EFFECTS OF HEATING RATE AND PARTICLE SIZE ON THE PRODUCTS YIELDS FROM RAPID PYROLYSIS OF BEECH-WOOD

Effects of pyrolysis temperature (300-1000 ^°C), heating rates (100, 500, 1000, and 10,000 ^°C/s), and particle sizes (53-63,104-120,177-270, and 270-500 urn) on the yields and formation rates of tar, light oils, total gases, and char from pyrolysis of beech-wood under 1 atm helium pressure were studied. Wood particles were pyrolyzed in strips of stainless steel wire mesh in a captive sample apparatus; and yields of products were measured in weight percent of original wood as a function of temperature for different heating rates and particle sizes. The overall weight loss achieved from pyrolysis of this wood was about 90%. The total yields of tar and light oils from pyrolysis of this wood accounted for up to 80% of the original wood above 400 ^°C. Due to the post-pyrolysis reactions of tar and light oils, the tar and light oils yields go through a maximum with pyrolysis temperature for all particle sizes and most heating rates studied here. As particle size increases from 53-63 μm to 270-500 μm the maximum tar yield decreases from 53% to about 38%. The maximum tar yield also decreases with increasing the heating rate from 70% at 100 ^°C/s to 48% at 10,000 ^°C/s heating rate. Theses results indicate that as the intra-panicle post-pyrolysis cracking reactions of tar increases at higher heating rates and with larger particles the tar yield decreases. Tar was also analyzed with GPC for the effects of above pyrolysis parameters on the tar molecular weight. The tar average molecular weight. remains relatively constant (M     

Thermo economic evaluation of oxy fuel combustion cycle in Kazeroon power plant considering enhanced oil recovery revenues简

Oxy fuel combustion and conventional cycle （currently working cycle） in Kazeroon plant are modeled using commercial thermodynamic modeling software. Economic evaluation of the two models regarding the resources of transport and injection of carbon dioxide into oil fields at Gachsaran for enhanced oil recovery in the various oil price indices is conducted and indices net present value （NPV） and internal rate of return on investment （IRR） are calculated. The results of the two models reveal that gross efficiency of the oxy fuel cycle is more than reference cycle （62% compared to 49.03%）, but the net efficiency is less （41.85% compared to 47.92%） because of the high-energy consumption of the components, particularly air separation unit （ASU） in the oxy fuel cycle. In this model, pure carbon dioxide with pressure of 20~ 105 Pa and purity of 96.84% was captured. NOx emissions also decrease by 4289.7 tons per year due to separation of nitrogen in ASU. In this model, none of the components of oxy fuel cycle is a major engineering challenge. With increasing oil price, economic justification of oxy fuel combustion model increases. With the price of oil at $ 80 per barrel in mind and $ 31 per ton fines for emissions of carbon dioxide in the atmosphere, IRR is the same for both models.     

Fabrication of circular microfluidic channels through grayscale dual-projection lithography

Circular microfluidic channels are in great demand since they are more realistic in mimicking physiological flow systems, generating axis-symmetrical flow, and achieving uniform shear stress. A typical microchannel with rectangular cross section can induce non-physiological gradients of shear rate, pressure, and velocity. This paper presents a novel method of fabricating microfluidic channels with circular and elliptical cross sections through grayscale dual-projection lithography. Our method utilizes two projecting systems to expose grayscale image face-to-face and simultaneously polymerize the photocurable material. The cross-sectional profiles of the fabricated microchannels are consistent with mathematical predictions and, therefore, demonstrate the capability of controlling the channel shapes precisely. Customized circular microchannels can be generated with complex features such as junctions, bifurcations, hierarchies, and gradually changed diameters. This method is capable of fabricating circular channels with a wide range of diameters (39 μm–2 mm) as well as elliptical channels with a major-to-minor axis ratio up to 600%. Microfluidic devices with circular cross sections suitable for particle analysis were made as a demonstrative application in nanoparticle binding and distribution within a mimetic blood vessel. A ready-to-use microfluidic device with customized circular channels can be fabricated within 1 h without the need of clean room or expensive photolithography devices.     

Geometric Patterns,Light and Shade: Quantifying Aperture Ratio and Pattern Resolution in the Performance of Shading Screens

This research focuses on the application and performance assessment of geometric patterns as shading screens and shows how the geometric patterns can function as a design agency, an environmental control system, and a cultural element. We begin with a brief review of the underlying rules of creating two-dimensional geometric patterns, and then look at how these patterns evolve as three-dimensional shading screens in buildings. We next discuss a predictive model for translating complex patterns to simple patterns concerning their perforation ratio, granularity, and morphology. This is followed by an experimental and simulation study for measuring the daylighting performance of some simple shading screens. The result of this phase assesses the agreement among experimental and numerical studies. Finally, we evaluate the performance of a screen inspired by a Persian pattern.     

Resistive switching memory using biomaterials

Resistive switching memory (ReRAM) is emerging as a developed technology for a new generation of non-volatile memory devices. Natural organic biomaterials are potential elements of environmentally-benign, biocompatible, and biodegradable electronic devices for information storage and resorbable medical implants. Here, we highlight progress in exploiting biomaterials to fabricate a special category of bio-nanoelectronic memories called biodegradable resistive random access memory (bio-ReRAM). Bio-ReRAMs are beneficial because they are non-toxic and environmentally benign. Various types of biomaterials with their chemical compound, bio-ReRAM device design and structure, their relevance resistive switching (RS) behavior, and conduction mechanism are considered in detail. Particularly, we report physically-transient devices, their corresponding switching mechanism, and their dissolution by immersion in water. Finally, we review recent progress in the development of various types of flexible bio-ReRAMs, focusing on their flexibility and reliability as bendable nanoelectronics. Because most of these devices are candidates to become wearable, skin-compatible, and even digestible smart electronics, we discuss the future improvement of natural materials and the perspective of novel bio-ReRAMs.     

An Overview on SARS‑CoV‑2(COVID‑19)and Other Human Coronaviruses and Their Detection Capability via Amplification Assay,Chemical Sensing,Biosensing,Immunosensing,and Clinical Assays

A novel coronavirus of zoonotic origin(SARSCoV-2)has recently been recognized in patients with acute respiratory disease.COVID-19 causative agent is structurally and genetically similar to SARS and bat SARS-like coronaviruses.The drastic increase in the number of coronavirus and its genome sequence have given us an unprecedented opportunity to perform bioinformatics and genomics analysis on this class of viruses.Clinical tests like PCR and ELISA for rapid detection of this virus are urgently needed for early identification of infected patients.However,these techniques are expensive and not readily available for point-of-care(POC)applications.Currently,lack of any rapid,available,and reliable POC detection method gives rise to the progression of COVID-19 as a horrible global problem.To solve the negative features of clinical investigation,we provide a brief introduction of the general features of coronaviruses and describe various amplification assays,sensing,biosensing,immunosensing,and aptasensing for the determination of various groups of coronaviruses applied as a template for the detection of SARS-CoV-2.All sensing and biosensing techniques developed for the determination of various classes of coronaviruses are useful to recognize the newly immerged coronavirus,i.e.,SARS-CoV-2.Also,the introduction of sensing and biosensing methods sheds light on the way of designing a proper screening system to detect the virus at the early stage of infection to tranquilize the speed and vastity of spreading.Among other approaches investigated among molecular approaches and PCR or recognition of viral diseases,LAMP-based methods and LFAs are of great importance for their numerous benefits,which can be helpful to design a universal platform for detection of future emerging pathogenic viruses.     

Study of the anticorrosive properties of polypyrrole/polyaniline bilayer via electrochemical techniques

In this work, using electrochemical techniques the authors investigated the protective properties of a polypyrrole/polyaniline bilayer as a conductive polymer. A polypyrrole/polyaniline bilayer was deposited on carbon steel substrate by potentiostatic method. The electric capacitance and resistance of the films were monitored with the immersion time in a corrosive solution to investigate the water permeability of the films. Polypyrrole/polyaniline bilayer has a relatively low permeability and good catalytic behavior in passivation of carbon steel in longer periods. The results show that the bilayer has a better anticorrosive behavior compared to homopolymers (polypyrrole and polyaniline).     

Kinetic Model for Invertase‐Induced Sucrose Hydrolysis: Initial Time Lag

The kinetics of sucrose hydrolysis by invertase was studied in order to find a comprehensive model for the reaction pathway and mechanism. First, three common models of Michaelis‐Menten (MM), substrate inhibition (S²), and substrate clusters' inhibition (S³(I)) were investigated. The third model was found to better predict the initial sucrose concentration. Then, the S³(I) model was modified to cover the remaining pathway (S³(II)). Finally, a new comprehensive model (S³(III)) was evaluated, which in addition to what is considered in the two previously mentioned models (S³(I) and S³(II)) also involved the initial time lag. The model predictions showed an excellent agreement with the experimental data. The mean absolute error for the MM model is significantly reduced for the S³(III) model.