Porous Silicon： Volume-Specific Surface Area Determination from AFM Measurement Data

Porous silicon layers manufactured by using （100）, 1-5 ohm-cm p-type （boron doped） wafer by electrochemical etching in HF etanol solution. Photoluminescence （PL） spectra of anodically etched silicon obtained for different conditions studied and surface characteristics are investigated by AFM. This study gives a simple way to determine specific surface are of porous silicon which plays a major role with porosity for explaining the blue shift in photoluminescence peak. Properties such as specific surface area, pore size, and pore size distribution, the main surface properties of layer are investigated from AFM data which are important material characteristics in many processing applications. The ＂specific surface area＂ （Sspecific） generally defined as the area of solid surface per unit mass of material, solid volume or cross section area. From 3-D reconstructions of AFM data, the surface area and the volume of the porous layer can be estimated directly and volume-surface specific area is calculated. For porous silicon this feature can be defined as the total surface area per volume and given by the unit m2/cm3. The method is simple not need to construct a special set up for measurement and non destructive.     

Taylor impact test for ductile porous materials—Part 1: theory

Taylor tests have been commonly employed to determine dynamic yield stress of solids at a high strain rate. In this paper, the original Taylor model is extended in order to provide a theoretical basis for testing ductile porous materials. The key difference between solids and porous materials in this respect is that porous materials are compressible and their density changes with the compressive strain. Calculations have been made for porous materials with a relative density that is a linear function of compressive strain e, i.e., ρ/ρ₀=1+ae. The final length of the projectile after impact, L₁/L, is plotted against parameter ρ₀U²/Y (see Fig. 9) and this plot is used in a Taylor test to determine the dynamic yield stress. The mean strain rate of the test can be estimated from Eqs. (21) or (22). In a companion paper (Int J Impact Eng), experiments for dynamic yield stress of porous materials will be reported based on the present theoretical analysis.     

高孔率网状Cu+CeO_2/Cu抗菌材料的制备及其抗菌性能

以泡沫海绵为基体材料,通过电镀的方法制备了高孔率网状Cu+CeO2/Cu抗菌材料,研究了制备条件并测定了其孔隙率和比表面积,评价了其抗菌性能.结果表明,网状Cu+CeO2/Cu抗菌材料的孔隙率高达95%以上,其比表面积约为31.4m2/cm3,对于大肠埃希氏菌、金黄色葡萄球菌和白色念珠菌3种菌种均具有良好的抗菌性能.     

MBS增韧PVC的脆韧转变

以ＭＢＳ增韧质ＰＶＣ,改变ＭＢＳ的填充量,得到材料的脆韧转变,得到发生脆韧转变时分散相的填充份数和分数粒径,计算出材料的临界断裂特征长度。     

离子注入技术与硅基发光材料

硅基发光材料是未来光电子集成的基础材料。离子注入技术在琪发光材料的研究与开发中有极重要的作用。多孔硅的发现是硅基发光材料的一项重大进展。     

Porous CuO nanowires as the anode of rechargeable Na-ion batteries

We report the preparation of porous CuO nanowires that are composed of nanoparticles （-50 nm） via a simple decomposition of a Cu（OH）2 precursor and their application as the anode materials of rechargeable Na-ion batteries. The as-prepared porous CuO nanowires exhibit a Brunauer-Emmett-Teller （BET） surface area of 13.05 m^2.g^-1, which is six times larger than that of bulk CuO （2.16 m^2.g^-1）. The anode of porous CuO nanowires showed discharge capacities of 640 mA.h.g^-1 in the first cycle and 303 mA.h.g^-1 after 50 cycles at 50 mA.g^-1 The high capacity is attributed to porous nanostructure which facilitates fast Na-intercalation kinetics. The mechanism of electrochemical Na-storage based on conversion reactions has been studied through cyclic voltammetry, X-ray diffraction （XRD）, Raman spectroscopy, and high resolution transmission electron microscopy （HRTEM）. It is demonstrated that in the discharge process, Na＋ions first insert into CuO to form a CuⅡ1-x CuⅠ x O1-x/2solid and a Na2O matrix then CuⅡ1-xCu Ⅰ xO1-x/2 reacts with Na＋ to produce Cu2O, and finally Cu2O decompose into Cu nanoparticles enclosed in a Na2O matrix. During the charge process, Cu nanopartides are first oxidized to generate Cu2O and then converted back to CuO. This result contributes to the design and mechanistic analysis of high-performance anodes for rechargeable Na-ion batteries.     

Flexible thermocells for utilization of body heat

Plastic thermo-electrochemical ceils （thermocells） involving aqueous potassium ferricyanide/ferrocyanide electrolyte have been investigated as an alternative to conventional thermoelectrics for thermal energy harvesting. Plastic thermocells that consist of all pliable materials such as polyethylene terephthalate （PET）, fabrics, and wires are flexible enough to be wearable on the human body and to be wrapped around cylindrical shapes. The performance of the thermocells is enhanced by incorporating carbon nanotubes into activated carbon textiles, due to improved charge transfer at the interface. In cold weather conditions （a surrounding temperature of 5 ℃）, the thermocell generates a short-circuit current density of 0.39 A/m2 and maximum power density of 0.46 mW/m2 from body heat （temperature of 36℃）. For practical use, we have shown that the thermocell charges up a capacitor when worn on a T-shirt by a person. We also have demonstrated that the electrical energy generated from waste pipe heat using a serial array of the thermocells and voltage converters can power a typical commercial light emitting diode （LED）.     

Microstructural effects on ductile fracture in heterogeneous materials. Part I: Sensitivity analysis with LE-VCFEM

Ductile failure of heterogeneous materials, such as cast aluminum alloys and discretely reinforced aluminums or DRA’s, initiates with cracking, fragmentation or interface separation of inclusions, that is followed by propagation in the matrix by a ductile mechanism of void nucleation and growth. Damage localizes in bands of intense plastic deformation between inclusions and coalesces into a macroscopic crack leading to overall failure. Ductile fracture is very sensitive to the local variations of the microstructure morphology. This is the first of a two part paper on the effect of microstructural morphology and properties on the ductile fracture in heterogeneous ductile materials. In this paper the locally enhanced Voronoi cell finite element method (LE-VCFEM) for rate-dependent porous elastic–viscoplastic materials is used to investigate the sensitivity of strain to failure to loading rates, microstructural morphology and material properties. A model is also proposed for strain to failure, incorporating the effects of important morphological parameters.     

A variational void coalescence model for ductile metals

We present a variational void coalescence model that includes all the essential ingredients of failure in ductile porous metals. The model is an extension of the variational void growth model by Weinberg et al. (Comput Mech 37:142–152, 2006). The extended model contains all the deformation phases in ductile porous materials, i.e. elastic deformation, plastic deformation including deviatoric and volumetric (void growth) plasticity followed by damage initiation and evolution due to void coalescence. Parametric studies have been performed to assess the model’s dependence on the different input parameters. The model is then validated against uniaxial loading experiments for different materials. We finally show the model’s ability to predict the damage mechanisms and fracture surface profile of a notched round bar under tension as observed in experiments.     

Removal of Arsenic from Waste Water by Using ZnO Nano-Materials

Zinc oxide has a unique position among semiconducting oxides due to its piezoelectric and transparent conducting properties. The catalyst-free synthesis of pure ZnO nanostructured material with 6-fold structural symmetry was synthesized by the chemical precipitation method. In this article, various nanostructures of ZnO which are grown by the chemical precipitation technique has been reported. Zinc oxide nanoparticles were synthesized by heating freshly prepared zinc hydroxide [Zn（OH）2] at 150℃ for two hours. The prepared compound was characterized by the X-Ray diffraction technique. Zinc oxide nanoparticles possess high removal capacity of As （III）, which can easily be separated and recycled during water treatment processes.     

Study of the Adsorption Space of Modified Clinoptilolites

Carbon dioxide （CO2） adsorption is an important adsorbent characterization method and a significant industrial process. In separation and recovery technology, the adsorption of the CO2 is important to reduce the concentration of this gas considered as one of the greenhouse gases. Natural zeolites, particularly clinoptilolite, are widely applied as adsorbents. In this regard, in the present research, the structure, composition and morphology of modified with hexafluorosilicate （HFSi） and orthophosphoric acid （H3PO4） clinoptilolites were investigated by characterizations and measurements made with, X-ray diffraction （XRD）, thermogravimetric analysis （TGA）, scanning electron microscopy-energy dispersive X-ray analysis （SEM-EDAX） and gravimetric adsorption. Additionally, the surface Chemistry of the modified clinoptilolites was analyzed by applying diffuse reflectance fourier transform infrared spectrometry （DRIFTS）. Further, the interaction of CO2 within the adsorption space of these modified clinoptilolites and a synthetic ZSM-5 zeolite was studied with the help of adsorption measurements. After all, an appropriate theoretical methodology for the analysis of the XRD and adsorption data was applied. The calculated cell parameters of the tested are similar to those reported for a typical clinoptilolite of： a = 17.662 A, b = 17.911A, c = 7.407 ~ and fl = 116.40 The resolution of the TGA derivative profiles indicated the presence of two steps for water release, one of them represents the loss of majority of the water present in the micropores. This was evidenced as a broad peak centered at about 50℃ for the CSW-HFSi-0.1, but at 100 ℃ for the samples CSW-HFSi-0.4. The SEM micrographs corresponding to the modified clinoptilolites, was evidenced that the CSW zeolite shows secondary particles exhibiting diameters from 3 to 40 μm, formed by primary clinoptilolite crystallites showing a crystallite size, φ = 40 nm. The EDAX elemental analysis it can be demonstrated that the exchange process replaced about 85% of the charge compensating ions. The DRIFT spectra of the modified clinoptilolites, specifically, CSW-HFSi-0.1, show a narrow band at about： 3,740 cm-1 corresponding to terminal silanol groups （Si-OH） and a band 3,600-3,650 cm1 resulting from extra-framework AI-OH. With the precision of the measured micropore volumes related to the excellent fitting of the adsorption data by the D-R isotherm equation, it can be affirm that carbon adsorption took only place in the micropore region. The isosteric heat of adsorption calculated for the modified clinoptilolites was greater than those values reported of ZSM-5 zeolite, particle packing silica, dealuminated Y zeolite （DAY） Cd, Zn and Ni-nitroprussides and Cu-nitroprusside and a Ni-MOF. With the obtained result it can be concluded that the modified clinoptilolites with HFSi showed a quality as adsorbent comparable to commercial synthetic zeolites.     

Nostoc Linckia as Biosorbent of Chromium and Nickel from Electroplating Industry Wastewaters

The present study relates to the use of cyanobaeterium Nostoc linkia for removal of chromium and nickel from wastewater of galvanic industry. To determine concentrations of Cr and Ni in wastewater samples atomic absorption spectrometry was used. The samples of dried nostoc biomass after exposure to wastewater were subject to nondestructive instrumental neutron activation analysis. During 30 rain of the contact ofbiomass with wastewater 84% of chromium was removed from the wastewaters. Beside chromium after 30 rain nostoc biomass accumulates the amount of iron and zinc that exceeds their concentrations in the control biomass samples by a factor of 6 and 8, respectively. Nickel content in biomass after interaction with Cr-containing wastewater increases sixty fold and copper-sixteen fold. During the same time of biomass-Ni-containing wastewater interaction, 50% of nickel were accumulated. The method of Fourier transform infrared spectroscopy was applied to identify functional groups responsible for metal binding.     

Management of the Quality of Corrosion Protection of Structural Steel Based on Corrosion Risk Level

The paper deals with the theoretical and practical aspects of improving regulatory and technical framework for assuring the quality and safety of metal structures and their protective coatings under the exposure of corrosive environment. Methodological approach has been developed to managing technological safety, assessing the risks of corrosion failures, and extension of an industrial facility＇s life based on company standards taking into account the requirements for safe operation of buildings and installations. Basic provisions of the method of limit states design have been analyzed to determine： design characteristics of corrosion impacts, computational models and design cases for affirming compliance of corrosion resistance, and durability and maintainability of structures and their protective coatings. Presented are practical examples of justifying the choice of means of primary and secondary protection, taking into account classification of the established levels of facility corrosion hazard. On the basis of limit state design principles, logistical control- and decision-making system is generated for reliability assurance of steel structures and protective coatings. Assessment criteria are specified for the risks with the use of the materials and technologies of primary and secondary corrosion protection.     

Evaluation of Effects of C60 Fullerene and Its Derivatives on Selected Microorganisms

The contribution deals with preparation of C50 fullerene derivatives （oxo derivative, bromo derivative, hydrolyzed bromoderivative, bromo-chloro derivative）, their identification and pilot testing of their biological effects on unicellular organisms. The contribution describes effects of C60 fullerene derivatives, both on prokaryotic organisms （bacteria, cyanobacteria） and eukaryotic organisms （algae） and assesses their potential use as biocides.     

Surface Active Additives for Galvanic Coating of High Quality Obtainment

This article is devoted to research of surface active additive, acrylic reagent of the ＂Nakphlok＂ in the process of galvanic coating obtainment. It was proved that the copper coating obtained in the presence of electrolyte additives Nakphlok-C are of high quality.     

Investigation of Cell Ratio Objects by Magnetic Resonance Imaging （MRI）

The physical model of cell ratio object is used for calculation of additional magnetic fields caused by the interaction of magnatic moments. There have been calculated the additional magnetic fields caused by the interaction of magnetic moments. The spatial density reconstruction of the modeled object with additional magnetic fields was obtained by MRI. The pseudo-inversion matrix method is used for spatial density reconstruction of investigated object. The calculation of additional magnetic fields while reconstruction of small objects gives more precise and full information about investigated objects.     

Light and Electron Microscopy Studies of the Visible Diffusion Zone of Mild Steel Pack Cyanided in Processed Cassava Leaves

This study investigates the microstructure of the processed cassava leaves. Standard parts machined from low visible diffusion zone formed in low carbon steel pack cyanided using carbon steel were pack cyanided by high temperature in-situ diffusion of nascent carbon and nitrogen into austenite. Formation of a visible diffusion zone was confirmed after observation with a Reichert-Jung Polyval optical microscope coupled with Zeiss AxioCam ICc 1 camera. High magnification Scanning Electron Microscope （SEM） imaging of the visible diffusion zone was done with a CamScan Series 2 scanning electron microscope. The zone was found variable in depth as measured from a representative position. The structure of all samples consists of ferrite and pearlite as determined by optical and SEM examination. Resulting products were thus both tough and hard suitable for service environments requiring high resistance to both wear and impact failure.     

Design,Prototype and Command for an Anthropomorphic Modular Reconfigurable Gripper with Three Fingers for Industrial Robots

This paper describes one anthropomorphic modular reconfigurable gripper for robots, including a prototype and one command solution. For the first time the stages of synthesis, analysis design and functional simulation are presented. The structural synthesis of the anthropomorphic grippers for robots can be made regarding the following main criteria： the number of fingers, the number of phalanxes, the relative dimensions of the phalanxes, the relative position of the fingers, the degree of freedom of the gripping mechanism and the characteristic constructive elements used. We have chosen a version with three identical fingers with three phalanxes on finger. The kinematic synthesis is used to obtain a correct closing of the finger and of the gripping mechanism. The static synthesis solves the problem to obtaining the necessary gripping force on each finger and the total gripping force. With the constructive dimensions a 3D model can be obtained using CATIA soft. Aspects regarding functional CAD and virtual simulations are shown too. For one variant of this type of gripper, the technical documentation is completed and the technical project has all the conditions for practical achievement and a prototype was made. There are two main constructive modules： the support, the palm and the finger. Main technical characteristics of the prototype are indicated. Some aspects regarding actuated and command schemes are shown.     

Multi-Year Observation of Lung Cancer Metastases to the Spleen

The purpose of our study was to show if there is any correlation between the location of the primary cancer site in the lungs, and the appearance of metastases in the spleen. 1,998 patients with confirmed lung cancer were analyzed. In 22 out of 22 cases, splenic lesions were detected by both, computer tomography （CT） and ultrasound （US） in all 22 of them. All patients with splenic lesions detected by the US underwent US-guided biopsy. Among these patients, metastases to the spleen were histopathologically confirmed in all 22 cases. 18 metastases in the spleen originated from left lung tumors, 3 from right lung tumor. In the 1 case remaining, a pattern of benign lesion was confirmed. The authors came to the conclusion that lung cancer metastases detected in the spleen originate mainly from the left lung cancer which can be caused by higher blood flow to the left lung as compared to the right lung.