The Architecture of Curved Shapes

In the 20th century, architecture remains the part of art where formal principles are very important for creators and spectators. Because form in architecture is so important, two questions arise: How can architects nowadays create forms? How can forms be described and classified? When we work only with formal analysis, we can point to an important criterion of innovation, that is, that certain forms have never before been seen in the history of architecture. In the present day, CAD/CAM technology permits us to realize any form our imaginations can create.     

Integral bread development with soybean, chia, linseed, and folic acid as a functional food for women

Six bread formulations were developed, using different proportions of whole-wheat flour, chia seeds and flaxseed flour. All of our formulations were added with folic acid. Sensorial and texture evaluations were performed, showing good acceptance of the products. Proximal chemical analysis was carried out; in addition, the following parameters were determined: calcium, phosphorus, total dietary fiber, folic acid, water hydration capacity, Glucose Dialysis Retardation Index (GDRI) and fatty acids. The results obtained showed higher protein levels in the developed breads (23.23-30.24 (g/100g dry matter) as compared to a control (21.00% of proteins in bread elaborated without chia or flaxseed). Furthermore, the breads contained 10.07-12.15 of lipids (g/100g dry matter) (linoleic acid: 2.43-4.05%; linolenic acid: 1.12-4.46 %; oleic acid: 2.93-6.13 %), GDRI values were between 89.1 and 98.1 % and folic acid was in the range 699.44 - 991.3 (microg/100g dry matter). The same parameters were determined in the chia seed and in the flaxseed flour. It was concluded that; due to their high levels of protein, insaturated fatty acids (omega-3 and omega-6), dietary fiber and folic acid, these breads have a high nutritional value, so they could have special benefits for woman.     

Assessment of organic coating degradation via local impedance imaging

The paper presents a new approach to organic coating condition evaluation at micrometer scale using localized impedance measurements. It is based on atomic force microscopy (AFM) in contact mode. Impedance is measured between conductive AFM tip and metal substrate covered with organic coating. A single-frequency voltage perturbation signal is applied between the electrodes and current response signal is registered. As the tip is scanned over the surface of the specimen a localized impedance characteristics of the material is obtained. In this way it is possible to map impedance of the scanned area along with other surface features available via classical AFM measurements such as height profile.Degradation of thin acrylic coating was induced by exposure to 3% sodium chloride solution. Localized impedance measurements were performed periodically along with classical ones carried out on macroscopic scale for comparison. Localized impedance data revealed good correlation with the height profile of the coating at each stage of the investigation. Spots of coating degradation were identified and localized. Their presence was confirmed by DC scanning spreading resistance measurements. The proposed method allows to overcome a shortage of the classical approach by provision of spatially resolved image of coating condition instead of an averaged one.     

Determination of Small Phenolic Compounds in Tequila by Liquid Chromatography with Ion Trap Mass Spectrometry Detection

Tequila is elaborated from Agave tequilana Weber blue variety and it is commercialized at different stages of aging. Chemical composition of this product has often been addressed; however, data on phenolic compounds are scarce. In this work, a high-performance liquid chromatography–electrospray ionization-ion trap mass spectrometry (HPLC–ESI-ITMS) procedure has been established for the determination of 34 small phenolic compounds. The combination of suitable separation conditions with extraction of chromatograms at individual m/z values has enabled for total analysis run of 17 min (11 min separation plus 6 min column cleaning/equilibration) with the detection limits in the range 1.28–75.0 μg l^?1 (0.07–6.1 pmol on-column). Commercial tequilas analyzed included 6 white, 12 rested, and 4 aged. The following acids were found and quantified: gallic, procatechuic, 4-hydroxybenzoic, vanillic, syringic, homovanillic, 3-hydroxybenzoic, ferulic, salicylic, and benzoic. The white tequilas contained fewer compounds and lower total phenolics concentrations (range 36–408 μg l^?1) as compared to the rested and aged liquors (515–4,296 and 2,048–3,249 μg l^?1, respectively). In the latter products, syringic, vanillic, procatechuic, and gallic acids were the most abundant, which indicates that maturation in wooden barrels is the main source of small phenolics in tequila. On the other part, homovanillic acid was found in all tequila types (medians for white, rested, and aged products 82, 153, and 162 μg l^?1, respectively), suggesting that some phenolics may originate from the raw material or might be formed during liquor elaboration.     

Synthesis and characterization of the manganese cobaltite spinel prepared using two “soft chemical” methods

Using the coprecipitation method and EDTA gel processes, manganese cobaltite (Mn_1.5Co_1.5O₄) powders were successfully synthesized. The thermal decomposition behavior of the gel precursors, phase formation and morphology of the Mn_1.5Co_1.5O₄ powders were characterized by means of DTA/TGA and MS analyses, X-ray diffraction (XRD), and scanning electron microscopy (SEM), respectively. Well-crystallized dual-phase manganese cobaltite spinel, containing both the cubic and tetragonal phases, was obtained at room temperature for both types of powders calcinated at 800 °C for 10 h in static air, without formation of any intermediate phase. SEM investigations show that the Mn_1.5Co_1.5O₄ powders prepared using two “soft chemical” methods were agglomerates composed of approximately micron-sized particles. The structure and morphology of the bulk samples, as well as their electrical conductivity, were investigated using XRD, SEM, and EIS, respectively. Mn_1.5Co_1.5O₄ spinels with different microstructure exhibited excellent electrical conductivity and structural stability. Major emphasis was placed on structural transformations of the spinel solid solutions with temperature and their effect on the electrical properties of these solutions.     

Study washboarding phenomenon in frame sawing machines

The paper concerns washboarding phenomenon where for every kind of sawing a very regular pattern is characterised by a sinusoidal – like variation in board thickness. That pattern is an effect of the saw blade lateral vibrations. It is palpable that these vibrations are detrimental to the cutting process, and lead to poor surface quality and dimensional accuracy, and raw material waste. For band saws in the contemporary literature models explaining a washboarding phenomenon are supported on self-excited (self-induced) vibration theories. However, these explanations cannot be simply broadened into the washboarding phenomenon in frame sawing machines. In this work based on theoretical and experimental investigation the washboard pattern formation is clarified by the authors with the use of a theoretical model, in which the rugged surface is an effect of vibrations generated by lateral cyclic loading and lagged wave formation. The authors hope that their obtained results contribute significantly to further understanding of this important but complicated phenomenon.     

Optimization of Scouring Alpaca Wool by Ultrasonic Technique

This paper presents a new method of scouring wool in small batches using ultrasonic techniques. Alpaca wool because of the variety of colors and delicate structure requires scouring in small batches (sorted colors) and mild conditions. Scouring of alpaca wool in industrial washers used for sheep wool results in strong loop entanglement of wool and makes its further processing impossible. The study on parameters and conditions of the scouring of alpaca wool was carried out on a specially prepared scouring unit developed on the basis of ultrasonic cleaner. Ultrasonic scouring equipment used in the study prevented displacements of wool in the bathtubs and the reaction of metal on the fiber. As the changing conditions, i.e., the scouring parameters, such as the sample mass, scouring time, and detergent concentration affecting the quantity of removed impurities were considered. As a result, the study determined the optimal conditions of the scouring of alpaca wool. The use of ultrasound technology reduces water and detergents consumption and it shortens the time of scouring. The most important result is the obtaining of the scouring wool without damages and entanglements.     

Fatigue Reliability of Multidimensional Vibratory Degrading Systems under Random Loading

In this paper, the basic methodology for the fatigue reliability assessment of randomly vibrating multidegree-of-freedom systems is presented within the coupled response-degradation model. The fatigue process in the system components is quantified by the fatigue crack growth equations which—via the stress range—are coupled with the system response. Simultaneously, the system dynamics is affected by fatigue process via its stiffness degradation so that it provides the actual stress values to the fatigue growth equation. In addition to the general coupled response-degradation analysis, its special case of noncoupled fatigue crack growth is treated as well for the wide-band stationary applied stress by the use of its first four spectral moments and the approximate, empirically motivated, Dirlik’s probability distribution for the stress range. Both, the general analysis and the illustrating exemplary problems elaborated in the paper provide the route to the fatigue reliability estimation in complex–hierarchical vibratory systems under random loading.