examples of growth induced bending of polyimide cantilevers for simple real-time yeast cell measurements and a microcantilever array for rapid, sensitive, and real-time measurement of nanomaterial toxicity on the C3A human liver cell line. In addition, other techniques for microcantilever arrays and microfluidics will be presented along with demonstrations for the ability for stem cell growth monitoring and pathogen detection

High-Performance Reverse Osmosis Membrane Enabled by Nanofillers and Surface Modification

With the rising demand for sustainably producing fresh water from saline sources, many researchers have been attracted to develop new reverse osmosis (RO) membranes with high water flux and salt rejection. Despite the great achievements researchers have made, there is still significant room for improving the water permeability and salt rejection of an RO membrane. Herein, we fabricated a RO membrane of advanced 3-layer structure and better performance both in anti-fouling and in water flux. This advanced membrane contains three layers with different modifications. The first modification was done by embedding zeolite and graphene oxide (GO) in the selective polyamide (PA) layer to introduce water flux channel. The second modification was an additional GO layer on the PA surface working as an anti-fouling layer. For final modification, we added a polyethylene glycol (PEG) layer which could serve to repel the organic foulant. The water permeability, salt rejection property, and anti-fouling ability of this new membrane have been investigated. We concluded that the combination of these structures led to an overall excellent RO performance which was supported by our experimental results

High-Performance Reverse Osmosis Membrane Enabled by Nanofillers and Surface Modification

With the rising demand for sustainably producing fresh water from saline sources, many researchers have been attracted to develop new reverse osmosis (RO) membranes with high water flux and salt rejection. Despite the great achievements researchers have made, there is still significant room for improving the water permeability and salt rejection of an RO membrane. Herein, we fabricated a RO membrane of advanced 3-layer structure and better performance both in anti-fouling and in water flux. This advanced membrane contains three layers with different modifications. The first modification was done by embedding zeolite and graphene oxide (GO) in the selective polyamide (PA) layer to introduce water flux channel. The second modification was an additional GO layer on the PA surface working as an anti-fouling layer. For final modification, we added a polyethylene glycol (PEG) layer which could serve to repel the organic foulant. The water permeability, salt rejection property, and anti-fouling ability of this new membrane have been investigated. We concluded that the combination of these structures led to an overall excellent RO performance which was supported by our experimental results