Effect of Particle Size on Mechanical Properties of Pellets Made from Biomass Blends

AbstractWoody biomass is densified in the form of pellets in order to improve its physical and mechanical properties during handling and storage. However, limited research work has been conducted on the mechanical properties of pellets made from agricultural and wood biomass blends. Two commonly available forestry biomass, spruce (S) and pine (P), and three agricultural biomasses, reed canary grass (RCG), timothy hay (H) and switchgrass (SW), were used to form pellets. The mechanical properties were evaluated for three different particle sizes (150-300, 300-425 and 425-600μm). An Instron attached with an in-house built single unit pelletizer and temperature controlled die was employed to produce a pellet. The aim of this study is to investigate the effect of particle size and blending (agricultural and woody biomass) on the mechanical properties (density and intrinsic yield stress). For all biomasses, pellets made from lower particle size (150-300μm) exhibited higher density (950-1178kg/m3 for spruce and pine; 668-800kg/m3 for RCG, H and SW; 900-970kg/m3 for blended biomass). The intrinsic yield stress exhibited differences in values for individual forestry (40MPa) and agricultural biomass (27-48MPa), however after blending the values converged closest to that value for forestry biomass. In conclusion, blending low cost and abundant available agricultural biomass with woody biomass could not only result in better mechanical properties but would also help to meet the pellet market demand in future

Assessment of Moisture Effect in Simulating Forestry Biomass Supply Chain Strategy: Case Study of New Brunswick, Canada

In order to investigate the effect of variation of the moisture content of forest biomass residues on a supply chain strategy, a simulation was performed using integrated biomass supply analysis and logistics modeling. A simple supply chain strategy was chosen and applied for Miramichi and Plaster Rock, two different regions in New Brunswick, Canada. These regions are selected based on three criteria: annual potential harvest of forest biomass residues, annual production potential of electric and thermal energy and distribution of transportation zones. The moisture content of forest biomass residues was dependant on the weather conditions of the selected regions. The results show that the moisture content of the biomass in Plaster Rock was more stable but higher than the biomass in the Miramichi region. In simulating the supply chain strategy, particular attention is given to harvest, baling, storage and transportation of the biomass. The simulation results show that, during harvest and baling of the biomass, the moisture content affects the dry matter loss and, as a consequence, the customer and ownership costs of the operations. It also affects the energy input and the quantity of carbon dioxide released in the atmosphere. However, dry matter loss and accordingly the cost of the operations are the main parameters affecting the storage and transportation of forest biomass residues

Nanoindentation characterization of microwave-pyrolysis biochar

This study investigates the nanoindentation hardness and Young’s modulus of microwave pyrolysis biochar developed from hemp and softwood feedstocks. Recent studies have produced encouraging results on the potential for biochar as a reinforcing filler in composite materials, owing to the high porosity and hardness of the carbonous material. In order to further the understanding of the effect of biochar as an additive, and to develop predictive models for the composites, mechanical properties of the chars are needed. The biochar was synthesized from both hemp and softwood feedstocks, in-house through a microwave-pyrolysis process at 2700 watts, for one hour, with heating rates reaching 50 °C/min and residence temperatures of up to 660°C. Proximate and ultimate analysis were performed as well as physiosorption analysis in order to relate the nanoindentation results to the biochar characteristics. Proximate analysis indicated larger fixed carbon content of softwood (71 wt%), and hemp (72 wt%) with inverse trend for volatile matter. Biochar samples of both softwood and hemp showed an H:C ratio of 2/g BET surface area and 2.58 m2/g micropore area, compared to 9.96 m2/g and 1.63 m2/g BET surface area and micropore area of softwood. Prior to nanoindentation, biochar samples from each feedstock were cold-mounted, then polished with decreasing grit sizes from 500 to 1200 microns. The Young’s modulus and hardness values of the biochar samples were obtained from an iMicro Nanoindentor using a 1mN load. An average of ten indentations were performed on the mounted biochar samples. Nanoindentation results indicated Young’s modulus of 5.98 and 5.64 GPa as well as hardness of 0.26 and 0.51 GPa for hemp and softwood char respectively. Considering the nanoindentation results it was observed that heating rates/residence temperatures of pyrolysis and porosity of the biochar are the main factors in overall hardness and modulus. High pyrolysis temperatures allow the char to carbonize to a hardened glass-like state, while faster heating rates aid in the release of softer pyrolytic tars and residue. Furthermore the higher development of healthy micropores at faster heating rates leads to a stronger porous structure, increasing the Young’s modulus. Overall the findings from this study are important indicators of the factors influencing the potential of biochar as a reinforcing filler in biocomposite materials. Knowing the Young’s modulus and hardness of biochar is highly useful in the development of analytical predictive models describing the behavior of biochar reinforced biocomposites under various loading conditions

Adsorption of Pb2+ on magnetic modified hemp biochar prepared using microwave-assisted pyrolysis

Magnetic modified hemp biochar with an aim of high adsorption capacity and rapid adsorption rate was prepared by two simple steps using microwave pyrolyzed biochar. This was investigated as a potential green adsorbent for lead remediation from wastewater in a batch-mode experiment. The 150 – 300 µm biochar particles obtained from microwave-assisted pyrolysis of 1.5 kg hemp biomass batch at an average temperature of 600˚C were first impregnated with H2O2 and then magnetized by mixing aqueous biochar suspensions with aqueous Fe3+/Fe2+ solutions. The composition, morphology and surface chemistries of this magnetic biochar was examined by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM) and BET surface area (SBET). The SBET of the magnetic hemp biochar is 83.76 m2 g-1. Batch sorption studies were performed for a 50 mg L-1 lead solution at room temperature and pH 5.5 using 0.02 g of the magnetic adsorbent in 20 ml solution for 2 hours. The experimental results have shown that the adsorption capacity of this magnetic adsorbent for Pb2+ is 43.97 mg g-1, about 87.94% removal within the 2 hours. Both pseudo-second-order and pseudo-first-order kinetic model could predict the adsorption and desorption kinetic process on the modified sorbent. EDX analysis are used to show the mechanisms for the adsorption of Pb2+ onto the adsorbent via mainly ion exchange. The Freundlich, Temkin and Langmuir models are used to predict the sorption isotherm in the system. The as-prepared magnetic hemp sorbent demonstrated a potential in heavy metal wastewater treatment

Biochar from microwave pyrolysis of selected feedstocks

This is a brief summary of work carried out by a team of researchers to produce biochar using microwave pyrolysis system developed at Bioenergy, Bioproducts Research Lab (BBRL), at UNB. Various feedstocks such as corn stalk, spruce, maple, switchgrass, and wood pellets were used to produce biochar. A batch type microwave reactor with a frequency of 2.45 GHz and a power generator of 3 kW was used in the pyrolysis experiments. The amount of biochar obtained depends on the microwave pyrolysis conditions and type of feedstock. For corn stalk briquettes, the yield of biochar ranged from 30.9 to 41.1 wt%. The average biochar yield for spruce, maple, and switchgrass was found to be 22.2 wt%, 22.0 wt%, and 24.4 wt% respectively. Please click on the file below for full content of the abstract

Erectile dysfunction: prevalence, risk factors and involvement of antihypertensive drugs intervention

Purpose: To explore the literature regarding prevalance, risk factors and the involvement of antihypertensive drugs in erectile dysfunction (ED).Methods: Original research articles, reviews, editorials and case reports published in English language on the prevalence of sexual/erectile dysfunction in hypertensive men taking antihypertensive drugs and risk factors were identified through a search of four bibliographic databases, namely, PubMed, EMBASE, CINAHL and EBSCO Health.Results: Recent analyses suggest that hypertensive men of almost all age groups suffer from ED but it is more prevalent in elderly male patients. The involvement of β-blockers was found to be controversial. Nevertheless, some evidence had been found regarding the use of propranolol in high doses.Conclusion: The present review indicates the need for research to unravel the role of β-blockers in the manifestation of ED in hypertensive males, whom there are no contributory factors such as sedentary lifestyle, aging, stress and anxiety, etc.Keywords: Hypertension, Antihypertensive drugs, β-Blockers, Propranolol, Erectile dysfunction, Life style, Risk factor

Experimental evaluation of vibrotactile training mappings for dual-joystick directional guidance

Two joystick-based teleoperation is a common method for controlling a remote machine or a robot. Their use could be counter-intuitive and could require a heavy mental workload. The goal of this paper is to investigate whether vibrotactile prompts could be used to trigger dual-joystick responses quickly and intuitively, so to possibly employ them for training. In particular, we investigate the effects of: (1) stimuli delivered either on the palm or on the back of the hand, (2) with attractive and repulsive mappings, (3) with single and sequential stimuli. We find that 38 participants responded quicker and more accurately when stimuli were delivered on the back of the hand, preferred to move towards the vibration. Sequential stimuli led to intermediate responses in terms of speed and accuracy

Envelope 2 protein phosphorylation sites S75 & 277 of hepatitis C virus genotype 1a and interferon resistance: A sequence alignment approach

<p>Abstract</p> <p>Background</p> <p>Hepatitis C is a major health problem affecting more than 200 million individuals in world including Pakistan. Current treatment regimen consisting of interferon alpha and ribavirin does not always succeed to eliminate virus completely from the patient's body.</p> <p>Results</p> <p>Interferon induced antiviral protein kinase R (PKR) has a role in the hepatitis C virus (HCV) treatment as dsRNA activated PKR has the capacity to phosphorylate the serine and threonine of E2 protein and dimerization viral RNA. E2 gene of hepatitis C virus (HCV) genotype 1 has an active role in IFN resistance. E2 protein inhibits and terminates the kinase activity of PKR by blocking it in protein synthesis and cell growth. This brings forward a possible relation of E2 and PKR through a mechanism via which HCV evades the antiviral effect of IFN.</p> <p>Conclusion</p> <p>A hybrid in-silico and wet laboratory approach of motif prediction, evolutionary and structural anlysis has pointed out serine 75 and 277 of the HCV E2 gene as a promising candidate for the serine phosphorylation. It is proposed that serine phosphorylation of HCV E2 gene has a significant role in interferon resistance.</p

Examining queue-jumping phenomenon in heterogeneous traffic stream at signalized intersection using UAV-based data

© 2020, Springer-Verlag London Ltd., part of Springer Nature. This research presents an in-depth microscopic analysis of heterogeneous and undisciplined traffic at the signalized intersection. Traffic data extracted from the video recorded using an unmanned aerial vehicle (UAV) at an approach of a signalized intersection is analyzed to study the within green time dynamics of traffic flow. Various parameters of Wiedemann 74, Wiedemann 99, and lateral behavior models used in microscopic traffic simulation package, Vissim, are calibrated for the local heterogeneous traffic. This research is aimed at exploring the queue-jumping phenomenon of motorbikes at signalized intersections and its impact on the saturation flow rate, travel time, and delay. The study of within green time flow dynamics shows that the flow of traffic within green time is not uniform. Surprisingly, the results indicate that the traffic flow for the first few seconds of the green time is significantly higher than the remaining period of green time, which shows a contradiction to the fact that traffic flow for the first few seconds is lower due to accelerating vehicles. Mode-wise traffic counted per second shows that this anomaly is attributed to the presence of motorbikes in front of the queue. Consequently, the outputs of simulation results obtained from calibrated Vissim show that the simulated travel time for motorbikes is significantly lower than the field-observed travel times even though the average simulated traffic flow matches accurately with the field-observed traffic flow. The findings of this research highlight the need to incorporate the queue-jumping behavior of motorbikes in the microsimulation packages to enhance their capability to model heterogeneous and undisciplined traffic