Ethanol production by Mucor indicus and Rhizopus oryzae from rice straw by separate hydrolysis and fermentation

Rice straw was successfully converted to ethanol by separate enzymatic hydrolysis and fermentation by Mucor indicus, Rhizopus oryzae, and Saccharomyces cerevisiae. The hydrolysis temperature and pH of commercial cellulase and β-glucosidase enzymes were first investigated and their best performance obtained at 45 °C and pH 5.0. The pretreatment of the straw with dilute-acid hydrolysis resulted in 0.72 g g^?1 sugar yield during 48 h enzymatic hydrolysis, which was higher than steam-pretreated (0.60 g g^?1) and untreated straw (0.46 g g^?1). Furthermore, increasing the concentration of the dilute-acid pretreated straw from 20 to 50 and 100 g L^?1 resulted in 13% and 16% lower sugar yield, respectively. Anaerobic cultivation of the hydrolyzates with M. indicus resulted in 0.36–0.43 g g^?1 ethanol, 0.11–0.17 g g^?1 biomass, and 0.04–0.06 g g^?1 glycerol, which is comparable with the corresponding yields by S. cerevisiae (0.37–0.45 g g^?1 ethanol, 0.04–0.10 g g^?1 biomass and 0.05–0.07 glycerol). These two fungi produced no other major metabolite from the straw and completed the cultivation in less than 25 h. However, R. oryzae produced lactic acid as the major by-product with yield of 0.05–0.09 g g^?1. This fungus had ethanol, biomass and glycerol yields of 0.33–0.41, 0.06–0.12, and 0.03–0.04 g g^?1, respectively.     

Effects of bovine serum albumin on the corrosion behaviour of AISI 316L, Co–28Cr–6Mo, and Ti–6Al–4V alloys in phosphate buffered saline solutions

The corrosion behaviour of AISI 316L, wrought Co–28Cr–6Mo and Ti–6Al–4V was studied in aerated solutions of phosphate buffered saline (PBS) at various concentrations of bovine serum albumin (BSA) at 37 °C. Open circuit potential, potentiodynamic polarization, linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) experiments along with X-ray photoelectron spectroscopy (XPS) on Co–28Cr–6Mo oxide layer were conducted to study the interaction of BSA and passive layers and to measure the corrosion rates. Ti–6Al–4V alloy had the lowest corrosion rate and the highest breakdown potential. It was shown that BSA has enhanced the alloy passive film stability at higher concentrations.     

Dynamic finite element simulation of the gunshot injury to the human forehead protected by polyvinyl alcohol sponge

Although there are some traditional models of the gunshot wounds, there is still a need for more modeling analyses due to the difficulties related to the gunshot wounds to the forehead region of the human skull. In this study, the degree of damage as a consequence of penetrating head injuries due to gunshot wounds was determined using a preliminary finite element (FE) model of the human skull. In addition, the role of polyvinyl alcohol (PVA) sponge, which can be used as an alternative to reinforce the kinetic energy absorption capacity of bulletproof vest and helmet materials, to minimize the amount of skull injury due to penetrating processes was investigated through the FE model. Digital computed tomography along with magnetic resonance imaging data of the human head were employed to launch a three-dimensional (3D) FE model of the skull. Two geometrical shapes of projectiles (steel ball and bullet) were simulated for penetrating with an initial impact velocity of 734 m/s using nonlinear dynamic modeling code, namely LS-DYNA. The role of the damaged/distorted elements were removed during computation when the stress or strain reached their thresholds. The stress distributions in various parts of the forehead and sponge after injury were also computed. The results revealed the same amount of stress for both the steel ball and bullet after hitting the skull. The modeling results also indicated the time that steel ball takes to penetrate into the skull is lower than that of the bullet. In addition, more than 21 % of the steel ball’s kinetic energy was absorbed by the PVA sponge and, subsequently, injury sternness of the forehead was considerably minimized. The findings advise the application of the PVA sponge as a substitute strengthening material to be able to diminish the energy of impact as well as the load transmitted to the object.     

NOx formation and selective non-catalytic reduction (SNCR) in a fluidized bed combustor of biomass

Caledonian Paper (CaPa) is a major paper mill, located in Ayr, Scotland. For its steam supply, it previously relied on the use of a Circulating Fluidized Bed Combustor (CFBC) of 58 MW_th, burning coal, wood bark and wastewater treatment sludge.It currently uses a bubbling fluidized bed combustor (BFBC) of 102 MW_th to generate steam at 99 bar, superheated to 465 °C. The boiler is followed by steam turbines and a 15 kg/s steam circuit into the mill. Whereas previously coal, wood bark and wastewater treatment sludge were used as fuel, currently only plantation wood (mainly spruce), demolition wood, wood bark and sludge are used.Since these biosolids contain nitrogen, fuel NO_x is formed at the combustion temperature of 850–900 °C. NO_x emissions (NO + NO₂) vary on average between 300 and 600 mg/Nm³ (dry gas). The current emission standard is 350 mg/Nm³ but will be reduced in the future to a maximum of 233 mg/Nm³ for stand-alone biomass combustors of capacity between 50 and 300 MW_th according to the EU LCP standards. NO_x abatement is therefore necessary.In the present paper we firstly review the NO_x formation mechanisms, proving that for applications of fluidized bed combustion, fuel NO_x is the main consideration, and the contribution of thermal NO_x to the emissions insignificant.We then assess the deNO_x techniques presented in the literature, with an updated review and special focus upon the techniques that are applicable at CaPa. From these techniques, Selective Non-catalytic Reduction (SNCR) using ammonia or urea emerges as the most appropriate NO_x abatement solution.Although SNCR deNO_x is a selective reduction, the reactions of NO_x reduction by NH₃ in the presence of oxygen, and the oxidation of NH₃ proceed competitively.Both reactions were therefore studied in a lab-scale reactor and the results were transformed into design equations starting from the respective reaction kinetics. An overall deNO_x yield can then be predicted for any operating temperature and NH₃/NO_x ratio.We then present data from large-scale SNCR-experiments at the CFBC of CaPa and compare results with the lab-scale model predictions, leading to recommendations for design and operation. Finally the economic impact is assessed of implementing SNCR-technology when applying an NH₃ SNCR or urea SNCR to the CFBC at CaPa.     

Investigation of chitosan‐g‐PEG grafted nanoparticles as a half‐life enhancer carrier for tissue plasminogen activator delivery

Tissue plasminogen activator (tPA) a thrombolytic agent is commonly used for digesting the blood clot. tPA half‐life is low (4–6 min) and its administration needs a prolonged continuous infusion. Improving tPA half‐life could reduce enzyme dosage and enhance patient compliance. Nano‐carries could be used as delivery systems for the protection of enzymes physically, enhancing half‐life and increasing the stability of them. In this study, chitosan (CS) and polyethylene glycol (PEG) were used for the preparation of CS‐g‐PEG/tPA nanoparticles (NPs) via the ion gelation method. Particles’ size and loading capacity were optimised by central composite design. Then, NPs cytotoxicity, release profile, enzyme activity and in vivo half‐life and coagulation time were investigated. The results showed that NPs does not have significant cytotoxicity. Release study revealed that a burst effect happened in the first 5 min and resulted in releasing 30% of tPA. Loading tPA in NPs could decrease 25% of its activity but the half‐life of it increases in comparison to free tPA in vivo. Also, blood coagulation time has significantly affected (p ‐value = 0.041) by encapsulated tPA in comparison to free tPA. So, CS‐g‐PEG/tPA could increase enzyme half‐life during the time and could be used as a non‐toxic candidate delivery system for tPA.Inspec keywords: drug delivery systems, nanofabrication, drugs, nanomedicine, coagulation, biomedical materials, cellular biophysics, enzymes, biochemistry, toxicology, molecular biophysics, biological tissues, blood, nanoparticles, polymersOther keywords: chitosan‐g‐PEG grafted nanoparticles, half‐life enhancer carrier, tissue plasminogen activator delivery, tPA half‐life, prolonged continuous infusion, enzyme dosage, polyethylene glycol, cytotoxicity, enzyme activity, encapsulated tPA, enzyme half‐life, blood coagulation, time 5.0 min     

Putative mechanism for anticancer properties of Ag–PP (NPs) extract

One of the most important challenges in treating cancer is the invasion and the angiogenesis of cancer cells. The synthesis of green nanoparticles (NPs) and their use in therapeutic fields is one of the most effective methods with minimal side effects in cancer treatment. In this study, cytotoxic and anti‐angiogenic effects of silver NPs (AgNPs) coated with palm pollen extract [Ag–PP(NPs)] were evaluated. For this purpose, the cells were treated with NPs and then were subjected to trypan blue testing (48 h). Then, the cancer invasion was evaluated by the scratch procedure and the expressions of the vascular endothelial growth factor (VEGF) and its receptor (VEGF‐R) genes were estimated using real‐time PCR assay. Also, the angiogenesis effect of the NPs was investigated with chick chorioallantoic membrane (CAM) assay. The Ag–PP(NPs) induced cytotoxicity on MCF7 cells. The findings also showed that Ag–PP(NPs) inhibit invasive cancer cells and reduce the expression of VEGF and VEGF‐R and significantly reduced the number and vessels lengths and the lengths and weights of the embryos in CAM assay. Ag–PP(NPs) with the induction of cytotoxic effects, metastatic inhibition and anti‐angiogenesis properties should be considered as an appropriate option for treatment of cancerInspec keywords: nanomedicine, genetics, cellular biophysics, toxicology, patient treatment, silver, cancer, biochemistry, biomedical materials, nanoparticles, nanofabrication, membranesOther keywords: minimal side effects, cancer treatment, silver NPs, cancer invasion, vascular endothelial growth factor, receptor genes, VEGF‐R, real‐time polymerase chain reaction assay, angiogenesis effect, chick chorioallantoic membrane assay, MCF7 cells, invasive cancer cells, cytotoxic effects, putative mechanism, anticancer properties, antiangiogenic effects, antiangiogenesis properties, Ag–PP‐induced cytotoxicity, metastatic inhibition, palm pollen extraction, trypan blue testing, time 48.0 hour, Ag     

Synthesis, characterization and application of allyl phenol modified amberlite XAD-4 resin for preconcentration and determination of copper in water samples

A new chelating resin was prepared by coupling Amberlite XAD-4 with phenol through an azo spacer, then modified by allyl bromide and characterized (by elemental analysis and IR) and studied for preconcentration of Cu(II) using flame atomic absorption spectrometry (FAAS) for metal monitoring. The optimum pH value for sorption of the above mentioned metal ion was 4.5. The resin was subjected to chemical evaluation through batch binding and column chromatography of Cu(II). The chelating resin can be reused for 15 cycles of sorption-desorption without any significant change in sorption capacity. A recovery of 98% was obtained for the metal ion with 0.5 M HNO₃ as eluting agent. The equilibrium adsorption data of Cu(II) on modified resin were analyzed by Langmuir, Freundlich and Temkin models. Based on equilibrium adsorption data the Langmuir, Freundlich and Temkin constants were determined to be 0.061, 0.193 and 0.045 at pH 4.5 and 25 °C. The method was applied for the copper determination from industrial waste water sample.     

Assessing mobile phone communication utility preferences in a social support network

While it is generally accepted that the mobile cell phone has become ubiquitous within society for communicating, the actual use of the utilities on a phone have not been reported. Understanding how communication patterns are changing in society as a result of the mobile cell phone will enable the development and/or modification of existing cell phone utilities, the concept of privacy, and a mobile literacy research domain. To explore mobile cell phone utility use, 99 people completed a mobile phone usage questionnaire. Key results from the questionnaire are physical location when using a mobile cell phone, the length of communication episodes, the usage of phone utilities and existing privacy concerns related to mobile cell phones.     

Surface defect detection in tiling Industries using digital image processing methods: Analysis and evaluation

Ceramic and tile industries should indispensably include a grading stage to quantify the quality of products. Actually, human control systems are often used for grading purposes. An automatic grading system is essential to enhance the quality control and marketing of the products. Since there generally exist six different types of defects originating from various stages of tile manufacturing lines with distinct textures and morphologies, many image processing techniques have been proposed for defect detection. In this paper, a survey has been made on the pattern recognition and image processing algorithms which have been used to detect surface defects. Each method appears to be limited for detecting some subgroup of defects. The detection techniques may be divided into three main groups: statistical pattern recognition, feature vector extraction and texture/image classification. The methods such as wavelet transform, filtering, morphology and contourlet transform are more effective for pre-processing tasks. Others including statistical methods, neural networks and model-based algorithms can be applied to extract the surface defects. Although, statistical methods are often appropriate for identification of large defects such as Spots, but techniques such as wavelet processing provide an acceptable response for detection of small defects such as Pinhole. A thorough survey is made in this paper on the existing algorithms in each subgroup. Also, the evaluation parameters are discussed including supervised and unsupervised parameters. Using various performance parameters, different defect detection algorithms are compared and evaluated.