Polyethylene/Aluminum/Polyethylene Composite Pipe for Fuel Gas Application

Polyethylene/aluminum/polyethylene(PAP)composite pipe has the advantages of corrosion resistance,limited joints and convenient installation.We started to use the PAP pipe in fuel gas conveyance 21 years ago.It has excellent performance in indoor gas application.Later,a unique method was designed to apply the PAP pipe in outdoor gas conveyance with the appearance of outdoor gas meter setting,which involves the addition of UPVC casing pipe as a protection technique to prevent the aging of PAP pipe.The method allows the PAP pipe to climb on the outer wall of building and get into user’s home directly after the connection with outdoor gas meter without any joints in the middle.Since 1996,the number of users has increased gradually and it achieves millions level globally today,including Europe,Asia,Oceania,South America and Africa.There were no quality and performance issues of using the PAP pipe in fuel gas conveyance indoor and outdoor in the past 20 years.In this paper,we put our effort on studying the effects of environmental temperature,sealing reliability,resistance to pipe pull-out,thermal compensation,and rat biting on PAP pipe and solve these problems.

Learnable digital signal processing:a new benchmark of linearity compensation for optical fiber communications

The surge in interest regarding the next generation of optical fiber transmission has stimulated the development of digital signal processing(DSP)schemes that are highly cost-effective with both high performance and low complexity.As benchmarks for nonlinear compensation methods,however,traditional DSP designed with block-by-block modules for linear compensations,could exhibit residual linear effects after compensation,limiting the nonlinear compensation performance.Here we propose a high-efficient design thought for DSP based on the learnable perspectivity,called learnable DSP(LDSP).LDSP reuses the traditional DSP modules,regarding the whole DSP as a deep learning framework and optimizing the DSP parameters adaptively based on backpropagation algorithm from a global scale.This method not only establishes new standards in linear DSP performance but also serves as a critical benchmark for nonlinear DSP designs.In comparison to traditional DSP with hyperparameter optimization,a notable enhancement of approximately 1.21 dB in the Q factor for 400 Gb/s signal after 1600 km fiber transmission is experimentally demonstrated by combining LDSP and perturbation-based nonlinear compensation algorithm.Benefiting from the learnable model,LDSP can learn the best configuration adaptively with low complexity,reducing dependence on initial parameters.The proposed approach implements a symbol-rate DSP with a small bit error rate(BER)cost in exchange for a 48%complexity reduction compared to the conventional 2 samples/symbol processing.We believe that LDSP represents a new and highly efficient paradigm for DSP design,which is poised to attract considerable attention across various domains of optical communications.

Comprehensive energy, economic, environmental assessment of a building integrated photovoltaic-thermoelectric system with battery storage for net zero energy building

To realize the goal of net zero energy building(NZEB),the integration of renewable energy and novel design of buildings is needed.The paths of energy demand reduction and additional energy supply with renewables are separated.In this study,those two are merged into one integration.The concept is based on the combination of photovoltaic,thermoelectric modules,energy storage and control algorithms.Five types of building envelope systems,namely PV+TE(S1),Grid+TE(S2),PV+Grid+TE(S3),PV+Battery+TE(S4)and PV+Grid+Battery+TE(S5)are studied,from aspects of energy,economic and environmental(E3)performance.The new envelope systems can achieve thermal load reduction while providing additional cooling/heating supply,which can promote advance of NZEBs.It is found that there is a typical optimum setting of thermal energy load for each one of them with minimum annual power consumption.Except for the S1 system,the rest can realize negative accumulated power consumption in a year-round operation,which means the thermal load of building envelope could be zero.The uniform annual cost for S1 to S5 under interest rate of 0.04 are 19.78,14.77,23.83,60.53,64.94$/m2,respectively.The S5 system has the highest environmental effect with 3.04 t/m2 reduction of CO_(2) over 30 years of operation.