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Fires are one of the most widespread factors of changes in the ecosystems of boreal forests. The paper presents the results of a study of the morphological and physicochemical properties and soil organic matter (SOM) of Albic Podzols under pine forests (Pinus sylvestris L.) of the middle taiga zone of Siberia (Krasnoyrsky kray) with various time passed after a surface fire (from 1 to 121 years ago). The influence of forest fires in the early years on the chemical properties of Albic Podzols includes a decrease in acidity, a decrease in the content of water-soluble compounds of carbon and nitrogen and an increase in the content of light polycyclic aromatic hydrocarbons (PAHs) in organic and upper mineral horizons. Podzols of pine forests that were affected by fires more than forty-five years ago are close to manure forest soils according to most physical and chemical properties. Significant correlations were found between the thickness (r = 0.75, p < 0.05), the moisture content (r = 0.90, p < 0.05) of organic horizons and the content of ∑PAHs in the organic horizon (r = −0.71, p < 0.05) with the time elapsed after the fire (i.e., from 1 to 121 years). The index of the age of pyrogenic activity (IPA) calculated as the ratio of ∑ PAHs content in the organic horizon to ∑ PAHs at the upper mineral horizon is significantly higher in forests affected by fires from 1 to 23 years than for plots with «older» fires (45–121 years). Thus, the article presents the conserved and most changing factors under the impact of fires in the boreal forests of Russia. [ABSTRACT FROM AUTHOR]

We present a high-fidelity refined unified nonlinear finite element formulation for the efficient and robust analysis of slender thin-walled bodies during highly nonlinear deformation. Our formulation utilizes an independent discretization of the displacement field along the beam axis and over the cross section. By matching different refinements in different cross sections, it is able to apply higher-order beam theories in highly deformed regions, to capture complex buckling and postbuckling behavior, whilst retaining the computational efficiency offered by lower refinements elsewhere. The exemplar structure for this paper is the tape spring--a commonly proposed component of deployable structures with ability to combine self-deployment, via a release of stored strain energy, with locking into a relatively stiff geometric configuration with a curved cross section. To simulate localized folds due to a flattening of the cross section, the arc-length method with an automatic increment technique is employed. [ABSTRACT FROM AUTHOR]

This paper describes salient features of the C++ programming language and its programming ecosystem, with emphasis on how the language affects scientific software development. Brief history of C++ and its predecessor the C language is provided. Most important aspects of the language that define models of programming are described in greater detail and illustrated with code examples. Special attention is paid to the interoperability between C++ and other high-level languages commonly used in cheminformatics, machine learning, data processing and statistical computing. [ABSTRACT FROM AUTHOR]

The evolution of computer hardware in the past decades has truly been remarkable. From scalar instruction execution through superscalar and vector to parallel, processors are able to reach astonishing speeds - if programmed accordingly. Now, writing programs that take all the hardware details into consideration for the sake of efficiency is extremely difficult and error-prone. Therefore we increasingly rely on compilers to do the heavy-lifting for us. A significant part of optimizations done by compilers are loop optimizations. Loops are inherently expensive parts of a program in terms of run time, and it is important that they exploit superscalar and vector instructions. In this paper, we give an overview of the scientific literature on loop optimization technology, and summarize the status of current implementations in the most widely used C and C++ compilers in the industry. [ABSTRACT FROM AUTHOR]

3D printed short carbon fiber reinforced thermoplastic (SCFRTP) composites have complex multi-scale morphologies. These morphologies significantly affect the mechanical properties of SCFRTP. However, the existing research on multi-scale structural morphology formation and multi-scale mechanical responses of 3D printed SCFRTP composites is obviously insufficient so far. Herein, full-process multi-scale morphological and mechanical analyses of 3D printed SCFRTP composites are conducted in depth. Initially, the SCFRTP composites with the special engineering plastic polyetheretherketone (PEEK) as matrix and short carbon fiber (SCF) as filler (SCF contents of 1 wt%, 3 wt%, 5 wt%, 7 wt% and 10 wt%) are manufactured by 3D printing based on the principle of fused deposition modeling. The multi-scale structural morphologies of these composites are systematically characterized. Then, theoretical investigations are conducted to describe the flow behavior, crystallization and viscosity changes during 3D printing molding process, as well as the conservation of mass, momentum and energy for SCF/PEEK composites. The fluid-solid interaction numerical model is established to analyze the printing process of SCFRTP composites. Based on this model, the multi-scale morphologies of 3D printed SCFRTP composites are predicted, and the generation mechanism of multi-scale void defects in 3D printed SCFRTP composites is clarified. Subsequently, the multi-scale mechanical analysis of 3D printed SCFRTP composites is performed to predict the mechanical parameters of micro-traces, the performances of meso-layers and the mechanical properties of macro-3D printed SCFRTP specimens. The full-process from generation in manufacturing to evolution under tension of multi-scale void defects is described by the proposed model. The deviation between the experiment result and the numerical prediction which takes multi-scale void defects and fiber probability density distributions into account is much smaller compared with numerical results ignoring the multi-scale structures. Therefore, the full-process multi-scale analysis method proposed in this paper is of great significance to accurately predict the mechanical properties of 3D printed SCFRTP composites. [Display omitted] [ABSTRACT FROM AUTHOR]

OpenCL is an open standard for parallel programming of heterogeneous compute devices, such as GPUs, CPUs, DSPs or FPGAs. However, the verbosity of its C host API can hinder application development. In this paper we present cf4ocl, a software library for rapid development of OpenCL programs in pure C. It aims to reduce the verbosity of the OpenCL API, offering straightforward memory management, integrated profiling of events (e.g., kernel execution and data transfers), simple but extensible device selection mechanism and user-friendly error management. We compare two versions of a conceptual application example, one based on cf4ocl, the other developed directly with the OpenCL host API. Results show that the former is simpler to implement and offers more features, at the cost of an effectively negligible computational overhead. Additionally, the tools provided with cf4ocl allowed for a quick analysis on how to optimize the application. [ABSTRACT FROM AUTHOR]

In 1987 V.I. Ponomarev and V.V. Tkachuk characterized strongly complete topological spaces as those spaces which have countable character in their Stone–Cˇech compactification. On the other hand, in 1998 S. Romaguera introduced the notion of cofinally Cˇech complete spaces and he showed that a metrizable space admits a cofinally complete metric (otherwise, called ultracomplete metric), a term introduced independently by N.R. Howes in 1971 and A. Csa´sza´r in 1975, if and only if it is cofinally Cˇech complete. In a recent paper the authors showed that these two notions are equivalent and in this way answered a question raised by Ponomarev and Tkachuk [Vestnik MGU 5 (1987) 16–19] about giving an internal characterization for strongly complete topological spaces (termed ultracomplete by the authors). In this paper, sums and products of ultracomplete spaces are studied. [Copyright &y& Elsevier]

The C Programming Language is known for being an efficient language that can be compiled on almost any architecture and operating system. However the absence of dynamic safety checks and a relatively weak type system allows programmer oversights that are hard to spot. In this paper, we present RTC, a runtime monitoring tool that instruments unsafe code and monitors the program execution. RTC is built on top of the ROSE compiler infrastructure. RTC finds memory bugs and arithmetic overflows and underflows, and run-time type violations. Most of the instrumentations are directly added to the source file and only require a minimal runtime system. As a result, the instrumented code remains portable. In tests against known error detection benchmarks, RTC found 98% of all memory related bugs and had zero false positives. In performance tests conducted with well known algorithms, such as binary search and MD5, we determined that our tool has an average run-time overhead rate of 9.7× and memory overhead rate of 3.5×. [ABSTRACT FROM AUTHOR]

In this article, four different numerical models for the investigation of phase change processes within latent heat storage are described and compared concerning accuracy, convergence behavior and computational efficiency. The models are based on different types of discretization, make use of different ways to model phase change and are implemented with C, MATLAB or ANSYS CFX. After a brief introduction into each investigated numerical model, the experimental reference setup is described. It consists of a flat plate latent heat storage with the eutectic mixture NaNO 3 (46 wt%)–KNO 3 (54 wt%) with a measured melting temperature of 219.5 °C as storage material. Based on the corresponding simulation model developed in this paper, the comparison of the numerical models is achieved. This methodology allows the investigation of the numerical performance of different software tools in the context of high temperature latent heat storage that was not achieved thus far. All four numerical models show good agreement to experimental results but differ significantly in speed and convergence behavior. [ABSTRACT FROM AUTHOR]

Embedded assertions have been recognized as a potentially powerful tool for automatic runtime detection of software faults during debugging, testing, maintenance and even production versions of software systems. Yet despite the richness of the notations and the maturity of the techniques and tools that have been developed for programming with assertions, assertions are a development tool that has seen little widespread use in practice. The main reasons seem to be that (1) previous assertion processing tools did not integrate easily with existing programming environments, and (2) it is not well understood what kinds of assertions are most effective at detecting software faults. This paper describes experience using an assertion processing tool that was built to address the concerns of ease-of-use and effectiveness. The tool is called APP, an Annotation PreProcessor for C programs developed in UNIX-based development environments. APP has been used in the development of a variety of software systems over the past five years. Based on this experience, the paper presents a classification of the assertions that were most effective at detecting faults. While the assertions that are described guard against many common kinds of faults and errors, the very commonness of such faults demonstrates the need for an explicit, high-level, automatically checkable specification of required behavior. It is hoped that the classification presented in this paper will prove to be a useful first step in developing a method of programming with assertions. [ABSTRACT FROM AUTHOR]

Graphene represents a high-performance material for field effect transistor (FET) manufacture. As a monolayer of carbon atoms, graphene offers flexibility, high carrier mobility, and transparency. Solution-gated graphene FETs based on flexible substrates have been developed for various applications. However, none of these FETs offer both flexibility and good insulation from the electrolyte simultaneously. This would restrict their applicability in certain areas, such as implantation. To solve this problem, we used commercially available graphene and polyimide to fabricate a graphene FET. Photosensitive polyimide was used as both substrate and insulator for our device. Two Au electrodes were used separately as source and drain, and the graphene was exposed to an electrolytic solution to form a solution-gated structure. In this paper, we have studied the resistance variation between source and drain during specific fabrication steps to optimize the fabrication process. By analyzing the FET performance after repeated bending tests, our device's performance reliability was also confirmed. When compared with similar published flexible devices, our FET showed higher transconductance and lower noise levels. Also, neural activities were recorded from cortex neurons cultured on graphene FET for the first time, which proved our device's biocompatibility and demonstrated its potential for electrophysiological applications. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to investigate continuous maps from the standpoint of geometric topology and algebraic topology. Using a direct system approach and an inverse system approach of continuous maps, we study the (co)shape and (co)homological properties of continuous maps. Applications of the obtained results include the constructions of long exact sequences of continuous maps for the (co)homology pro-groups and (co)homology inj-groups, spectral Čech (co)homology groups and spectral singular (co)homology groups. [ABSTRACT FROM AUTHOR]

There has been a rapidly growing interest in optoelectronic properties of graphene and associated structures. Despite the general belief on absence of spontaneous emission in graphene, which is normally attributed to its unique ultrafast carrier momentum relaxation mechanisms, there exist a few recent evidences of strong optical gain and spontaneous light emission from monolayer graphene, supported by observations of dominant role of out-of-plane excitons in polycyclic aromatic hydrocarbons. In this paper, we develop a novel concept of light emission and optical gain from simple vertical graphene/dielectric tunnel junctions. It is theoretically shown that the possible optical gain or emission spectrum will be easily tunable by the applied voltage. We present details of quantum mechanical calculations and perform an exact analysis of field-assisted tunneling using transfer matrices combined with expansion on Airy's functions. [ABSTRACT FROM AUTHOR]

Estimating the carbon (C), nitrogen (N), and phosphorus (P) contents of a large-span grassland transect is essential for evaluating ecosystem functioning and monitoring biogeochemical cycles. However, the field measurements are scattered, such that they cannot indicate the continuous gradient change in the grassland transect. Although remote sensing methods have been applied for the estimation of nutrient elements at the local scale in recent years, few studies have considered the effective estimation of C, N, and P contents over large-span grassland transects with complex environment including a variety of grassland types (i.e., meadow, typical grassland, and desert grassland). In this paper, an information enhancement algorithm (involving spectral enhancement, regional enhancement, and feature enhancement) is used to extract the weak information related to C, N, and P. First, the spectral simulation algorithm is used to enhance the spectral information of Sentinel-2 imagery. Then, the enhanced spectra and meteorological data are fused to express regional characteristics and the fractional differential (FD) algorithm is used to extract sensitive spectral features related to C, N, and P, in order to construct a partial least-squares regression (PLSR) model. Finally, the C, N, and P contents are estimated over a West–East grassland transect in Inner Mongolia, China. The results demonstrate that: (i) the contents of C, N, and P in large-span transects can be effectively estimated through use of the information enhancement method involving spectral enhancement, regional feature enhancement, and information enhancement, for which the estimation accuracies (R2) were 0.88, 0.78, and 0.85, respectively. Compared with the estimation results of raw Sentinel-2 imagery, the RMSE was reduced by 3.42 g/m2, 0.14 g/m2, and 13.73 mg/m2, respectively; and (ii) the continuous change trend and spatial distribution characteristics of C, N, and P contents in the west–east transect of the Inner Mongolia Plateau were obtained, which showed decreasing trends in C, N, and P contents from east to west and the characteristics of meadow > typical grassland > desert grassland. Thus, the information enhancement algorithm can help to improve estimates of C, N, and P contents when considering large-span grassland transects. [ABSTRACT FROM AUTHOR]

Pseudospark switches are fast-closing low-pressure gas discharge switches with a hollow-cathode geometry. They can be triggered optically or by electron injection, where electrons emitted from a cold cathode emitter are accelerated in the electric field and initiate breakdown. The efficiency of charge carrier accumulation in the hollow-cathode structure determines the performance of the switch operation. The advantages of such switches include high hold-off voltage, high conduction current, fast current rise time, low delay and jitter time, and long lifetime. In this paper, the operating characteristics of a pseudospark switch, triggered by a carbon-nanotube (CNT)-coated electron emitter, are presented. The electron emitter is fabricated by coating randomly oriented CNTs on silicon substrate using chemical vapor deposition method. Field emission characteristics of CNTs are determined and then used as part of the trigger electrode which is integrated into an in-house constructed pseudospark switch. The operating characteristics of the switch are tested under different background pressures and different trigger voltages. Delay and jitter time under different working conditions are analyzed. Hold-off voltage and current rise time are also presented. [ABSTRACT FROM AUTHOR]

The high-hardness diamond-like carbon (DLC) films synthesized by filtered cathodic vacuum arc (FCVA) deposition may have high residual stress, which will cause the DLC film/substrate interfacial crack and film failure. Therefore, it is essential to analyze and control the residual stress during the DLC deposition. In this paper, the low-hardness DLC monolithic layer films (rich in sp2 content, soft DLC), the high-hardness DLC monolithic layer films (rich in sp3 content, hard DLC), and a series of soft/hard DLC multilayer films with modulation ratio of 1 : 1 and modulation periods ranging from 70 to 280 nm are deposited, respectively, on Si (100) wafer and Ti-6Al-4V by FCVA technology with periodic adjustments of the substrate negative bias. The effects of modulation periods (bilayer thickness) on residual stress and wear resistance of multilayer DLC films are studied. The results show that the residual stress decreases in soft/hard multilayer DLC films with decreasing modulation periods, and the films with modulation period of 140 nm have excellent wear resistance. ANSYS finite-element software is used to simulate the residual stress generation during FCVA deposition in the DLC film on a silicon substrate. The result of the finite-element simulation is consistent with that of the experiment, and the finite-element technique has a potential application in the optimization process of DLC multilayer films. [ABSTRACT FROM PUBLISHER]

Let G be a simple graph with vertex set V (G) and edge set E(G). A subset S of V (G) is called an independent set if no two vertices of S are adjacent in G. The minimum number of independent sets which form a partition of V (G) is called chromatic number of G, denoted by χ(G). A subset S of E(G) is called an edge cover of G if the subgraph induced by S is a spanning subgraph of G. The maximum number of edge covers which form a partition of E(G) is called edge covering chromatic number of G, denoted by χ'c(G). Given nonnegative integers r, s, t and c, an [r, s, c, t]-coloring of G is a mapping f from V (G) υ E(G) to the color set {0, 1, …,k-1} such that the vertices with the same color form an independent set of G, the edges with the same color form an edge cover of G, and |f(vi) - f(vj )| ≥ r if vi and vj are adjacent, | f(ei)- f(ej )| ≥ s for every ei; ej from different edge covers, |f(vi) - f(ej )| ≥ t for all pairs of incident vertices and edges, respectively, and the number of edge covers formed by the coloring of edges is exactly c. The [r, s, c, t]-chromatic number χr, s, c, t (G) of G is defined to be the minimum k such that G admits an [r, s, c, t]-coloring. In this paper, we present the exact value of χr, s, c, t (G) when δ(G) = 1 or G is an even cycle. [ABSTRACT FROM AUTHOR]

Abstract: This paper addresses the problem of solid solution strengthening of α-iron. The strengthening effect by alloying of substitutionally or interstitially dissolved atoms is obtained by simulating the interaction of a dislocation in an α-iron crystal with random as well as special arrangements of dissolved atoms. For the detection of the position of a dislocation during the simulation an algorithm is implemented which allows to analyze dislocation movements in detail. Solid solution strengthening is determined for different concentrations of Cu and Ni atoms. It is found that the movement of edge dislocations in the case of Ni atoms is nearly unhindered in contrast to when Cu atoms are present. The critical shear stress for dislocation movement is found to be significantly higher for Cu-alloyed α-iron as compared to Ni-alloyed α-iron. Interstitial C atoms in α-iron are significantly stronger obstacles for the dislocation movement than substitutional Cu atoms. The strengthening level thereby attains values similar to those found in experiments. In order to analyze the mechanisms of solid solution strengthening, a model system is used by the construction of a special interaction potential in which by the choice of the interaction parameters the lattice constants and the shear modulus of the alloyed element can be modified independently. Especially, dissolved elements can be simulated which are different from α-iron only by their lattice constants or only by their shear modulus, respectively. In this way it is found that dissolved elements with a smaller shear modulus than α-iron lead to a larger strengthening value than elements with a larger shear modulus than α-iron. Moreover, elements with a larger lattice constant than α-iron are found to be stronger obstacles than elements with a smaller lattice constant than α-iron. [ABSTRACT FROM AUTHOR]

This paper presents CMOD, a novel tool that provides a sound module system for C. CMOD works by enforcing a set of four rules that are based on principles of modular reasoning and on current programming practice. CMOD's rules flesh out the convention that . h header files are module interfaces and . c source files are module implementations. Although this convention is well known, existing explanations of it are incomplete, omitting important subtleties needed for soundness. In contrast, we have formally proven that CMOD's rules enforce both information hiding and type-safe linking. To use CMOD, the programmer develops and builds their software as usual, redirecting the compiler and linker to CMOD's wrappers. We evaluated CMOD by applying it to 30 open source programs, totaling more than one million lines of code. Violations to CMOD's rules revealed more than a thousand information hiding errors, dozens of typing errors, and hundreds of cases that, although not currently bugs, make programming mistakes more likely as the code evolves. At the same time, programs generally adhere to the assumptions underlying CMOD's rules and, so, we could fix rule violations with a modest effort. We conclude that CMOD can effectively support modular programming in C: It soundly enforces typesafe linking and information hiding while being largely compatible with existing practice. [ABSTRACT FROM AUTHOR]

In this paper we introduce an improved implementation of locally weighted projection regression (LWPR), a supervised learning algorithm that is capable of handling high-dimensional input data. As the key features, our code supports multi-threading, is available for multiple platforms, and provides wrappers for several programming languages. [ABSTRACT FROM AUTHOR]

Abstract: The forensic diagnosis of cardiac contusion has hitherto been based mainly on anamnesis, concomitant thoracic injuries and the detection of macroscopic changes to the heart. Parallel histological and serological investigations of the heart-specific troponins have been conducted with varying results. This paper aims to show whether heart-specific troponins are suitable as a means of securing the diagnosis in proven cases of cardiac contusion and of determining which of the three heart-specific troponins cTnT, cTnI and cTnC are most significant in serology and histology for postmortem diagnosis. In the study, 25 cases of known cardiac contusion and 11 controls without vital myocardial trauma taken from autopsy material were prospectively investigated. Investigation of the venous serum revealed significant differences in the concentrations of the case and control groups for troponin T (mean value 5.5056 versus 0.4982; p =0.014), for troponin C (mean value 263.9280 versus 68.5640; p =0.001) and for troponin I (mean value 1404.0560 versus 36.1650; p =0.003). In histology there are also significantly different depletions between the groups investigated (cTnT: p =0.002; cTnC: p =0.003; cTnI: p <0.001) taking into account the autolysis time. [Copyright &y& Elsevier]

Question: The relationship between carbon-13 in soil organic matter and C, and C4 plant abundance is complicated because of differential productivity, litter fall and decomposition. As a result, applying a mass balance equation to δ13C data from soils cannot be used to infer past C3 and C4 plant abundance; only the proportion of carbon derived from C3 and C4 plants can be estimated. In this paper, we compare δ13C of surface soil samples with vegetation data, in order lo establish whether the ratio of C3:C4 plants (rather than the proportion of carbon from C3 and C4 plants) can be inferred from soil δ13C. Location: The Tsavo National Park, in southeastern Kenya. Methods: We compare vegetation data with δ13C of organic matter in surface soil samples and derive regression equations relating the δ13C of soil organic matter to C3:C4 plant abundance. We use these equations to interpret δ13C data from soil profiles in terms of changes in inferred C3:C4 plant ratio. We compare our method of interpretation with that derived from a mass balance approach. Results: There was a statistically significant, linear relationship between the δ13C of organic matter in surface soil samples and the natural logarithm of the ratio of C3:C4 plants in the 100m² surrounding the soil sample. Conclusions: We suggest that interpretation of δ13C data from organic matter in soil profiles can be improved by comparing vegetation surveys with δ13C of organic matter in surface soil samples. Our results suggest that past C, plant abundance might be under-estimated if a mass balance approach is used. [ABSTRACT FROM AUTHOR]

This is the first empirical study of the use of the C macro preprocessor, Cpp. To determine how the preprocessor is used in practice, this paper analyzes 26 packages comprising 1.4 million lines of publicly available C code. We determine the incidence of C preprocessor usage -- whether in macro definitions, macro uses, or dependences upon macros -- that is complex, potentially problematic, or inexpressible in terms of other C or C++ language features. We taxonomize these various aspects of preprocessor use and particularly note data that are material to the development of tools for C or C++, including translating from C to C++ to reduce preprocessor usage. Our results show that, while most Cpp usage follows fairly simple patterns, an effective program analysis tool must address the preprocessor. The intimate connection between the C programming language and Cpp, and Cpp's unstructured transformations of token streams often hinder both programmer understanding of C programs and tools built to engineer C programs, such as compilers, debuggers, call graph extractors, and translators. Most tools make no attempt to analyze macro usage, but simply preprocess their input, which results in a number of negative consequences; an analysis that takes Cpp into account is preferable, but building such tools requires an understanding of actual usage. Differences between the semantics of Cpp and those of C can lead to subtle bugs stemming from the use of the preprocessor, but there are no previous reports of the prevalence of such errors. Use of C++ can reduce some preprocessor usage, but such usage has not been previously measured. Our data and analyses shed light on these issues and others related to practical understanding or manipulation of real C programs. The results are of interest to language designers, tool writers, programmers, and software engineers. [ABSTRACT FROM AUTHOR]

Cˇech cohomology fibrations in the sense of Ferry–McDuff–Segal are redefined for arbitrary proper maps. The main result of this paper is that R-cohomology fibrations resemble locally trivial bundles if the cohomology of the fibers is finitely generated.TheoremSuppose f :X→Y is a proper map and {Mk}k&ges;0 is a sequence of finitely generated R-modules such that the following conditions are satisfied: (a)Mk is a submodule of Hk(X;R),(b)each inclusion induced homomorphism Hk(X;R)→Hk(f−1(y);R), y∈Y, sends Mk isomorphically onto Hk(f−1(y);R). Then: (i)Given a point y in Y and m&ges;0, there is a neighborhood U of y in Y such that for all compact subsets A of U, y∈A, there is an isomorphism φA :Hm(f−1(A);R)→Hm(A×f−1(y);R). Moreover, if y∈B⊂A⊂U, then the diagram (1) is commutative.(ii)If A⊂U, y∈A, is pathwise connected and compact, then Hm(f−1(A);R)∼Hm(A×f−1(z);R) for any z∈A. [Copyright &y& Elsevier]

The main result of the paper is the following:Theorem. Suppose all the Cˇech cohomology groups of a space X are finitely generated and Hm(X;Z) is free for some m&ges;2. There is a metrizable space Y∈Cm−1∩LC∞ and a map f :X→Y such that f&ast; :Hk(Y;Z)→Hk(X;Z) is an isomorphism for all k&ges;m. If dimX is finite or X is uniformly movable and Hk(X;Z) vanish for large k, then Y is a finite polyhedron. [Copyright &y& Elsevier]

New phantom models that can simulate the effect of electromagnetic waves on human tissues have been developed. These phantom models can be designed to fit a wide range of complex permittivities by using two types of carbon fiber within a silicone rubber base. Tissues with low water content, such as fat and bone, and tissues with high water content, such as skin and muscle, can both be modeled using the phantom models discussed in this paper. When using conventional phantom model materials, care must be taken to prevent decomposition and dehydration during storage. The materials used for these new phantom models do not dry out and can be used repeatedly with reliable results. [ABSTRACT FROM AUTHOR]

In recent years, carbon aerogels have attracted much attention in basic research and as potential applications in many fields. Herein, the authors report a novel approach using bamboo powder as raw material to fabricate cellulose nanofibers (CNFs)/multi‐walled carbon nanotubes (MWCNTs) carbon aerogels by a simple dipping and carbonisation process. The developed material exhibits many exciting properties including low density (0.056 g cm−3), high porosity (95%), efficient capability for separation of oily droplets from water, and high adsorption capacity for a variety of oils and organic solvents by up to 110 times its own weight. Furthermore, the CNF/MWCNT carbon aerogels (CMCA) can be recycled many times by distillation and combustion, satisfying the requirements of practical oil‐water separation. Taken together with its economical, environmentally benign manufacturing process, sustainability of the precursor and versatility of material, the CMCA developed in this study will be a promising candidate for addressing the problems arising from the spills of oily compounds. [ABSTRACT FROM AUTHOR]