The primary objective of this work was the examination of modified activated carbons with tailored adsorption capacity properties. Production of activated carbons with desired properties was ...accomplished by modification of surface functional groups and introduction of acidic/basic properties. Modification of an activated carbon was performed using partial oxygen gasification, nitric acid treatment, urea impregnation followed by pyrolysis and pyrolysis in a urea saturated stream. The surface properties of the produced samples were estimated by the multibasic titration method of Boehm and by the CO/CO
2 gas evolution profiles, while pore structure development was measured by the N
2 and CO
2 gas adsorption isotherms. Oxygen gasification resulted in samples with surface area slightly lower that the raw activated carbon; the introduction of surface functional groups depended upon the severity of the treatment: carbonylic and phenolic type groups were introduced in all partially gasified samples, while low temperatures and short reaction times enhanced the basic character of the carbon. However, nitric acid treatment resulted in the introduction of high nitrogen amounts in the samples, the reduction of surface area and the development of a surface containing carboxylic, lactonic, phenolic and carbonylic groups with negligible HCl neutralization capacity. Treatment of activated carbon by urea supported the formation of basic groups and carbonyls. The presence of surface functional groups affected the adsorption capacity of the produced samples for the removal of specific pollutants such as phenols. Urea treated samples with a basic character and high nitrogen content presented the highest phenol uptake capacity; nitric acid treated carbons and oxygen gasified samples presented an acidic surface functionality and a low phenol adsorption capacity. The beneficial role of nitrogen on phenol adsorption was attributed to adsorbate–adsorbent interactions.
The increasing ageing global population is causing an upsurge in ailments related to old age, primarily dementia and Alzheimer's disease, frailty, Parkinson's, and cardiovascular disease, but also a ...general need for general eldercare as well as active and healthy ageing. In turn, there is a need for constant monitoring and assistance, intervention, and support, causing a considerable financial and human burden on individuals and their caregivers. Interconnected sensing technology, such as IoT wearables and devices, present a promising solution for objective, reliable, and remote monitoring, assessment, and support through ambient assisted living. This paper presents a review of such solutions including both earlier review studies and individual case studies, rapidly evolving in the last decade. In doing so, it examines and categorizes them according to common aspects of interest such as health focus, from specific ailments to general eldercare; IoT technologies, from wearables to smart home sensors; aims, from assessment to fall detection and indoor positioning to intervention; and experimental evaluation participants duration and outcome measures, from acceptability to accuracy. Statistics drawn from this categorization aim to outline the current state-of-the-art, as well as trends and effective practices for the future of effective, accessible, and acceptable eldercare with technology.
Additive manufacturing is a technology rapidly expanding on a number of industrial sectors. It provides design freedom and environmental/ecological advantages. It transforms essentially design files ...to fully functional products. However, it is still hampered by low productivity, poor quality and uncertainty of final part mechanical properties. The root cause of undesired effects lies in the control aspects of the process. Optimization is difficult due to limited modelling approaches. Physical phenomena associated with additive manufacturing processes are complex, including melting/solidification and vaporization, heat and mass transfer etc. The goal of the current study is to map available additive manufacturing methods based on their process mechanisms, review modelling approaches based on modelling methods and identify research gaps. Later sections of the study review implications for closed-loop control of the process.
Drug-induced pemphigoid: a review of the literature Stavropoulos, P.G.; Soura, E.; Antoniou, C.
Journal of the European Academy of Dermatology and Venereology,
September 2014, Letnik:
28, Številka:
9
Journal Article
Recenzirano
Bullous pemphigoid is an acquired autoimmune disease that is characterized by subepidermal blistering and affects mainly the elderly. The pathogenesis of the condition has not yet been fully ...elucidated, but it is widely accepted that a strong correlation with various medications may exist. In reality, more than 50 different drugs have been associated with the appearance of bullous pemphigoid and as new therapies emerge, this number is very likely to increase. A number of pathogenetic mechanisms have been proposed in the past. It is true that a delicate immunological balance is disturbed in all patients with the disease. The variable effects that may be exhibited by the use of biological drugs could shed some light in this complex immunological behaviour. At the same time, drug‐induced bullous pemphigoid is difficult to differentially diagnose from its idiopathic counterpart, as the clinical picture and histopathological findings in both conditions may only have subtle differences. Patients who present with bullous pemphigoid and receive multiple regimens should always be suspected of suffering from the drug‐induced variant of the condition. This possibility must be considered, as after the withdrawal of the suspect medication most patients respond rapidly to treatment and do not experience relapses.
Olive-seed waste residue char was employed as the precursor for the production of activated carbons with KOH activation. The effects of activation time and activation temperature on porosity of the ...prepared carbons were studied. The products were characterized by N
2 adsorption at 77
K, using the BET,
α
s and Dubinin–Radushkevich methods while the adsorption capacity from liquid phase was demonstrated by the isotherms of methylene blue adsorption from aqueous solutions. In comparison with the commercial grade carbons, the activated carbons from olive-seed waste residue showed considerably higher surface areas and can be characterized as “super-activated carbons”. The pores of the produced carbons are composed of micropores at the early stages of activation and of both micropores and mesopores at the late stages. Surface area and the pore volume were found to increase with the degree of burn-off, i.e. the activation time and temperature. Methylene blue removal capacity appeared to be comparable to commercial products and even higher at high degrees of activation.
A detailed economic evaluation of activated carbons production process from various raw materials is undertaken using the conventional economic indices (ROI, POT, and NPV). The fundamental factors ...that affect production cost were taken into account. It is concluded that for an attractive investment in activated carbons production one should select the raw material with the highest product yield, adopt a chemical activation production scheme and should base product price on product-surface area (or more generally on product adsorption capacity for the adsorbate in consideration).
A raw material that well meets the above-mentioned criteria is petroleum coke but others are also promising (charcoals, and carbon black). Production cost then can be optimized by determining its minimum value of cost that results from the intercept between the curves of plant capacity and raw material cost – if any. Taking into account the complexity of such a techno-economic analysis, a useful suggestion could be to start the evaluations from a plant capacity corresponding to the break-even point, i. e. the capacity at which income equals production cost.
In the present work four series of composite nanodielectrics were developed by employing a thermosetting polymer (epoxy resin), as matrix, and magnetic nanoparticles of various crystal structures and ...magnetic behaviour, namely ZnFe2O4, Fe3O4, BaFe12O19, SrFe12O19, as reinforcing phase. In all four series of nanocomposites, filler type and content were varying parameters. Aiming to investigate the structure/properties relationships as well as to evaluate the multifunctional behaviour of the developed systems, several characterization techniques were employed. Experimental results indicate that the incorporation of hard magnetic hexaferrite nanoparticles (such as BaFe12O19 and SrFe12O19) leads to the optimum thermomechanical performance of the nanocomposites, while the systems filled with soft magnetic particles (such as Fe3O4 and ZnFe2O4) of spinel structure, demonstrate enhanced values of both dielectric permittivity (ε′) and AC conductivity, as well as energy storage efficiency. The examined systems demonstrated versatile magnetic properties that could be proved beneficial in various applications.
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•Magnetic particles/epoxy nanocomposites were successfully manufactured and studied.•Their thermal, mechanical, and electrical properties were enhanced significantly.•Recorded relaxation processes are related to both filler and matrix.•Magnetic response reflects the type of the employed nanoparticles.•Energy storing/retrieving efficiency increases with magnetic nanoparticles.
Coal is an important resource for the production of activated carbon. Among the numerous applications of activated carbon as a powerful adsorbent, the removal of anions from contaminated streams is ...one of the less investigated issues of industrial importance. A waste water pollutant of special interest is cyanide that attracts considerable concern due to its effects on humans and environment. Liquid phase adsorption is affected by various parameters, especially those concerning solution. The effects on cyanide adsorption capacity of the three most important parameters, namely solution temperature, pH and ionic strength, are investigated. Temperature enhances cyanide adsorption considerably, indicating an energy barrier in adsorption, most probably due to the hydration shell of cyanide ion. The optimum pH value is found to be 10 in accordance with carbon pHPZC value and cyanide pKa. Ionic strength effect demonstrated an outer sphere adsorption mechanism. From these effects it is concluded an adsorption mechanism based on electrostatic interaction between cyanide ion and positively charged carbon surface sites.
Background
Accurate diagnosis of cardiovascular involvement in systemic lupus erythematosus (SLE) remains challenging, due to limitations of echocardiography. We hypothesized that cardiovascular ...magnetic resonance can detect cardiac lesions missed by echocardiography in SLE patients with atypical symptoms.
Aim
To use cardiovascular magnetic resonance in SLE patients with atypical symptoms and investigate the possibility of silent heart disease, missed by echocardiography.
Patients/methods
From 2005 to 2015, 80 SLE patients with atypical cardiac symptoms/signs (fatigue, mild shortness of breath, early repolarization and sinus tachycardia) aged 37 ± 6 years (72 women/8 men), with normal echocardiography, were evaluated using a 1.5 T system. Left and right ventricular ejection fractions, T2 ratio (oedema imaging) and late gadolinium enhancement (fibrosis imaging) were assessed. Acute and chronic lesions were defined as late gadolinium enhancement-positive plus T2>2 and T2<2, respectively. Lesions were characterized according to late gadolinium enhancement patterns as: diffuse subendocardial, subepicardial and subendocardial/transmural, due to vasculitis, myocarditis and myocardial infarction, respectively.
Results
Abnormal cardiovascular magnetic resonance findings were identified in 22/80 (27.5%) of SLE patients with normal echocardiography, including 4/22 with recent silent myocarditis, 5/22 with past myocarditis (subepicardial scar in inferolateral wall), 9/22 with past myocardial infarction (six inferior and three anterior subendocardial infarction) and 4/22 with diffuse subendocardial fibrosis due to vasculitis. No correlation between cardiovascular magnetic resonance findings and inflammatory indices was identified.
Conclusions
Cardiovascular magnetic resonance in SLE patients with atypical cardiac symptoms/signs and normal echocardiography can assess occult cardiac lesions including myocarditis, myocardial infarction and vasculitis that may influence both rheumatic and cardiac treatment.
Three series of epoxy composite systems were fabricated and tested varying the filler type and content. An epoxy resin was employed as the matrix, while boron carbide (B
4
C), titanium carbide (TiC), ...and graphite (C) microparticles were the reinforcing phases. The behavior of these systems under the influence of time-varying mechanical stress was investigated via dynamic mechanical analysis (DMA), while their thermal response was examined by means of differential scanning calorimetry (DSC). Furthermore, systems’ morphology was investigated via scanning electron microscopy, whereas their dielectric properties were examined using broadband dielectric spectroscopy. Storage modulus, loss tangent, dielectric permittivity, and electrical conductivity were studied with parameters filler type, content, and temperature. Glass transition temperature was also determined using DMA and DSC tests. The present work examines the reinforcing ability of the employed fillers, upon the dynamic mechanical properties as well as on the electrical properties and the energy storing ability of their epoxy composites, which have been prepared under identical filler loadings and fabrication conditions. Moreover, the optimum thermomechanical or electrical performance is determined as a function of the reinforcing phase type and content.
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