1,024 research outputs found

    Green synthesis of vanillin: Pervaporation and dialysis for process intensification in a membrane reactor

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    In the present work, two different membrane processes (pervaporation and dialysis) are compared in view of their utilization in a membrane reactor, where vanillin, which is probably the most important aroma of the food industry, is synthesized in a green and sustainable way. The utilized precursor (ferulic acid, which is possibly a natural product from agricultural wastes) is partially oxidized (photocatalytically or biologically) and the product is continuously recovered from the reacting solution by the membrane process to avoid its degradation. It is observed that pervaporation is much more selective towards vanillin than dialysis, but the permeate flux of dialysis is much higher. Furthermore, dialysis can work also at lower temperatures and can be used to continuously restore the consumed substrate into the reacting mixture. A mathematical model of the integrated process (reaction combined with membrane separation) reproduces quite satisfactorily the experimental results and can be used for the analysis and the design of the process

    Sequential biological and photocatalysis based treatments for shipboard slop purification: A pilot plant investigation

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    This study investigated the treatment of a shipboard slop containing commercial gasoline in a pilot plant scale consisting of a membrane biological reactor (MBR) and photocatalytic reactor (PCR) acting in series. The MBR contributed for approximately 70% to the overall slop purification. More precisely, the biological process was able to remove approximately 40%, on average, of the organic pollution in the slop. Nevertheless, the membrane was capable to retain a large amount of organic molecules within the system, amounting for a further 30% of the influent total organic content removal. However, this affected the membrane fouling, thus resulting in the increase of the pore blocking mechanism that accounted for approximately 20% to the total resistance to filtration (2.85∙10 13 m −1 ), even if a significant restoration of the original membrane permeability was obtained after chemical cleanings. On the other hand, the biological treatment produced a clear solution for the photocatalytic system, thereby optimizing the light penetration and generation of highly oxidizing active oxygen species that enabled the degradation of bio-recalcitrant compounds. Indeed, low total organic carbon (TOC) values (<10 mg L −1 ) were achieved in the output of the photocatalytic reactor by means of only 60 Einstein (E) of cumulative impinging energy after the addition of K 2 S 2 O 8 . Overall, coupling the two processes enabled very high TOC removal (ca. 95%)

    The Milk Yield by Cinisara Cows in Different Management Systems: 1. Effect of Season of Calving

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    The Cinisara cow is Sicilian autochthonous breed; the milk has very interesting qualitative characteristics (chemical, physical and technologic parameters, principally due to its high part β of K casein) and is processed to make Caciocavallo cheese. Characteristics of milk yield are influenced by exogenous factors, such as management system, lactation number and season of calving. Pastures provide the basic feed but grazing is not continuous through the year. The aim of this research was to optimize the distribution of production over the year through the study of the effect of season of calving on qualitative characteristics of milk from Cinisara cows on three farms located at different altitudes (P=plain, C=hill and M=mountain) near Trapani

    The Milk Yield by Cinisara Cows in Different Management Systems: 2. Effect of Season of Production

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    Cinisara is a Sicilian autochthonous breed of dairy cow. Qualitative characteristics of milk yield are influenced by composition of pasture and its changes over the seasons (Di Grigoli et al., 2000). The grazing resource is characterized by notable variability, even in adjacent areas, because of different environmental conditions, such as aspect, the nature of soil and altitude. The aim of this research is to study the effect of season of production on qualitative characteristics of Cinisara cow milk in farms located at different altitudes

    Copper deficiency-associated myelopathy in cryptogenic hyperzincemia: A case report

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    Copper deficiency syndrome is an underestimated cause of posterior myelitis. We describe the case of a 41-year-old woman, who developed a subacute ataxic paraparesis associated with low back pain. Her 3T spine MRI showed a thin hyperintense FS-Echo T2 longitudinally extensive lesion involving the posterior columns of the cervical cord (from C2 to C6). An extensive diagnostic work-up excluded other causes of myelopathy and blood tests pointed out hypocupremia and mild hyperzincemia. Patients affected by this rare form of oligoelement deficiency typically develop progressive posterior column dysfunction with sensory ataxia and spasticity, sometimes associated with sensori-motor polyneuropathy. Clinical and radiological characteristics of posterior myelopathy due to copper deficiency are briefly reviewed. Physicians should be aware of this condition since a prompt introduction of copper supplementation can avoid progression of the neurological damage. (www.actabiomedica.it)

    Alcohol-Selective Oxidation in Water under Mild Conditions via a Novel Approach to Hybrid Composite Photocatalysts

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    The oxidation of alcohols to carbonyl compounds in a clean fashion (i.e., with water as a solvent or under solvent-free conditions, and using O2 or H2O2 as the primary oxidant) is the subject of considerable research efforts. A new approach for the selective oxidation of soluble aromatic alcohols in water under mild conditions via a novel composite photocatalyst has been developed. The catalyst is synthesized by grafting 4-(4-(4-hydroxyphenylimino)cyclohexa-2,5dienylideneamino)phenol and silver nanoparticles onto the surface of moderately crystalline titanium dioxide. The titanium dioxide-based composite was first extensively characterized and then employed in the catalytic oxidation of 4-methoxybenzyl alcohol to 4-methoxybenzaldehyde under UV irradiation in water at room temperature. The corresponding aldehyde was obtained with unprecedented high selectivity (up to 86 %). The method is general and opens the route to fabrication of photocatalytic composites based on titanium dioxide functionalized with shuttle organic molecules and metal nanoparticles for a variety of oxidative conversions

    A Distributed IoT Air Quality Measurement System for High-Risk Workplace Safety Enhancement

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    The safety of an operator working in a hazardous environment is a recurring topic in the technical literature of recent years, especially for high-risk environments such as oil and gas plants, refineries, gas depots, or chemical industries. One of the highest risk factors is constituted by the presence of gaseous substances such as toxic compounds such as carbon monoxide and nitric oxides, particulate matter or indoors, in closed spaces, low oxygen concentration atmospheres, and high concentrations of CO2 that can represent a risk for human health. In this context, there exist many monitoring systems for lots of specific applications where gas detection is required. In this paper, the authors present a distributed sensing system based on commercial sensors aimed at monitoring the presence of toxic compounds generated by a melting furnace with the aim of reliably detecting the insurgence of dangerous conditions for workers. The system is composed of two different sensor nodes and a gas analyzer, and it exploits commercial low-cost commercially available sensors

    The Black Box of Prescription Drug Diversion

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    A variety of surveys and studies are examined in an effort to better understand the scope of prescription drug diversion and to determine whether there are consistent patterns of diversion among various populations of prescription drug abusers. Data are drawn from the RADARS System, the National Survey of Drug Use and Health, the Delaware School Survey, and a series of quantitative and qualitative studies conducted in Miami, Florida. The data suggest that the major sources of diversion include drug dealers, friends and relatives, smugglers, pain patients, and the elderly, but these vary by the population being targeted. In all of the studies examined, the use of the Internet as a source for prescription drugs is insignificant. Little is known about where drug dealers are obtaining their supplies, and as such, prescription drug diversion is a black box requiring concentrated, systematic study
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