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41.
42.
Agglomeration of struvite crystals 总被引:2,自引:0,他引:2
Struvite crystallisation is widely studied as a way to remove phosphorus from wastewater effluents and simultaneously generates a valuable product for the fertiliser industry. However, to date, some crystallisation processes experimented at either pilot/or full scale face problems linked to the formation of fines. This paper presents results on the investigation of struvite agglomerative properties and the possible application of coagulants and/or flocculants to remove fines. Coagulants investigated were hydrolysing metals salts (Al(3+) and Fe(3+)), calcium compounds and a cationic polymer, polydiallyldimethylammoniumchloride (polyDADMAC). The effects of a natural flocculant (alginate) have also been tested. Results demonstrated that destabilisation of struvite particles by chemical addition was feasible and identified polyDADMAC as a good option for the agglomeration of struvite particles. However, optimisation of its dosage under typical pH conditions for struvite formation showed floc formation to be very pH sensitive. 相似文献
43.
In recent years, the growing attention to environmental challenges has shown that these issues are becoming of more and more interest to both research and industry. Companies are expected to ensure their products are fully traceable and more sustainable, which requires the involvement of all of the actors in the production network. According to this aim, this study proposes a structured approach that uses the traditional traceability concept as a means to identify the main information needed to assess environmental impacts along the whole supply chain (SC). The proposed approach is composed of four main steps: (i) SC modelling to identify all stakeholders and their inter-relations, (ii) data sharing to collect all relevant data, (iii) data elaboration to calculate performance at different levels of detail and (iv) result interpretation to optimise the SC. The distributed implementation of the approach at different SC steps represents a useful means to practically realise a sustainable SC management. A case study involving a leather shoe SC is used to demonstrate the effectiveness of the approach in identifying criticalities, supporting the selection of the most appropriate suppliers and correctly setting a management strategy towards the optimisation of internal and external traceability and environmental sustainability performances. 相似文献
44.
Grose JE Tam ES Timm C Scheloske M Ulgut B Parks JJ Abruña HD Harneit W Ralph DC 《Nature materials》2008,7(11):884-889
The manipulation of single magnetic molecules may enable new strategies for high-density information storage and quantum-state control. However, progress in these areas depends on developing techniques for addressing individual molecules and controlling their spin. Here, we report success in making electrical contact to individual magnetic N@C(60) molecules and measuring spin excitations in their electron tunnelling spectra. We verify that the molecules remain magnetic by observing a transition as a function of magnetic field that changes the spin quantum number and also the existence of non-equilibrium tunnelling originating from low-energy excited states. From the tunnelling spectra, we identify the charge and spin states of the molecule. The measured spectra can be reproduced theoretically by accounting for the exchange interaction between the nitrogen spin and electron(s) on the C(60) cage. 相似文献
45.
Stanis?aw Kaliciński Tomasz Bieniek Pawe? Janus Piotr Grabiec 《Microelectronics Reliability》2011,51(7):1192-1197
This paper describes a simple technique for characterization of capacitive MEMS accelerometers. The method is based on electrical impedance (admittance) measurements of capacitive MEMS accelerometers treated as electrostatically-driven microelectromechanical resonators. By using this method, it is possible to determine some electrical and mechanical parameters including the shunt capacitance, the mechanical resonance frequency and quality factor. These parameters may serve as measures of structural integrity of the tested structures and their packages during reliability testing, for instance. 相似文献
46.
Alexander Gelman Eugenia Benjamin 《Journal of the science of food and agriculture》1989,47(2):225-241
The quality of fresh, chilled and frozen mince made from the flesh of pond-bred silvercarp (Hypophthalmichthys molitrix (Val)) was evaluated. Flavour panel scores for all minces were acceptable and this quality did not deteriorate during storage for one week in a domestic refrigerator (5–6°C) or for one year at ?20°C. The levels of oxidative rancidity (2-thiobarbituric acid analysis) in the minces were consistent with this maintenance of quality. Aerobic plate counts at 25°C of fresh mince rose from 7–9 × 104 to 1.1 × 105 after 6 days' storage at 5–6°C. Coliform and psychrotroph counts rose from 1.0 × 101 and 7–8 × 103 to 5–4 × 102 and 1.3 × 104, respectively. The functional and textural properties of pond-bred silvercarp mince in terms of salt-soluble protein content, water binding capacity and penetrometer values were measured on fresh, refrigerated and frozen samples. All-fish sausages and frankfurters developed from pond-bred silvercarp mince were assessed in laboratory and consumer tests against commercial beef sausages and frankfurters. The fish products competed well and achieved levels of acceptance similar to those of the beef-containing products. Texture measurements revealed slight changes in the fish products during storage for 7 days at 5–6°C. No spoilage was detected in any of the products after a week at 5–6°C. The nutritional advantages of the fish sausages and frankfurters are discussed. 相似文献
47.
Eugenia D. Namiot Aleksandr V. Sokolov Vladimir N. Chubarev Vadim V. Tarasov Helgi B. Schith 《International journal of molecular sciences》2023,24(1)
Nanoparticles are heterologous small composites that are usually between 1 and 100 nanometers in size. They are applied in many areas of medicine with one of them being drug delivery. Nanoparticles have a number of advantages as drug carriers which include reduced toxic effects, increased bioavailability, and their ability to be modified for specific tissues or cells. Due to the exciting development of nanotechnology concomitant with advances in biotechnology and medicine, the number of clinical trials devoted to nanoparticles for drug delivery is growing rapidly. Some nanoparticles, lipid-based types, in particular, played a crucial role in the developing and manufacturing of the two COVID-19 vaccines—Pfizer and Moderna—that are now being widely used. In this analysis, we provide a quantitative survey of clinical trials using nanoparticles during the period from 2002 to 2021 as well as the recent FDA-approved drugs (since 2016). A total of 486 clinical trials were identified using the clinicaltrials.gov database. The prevailing types of nanoparticles were liposomes (44%) and protein-based formulations (26%) during this period. The most commonly investigated content of the nanoparticles were paclitaxel (23%), metals (11%), doxorubicin (9%), bupivacaine and various vaccines (both were 8%). Among the FDA-approved nanoparticle drugs, polymeric (29%), liposomal (22%) and lipid-based (21%) drugs were the most common. In this analysis, we also discuss the differential development of the diverse groups of nanoparticles and their content, as well as the underlying factors behind the trends. 相似文献
48.
Olimpia Daniela Frent Laura Gratiela Vicas Narcis Duteanu Claudia Mona Morgovan Tunde Jurca Annamaria Pallag Mariana Eugenia Muresan Sanda Monica Filip Roxana-Liana Lucaciu Eleonora Marian 《International journal of molecular sciences》2022,23(20)
From the multitude of materials currently available on the market that can be used in the development of microparticles, sodium alginate has become one of the most studied natural anionic polymers that can be included in controlled-release pharmaceutical systems alongside other polymers due to its low cost, low toxicity, biocompatibility, biodegradability and gelatinous die-forming capacity in the presence of Ca2+ ions. In this review, we have shown that through coacervation, the particulate systems for the dispensing of drugs consisting of natural polymers are nontoxic, allowing the repeated administration of medicinal substances and the protection of better the medicinal substances from degradation, which can increase the capture capacity of the drug and extend its release from the pharmaceutical form. 相似文献
49.
Henley SJ Connell CJ Richter P Husten C Pechacek T Calle EE Thun MJ 《Tobacco control》2007,16(1):22-28
Background
Although several epidemiological studies have examined the mortality among users of spit tobacco, none have compared mortality of former cigarette smokers who substitute spit tobacco for cigarette smoking (“switchers”) and smokers who quit using tobacco entirely.Methods
A cohort of 116 395 men were identified as switchers (n = 4443) or cigarette smokers who quit using tobacco entirely (n = 111 952) when enrolled in the ongoing US American Cancer Society Cancer Prevention Study II. From 1982 to 31 December 2002, 44 374 of these men died. The mortality hazard ratios (HR) of tobacco‐related diseases, including lung cancer, coronary heart disease, stroke and chronic obstructive pulmonary disease, were estimated using Cox proportional hazards regression modelling adjusted for age and other demographic variables, as well as variables associated with smoking history, including number of years smoked, number of cigarettes smoked and age at quitting.Results
After 20 years of follow‐up, switchers had a higher rate of death from any cause (HR 1.08, 95% confidence interval (CI) 1.01 to 1.15), lung cancer (HR 1.46, 95% CI 1.24 to 1.73), coronary heart disease (HR 1.13, 95% CI 1.00 to 1.29) and stroke (HR 1.24, 95% CI 1.01 to 1.53) than those who quit using tobacco entirely.Conclusion
The risks of dying from major tobacco‐related diseases were higher among former cigarette smokers who switched to spit tobacco after they stopped smoking than among those who quit using tobacco entirely.Several epidemiological studies have examined morbidity and mortality among users of spit tobacco (spit‐tobacco users),1,2 but none have compared the mortality of former cigarette smokers who substitute spit tobacco for cigarette smoking (“switchers”) to those of smokers who quit using tobacco entirely. Comprehensive reviews by the US Surgeon General,3 and the International Agency for Research on Cancer4 and others5 have concluded that evidence is sufficient that the use of spit tobacco causes several types of cancer in humans. Although the evidence linking use of spit tobacco to increased risk of cardiovascular diseases is limited,6 these products cause acute increases in heart rate and blood pressure, as well as long‐term adverse effects on blood pressure and lipid profiles.7We compared mortality of switchers to those of former cigarette smokers who quit using tobacco entirely among men enrolled in a large prospective cohort. 相似文献50.
Marina Georgalaki Eugenia Manolopoulou Rania Anastasiou Marina Papadelli Effie Tsakalidou 《International Dairy Journal》2009,19(2):96-99
The aim of the present work was the detection and enumeration of Streptococcus macedonicus in Greek traditional cheeses. A total of 68 traditional cheese samples have been examined. Enumeration was performed by plating on the S. macedonicus differential medium Bromothymol Blue Streptococcus macedonicus (BBSM). Detection of S. macedonicus was confirmed by species-specific polymerase chain reaction (PCR), using as template either cheese DNA or DNA from colonies isolated from the BBSM medium. Counts of S. macedonicus on BBSM medium ranged from less than 1 to 6.84 log cfu g?1. S. macedonicus has been detected in 15 samples out of the 68 tested, corresponding to 13 out of the 20 different cheese varieties examined, originating from various geographical areas in Greece. This indicates that S. macedonicus is widespread in Greek cheeses. However, its presence could not be correlated either with the cheese variety or the cheese manufacturing procedures. 相似文献