General Necessity Research Articles

Modified Rectorite Provides Reliable Rheology and Suspendability in Biodiesel-Based Fluids

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 189310, “Novel Modified Rectorite Provides Reliable Rheology and Suspendability for Biodiesel-Based Drilling Fluid,” by Wai Li, SPE, Beijing Oilchemleader Science and Technology Development Company; Jishan Liu, The University of Western Australia; Xionghu Zhao, Jian Zhang, and Jiwei Jiang, SPE, China University of Petroleum; Tao He, GWDC Drilling Fluid Company; Liu Liu and Peiyuan Shen, The University of Western Australia; and Min Zhang, Sinopec, prepared for the 2018 SPE/IADC Middle East Drilling Technology Conference and Exhibition, Abu Dhabi, 29–31 January. The paper has not been peer reviewed. The use of organophilic clays as additives to provide proper rheological and filtration properties in nonaqueous drilling fluids (NADFs) has long been a topic of study. Currently, most of these clays are based on the modification of bentonite with quaternary ammonium salts. As new NADF systems emerge, novel clay-modification technologies are needed to obtain more-effective organophilic clays for specific drilling fluids. This paper introduced a modified rectorite designed for biodiesel-based drilling fluid (BBDF). Introduction Biodiesel has drawn a great deal of attention from petroleum scientists and drilling engineers who are seeking environmentally friendly, high-performance, low-cost drilling fluids. The advantageous properties of biodiesel—such as a high flash point (for fire safety), sufficient viscosity (to carry cuttings to the surface during drilling), low eco-toxicity, excellent biodegradability, and good lubricity—make it suitable as a base oil for drilling fluid. Biodiesel also is relatively inexpensive in many situations. Many investigations and trials are being con-ducted on BBDF, suggesting some exciting results. A general necessity for new drilling-fluid techniques is to customize a series of corresponding chemical additives; BBDF is no exception. Preliminary experience has shown that an additive used in traditional oil-based drilling fluids (OBDFs) may be unable to perform well in a BBDF system. Consequently, new additives should be developed for BBDF in order to obtain the optimal operational and environmental properties. Traditionally, most organophilic clays for drilling fluids are based on the intercalating reaction between bentonite and quaternary ammonium salts, which are classified as cationic surfactants. However, this type of organobentonite (OB) still has some disadvantages, such as eco- toxicity and high resistance to degradation when discarded in the environment. Inexpensive rectorite has been selected to replace the commonly used bentonite as the raw clay to produce organophilic clay through a modification reaction with nonionic surfactants. Crucial properties, including swelling index, viscosity, yield point, gel strength, and suspendability, were evaluated.

INFLUENCE OF MILK THISTLE SHOT ON QUALITY PARAMETERS OF THE SOUR-MILK BEVERAGE

Modern complicated ecological conditions cause a general necessity in improving the food structure of the population due to improving the quality, biological value and taste characteristics of products. Just that is why, the aim of the work was to study the influence of milk thistle shot on quality parameters of the sour-milk beverage – kefir. It was established, that it had the homogenous consistence with a broken clot and color from white to creamy with shot particles. The increase of the milk thistle shot dose to 3 % and 4 % results in the taste with the brightly expressed milk thistle smack and brown color with the expressed milk thistle content. The viscosity of kefir with fms 2,5 % changes during seven days of storage, although remains rather high at 8 day, namely 47 s. The increase of the viscosity of kefir with milk thistle shot is explained by its hygroscopic properties, in which result free moisture of the product is bound. The analysis of microbiological parameters in the process of storage of kefir with milk thistle shot allows to make a conclusion about the satisfactory sanitary condition of the new product and its harmlessness for consumer’s health. In the kefir with milk thistle shot the general amount of amino acids grew by 11,6 %, including irreplaceable ones – by 10,1 %, replaceable – by 12,6 %, that indicates its biological value. Addition of milk thistle shot to kefir didn’t cause changes of the biological value of the protein component of the combined product. It is testified by the mean value of amino acid scores of control (129,3 %) and experimental (127,9 %) samples of kefir. Some growth of the valine score (3,6 %) can be noted. So, the combined product is characterized by the balanced amino acid composition. Due to adding milk thistle shot, consumption of amino acids, necessary for synthesis of proteins and essential number of compounds, vitally important for the human organism, grew.

The Work of the Ukraine’s Diplomatic Missions in Conditions of Martial Law

The article deals with the issues of organization of practical work of foreign diplomatic institutions of Ukraine in conditions of martial law. Recommendations based on previous actions of diplomats with the purpose of the most effective preparation for a new emergency situation and further activity of institutions are given. Problematic issues are revealed on the materials of the work of the Embassy of Ukraine in the Federal Republic of Yugoslavia in 1997-1999. Based on the analysis of the work of the Embassy of Ukraine in the FRY, the most important issues of the activities of a diplomatic institution in a military condition were identified, namely: assistance to representatives of the Ukrainian diaspora and citizens who work in other Ukrainian organizations, support for contacts with other foreign institutions, the Ministry of Foreign Affairs of the host country, and others. The necessity of generalization of experience of work of all diplomatic institutions of Ukraine, which worked in conditions of military condition, was emphasized.

Many-body effects in the excitation spectrum of weakly interacting Bose-Einstein condensates in one-dimensional optical lattices

In this work, we study many-body excitations of Bose-Einstein condensates (BECs) trapped in periodic one-dimensional optical lattices. In particular, we investigate the impact of quantum depletion onto the structure of the low-energy spectrum and contrast the findings to the mean-field predictions of the Bogoliubov-de Gennes (BdG) equations. Accurate results for the many-body excited states are obtained by applying a linear-response theory atop the MCTDHB (multiconfigurational time-dependent Hartree method for bosons) equations of motion, termed LR-MCTDHB. We demonstrate for condensates in a triple well that even weak ground-state depletion of around $1\%$ leads to visible many-body effects in the low-energy spectrum which deviate substantially from the corresponding BdG spectrum. We further show that these effects also appear in larger systems with more lattice sites and particles, indicating the general necessity of a full many-body treatment.

Geological and geotechnical characterization of the debris avalanche and pyroclastic deposits of Cotopaxi Volcano (Ecuador). A contribute to instability-related hazard studies

The huge volcanic debris avalanche occurred at 4.5ka is a major event in the evolution of the Cotopaxi volcano, Ecuador. The present volcanic hazard in the Cotopaxi region is related to lahars generated by volcanic eruptions and concurrent ice melting. This paper presents the geological and geotechnical field and laboratory characterization of the 4.5ka Cotopaxi debris avalanche deposit and of the younger unconsolidated pyroclastic deposits, representing the probable source of future shallow landslides. The debris avalanche formed a deposit with a well-developed hummocky topography, and climbed a difference in height of about 260m along the slopes of the adjacent Sincholagua volcano. The debris avalanche deposit includes four lithofacies (megablock, block, mixed, and sheared facies) that represent different flow regimes and degrees of substratum involvement. The facies distribution suggests that, in the proximal area, the debris avalanche slid predominantly confined to the valleys along the N and NE flank of the volcanic cone, emplacing a stack of megablocks. When the flow reached the break in slope at the base of the edifice, it became unconfined and spread laterally over most of the area of the Rio Pita valley. A dynamic block fragmentation and dilation occurred during the debris avalanche transport, emplacing the block facies. The incorporation of the older Chalupas Ignimbrite is responsible for the mixed facies and the sheared facies. Geotechnical results include a full-range grain size characterization, which enabled to make broader considerations on possible variability among the sampled facies. Consolidated drained triaxial compression tests, carried out on the fine fraction <4.76mm, point out that shear strength for cohesionless sandy materials is only due to effective friction angle, and show a quite homogeneous behaviour over the set of tested samples.The investigated post-4.5 pyroclastic deposits constitute a 5–12m thick sequence of poorly consolidated materials that are interlayered with lava flows. Their geotechnical analyses have evidenced a strong variability in grain size distribution, reflecting the depositional processes, and a generally high porosity. Consolidated drained triaxial compression tests delineated a similar shear stress-strain behaviour among the different units, where shear strength is only due to friction angle. Failure surfaces are always well developed, indicating that the poorly consolidated pyroclastic cover could undergo failure leading to the formation of a gravity driven instability phenomena, like granular or debris flows, which are mainly controlled by the fine fraction.This work underlies the general necessity for a site-specific, and interdisciplinary approach in the characterization of volcanic successions to provide reliable data for gravitational instability studies.

Utility-Deviation-Risk Portfolio Selection

We here provide a comprehensive study of the utility-deviation-risk portfolio selection problem. By considering the first-order condition for the corresponding objective function, we first derive the necessary condition that the optimal terminal wealth satisfying two mild regularity conditions solves for a primitive static problem, called the nonlinear moment problem. We then illustrate the application of this general necessity result by revisiting the nonexistence of the optimal solution for the mean-semivariance problem. Second, we establish an alternative version of the verification theorem serving as the sufficient condition that the solution, which satisfies another mild condition different from that for necessity, of the nonlinear moment problem is the optimal terminal wealth of the original utility-deviation-risk portfolio selection problem. We then apply this general sufficiency result to revisit the various well-posed mean-risk problems already known in the literature and to also establish the ex...

The concept of national interests and foreign politics of contamporary Ukraine

The article is devoted to the problem of peculiarities of conceptual principles of foreign politics of Ukraine through the prism of the concept of national interests. National interests are expressed by general necessities of the state which swim out from its socio-political nature, and also its place and role in the system of international relations. On the example of Ukraine the intercommunication of domestic and external politics and the design of the system of defence are probed. On the modern stage Ukrainian national interests are concentrated on the necessity of democratic transformation of public relations. The state is called to overcome a crisis, to provide support of socio-cultural and spiritual revival of Ukrainian society, and to provide effective functioning of political system in conditions of stability and social consent. It remains a question: is it possible the achievement of this aim in unfavourable international terms? Principles of Ukrainian foreign policy on this time are mostly certain, but there is the field for legislative work. Bright confirmation until today is the absence of the law on national interests, ore, for ex., very frequent mention about the dependence of forming of Ukrainian foreign politics on other international actors. The current legislation of Ukraine envisages basic foreign-policy directions, normative base partly touches national interests, but there is no permanent strategy of the Euro- Atlantic integration.

Atmosphere and Religion: The Phenomenology of Hermann Schmitz and the Possibility for a Comparative Study of Religion

[full article, abstract in English; abstract in Lithuanian]&#x0D; On the basis of his phenomenological theory of body and emotion, and especially his concept of emotion as atmosphere, Hermann Schmitz (1928–) defines religion as “behavior derived from affectedness by the divine,” i.e., communication with a powerful atmosphere overwhelming human beings. This definition enables us to explore religion in a broader context, such as dwelling, daily practice, rituals, architecture, art, etc. From this perspective, religion cannot be confined to the fields of theory, practice, institution, or convention but covers a much richer field in life. On the other hand, this view means that our daily existence is more profoundly related to the religious. This makes it understandable why new religious movements appear repeatedly, and why social phenomena appear that are not called religions but have some religious aspects even in a modern, secularized society. In this way, the theory of atmosphere can give us insight into the general necessity of the religious for human existence in each culture. Schmitz’s phenomenology of religion has, therefore, its advantage in the analysis of folk religion, which is rooted more deeply in folk culture and such of its aspects as customs, festivals, and folklore. This article will address some characteristics of Japanese folk religion and then compare monotheism with polytheism.

Garnet morphology distribution in the northern part of the Moine Supergroup, Scottish Caledonides

AbstractGarnet is a versatile and useful indicator mineral exploited in numerous geological studies. Despite its utility in providing thermobarometry and geochronology constraints, many difficulties remain in making meaningful interpretations of such data. In this paper, we characterize garnet grains from over 140 garnet‐bearing metasedimentary rock samples collected from the northern part of the Moine Supergroup (Scottish Caledonides). Large, euhedral garnet grains are interpreted to be indicative of prograde metamorphic growth during the most recent (Scandian, c. 430 Ma) phase of orogenesis. Anhedral garnet is largely restricted to the relatively low‐grade (greenschist – lower amphibolite facies) Moine thrust sheet, with an abrupt change in morphology and grain size when traced across the overlying Ben Hope and Sgurr Beag thrusts into the higher grade, more hinterland‐positioned thrust sheets. Our results suggest that caution should be exercised in using anhedral garnet in the Moine thrust sheet to estimate peak P–T conditions associated with low temperature (&lt; ~500 °C) Scandian metamorphism, because in at least some cases garnet growth may have occurred during an earlier metamorphic event. However, chemical and isotopic data from this structurally lower anhedral garnet may still be useful for deconvolving a possible polymetamorphic history for this thrust sheet. In the immediately overlying Ben Hope thrust sheet, garnet has prograde euhedral (Scandian?) rims, indicating that the Ben Hope thrust must represent a significant thermal and/or chemical break. Inclusion distribution and mineral assemblages in garnet have been used to gain further insight on garnet growth conditions and to distinguish garnet that likely contains multiple generations of growth. Although our results are specific to the Caledonides of northern Scotland, this work highlights the general necessity of a comprehensive petrographic assessment in advance of interpreting large suites of garnet‐derived thermodynamic and geochronological data.

History of research of phytomass of steppe vegetable groupments in reserve steppe «Askania-Nova»

Complex research of productive processes of ecosystems of different level was begun by the International union of biological sciences (International Union of Biological Sciences – IUBS), that in 1964 initiated development of the International biological program (International Biological Program, IBP) for research of the biological productivity of biogeocenosis of dry land and reservoirs. Scientists from many countries, that participated in execution put IBP of tasks, investigated the biological productivity of natural and created by the man of vegetable and animal community in the scale of all planet. Research of the biological productivity and phytomass on territory of dry steppe in Askania-Nova began to carry out yet 150 over back. Unfortunately, there were protracted gaps in researches, however, beginning from 1949 they can be considered continuous. And without regard to the slump of interest in the study of the productivity in 1990–2000, in Biosphere reserve «Askania-Nova», due to the active collective of scientists, research not interrupted. Therefore the far of fact sheets accumulated as a result of the advanced study of many researchers. In summarizing works for histories of botanical researches of askanian steppe authors anymore paid attention to description of history of reserve, in works the given description of researchers of the protected steppe with pointing of direction of their works, analysis of succession changes of vegetation, research of change of floristic composition, but the results of study of phytomass are not almost lighted up. Thus there was an urgent necessity of estimation and generalization up-to-date development of science of previous works of scientists in relation to above-ground and underground phytomass of vegetable community of askanian steppe. Aim of this work : to systematize and conduct the retrospective review of the advanced studies there are the lighted up results of research of above-ground and underground phytomass of vegetable community of askanian steppe in that. Materials scientific publications served as for work, scientific current documentation of Biosphere reserve «Askania-Nova» the names of F. E. Falz-Fein and Askania Nova institute of animal breeding in the steppe regions named after M. F. Ivanov. The worked out sources were brought to the bibliographic database, spreadsheet of Microsoft Excel executed in a format. To the table basic descriptions of literary source were brought in: the name of work, year of publication, name of edition, direction of researches, short annotation. For this temporal segment 3 stages of researches are distinguished: І (1842–1948) – for it typical works of descriptive direction; ІІ (1948–1990) – the subjects of the advanced studies of ecological direction are distinguished; ІІІ (1990 till this time) is appearance of the advanced studies sanctified to the study of phytomass by means of the new controlled from distance methods of research. First period protracted, but it only through considerable interruption in researches after works of F. Teetzmann in 1845, up to 1924, when in the Askania-Nova begins to work M. S. Shalyt. And this period differs in the least amount of the written works (4). The considerable are accumulated the archived materials on phytomass give an opportunity more detailed to describe her changes and dynamics.

Experience of teachers of kherson province in second half of XXI – early XX century in the context of art education development

The modern problems of art education development in educational institutions are familiar to the ones that were solved in the second part of ХІХ – early ХХ centuries. The necessity of creative generalization of historical native experience of the teachers of the past causes the interest to studying the scientific and creative contribution of the famous native scientists, theorists and practicians in the art education development. In the article author aims at the elucidation of the experience of the teachers from the Kherson region of the second half of ХІХ – early ХХ centuries as the background of improvement of art education in the modern socio-cultural conditions. By the way of retrospective analysis of archival and scientific sources the node personalities of art education of South of Ukraine were defined; their methodical approaches to the art education were defined. As the result of analysis of the works of the teachers of Kherson province were learned persons who disseminated the ideas that had the progressive impact on the pedagogical thought development of the end of ХІХ – early ХХ century: I. Derkachev, M. Korf, M. Lange, O. Muzichenko, M. Pirogov, Y. Chepiga and the others. The contribution of each person in the art education development of the South of Ukraine of the aforesaid period was defined. It was established that scientists who proved the necessity of reformation of the school education paid attention to the fact that art education of the child is the obligatory component of educational process and the knowledge of graphic grammar helps to the pupils to understand the surrounding world better, favors the intensive development of thinking, develops the esthetic taste. The scientists paid attention to the necessity of art education as the component of educational process and the knowledge of graphic grammar helps to the pupils to understand the surrounding world better, favors the intensive development of thinking, develops the esthetic taste. The author proves that Ukraine has some experience of organization of art education that favors the critical understanding and creative use of heritage of progressive native teachers-artists

Effect of Transformations of Russian Society on Forming of Value Orientation of Today Youth (on an Example of Sverdlovskaya Region)

Scientific and technical progress, evolution of relations between the state as substituting whole and its elements – population, form the base of emergence and revealing new types of contradictions in different spheres of society functioning. Relatively wide range of terms that describe the category of population under research as well as used concepts are used depending on the branch of knowledge, scientific school and author point of view of researcher. New approaches to study of the problem of younger generation are required relevant to globalization and internationalization of economic relations. These approaches should fix the necessity of generalization of requests and possibilities of capable of working population aged 14-30, reveal general theoretical and practical basics of young people behaviour. This trend may indicate both irrelevance of the content and technologies of getting of higher professional education to changed labor market and change of relation of the Generation Y to the value of labor as a way of self-fulfillment and reveal of potential.

Liberté, nécessité, contrainte chez Jansénius, Arnauld et Nicole

<titre>Résumé</titre>Les théologiens jansénistes s’évertuent à réconcilier la thèse selon laquelle l’homme est assujetti à une nécessité générale de pécher avec le libre arbitre. Jansénius affirme que, malgré la nécessité générale, nous avons la liberté d’indifférence en ce qui concerne les actes particuliers ; mais il prétend aussi (en dépit d’Aristote) que la concupiscence, source des actes particuliers, se ramène à une forme de contrainte. Arnauld se contente d’affirmer la compatibilité de la nécessité générale de pécher avec l’indifférence, tandis que Nicole s’attaque à la conception de la concupiscence comme une forme de contrainte.

NEW MASER EMISSION FROM NONMETASTABLE AMMONIA IN NGC 7538. IV. COINCIDENT MASERS IN ADJACENT STATES OF PARA-AMMONIA

We present the first detection of para-ammonia masers in NGC 7538: multiple epochs of observation of the 14NH3 (J,K) = (10,8) and (9,8) lines. We detect both thermal absorption and nonthermal emission in the (10,8) and (9,8) transitions and the absence of a maser in the (11,8) transition. The (9,8) maser is observed to increase in intensity by 40% over six months. Using interferometric observations with a synthesized beam of 0.25", we find that the (10,8) and (9,8) masers originate at the same sky position near IRS1. With strong evidence that the (10,8) and (9,8) masers arise in the same volume, we discuss the application of pumping models for the simultaneous excitation of nonmetastable (J > K) para-ammonia states having the same value of K and consecutive values of J. We also present detections of thermal absorption in rotational states ranging in energy from E/k_B ~ 200 K to 2000 K, and several non-detections in higher-energy states. In particular, we describe the populations in eight adjacent rotational states with K=6, including two maser transitions, along with the implications for ortho-ammonia pumping models. An existing torus model for molecular gas in the environment of IRS1 has been applied to the masers; a variety of maser species are shown to agree with the model. Historical and new interferometric observations of 15NH3 (3,3) masers in the region indicate a precession of the rotating torus at a rate comparable to continuum-emission-based models of the region. We discuss the general necessity of interferometric observations for diagnosing the excitation state of the masers and for determining the geometry of the molecular environment.

Развитие теории конформности: семантики, формальные модели, алгоритмы

The paper covers theoretical and practical works on conformance testing performed in ISP RAS since 1994 till now. The conformance theory development was done in various directions and, in the whole, was characterized by generalization of the interaction semantics, models and conformances in use. The necessity of such generalization was imposed, first of all, by requirements of testing practice. It is true for such system properties as nondeterminism, partial specified, asynchronous behavior, diversity of test stimuli and observations of the implementation behavior etc. It was always focused on testing effectiveness defined both by optimization of tests suites and by test generation algorithms including on-the-fly. We consider the main milestones on this way in a brief and informal discussion, paying attention not to details, but to the main problems and their solutions trying to reveal the common tendency of the development

Furosemide Cocrystals: Structures, Hydrogen Bonding, and Implications for Properties

In this paper, we report the crystal growth of four cocrystals of furosemide (4-chloro-2-[(2-furanylmethyl)amino]-5-sulfamoylbenzoic acid), a loop diuretic drug used for the treatment of hypertension and edemas, prepared with p-aminobenzoic acid, nicotinamide, and isonicotinamide as coformers. We present four new crystal structures and elucidate the intermolecular interactions present in the cocrystals. The structures display interesting supramolecular chemistry: a number of different synthons, as well as short strong hydrogen bonds with partial proton transfer and indications of proton disorder. Using powder X-ray diffraction, solid state NMR, and thermal analysis, we provide evidence for the preparation of bulk samples of two compositions, namely, the 1:1 cocrystal of furosemide and p-aminobenzoic acid and 2:1 cocrystal of furosemide and isonicotinamide, highlighting the general necessity of such multitechnique approaches to characterize organic solids (including cocrystals and solvates) prepared by gri...

HPMA-LMA Copolymer Drug Carriers in Oncology: An in Vivo PET Study to Assess the Tumor Line-Specific Polymer Uptake and Body Distribution

Polymeric drug carriers aim to selectively target tumors in combination with protecting normal tissue. In this regard polymer structure and molecular weight are key factors considering organ distribution and tumor accumulation of the polymeric drug delivery system. Four different HPMA based copolymer structures (random as well as block copolymers with lauryl methacrylate as hydrophobic block) varying in molecular weight, size and resulting architecture were analyzed in two different tumor models (AT1 prostate carcinoma and Walker-256 mammary carcinoma) in vivo. Polymers were labeled with (18)F and organ/tumor uptake was followed by μPET imaging and ex vivo biodistribution. Vascular permeability was measured by dextran extravasation and vascular density by immunohistochemistry. Cellular polymer uptake was determined in vitro using fluorescence-labeled polymers. Most strikingly, the high molecular weight HPMA-LMA random copolymer demonstrated highest tumor uptake and blood pool concentration. The molecular structure (e.g., amphiphilicity) is holding a higher impact on desired in vivo properties than polymer size. The results also revealed pronounced differences between the tumor models although vascular permeability was almost comparable. Accumulation in Walker-256 carcinomas was much higher, presumably due to a better cellular uptake in this cell line and a denser vascular network in the tumors. These investigations clearly indicate that the properties of the individual tumor determine the suitability of polymeric drug carriers. The findings also illustrate the general necessity of a preclinical screening to analyze polymer uptake for each individual patient (e.g., by noninvasive PET imaging) in order to individualize polymer-based chemotherapy.

Sinuolinea infections in the urinary system of Cynoscion species (Sciaenidae) and phylogenetic position of the type species of Sinuolinea Davis, 1917 (Myxozoa: Myxosporea)

Myxosporean infections that we diagnosed frequently in the urinary tract of Cynoscion nebulosus (Cuvier, 1830) and Cynoscion regalis (Bloch and Schneider, 1801) (Sciaenidae) collected in the estuarine systems of SC, USA, are described together with their etiological agent. Based on the morphology of spores and plasmodial stages, we identified the agent, in both fish host species, as Sinuolinea dimorpha (Davis, 1916), which is the type species of the genus. Based on sequences of SSU rDNA generated in this study from type host material, this species of SinuolineaDavis, 1917 has found its place in the current phylogenetic reconstruction of Myxozoa and enlarged the limited number of myxosporean genera represented in phylogenetic analyses by sequences of type species. Sequences of SSU rDNA of S. dimorpha from Cynoscion host species formed two clusters, irrespective of their host species, and also revealed differences within each cluster. These findings contribute to the acknowledgement of myxosporean cryptic species diversity, an important topic that emphasizes the general necessity of species delimitation and of continued effort to improve our knowledge of Myxosporea based on both morphology of spores and molecular data.

KAPPA-DEFORMED RANDOM-MATRIX THEORY BASED ON KANIADAKIS STATISTICS

We present a possible extension of the random-matrix theory, which is widely used to describe spectral fluctuations of chaotic systems. By considering the Kaniadakis non-Gaussian statistics, characterized by the index κ (Boltzmann–Gibbs entropy is recovered in the limit κ → 0), we propose the non-Gaussian deformations (κ ≠ 0) of the conventional orthogonal and unitary ensembles of random matrices. The joint eigenvalue distributions for the κ-deformed ensembles are derived by applying the principle maximum entropy to Kaniadakis entropy. The resulting distribution functions are base invariant as they depend on the matrix elements in a trace form. Using these expressions, we introduce a new generalized form of the Wigner surmise valid for nearly-chaotic mixed systems, where a basis-independent description is still expected to hold. We motivate the necessity of such generalization by the need to describe the transition of the spacing distribution from chaos to order, at least in the initial stage. We show several examples about the use of the generalized Wigner surmise to the analysis of the results of a number of previous experiments and numerical experiments. Our results suggest the entropic index κ as a measure for deviation from the state of chaos. We also introduce a κ-deformed Porter–Thomas distribution of transition intensities, which fits the experimental data for mixed systems better than the commonly-used gamma-distribution.

Enhancing the specificity and efficiency of polymerase chain reaction using polyethyleneimine-based derivatives and hybrid nanocomposites

There is a general necessity to improve the specificity and efficiency of the polymerase chain reaction (PCR), and exploring the PCR-enhancing mechanism still remains a great challenge. In this paper we report the use of branched polyethyleneimine (PEI)-based derivatives and hybrid nanocomposites as a novel class of enhancers to improve the specificity and efficiency of a nonspecific PCR system. We show that the surface-charge polarity of PEI and PEI derivatives plays a major role in their effectiveness to enhance the PCR. Positively charged amine-terminated pristine PEI, partially (50%) acetylated PEI (PEI-Ac50), and completely acetylated PEI (PEI-Ac) are able to improve PCR efficiency and specificity with an optimum concentration order of PEI < PEI-Ac50 < PEI-Ac, whereas negatively charged carboxyl-terminated PEI (PEI-SAH; SAH denotes succinamic acid groups) and neutralized PEI modified with both polyethylene glycol (PEG) and acetyl (Ac) groups (PEI-PEG-Ac) are unable to improve PCR specificity and efficiency even at concentrations three orders of magnitude higher than that of PEI. Our data clearly suggests that the PCR-enhancing effect is primarily based on the interaction between the PCR components and the PEI derivatives, where electrostatic interaction plays a major role in concentrating the PCR components locally on the backbones of the branched PEI. In addition, multiwalled carbon nanotubes modified with PEI and PEI-stabilized gold nanoparticles are also able to improve the PCR specificity and efficiency with an optimum PEI concentration less than that of the PEI alone, indicating that the inorganic component of the nanocomposites may help improve the interaction between PEI and the PCR components. The developed PEI-based derivatives or nanocomposites may be used as efficient additives to enhance other PCR systems for different biomedical applications.