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Caribou (Rangifer tarandus) rely on the short Arctic growing season to restore body condition, support the demands of lactation, and prepare for the long arctic winter, making them susceptible to even small changes in forage availability or quality. Body condition in the summer and autumn is linked to winter survival rates and fecundity in cows, critical factors in the productivity of caribou populations. Climate change predictions of warmer and wetter northern winters suggest increased snowfall over Alaska's North Slope, which has recently been verified between 1995 and 2017. However, a comprehensive analysis of how deeper snow will affect caribou forage quality is absent across Alaska. In this study, we quantify how snow depth alters the quality and seasonality of caribou forage using a long‐term (24 yr) International Tundra Experiment snow depth manipulation to evaluate how winter climate change scenarios may affect tussock tundra systems in northern Alaska. Deeper snow in prior winters leads to increases in growing season leaf N and digestible protein (DP) in deciduous shrubs (Salix spp. and Betula spp.) and graminoids (Carex spp. and Eriophorum spp.), but not evergreen dwarf shrubs (Rhododendron spp. and Vaccinium spp.). Dry matter digestibility varied among species with small differences (

The film samples of polylactide/montmorillonite (PLA/MMT) nanocomposite were formed by compression molding, film extrusion or melt blowing. The orientation of the single-layer platelets of fully exfoliated MMT was probed in these films with X-ray diffraction utilizing analysis of 2-D WAXS patterns and the pole figure technique. The reflections of the (0 2 0) and (2 1 0) crystallographic planes of MMT, both perpendicular to the plane of the platelet, were studied. It was found that the texture of MMT created upon processing is the (1 0 0) planar texture, i.e. with MMT platelets oriented preferentially parallel to the film plane. That texture becomes significantly stronger and sharper with increasing shear deformation, according to the following order: compression molding → extrusion → blow molding. At the blow ratio of 7 the maximum of MMT orientation distribution reaches value of 8 m.r.d. and the estimated Hermans orientation factor of the platelet normal with respect to the film normal, is very high, f001 = 0.96. The results obtained by X-ray pole figure technique were verified positively by direct TEM observations.

Poly( l -lactide), PLLA, belongs to the most widely used biodegradable polyesters. These polymers have attracted great attention in recent years due to their excellent material properties, which give a rise to potential applications in various commercial areas. Previously, PLLA reprocessing in a co-rotating twin-screw extruder was used as a model test for material recycling. It may be assumed basing on this study, that PLLA technological wastes may be suitable for reuse, for example, as an additive for neat PLLA. In order to verify such suitability of reprocessed PLLA its degradability under industrial composting conditions was studied at the static composting open-air pile. Incubation of this material in water at 70 °C (abiotic conditions) was also conducted. The progress of the degradation process was monitored by surface changes and measurements of sample weight loss and changes in the PLLA molecular weight. The molecular level structure of the water soluble degradation products of PLLA samples was determined by electrospray ionization multistage mass spectrometry (ESI-MS n ). Lactic acid and its oligomers terminated by hydroxyl and carboxyl end groups were identified as hydrolytic degradation products. The obtained results indicated that in selected environments (industrial composting and incubation under abiotic conditions) hydrolytic degradation via random ester bond scission occurs preferentially. It was demonstrated, that multi-reprocessing of PLLA did not significantly affect the rate of degradation and only slightly affected the disintegration progress of the PLLA samples.

The influence of shungite and graphite on some properties of composites with polylactide as matrix and containing up to 50 wt% of these fillers was investigated. It was found that the composites loaded with graphite, as compared to those with shungite, exhibit superior mechanical and thermomechanical properties (higher tensile strength, impact strength, and storage modulus) as well as lower melt flow rate, water vapour permeability, volume resistivity and surface resistivity. The phenomenon of percolation related to the passage of electric current was observed in the composites containing above 30 wt% of graphite, which caused abrupt reduction in volume and surface resistivity. This was not the case for the composites with shungite, the advantage of which is a lower price, especially when the filler loading is high.

The results of the investigations of the effect of blow-up ratio of nanocomposite poly(lactic acid) (PLA) films on the mechanical properties determined under static tension are discussed. Investigated films contain additives in the form of a montmorillonite (MMT) nanofiller (LC sample) or MMT and poly(methyl methacrylate) (PMMA) as a modifier (LCM sample) or MMT and poly(ethylene glycol) (PEG) as a plasticizer (LCG sample). Using the X-ray diffraction (XRD) method, it was found that the screw shape of the co-rotating twin-screw extruder, applied to prepare a granulated nanocomposite, significantly influenced the dispersion of MMT within the PLA matrix. The PLA film containing the additives and subjected to a proper extrusion blow molding have better mechanical properties as compared to those of a neat PLA (L sample) film. These properties were found to be the best when the blow-up ratio (R) of the nanocomposite films was equal to 4. The images obtained by means of the transmission electron microscopy (TEM) confirmed that ordering of the MMT platelets within the PLA matrix occurred during the film blowing, which induced an improvement in the film mechanical properties. The presented results prove usefulness of the extrusion blow molding as a method of manufacturing nanocomposite films based on the PLA matrix.

Results are presented of an investigation of the effect of blow moulding ratio of a nanocomposite polylactic acid (PLA) film, containing (i) a montmorillonite (MMT) nanofiller or (ii) MMT and poly(methyl methacrylate) (PMMA) as a modifier or (iii) MMT and poly(ethylene glycol) (PEG) as a plasticiser, on transmission of water vapour, oxygen and carbon dioxide, as well as on the arrangement of the MMT platelets within the PLA matrix. It was found that introduction of 5 wt. % of MMT into the PLA matrix significantly improved barrier properties of the film, which was reflected by a decrease in the transmission of water vapour by more than 40%, of oxygen by almost 40%, and of carbon dioxide by up to more than 80%. A further decrease in the film permeability (by 10–27%) was achieved by extrusion blow moulding, the less-permeable films being obtained at a blow moulding ratio of 4. Such a reduction in the permeability was caused mainly by ordering of the MMT platelets within the PLA matrix during the blow moulding process, which has been proved by transmission electron microscopy (TEM). The obtained results confirm the effectiveness of extrusion blow moulding as a technique for manufacturing nanocomposite films containing PLA as a matrix, which exhibit favourably modified barrier properties.

The results of investigations of the influence of shungite content (up to 50 weight %) in polypropylene matrix on the selected functional and processing properties of the composites are presented. Among others, mechanical strength (Fig. 2—5), impact strength (Fig. 6), and melt flow rate (Fig. 7) were evaluated. Thermal characteristics of the composites prepared was studied by differential scanning calorimetry (DSC, Fig. 8, 9) and thermogravimetry (Fig. 10,11). Thermo-mechanical properties were determined by dynamic mechanical analysis (DMA, Fig. 12). Surface and volume resistivity has been studied as well (Fig. 14). Wettability was also determined (Fig. 13) and on this basis the values of surface free energy were calculated according to Owens-Wendt method. It was found that shungite filled polypropylene composites were hydrophobic materials less susceptible to longitudinal strain at tension, showing lower impact strength, better anti-electrostatic properties and worse electro-insulating ones.

The effect of multiple (up to 10 times) extrusion of polylactide on its mechanical properties (determined by a static tension test), Charpy impact strength, melt flow rate, phase transition temperatures, degradation temperature, and permeability of water vapour and oxygen is presented. It was found that, with raising the number of the extrusion cycles, the tensile strength at break slightly diminished and the impact strength clearly decreased, while the melt flow rate and water vapour and oxygen transmission rates steadily increased. Variation of the number of extrusion cycles did not affect the glass transition temperature, whereas it did cause a lowering of the cold crystallisation temperature and slight diminishing of the melting point. The presented results indicate that PLA technological waste is suitable to be reused as an additive to a neat polymer.

Influence of the unit energy (Eu) of corona discharge used for modification of pure polylactide (PLA) and polylactide nanocomposite (PLAC) containing 5 wt% of an aluminosilicate nanofiller (Cloisite 30B) on water (ΘW) and diiodomethane (ΘD) contact angles as well as on surface free energy (γs) of these polymers was studied. ΘW and ΘD as advancing contact angles were measured with use of a goniometer while γs was calculated by the Owens–Wendt method. It was found that ΘW increased with the rising Eu while ΘD remained approximately constant. Assuming Eu = const, it could be stated that the increase in γs was much more evident for PLA than for PLAC. This increase resulted practically from the change in the polar component of γs because the dispersive component for the two materials only slightly decreased with increase in Eu.

An array of carbazoles (23 examples) can be synthesized from substituted biaryl azides at 60 degrees C using substoichiometric quantities of Rh(2)(O(2)CC(3)F(7))(4) or Rh(2)(O(2)CC(7)H(15))(4).

Influence of two types of montmorillonite nanofillers (Cloisite 30B and Nanofil 2), two kinds of organic modifiers (poly(methyl methacrylate) and ethylene/vinyl alcohol copolymer) and two types of compatibilizers (polycaprolactone and poly(ethylene glycol)) on transmission rates of water vapour, oxygen, and carbon dioxide through polylactide films is discussed. It was found that Cloisite 30B decreased the film permeability much more than Nanofil 2. All the modifiers and compatibilizers reduced the carbon dioxide transmission rate, while only the modifiers reduced the transmission rates of water vapour and oxygen. The sample containing 75, 5, and 20 wt% of polylactide, Cloisite 30B, and poly(methyl methacrylate), respectively, appeared to be the film with the best barrier properties from among 27 studied materials. The permeabilities of this film to water vapour, oxygen and carbon dioxide decreased by 60, 55 and 90%, respectively, as compared to those of the pure polylactide film. Physicochemical processes associated with the transmission rates of various substances through the polylactide nanocomposite films are still not sufficiently recognised and require further investigation.

The chromium-catalyzed allylic oxidation of triterpene 1 with O2 and N-hydroxyphthalimide (NHPI, 5 equiv) formed endoperoxide 2 in 76% yield at ambient temperature. Unlike standard allylic oxidations, this oxidation is catalytic in chromium because oxygen, not the chromium reagent, is the oxidant. This oxidation is sensitive to the precise structure of the substrate. The endoperoxide is only formed if ring A is unsaturated and ring C contains an enone. A mechanism is proposed that involves the coupling of two stabilized radicals on rings A and C to form endoperoxide 2.

A single step acid-catalyzed addition of H2O2 to β,γ-epoxy ketones is developed to synthesize hydroperoxy-substituted 1,2-dioxolanes as mixture of diastereomers.

Five-membered ring peroxides were prepared in one step in 31–86% yield from readily accessible β,γ-epoxy ketones and H2O2. The reaction proceeded via a tetrahydrofuran, which was converted to the thermodynamically favored 1,2-dioxolane. The product contains a leaving group, which can be displaced to synthesize analogues of the plakinic acid natural products.

We present a comparison of our model treating fission dynamics in conjunction with light-particle (n, p, alpha) evaporation with the available experimental data for the nuclei 126Ba, 188Pt and three isotopes of the element Z=110. The dynamics of the symmetric fission process is described through the solution of a classical Langevin equation for a single collective variable characterizing the nuclear deformation along the fission path. A microscopic approach is used to evaluate the emission rates for pre-fission light particles. Entrance-channel effects are taken into account by generating an initial spin distribution of the compound nucleus formed by the fusion of two deformed nuclei with different relative orientations.

Although humanistic and narrative approaches to psychotherapy make some different assumptions about the nature of the human condition and emphasize different aspects of human functioning in their therapeutic endeavors, I argue here that the underlying assumptions of these two approaches reflect a common view of humanness, thus making these two approaches candidates for attempts at integration. Four areas of commonality are discussed in detail: (a) life as a process of continual development, (b) the nature of experience and the process of meaning creation, (c) the nature of psychological dysfunction, and (d) the nature and importance of human relationships. The implications of these commonalities for the practice of therapy from an integrated perspective are explored in an extended case example.

Although the humanistic/existential and the narrative approaches to psychotherapy are clearly distinct perspectives with some marked differences at the level of metatheory, they also show very important similarities in their conceptualization of the human condition and the processes involved in living adaptively (Richert, 1999). These similarities make these two approaches reasonable candidates for integration. The present paper examines five specific points of integration at the level of strategy and techniques (Neimeyer, 1993b): Interplay of experiential meanings and narrative structure in developing client meaning, use of existential themes in client narratives, deconstruction as a means of dealing with existential guilt, contextualization of wishes as a means of mobilizing will, and reflexivity as a way of developing the “I–Thou” relationship. A brief theoretical rationale is offered for each of these points of integration, and each is illustrated with clinical examples.

We have used the bond percolation model to study the multifragmentation of projectiles after collisions with a Cu target at an incident energy of 600 MeV/nucleon. The charge correlations have been analysed. The theoretical results agree well with the experimental data of the ALADIN collaboration. This shows that the percolation model can reasonably describe the universal property of nuclear fragmentation in nucleus - nucleus collisions.

The emission of nucleons from a hot, deformed and rotating nucleus is treated within the Thomas-Fermi approximation. We study in particular the dependence of the transmission coefficient on the deformation and the rotational frequency of the emitting nucleus. A tractable form of the transmission coefficient is given.

Obtaining quality DNA profiles from firearms can be instrumental in assisting criminal investigations. Typically, swabbings of firearms for handler's DNA are conducted on specific regions of the firearm prior to submission to the laboratory for analysis. This review examines and compares 32 cases whose gun swabbings were either analyzed individually according to the specific region which was swabbed, or analyzed collectively by combining the swabbings from all the individual areas. Those firearms whose swabs were analyzed separately exhibited lower DNA yields and consequently fewer loci exhibiting genotypes. Those cases whose swabs were analyzed collectively exhibited higher DNA yields and consequently greater numbers of loci exhibiting genotypes. These findings demonstrate that collective swabbings result in more complete profiles and lead to the recommendation that a firearm be swabbed in its entirety using no more than two swabs.

We discuss conditions and mechanisms through which intermittent fluctuations could be generated in final charge or mass distributions obtained in the fragmentation of complex systems. We analyse the specific case of power-law distributions and the results obtained by means of a class of break-up processes which are governed by non-linear rate equations.

We show how the charge input signal applied to the gate electrode in a double and triple quantum dot may be converted to a pulse in the Kondo cotunneling current being a spin response of a nano-device under a strong Coulomb blockade. The stochastic component of the input signal results in the infrared cutoff of Kondo transmission. The stochastization of the orbital component of the Kondo effect in triple quantum dots results in a noise-induced SU(4) - SU(2) quantum transition., 16 pages, 12 figures

Iridium(I) catalyzes the intramolecular benzylic C−H bond amination of ortho-homobenzyl-substituted aryl azides to produce indolines at 25 °C.

Quantum tunnelling induces transitions not only through potential barriers, but also through energy barriers of dynamical origin. The coupling to a noisy environment introduces dissipation which affects tunnelling. This effect is studied by an analytic non-perturbative solution of a problem involving tunnelling through a dynamical barrier in the presence of a noisy environment. The accessibility to the classically forbidden energy region above the dynamical barrier is reduced (enhanced) by the friction(diffusion) effect. The occupation of each level above the dynamical barrier is characterized by the succession in time of two different regimes. The transition between both regimes is ruled by an energy criterion which is discussed.

With the help of the Ward-Takahashi identities associated with a specific non linear chiral transformation of the quark fields we show, in the framework of massless QCD, that in addition to scale invariance breaking gluon condensation implies dynamical chiral symmetry breaking, that is to say the appearance of a non vanishing quark condensate. Moreover the dynamically generated quark mass is directly connected to the quark and gluon condensates.

The use of a rhodium(II) carboxylate catalyst enables the mild and stereoselective formation of carbazoles from biaryl azides. Intramolecular competition experiments of triaryl azides suggested the source of the selectivity. A primary intramolecular kinetic isotope effect was not observed, and correlation of the product ratios with Hammett sigma(+) values produced a plot with two intersecting lines with opposite rho values. These data suggest that electronic donation by the biaryl pi-system accelerates the formation of rhodium nitrenoid and that C-N bond formation occurs through a 4pi-electron-5-atom electrocyclization.

Iridium(I) catalyzes the intramolecular benzylic C-H bond amination of ortho-homobenzyl-substituted aryl azides to produce indolines at 25 degrees C.

Due to the ever increasing efficiency of computers (hardware and software), it is now possible to represent a near lifelike model of the engineer's working environment in the computer. Apart from the hierarchical structuring of mechatronic systems the software components dealing with the graphical, symbolic, and numerical representations of these models are organized on different levels The image of a mechatronics laboratory serves as an object-oriented representation of hierarchically organized objects, such as projects, experiments, systems, and devices A development framework for the integration of existing software (components developed at our institute as well as selected external programs) is suggested using modern software techniques such as the Ada®-Task concept and the object-oriented approach The demands are listed and the structures of the so called Computer-Aided Mechatronic Laboratory (CAMeL) are represented. By way of an example of a parameter-optimization experiment built up by different devices, the possibility of parallel operations of individual lab devices on suitable hardware isexplained

Giant shape vibrations of fission fragments are described in a simple model which is based on nuclear transport theory. The friction and inertial parameters are calculated within the linear response and cranking theory, respectively. The initial conditions are chosen in the scission region following the conventional picture of the fission process at low energy. The emission of electromagnetic radiation by the form vibration is treated classically.

We propose a new approach for the derivation of an effective Hamiltonian in the framework of the many body bound state problem by imposing statistical features on some of the states which span the physical space. We discuss the formal problems as well as the physical aspects which come up along the derivation.

The Eating Attitudes Test (EAT) was given to 310 males and 302 females undergraduate volunteers who represented a cross section of students enrolled at a regional university. The responses of the 612 subjects to the EAT items were factor-analyzed separately by sex using a principal components procedure and a varimax rotation

Recent experimental data concerning fusion cross sections, spin distributions and their moments are analysed in the framework of a transport model by solving Langevin equations based on the surface friction model. Experiment and theory are in good agreement at energies above the funsion barrier. Below the barrier a modification of the Einstein relation again yields satisfactory results for fusion-evaporation systems but there remain large discrepancies for 〈l 2 〉 in the case of fusion-fission systems.