The Use of Organic Rankine Cycles for Recovering the Heat Lost in the Compression Area of a Cryogenic Air Separation Unit

The use of organic Rankine cycles (ORCs) is a viable solution for the recovery of waste heat. For an air separation unit (ASU) with a production of V˙O2=58300mN3/h operating in Romania, the value of utilization of the heat transferred to the cooling system of the compression area represents 21% of the global system electrical energy input. To recover this thermal energy and transform it into mechanical energy, an ORC system was proposed. To maximize the production of mechanical power, an exergy analysis was performed. Exergy analysis was used to choose the most suitable organic fluid and find the optimum constructive structure of the Rankine cycle. The calculation of the exergy destruction in the key apparatuses of the system allowed investigation into the optimization search procedure. The large exergy destruction in the liquid preheater suggested the decrease in the temperature difference in this part of the evaporator by increasing the inlet temperature of the liquid; and an internal recuperative heat exchanger was used for this purpose. When permitted, the overheating of the vapors also reduced the temperature difference between the heat source and the organic fluid during the heat transfer process. The analysis was comparatively performed for several organic fluids such as R-245fa, R123, n-pentane and R717. The use of ammonia, that offered the possibility of superheating the vapors at the turbine inlet, brought a gain of mechanical power corresponding to 6% economy in the electrical energy input of the global plant.     

Comparative Study of Useful Compounds Extracted from Lophanthus anisatus by Green Extraction

Essential oils were obtained from different parts of Agastache foeniculum (Lophanthus anisatus) plants by means of extraction: green extraction using hydro-distillation (HD) and bio-solvent distillation, BiAD, discontinuous distillation, and supercritical fluid extraction, in two stages: (1) with CO₂, and (2) with CO₂ and ethanol co-solvent. The extraction yields were determined. The yield values varied for different parts of the plant, as well as the method of extraction. Thus, they had the values of 0.62 ± 0.020 and 0.92 ± 0.015 g/100 g for the samples from the whole aerial plant, 0.75 ± 0.008 and 1.06 ± 0.005 g/100 g for the samples of leaves, and 1.22 ± 0.011 and 1.60 ± 0.049 g/100 g for the samples of flowers for HD and BiAD, respectively. The yield values for supercritical fluid extraction were of 0.94 ± 0.010 and 0.32 ± 0.007 g/100 g for the samples of whole aerial plant, 0.9 ± 0.010 and 1.14 ± 0.008 g/100 g for the samples of leaves, and 1.94 ± 0.030 and 0.57 ± 0.003 g/100 g for the samples of flowers, in the first and second stages, respectively. The main components of Lophanthus anisatus were identified as: estragon, limonene, eugenol, chavicol, benzaldehyde, and pentanol. The essential oil from Agatache foeniculum has antimicrobial effects against Staphylococcus aureus, the Escherichia coli and Pseudomonas aeruginosa. Acclimatization of Lophantus anisatus in Romania gives it special qualities by concentrating components such as: estragole over 93%, limonene over 8%, especially in flowers; and chavicol over 14%, estragole over 30%, eugenol and derivatives (methoxy eugenol, methyl eugenol, etc.) over 30% and phenyl ether alcohol over 20% in leaves. As a result of the research carried out, it was proven that Lophanthus anisatus can be used as a medicinal plant for many diseases, it can be used as a spice and preservative for various foods, etc.     

Nutritional Profiling,Phytochemical Composition and Antidiabetic Potential of Taraxacum officinale,an Underutilized Herb

Taraxacum officinale (T. officinale), a wild vegetable with a number of health claims, has been mostly ignored and unexplored. The study aims to compare the nutritional, phytochemical as well as antidiabetic potential of fresh as well as shade-dried leaves of T. officinale, in order to recommend its best form as a dietary antidiabetic product. The results revealed that as compared to fresh leaves, the shade-dried leaves, in addition to possessing higher levels of carbohydrates, crude protein, crude fat, crude fiber, etc., also contain appreciable amounts of total phenols (5833.12 ± 4.222 mg/100), total flavonoids (188.84 ± 0.019 mg/100 g), ascorbic acid (34.70 ± 0.026 mg/100 g), β-carotene (3.88 ± 1.473 mg/100 g) and total chlorophyll (239.51 ± 0.015 mg/100 g) antioxidants. The study revealed the presence of medicinally important antidiabetic flavonoid quercetin present in T. officinale leaves. Among the three solvent systems used, the aqueous extract of shade-dried T. officinale leaves comparatively demonstrated potent antidiabetic activity under in vitro conditions in a dose-dependent manner via targeting α-amylase and α-glucosidase, the two potent enzymes of carbohydrate metabolism. Therefore, in addition to being a nutritious herb, the shade-dried leaves of T. officinale have great potential to suppress post-prandial glucose rise and can be better exploited through clinical trials to be used as a dietary intervention for better management of diabetes.     

Inflation and integrable one‐field cosmologies embedded in rheonomic supergravity

In this paper we show that the new approach to the embedding of the inflationary potentials into supergravity, presented in a quite recent paper [11] of Ferrara, Kallosh, Linde and Porrati can be formulated within the framework of standard matter coupled supergravity, without the use of the new minimal auxiliary set and of conformal compensators. The only condition is the existence of a translational Peccei Quinn isometry of the scalar Kähler manifold. We suggest that this embedding strategy based on a nilpotent gauging amounts to a profound Copernican Revolution. The properties of the inflaton potential are encoded in the geometry of some homogeneous one‐dimensional Kähler manifolds that now should be regarded as the primary object, possibly providing a link with microscopic physics. We present a simple and elegant formula for the curvature of the Kähler manifold in terms of the potential. Most relevant consequence of the new strategy is that all the integrable potentials quite recently classified in a paper [7] that we have coauthored, are automatically embedded into supergravity and their associated Kähler manifolds demand urgent study. In particular one integrable potential that provides the best fit to PLANCK data seems to have inspiring geometrical properties deserving further study.     

Nanotopography Engineering on Homopolymeric Surfaces Using Cold Plasma Generated Charges

Summary : Cold plasma as source for charged particles was used to induce nanotopographies on homopolymeric surfaces (nylon 12, PMMA, PMA, etc.). Hydrogen and helium plasmas were successfully used for surface nanoengineering of polymers using inductively coupled or atmospheric pressure non-equilibrium barrier discharge reactors. AFM analyses reveal the presence of nanotopographies on the treated surfaces. Physical factors control the process below the T_g and chemical factors dominate the process above T_g. Pyrolysis GC/MS analyses have been performed in order to obtain more information about the plasma processes. Cold plasma chemical processes, including charges effects are discussed as tools that open-up new ways for nanoengineering of the polymers' surfaces with specific functionalities and / or topography. Future nanomanufacturing techniques can generate anti-scratch, superhydrophobic or superhydrophilic properties on surface of every day use polymeric products by simple and convenient plasma enhanced processes.     

Mapping the Distribution of Melanin Concentration in Different Fitzpatrick Skin Types Using Hyperspectral Imaging Technique

Measuring skin melanin concentration in order to assess skin phototype according to Fitzpatrick's classification is a constant research goal. In this study, a new approach for assessing skin melanin concentration based on hyperspectral imaging combined with an appropriate analytical model that exploits specific spectral bands to generate maps of melanin content distribution on different Fitzpatrick skin phototypes is presented. Hyperspectral images from the proximal inner side of the forearms of 51 young volunteers covering the first four classes of Fitzpatrick's phototypes were acquired using a hyperspectral imaging system. The images were analyzed using a modified Beer–Lambert law that segregates the contribution of melanin from the other constituents to the skin absorption spectrum. The performance of the model was evaluated using the coefficient of determination (r-squared). The results revealed that the approach proposed in this study generated accurate melanin concentration distribution maps that allowed a correct classification of skin phototype. In conclusion, the proposed approach for assessing skin melanin concentration proved to be very reliable for classifying skin phototypes, and, as it provides maps that are easily read, it has the advantage of a possible extension of its applications to other research concerning skin pigmentation.     

Vibrations Action of the Trilling Machine MA750 on the Human Operator Hand

The Work includes identifying and analyzing vibrations produced by a trilling machine MA750 within space work. To identify vibration is used a special method, which has not been used so far in identifying vibrations, with the action on the human body. For obtaining a very good identification of the human body vibrations has been used the Moiré projection method. General conditions were applied to human hand operator during working hours on a trilling machine, with different speeds of main shaft. In the paper are presented successively two methods of measuring the vibrations: the Moiré projection method and conventional method of measuring the vibrometer. The results in the booth situation (classical measurements and Moiré projection method) were in the same order of the unit scale, and the optical method named Moiré projection method can be considered a valid method for the human vibrations measurements without touch of the surface. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)