Procedure for determining the constants of JH-2 (Johnson – Holmquist) dynamic fracture model for brittle materials

A simplified method for evaluating the constants in the JH-2 (Johnson – Holmqvist) model of the dynamic fracture for brittle materials is presented. The classical procedure suggests the use of 21 independent parameters describe the material, and the problem of their determination entails a large number of calculations experiments which hamper the use of the JH-2 model. The proposed technique requires fewer complex calculations and experimental data to determine the parameters of the material thus making it more feasible in use. In this work, the technique is used to search for the parameters of aluminum oxide (Al2O3) with a density of 99.5%, which is the material of a ceramic barrier subjected to high-speed interaction with the impactor. We present the results of three tests for penetration of a corundum plate: two of them are used to determine the constants of the model, and the third is used to verify the obtained values. Note that, the results obtained using the presented approach match quite accurately the experimental data, which is demonstrated in the course verification of the procedure.

A Simple Synthesis Route for Selectively Methylated β-Cyclodextrin Using a Copper Complex Sandwich Protecting Strategy

This communication reports a novel synthesis route for the preparation of monofunctionalized β-cyclodextrin in a single stage. The approach involves only the in-situ protection of secondary hydroxyl groups as an excellent alternative to the classical procedure involving a series of five steps of protection and deprotection of hydroxyl groups (both primary and secondary ones) belonging to β-cyclodextrin.

A Bayesian Copula Approach for Flood Analysis

This study aims to provide joint modelling of rainfall characteristics in Peninsular Malaysia using two-dimensional copula. Two commonly regarded as important variables in the field of hydrology, namely rainfall severity and duration were derived using the Standard Precipitation Index (SPI) and their univariate marginal distributions are further identified by fitting into several distributions. The paper uses a Bayesian framework to estimate the parameter values in the marginal and copula model. The approximation of the posterior distribution by random sampling has been done by Monte Carlo Markov Chain (MCMC). Next, the authors compared these findings with those based on the classical procedure. The results indicated that the Bayesian approach can be substantially more reliable in parameter estimation for small samples.

Comparative Clinical Study of Nasya and Jala Neti in Allergic Rhinitis

Allergic rhinitis is a type of inflammation associated with a group of symptoms affecting the nose. When a person with allergic rhinitis breathes in an allergen such as pollen, animal dander, mold, or dust, the body releases chemicals that cause allergy symptoms. Now-a-days, it is a common inflammation in the population. Nasya is very commonly performed in Ayurveda for the same. In the present study another procedure “Jalaneti '' is also selected, which is a classical procedure of Yoga Therapy. The present study has been done to compare the effect of nasya and jalaneti in allegic rhinitis. The study was conducted at Panchkarma Department of Shree Saptashrungi Ayurved Mahavidyala and Hospital, panchvati, Nashik, Maharashtra. Total number of 20 patients of age 10-70 years having allegic rhinitis or Jirnapratishyay as mentioned in Ayurvedic classics were selected. Out of which Nasya with Vacha Tail was given to 10 patients and Jalaneti with Saindhav Jala was given to another 10 patients. Comparison was done by subjective assessment. It was observed that Nasya done as per the textual methods is highly effective in Allergic Rhinitis and showing a way out to the individual suffering from chronic disease. The study confirmed the effect of Nasya in Allergic Rhinitis in improving the quality of life of patients without any untoward effects.

Reconstruction of Paleoecology of Early Miocene Subsurface Deposits from Microflora in the Eboïnda Area (South-Eastern Côte d'Ivoire,West Africa)

The early Miocene palynoflora was recovered from well P1 located in the Aboisso area, about 175 km around of Abidjan (south-eastern Côte d'Ivoire, West Africa). Pteridophyta spores, angiosperm and gymnosperm pollen grains have been identified. The main objective of this work is to inventory all the palynomorphs encountered, to propose a local palynostratigraphy and to reconstitute the paleobotany of our study area during the Tertiary formations north of the lagoon fault. The samples were processed according to the classical procedure of extraction and concentration of palynomorphs. The lithology contains brown to black clays, coarse to fine sands, and reddish to motley clays. This study showed that the dominance of freshwater ferns such as Verrucatosporites usmensis, Laevigatosporites ovatus, Polypodiaceiosporites simplex, Cingulatisporites pseudocicatricosus and leiotriletes adriensis which evokes a swampy environment. Also the development of Bombacaceae (Bombacacidites annae), and the abundance of Pteridophyte spores of the Polypodiaceae family (Verrucatosporites usmensis, Laevigatosporites ovatus, and Polypodiaceiosporites simplex) indicate the climate was tropical with alternating dry and wet periods. Early Miocene sediments are placed in a continental type environment.

Pedal equation and Kepler kinematics

Kepler's laws is an appropriate topic which brings out the significance of pedal equation in Physics. There are several articles which obtain the Kepler's laws as a consequence of the conservation and gravitation laws. This can be shown more easily and ingeniously if one uses the pedal equation of an Ellipse. In fact the complete kinematics of a particle in a attractive central force field can be derived from one single pedal form. Though many articles use the pedal equation, only in few the classical procedure (without proof) for obtaining the pedal equation is mentioned. The reason being the classical derivations can sometimes be lengthier and also not simple. In this paper using elementary physics we derive the pedal equation for all conic sections in an unique, short and pedagogical way. Later from the dynamics of a particle in the attractive central force field we deduce the single pedal form, which elegantly describes all the possible trajectories. Also for the purpose of completion we derive the Kepler's laws.

Organization and conducting the state final certification using distancelearning technologies

The classical procedure for conducting state final certification of students in critical conditions, such as a pandemic in 2020, is impossible without observing all measures to ensure the safety of participants in the procedure. Educational organizations faced legal, technical and organizational challenges when organizing the state final certification in June 2020. The implementation of basic educational programs both in the second academic semester of the academic year and during the final certification was carried out remotely through electronic technologies. The educational institutions were not ready for the situation, but in general they coped with it successfully. The purpose of the work is to study the experience of an educational organization in adapting to remote technologies in a pandemic.The experience of organizing the educational process in the context of a pandemic, technical and technological training of teaching staff, ensuring the operation of an electronic information and educational environment, or ganizing preparatory stages and directly conducting the state final certification in the SamGUPS branch in Nizhny Novgorod according to secondary vocational education programs. Legal aspects, issues of technical organization of the procedure and related processes, modernization of workflow and work of the commission online are considered. The results of the work of the state examination commission in 2020 were summed up and recommendations for the use of this experience in the future were proposed.

High-temperature three-axis IRM Lowrie test

<p>The three-axis isothermal remanent magnetization (IRM) test (the Lowrie test; Lowrie, 1990, Geophys. Res. Lett., 17, 159-162) is a useful tool to identify ferromagnetic minerals by their coercivity and unblocking temperature spectra. In this study, we explore a variant of the Lowrie test in which measurements are conducted directly at elevated temperatures, and compare its performance with the results of the conventional stepwise procedure. IRM acquisition fields applied along three orthogonal axes were 1 T, 200 mT and 40 mT, respectively. The field value for the soft component was chosen so as to include ca. 90% of its coercivity spectrum. For the hard component the maximum available field was used. The test is applied to characterize the magnetic mineralogy of archaeological baked clays and bricks from Bulgaria and Russia. Bulgarian samples are baked clays from various Neolithic (5700-5300 BCE) archaeological sites and several bricks of the Roman epoch (III-IV c. AD). Samples from Russia are bricks originating from several regions with ages from XIII to early XIX c. AD.</p><p>The low- and intermediate-coercivity components of IRM in the studied samples are typically demagnetized by 520-550°C, compatible with substituted or cation-deficient magnetite or, possibly, maghemite. This is supported by the absence of the Verwey transition in studied samples (Kosterov et al., 2021, Geophys. J. Int., 224(2), 1256-1271). The high-coercivity component appears to be carried by two mineral phases with very distinct unblocking temperatures, 120-200°C and 500 to 640°C. The first phase is similar to the high coercivity, low unblocking temperature (HCSLT) phase described by McIntosh et al., 2007 (Geophys. Res. Lett., 34, L21302, doi: 10.1029/22007GL031168), and the second one appears to be hematite with variable degree of substitution.</p><p>Performance of the high-temperature variant of the Lowrie test compares favorably with the classical procedure, while the former is also significantly faster and yields a superior temperature resolution.</p><p>This study is supported by Russian Foundation of the Basic Research, grant 19-55-18006, and by Bulgarian National Science Fund, grant KP-06-Russia-10.</p>

A new strategy implementing mass spectrometry in the diagnosis of congenital disorders of N-glycosylation (CDG)

ObjectivesCongenital disorders of N-glycosylation (CDG) are a large group of rare metabolic disorders caused by defects in the most common post-translational modification of proteins. CDGs are often difficult to diagnose as they are manifested with non-specific symptoms and signs. Analysis of serum transferrin (TRF) isoforms, as the classical procedure used to identify a CDG patient, enables to predict pathological steps in the N-linked glycosylation process.MethodsWe devised a new strategy based on liquid chromatography-mass spectrometry (LC-MS) for the analysis of TRF isoforms by combining a simple and fast sample preparation with a specific chromatographic cleanup/separation step followed by mass-spectrometric measurement. Single TRF isoform masses were obtained through reconstruction of multiply charged electrospray data collected by quadrupole-MS technology. Hereby, we report the first analyzed serum samples obtained from 20 CDG patients and 100 controls.ResultsThe ratio of desialylated isoforms to total TRF was calculated for patients and controls. CDG-Type I patients showed higher amounts of bi-sialo isoform (range: 6.7–29.6%) compared to controls (<5.5%, mean percentage 3.9%). CDG-Type II pattern showed an increased peak of tri-sialo isoforms. The mean percentage of tri-sialo-TRF was 9.3% (range: 2.9–12.9%) in controls, which was lower than that obtained from two patients with COG5-CDG and MAN1B1-CDG (18.5 and 24.5%). Intraday and between-day imprecisions were less than 9 and 16%, respectively, for bi-sialo- and less than 3 and 6% for tri-sialo-TRF.ConclusionsThis LC-MS-based approach provides a simple, sensitive and fast analytical tool for characterizing CDG disorders in a routine clinical biochemistry while improving diagnostic accuracy and speeding clinical decision-making.

Chandrasekhar's integral stability criterion for an equilibrium spherical cloud of a protostar, modified in the framework of non-Gaussian kappa-statistics

Within the framework of the non-extensive statistical mechanics of Kanyadakis, a generalization of the integral stability theorem of Chandrasekhar for the spherically symmetric distribution of matter and black radiation in an exoplanetary cloud in a state of gravitational equilibrium is obtained. For this purpose, the elements of deformed thermodynamics for an ideal gas, deformed canonical Gibbs distribution, as well as the effective gravitational constant, calculated in the formalisms of Kanyadakis and Verlinde, are used. In this, the deformation parameter κ (kappa) measures the so-called degree of nonextensiveness of the cloud system. In addition, the modified thermodynamic properties of blackbody radiation, in particular, the analogue of Stefan's law for radiation energy and generalized expressions for the entropy, heat capacity and radiation pressure, are discussed in the context of κ -statistics. The presented method of combining the indicated anomalous physical processes provides an alternative to the classical procedure of Chandrasekhar's derivation of the well-known integral theorems for gas configurations in gravitational equilibrium, and restores all standard expressions in the limit κ → 0. The results obtained will be able, according to the author, to explain some astrophysical problems of stellar-planetary cosmogony, associated, in particular, with modeling the processes of joint formation and evolution of a protosun and an exoplanetary cloud from a single nebula.