Nano spray-dried sodium chloride and its effects on the microbiological and sensory characteristics of surface-salted cheese crackers

Use of advanced microwave technology for biodiesel production from vegetable oil is a relatively new technology. Microwave dielectric heating increases the process efficiency and reduces reaction time. Microwave heating depends on various factors such as material properties (dielectric and thermo-physical), frequency of operation and system design. Although lab scale results are promising, it is important to study these parameters and optimize the process before scaling up. Numerical modeling approach can be applied for predicting heating and temperature profiles including at larger scale. The process can be studied for optimization without actually performing the experiments, reducing the amount of experimental work required. A basic numerical model of continuous electromagnetic heating of biodiesel precursors was developed. A finite element model was built using COMSOL Multiphysics 4.2 software by coupling the electromagnetic problem with the fluid flow and heat transfer problem. Chemical reaction was not taken into account. Material dielectric properties were obtained experimentally, while the thermal properties were obtained from the literature (all the properties were temperature dependent). The model was tested for the two different power levels 4000 W and 4700 W at a constant flow rate of 840ml/min. The electric field, electromagnetic power density flow and temperature profiles were studied. Resulting temperature profiles were validated by comparing to the temperatures obtained at specific locations from the experiment. The results obtained were in good agreement with the experimental data

Itraconazole-loaded poly(lactic-co-glycolic) acid nanoparticles for improved antifungal activity

Advanced microwave technology has the potential to significantly enhance the biodiesel production process. Knowledge of dielectric properties of materials plays a major role in microwave design for any process. Dielectric properties (ε\u27 and ε ) of biodiesel precursors: soybean oil, alcohols and catalyst and their different mixtures were measured using a vector network analyzer and a slim probe in an open ended coaxial probe method at four different temperatures (30, 45, 60 and 75 °C) and in the frequency range of 280 MHz to 4.5 GHz. Results indicate that the microwave dielectric properties depend significantly on both temperature and frequency. Addition of catalyst significantly affected the dielectric properties. Dielectric properties behaved differently when oil, alcohol and catalyst was mixed at room temperature before heating and when the oil and the alcohol catalyst mixture was heated separately to a pre-determined temperature before mixing. These results can be used in designing microwave based transesterification system

Oil extraction from sheanut (Vitellaria paradoxa Gaertn C.F.) kernels assisted by microwaves

A 1.2 kW, 2450 MHz resonant continuous microwave processing system was designed and optimized for oil extraction from green algae (Scenedesmus obliquus). Algae-water suspension (1:1 w/w) was heated to 80 and 95°C, and subjected to extraction for up to 30 min. Maximum oil yield was achieved at 95°C and 30 min. The microwave system extracted 76-77% of total recoverable oil at 20-30 min and 95°C, compared to only 43-47% for water bath control. Extraction time and temperature had significant influence (p\u3c0.0001) on extraction yield. Oil analysis indicated that microwaves extracted oil containing higher percentages of unsaturated and essential fatty acids (indicating higher quality). This study validates for the first time the efficiency of a continuous microwave system for extraction of lipids from algae. Higher oil yields, faster extraction rates and superior oil quality demonstrate this system\u27s feasibility for oil extraction from a variety of feedstock

Effects of biomass particle size on yield and composition of pyrolysis bio-oil derived from Chinese tallow tree (<i>Triadica Sebifera L.</i>) and energy cane (<i>Saccharum</i> <i>complex</i>) in an inductively heated reactor

In the face of fluctuating petroleum costs and a growing demand for energy, the need for an alternative and sustainable energy source has increased. A viable solution for this problem can be attained by using thermochemical conversion, pyrolysis, of existing biomass sources for the production of liquid fuels. This study focuses on the effect that biomass particle size has on the conversion of biomass into liquid pyrolysis oil. Energy cane and Chinese tallow tree biomass were pyrolyzed at 550 ℃. The particle size ranges studied were &lt; 0.5, 0.5 to 1.4, 1.4 to 2.4 and, 2.4 to 4.4 mm. The results indicate that the range from 0.5-1.4 mm is a better range for optimizing bio-oil production while keeping water content low

Effect of frequency and reaction time in focused ultrasonic pretreatment of energy cane bagasse for bioethanol production

Pretreatment of lignocellulosic biomass is a critical steps in bioethanol production. Ultrasonic pretreatment significantly improves cellulose hydrolysis increasing sugar yields, but current system designs have limitations related to efficiency and scalability. This study evaluates the ultrasonic pretreatment of energy cane bagasse in a novel scalable configuration and by maximizing coupling of ultrasound energy to the material via active modulation of frequency. Pretreatment was conducted in 28% ammonia water mixture at a sample:ammonia:water ratio of 1:0.5:8. Process performance was investigated as a function of frequency (20, 20.5, 21kHz), reaction time (30, 45, 60min), temperature, and power levels for multiple combinations of ammonia, water and sample mixture. Results indicated an increased enzymatic digestibility, with maximum glucose yield of 24.29g/100g dry biomass. Theoretical ethanol yields obtained ranged from 6.47 to a maximum of 24.29g/100g dry biomass. Maximum energy attainable was 886.34kJ/100g dry biomass

Obesity inhibits the osteogenic differentiation of human adipose-derived stem cells

Numerical models were developed to simulate temperature profiles in Newtonian fluids during continuous flow microwave heating by one way coupling electromagnetism, fluid flow, and heat transport in ANSYS 8.0 and COMSOL Multiphysics v3.4. Comparison of the results from the COMSOL model with the results from a pre-developed and validated ANSYS model ensured accuracy of the COMSOL model. Prediction of power Loss by both models was in close agreement (5-13% variation) and the predicted temperature profiles were similar. COMSOL provided a flexible model setup whereas ANSYS required coupling incompatible elements to transfer load between electromagnetic, fluid flow, and heat transport modules. Overall, both software packages provided the ability to solve multiphysics phenomena accurately

Pyrolysis and Catalytic Upgrading of Pinewood Sawdust Using an Induction Heating Reactor

The upgrading of pyrolysis bio-oil is an important process for obtaining stable, high-quality bio-oil. Rapid and uniform heating of both the biomass and the catalyst bed plays an important role in the product quality and in the overall process efficiency. Induction heating offers numerous advantages over conventional heating methods: rapid, efficient heating and precise temperature control. In this study, an advanced induction heating technology was tested for pyrolysis as well as catalyst bed heating. Three different catalyst-to-biomass ratios were studied (1:1, 1.5:1, and 2:1 weight basis), and the effect of catalyst bed temperature (290, 330, and 370 °C) was also investigated. The results were compared with conventionally heated catalyst bed reactor. Higher-quality bio-oil was obtained with induction heating reactor with increased yield of aromatic hydrocarbons and reduced oxygen content compared to conventional heating. Inductively heated catalyst was also observed to have lower carbon deposition after reaction, compared to conventionally heated catalyst. Higher Brunauer–Emmett–Teller (BET) surface area was available post-reaction for inductively heated catalysts. This observation could be attributed to higher thermal gradients in conventional reactors, which causes the condensation of molecules on the catalyst surface with cooler temperatures; these effects are less pronounced for the inductively heated catalyst

Nanoparticle coatings for controlled release of quercetin from an angioplasty balloon

Peripheral artery disease (PAD) is a systemic vascular disease of the legs that results in a blockage of blood flow from the heart to the lower extremities. Now one of the most common causes of mortality in the U.S., the first line of therapy for PAD is to mechanically open the blockages using balloon angioplasty. Coating the balloons with antiproliferative agents can potentially reduce vessel re-narrowing, or restenosis after surgical intervention, but current drug-coated balloons releasing chemotherapy agents like paclitaxel have in some cases shown increased mortality long-term. Our aim was to design a novel drug-coated balloon using a polymeric nanodelivery system for a sustained release of polyphenols that reduce restenosis but with reduced toxicity compared to chemotherapy agents. Poly (lactic-co-glycolic acid) (PLGA) nanoparticles with entrapped quercetin, a dimethoxy quercetin (rhamnazin), as well as quercetin covalently attached to PLGA, were developed. Balloon catheters were coated with polymeric nanoparticles using an ultrasonic method, and nanoparticle characteristics, drug loading, coating uniformity and drug release were determined. The adhesion of nanoparticles to vascular smooth muscle cells and the antiproliferative effect of nano-delivered polyphenols were also assessed. Of the nanoparticle systems tested, those with covalently attached quercetin provided the most sustained release over a 6-day period. Although these particles adhered to cells to a smaller extent compared to other nanoparticle formulations, their attachment was resistant to washing. These particles also exhibited the greatest anti-proliferative effect. In addition, their attachment was not altered when the cells were grown in calcifying conditions, and in PAD tissue calcification is typically a condition that impedes drug delivery. Moreover, the ultrasonic coating method generated a uniform balloon coating. The polymeric nanoparticle system with covalently attached quercetin developed herein is thus proposed as a promising platform to reduce restenosis post-angioplasty