DOProC-based reliability analysis of structures

Petr Janas,Martin Krejsa,Jiri Sejnoha,Vlastimil Krejsa 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.64 No.4

Probabilistic methods are used in engineering where a computational model contains random variables. The proposed method under development: Direct Optimized Probabilistic Calculation (DOProC) is highly efficient in terms of computation time and solution accuracy and is mostly faster than in case of other standard probabilistic methods. The novelty of the DOProC lies in an optimized numerical integration that easily handles both correlated and statistically independent random variables and does not require any simulation or approximation technique. DOProC is demonstrated by a collection of deliberately selected simple examples (i) to illustrate the efficiency of individual optimization levels and (ii) to verify it against other highly regarded probabilistic methods (e.g., Monte Carlo). Efficiency and other benefits of the proposed method are grounded on a comparative case study carried out using both the DOProC and MC techniques. The algorithm has been implemented in mentioned software applications, and has been used effectively several times in solving probabilistic tasks and in probabilistic reliability assessment of structures. The article summarizes the principles of this method and demonstrates its basic possibilities on simple examples. The paper presents unpublished details of probabilistic computations based on this method, including a reliability assessment, which provides the user with the probability of failure affected by statistically dependent input random variables. The study also mentions the potential of the optimization procedures under development, including an analysis of their effectiveness on the example of the reliability assessment of a slender column.

Steam reforming on reactive carbon nanotube membranes

Dawid Janas,Stefanie K. Kreft,Krzysztof K.K. Koziol 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.25 No.-

We developed the first self-heated catalytic membrane made of carbon nanotubes (CNT) and used it for steam reforming of alcohols. After exploring a variety of Ni catalyst preparation methods, we selected the most promising route and made Ni@CNT membranes. Then, we used them to produce hydrogen from methanol, ethanol and iso-propanol whilst current was passed through to deliver thermal energy required for the catalytic reaction to take place. By employing Joule heating, we were able to reach temperatures up to about 450 8C and probe the catalytic activity of the system. Despite that such selfheated metal–CNT hybrid is still in early phase of development, it has already shown promises for microscale steam reforming and many other chemical transformations that require efficient and uniform heating conditions.

Serum Concentrations of Insulin, Ghrelin, Adiponectin, Leptin, Leptin Receptor and Lipocalin-2 in Children with Celiac Disease Who Do and Do Not Adhere to a Gluten-Free Diet

Roman M. Janas,Anna Rybak,Aldona Wierzbicka-Rucińska,Piotr Socha,Rafał Śnitko,Anna Szaflarska-Popławska,Anna Stolarczyk,Beata Oralewska,Elżbieta Cytra-Jarocka,Barbara Iwańczak,Urszula Grzybowska-Chleb 거트앤리버 소화기연관학회협의회 2016 Gut and Liver Vol.10 No.4

Background/Aims: The roles of the many bioactive peptides in the pathogenesis of celiac disease remain unclear. To evaluate the serum concentrations of insulin, ghrelin, adiponectin, leptin, leptin receptor, and lipocalin-2 in children with celiac disease who do and do not adhere to a gluten-free diet (GFD, intermittent adherence). Methods: Prepubertal, pubertal, and adolescent celiac children were included in this study (74 girls and 53 boys on a GFD and 80 girls and 40 boys off of a GFD). Results: Insulin levels in prepubertal (9.01±4.43 μIU/mL), pubertal (10.3±3.62 μIU/mL), and adolescent (10.8±4.73 μIU/mL) girls were higher than those in boys (5.88±2.02, 8.81±2.88, and 8.81±2.26 μIU/mL, respectively) and were neither age-dependent nor influenced by a GFD. Prepubertal children off of a GFD exhibited higher ghrelin levels than prepubertal children on a GFD. Adiponectin levels were not age-, sex- nor GFD-dependent. Adherence to a GFD had no effect on the expression of leptin, leptin receptor, and lipocalin-2. Conclusions: Adherence to a GFD had no influence on the adiponectin, leptin, leptin receptor, and lipocalin-2 concentrations in celiac children, but a GFD decreased highly elevated ghrelin levels in prepubertal children. Further studies are required to determine whether increased insulin concentrations in girls with celiac disease is suggestive of an increased risk for hyperinsulinemia.

Determination of the load carrying capacity of closed steel supports used in underground construction and mining

Lenka Koubova,Petr Janas,Karel Janas,Martin Krejsa 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.45 No.5

Closed steel supports of different shapes are used in mining and underground constructions. The supports are prefabricated from rolled, usually robust, steel profiles. The load carrying capacity of a support is considerably influenced by the active loading and passive forces. The passive forces are induced by interactions between the support and the surrounding rock mass. The analysis herein comprises three parts: The first part consists of structural geometry processing. The second part involves finding the numerical solution of a statically indeterminate structure for a specified load. The third part is calculation of the load carrying capacity and the components of internal forces and deformations. For this, the force method and numerical integration are used. The Winkler model is applied when the support interacts with the surrounding environment. The load carrying capacity is limited by the slip resistance of the connected parts and it is limited by reaching the ultimate state of the profile. This paper serves as a comprehensive reference for the determination of the load carrying capacity of closed steel supports and includes stepwise derivations of the governing formulas.

Nonlinear analyses of steel beams and arches using virtual unit moments and effective rigidity

Lenka Koubova,Petr Janas,Alexandros Markopoulos,Martin Krejsa 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.33 No.5

This study examined geometric and physical nonlinear analyses of beams and arches specifically from rolled profiles used in mining and underground constructions. These profiles possess the ability to create plastic hinges owing to their robustness. It was assumed that displacements in beams and arches fabricated from these profiles were comparable with the size of the structure. It also considered changes in the shape of a rod cross-section and the nonlinearities of the structure. The analyses were based on virtual unit moments, effective flexural rigidity of used open sections, and a secant method. The use of the approach led to a solution for the "after-critical" condition in which deformation increased with decreases in loads. The solution was derived for static determinate beams and static indeterminate arches. The results were compared with results obtained in other experimental tests and methods.

Effect of cytokinins on in vitro multiplication of Sophora tonkinensis

Jana, S.,Sivanesan, I.,Jeong, B.R. China Humanity Technology Publishing House 2013 Asian Pacific journal of tropical biomedicine Vol.3 No.7

Objective: To determine the effects of different cytokinins at various concentrations on in vitro shoot multiplication of an important medicinal plant. Methods: Nodal explants (1.5-2.0 cm) of Sophora tonkinensis were used. Multiple shoots were induced from nodal explants cultured on the Murashige and Skoog (MS) medium supplemented with 0.0, 0.5, 1.0, 2.0, 4.0, 8.0, or 16.0 μmol 2-isopentyladenine (2iP), N6 benzyladenine, kinetin or thiadiazuron. Results: Among the four investigated cytokinins, 2iP showed the best response for shoot multiplication. Maximum shoot induction (75%) was achieved on the MS medium supplemented with 2.0 μmol 2iP, with a mean number of 5.0 shoots per explant. In comparison to other cytokinins tried, 2iP showed the highest shoot elongation with a mean shoot length of 4.8 cm. Root initiation was observed within 15 d within the transfer of shoots onto the MS basal medium, and the rooting percentage was 100% with a mean number of 5.4 roots per shoot and root length of 6.2 cm over a period of 4 weeks. The healthy plants, hardened and transferred to a greenhouse for proper acclimatization, exhibited 100% survival. Conclusions: It can be summarized that 2iP is the optimal plant growth regulator for Sophora multiplication.

Extraction of Carotenoids from Phaffia rhodozyma: A Comparison between Different Techniques of Cell Disruption

Mariano Michelon,Thais de Matos de Borba,Ruan da Silva Rafael,Carlos André Veiga Burkert,Janaína Fernandes de Medeiros Burkert 한국식품과학회 2012 Food Science and Biotechnology Vol.21 No.1

The yeast Phaffia rhodozyma is known for producing carotenogenic pigments, commonly used in aquaculture feed formulation as well as in cosmetic,pharmaceutical, and food industries. Despite the high production of carotenoids from microorganisms by biotechnology, their use has limitation due to the cell wall resistance, which constitutes a barrier to the bioavailability of carotenoids. Therefore, there is a need to improve carotenoids recovering technique from microorganisms for the application of food industries. This study aimed to compare mechanical, chemical, and enzymatic techniques of cell disruption for extracting carotenoids produced by P. rhodozyma NRRL Y-17268. Among the techniques studied, the highest specific concentration of carotenoids (190.35 μg/g) resulted from the combined techniques of frozen biomass maceration using diatomaceous earth and enzymatic lysis at pH of the reaction medium of 4.5 at 55oC, with initial activity of β-1,3 glucanase of 0.6 U/mL for 30 min.

Response Surface Methodology Applied to the Enzymatic Synthesis of Galacto-oligosaccharides from Cheese Whey

Cristiane Reinaldo Lisboa,Luciana de Simoni Martinez,Renata Aguirre Trindade,Fátima Aparecida de Almeida Costa,Janaína Fernandes de Medeiros Burkert,Carlos André Veiga Burkert 한국식품과학회 2012 Food Science and Biotechnology Vol.21 No.6

In this study, a strategy was proposed for making galacto-oligossaccharides (GOS), a high valueadded product, from a byproduct of the dairy industry,cheese whey, using a commercial β-galactosidase from Kluyveromyces lactis (Lactozym® 3000L). The effects of the substrate concentration, temperature, and enzyme dosage were statistically studied and their optimum combinations were determined using response surface methodology. The increase in lactose concentration, temperature, and enzyme concentration favored a transgalactosylation reaction. The maximum values for GOS concentration (119.8 mg/mL)and yield (29.9%) in a 4 h process were obtained in the reaction system, composed of 400 mg/mL of lactose and 10 U/mL of enzyme at 40°C. Under these conditions, the lactose conversion was 68.7%. The maximum value for lactose conversion (87.8%) was observed at the same temperature and enzyme concentration, although the lactose level was 20%.

Red Chinese cabbage Transcriptome Analysis Revealed Functional MYB 75, MYB 90 and MYBL2 Genes in Regulation of Reddish Purple Color

Jana Jeevan Rameneni,Su Ryun Choi,Sushil Satish Chhapekar,Sonam Singh,Sang Heon Oh,Yong Pyo Lim 한국원예학회 2020 한국원예학회 학술발표요지 Vol.2020 No.11

Immunomodulatory properties of medicinal maggots Lucilia sericata in wound healing process

Jana Bohova,Juraj Majtan,Peter Takac 셀메드 세포교정의약학회 2012 셀메드 (CellMed) Vol.2 No.3

The healing properties of medicinal maggots (larval stage of Lucilia sericata) are widely used in the chirurgical debridement of non-healing wounds including diabetic foot ulcers, venous and pressure ulcers, where classical approaches have failed. Several kinds of wounds are prone to complications coming out of a specific wound bed environment. There are multi-resistant bacterial species present, their pathogenic impact is multiplied by their ability to form a biofilm. Moreover, immunological events in chronic wounds differ from those in acute wounds. Non-healing wounds are cycled in the early inflammation phase with increased levels of inflammation attributes like inflammation cytokines and matrix metalloproteinases produced by inflammation phase cells. Application of larval therapy promotes progress in the healing process to the next stages involving tissue granulation and re-epithelisation. Larval debridement is an effective method of cleaning the wound of cell debris, necrotic tissue and bacterial load. This happens in a mechanical and biological manner, but the whole complex mechanism of the maggot healing activity is still not fully elucidated. Centuries of clinical practice brings noticeable proof of the maggots’ beneficial effect in wound healing management. This long history led to the investigation of the bioactive components of the larval body and its extracts in vitro. We introduce a review which describes the immunomodulation impact of maggot body components on the cellular and molecular levels of the wound healing process.