Nanoarchitectonics of nitrogen-doped porous carbon derived from leather wastes for solid-state supercapacitor

Journal of Materials Science: Materials in Electronics - Leather solid wastes not only endanger the environment, but also lead to a significant waste of biomass resources. The efficient utilization...     

Recycling of solid waste rich in organic nitrogen from leather industry: mineral nutrition of rice plants

The leather industry produces a large quantity of solid waste (wet blue leather), which contains a high amount of chromium. After its removal from wet blue leather, a solid collagenic material is recovered, containing high nitrogen levels, which can be used as a nitrogen source in agriculture. In order to take more advantage of the collagen, it was enriched with mineral P and K in order to produce NPK formulations. The objective was also to evaluate the efficiency of such formulations as a nutrient supply for rice plants in an Oxisoil, under greenhouse conditions. The application of PK enriched-collagen formulations resulted in N contents in the vegetative parts and grains of rice plants which were equivalent or superior to those obtained with urea and commercial NPK formulations.     

Agro-residues for enhanced production of bio-colorants: a feasible approach for dyeing and surface coating of leather

Clean Technologies and Environmental Policy - There is a growing demand for eco-friendly and non-toxic dyes that can be used to impart color to a wide variety of materials. Synthetic dyes are known...     

A novel assessment tool for reusability of wastes

This paper presents a new assessment method, which is able to determine the practicality of opportunities to reuse wastes. In this study, the term--reuse has much wider concepts than simply recycling to a process. In other words, reuse in this case can include recycling, utilisation as a raw material for other processes, and particularly transformation of the waste to low or preferably high value added products. Preliminary opportunities for the reuse of a waste can be generated by various methods such as brainstorming, desk research, consultation with industrial and academic contacts, and the like. In this work, each preliminary solution is then assessed according to three different categories--technical, economic, and environmental and regulatory, in order to determine the viability for reuse. The responses of nine collaborating companies to questionnaires pertaining to the three categories were used to set up feasible boundaries of each category in terms of the reuse of their wastes. Based on the replies, lower bounds for each category were determined, and then the preliminary solutions generated were ranked. The approach was applied to several industrial examples. The ranking of the high-dimensional information was aided by visual representation on a parallel coordinate graphic plot. Although the selection or rejection of an opportunity was highly dependent on the boundaries obtained, the approach proposed could provide a useful guideline to decision-makers for selection/rejection of the reuse opportunities available.     

Connecting wastes to resources for clean technologies in the chlor-alkali industry: a life cycle approach

Clean Technologies and Environmental Policy - Our current economic model is experiencing increasing demand and increasing pressure on resource utilisation, as valuable materials are lost as waste....     

Viscoelasticity studies for a fibrous collagen material: chrome-free leather

Chrome-free leather such as glutaraldehyde-tanned leather behaves very differently from chrome-tanned leather. Information regarding its viscoelasticity has not been previously reported. Hysteresis and stress relaxation are two essential properties associated with viscoelasticity. We have designed a cyclic tensile test to measure these properties to gain insight into the structural difference between chrome-free and chrome-tanned leather. Observations revealed that chrome-free leather tanned with glutaraldehyde has a higher hysteresis than chrome-tanned leather. Stress relaxation experiments, on the other hand showed chrome-free leather has very similar relaxation curves as chrome-tanned leather. Both leathers demonstrate a rapid decrease in stress for the first few seconds followed by a much slower decay thereafter. The chrome-free leather, however, has a greater initial stress than chrome-tanned leather, indicating a higher stiffness than chrome-tanned leather. Moreover, observations showed the viscoelasticity of leather was affected significantly by its fatliquor content. A decrease of loading energy in a cyclic stress–strain experiment resulted from higher fatliquor content in leather. Mention of trade names or commercial products in this article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture.     

Document image mosaicing: A novel approach

There are situations where it is not possible to capture large documents with the given imaging media such as scanners or copying machines in a single stretch because of their inherent limitations. This results in capture of a large document in terms of split components of a document image. Hence, the need is to mosaic the split components into the original and put together the document image. In this paper, we present a novel and simple approach to mosaic two split images of a large document based on pixel value matching. The method compares the values of pixels in the columns of split images to identify the common or overlapping region (OR) in them, which helps in mosaicing of split images of a large document     

Disassembly line design with multi-manned workstations: a novel heuristic optimisation approach

As the first and the most time consuming step of product recovery, disassembly is described as the systematic separation of constituent parts from end-of-life products through a series of operations. In this context, designing and balancing disassembly lines are critical in terms of the efficiency of product recovery. Recent research on disassembly line balancing (DLB) has focused on classical stations where only one worker is allocated. However, such a line results in larger space requirement and longer disassembly lead time. In this paper, disassembly line balancing problem (DLBP) with multi-manned stations is introduced to the relevant literature as a solution to overcome these disadvantages. A mixed integer linear programming (MILP) model and two novel framework heuristic algorithms are developed to minimise the number of workers and workstations. MILP model has been applied to a dishwasher disassembly system. The application results indicate the superiority of establishing multi-manned stations over classical disassembly system design with single-worker stations with shorter disassembly lead time (80.9%) and line length (60.2%). Moreover, the proposed heuristics have been compared on newly generated test problems (instances) for DLBP. The results validate that the heuristics provide acceptable solutions in a reasonable amount of time even for large-sized problems.     

Mathematical virology: a novel approach to the structure and assembly of viruses

Understanding the structure and life cycle of viruses is a fascinating challenge with a crucial impact on the public health sector. In the early 1960s, Caspar & Klug (Caspar & Klug 1962 Cold Spring Harbor Symp. Quant. Biol. 27, 1-24) established a theory for the prediction of the surface structures of the protein shells, called viral capsids, which encapsulate and hence provide protection for the viral genome. It is of fundamental importance in virology, with a broad spectrum of applications ranging from the image analysis and classification of experimental data to the construction of assembly models. However, experimental results have provided evidence for the fact that it is incomplete and, in particular, cannot account for the structures of Papovaviridae, which are of particular interest because they contain cancer-causing viruses. This gap has recently been closed by the viral tiling theory, which describes the locations of the protein subunits and inter-subunit bonds in viral capsids based on mathematical tools from the area of quasicrystals. The predictions and various recent applications of the new theory are presented, and it is discussed how further research along these lines may lead to new insights in virology and the design of anti-viral therapeutics.     

Complexation of furosemide with fulvic acid extracted from shilajit: a novel approach

The aim of the present work was to complex furosemide (FSM) with fulvic acid (FA) extracted from shilajit with the hope of having a better understanding of the complexation behavior. The effect of FA on the aqueous solubility, dissolution rate, and permeability of FSM was investigated. Different techniques, such as grinding, freeze drying, solvent evaporation, and so forth, were used for the preparation of the complex. The complexes were prepared in molar ratios of 1:1 and 1:2 FSM:FA and were evaluated for drug inclusion, solubility, differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, dissolution study, and permeation study. These methods confirm the formation of an amorphous inclusion complex of FSM with FA.     

Grindability of finished surfaces

Conclusions In a space having linear dimensions on the order of tenths of a micrometer and less and bounded by solid phases, evacuation occurs. As a result of such evacuation from the micropores of ground measures grease flows out. The grindability depends significantly on the amount of grease accumulated in the micropores of the metal, for which it is desirable periodically to store measures in grease.Grindability can be evaluated most objectively with respect to the distribution and the parameters of drops of grease coming out onto the surface.Translated from Izmeritel'naya Tekhnika, No. 11, pp. 76–77, November, 1972.     

Use of plastic wastes as a binding material in the manufacture of tiles: case of wastes with a basis of polypropylene

This paper aims to study the possibility of using plastic waste as a binding material instead of cement in the manufacturing of roofing tiles. The study bears on plastics with a polypropylene basis. Plastic waste is carried to melt and mixed with a varying proportion of sand (variation between 50 and 80% in weight). Five compsitions of tiles characterized by their proportion in plastic waste of 0% (tiles in mcro-concrete), 20, 30, 40 and 50% were studied. The measuremens of physical and mechanical properties show that plastic waste tiles whose proportion in plastic is 40%, give better results than micro-concrete tiles (TP0). Those tiles have a porosity that is below 1% and are practically impervious even after breaking impact tests.     

Free edge delamination in carbon-epoxy laminates: a novel numerical/experimental approach

A geometrically and physically nonlinear finite element approach is presented for the analysis of mode-I and mixed-mode free edge delamination in composite laminates which properly accounts for the effects of initial thermal and hygroscopic stresses. A constitutive model based on nonlinear fracture mechanics is used to describe delamination. An orthotropic softening plasticity model is used to determine the initiation and propagation of delamination. Although the orthotropic yield surface is based on stresses, it is proved, that, in combination with a softening type of post-failure response controlled by the fracture toughness, the approach results in a unique and physically realistic solution upon mesh refinement. The results from the nonlinear finite element computations, including predictive analysis, are compared with mode-I and mixed-mode free edge delamination experiments. This comparison shows that the numerical results are within 10% of the experimental data.     

Solving electromagnetic problems using a novel symmetric FEM-BEM approach

This paper presents a novel symmetric finite element method-boundary element method (FEM-BEM) formulation for solving unbounded electromagnetic problems. The proposed method offers two very attractive features: 1) it is variational, leading to a symmetric system of equations and 2) the meshes for the computations of FEM and BEM can be nonconformal, leading to decoupled computations of FEM and BEM. The accuracy and efficiency of the method are studied for both electromagnetic radiation and scattering problems.     

废弃皮革制备复合皮革的耐水性研究

有关资料表明，皮革业固体废物产生速度正以快于经济增长的速度发展，构成对生态环境的严重威胁，因此，废弃皮革的处理已成为环保领域中十分迫切需要解决的问题和重要任务。我国目前皮革生产企业达1．6万多家，已形成相当大的规模，因而皮革工业持续发展及废弃皮革资源化研究十分重要。将废弃革屑溶解在极性非质子溶剂中，通过化学交联反应和化学修饰制备复合皮革，使废弃皮革得到了有效利用。这种复合皮革微观上呈网状结构，耐水性较高。     

共沉淀法制备新型硅-锆除氟复合材料及物相表征

以氧氯化锆和硅酸钠的盐溶液为原料,采用共沉淀法制备了硅-锆复合的新型除氟材料(Si-Zr),利用SEM、FTIR和XRD分析了其表面形态和内部结构特征,并研究了相关的制备参数对材料除氟性能的影响。结果表明,600℃高温焙烧条件下的新型Si-Zr表面孔隙结构发达,比表面积大,有利于材料对氟离子的吸附; 材料中 Zr与Si以Si—O—Zr复合氧化物的形态结合,其性质结构稳定,对氟离子吸附后不易脱附。在制备参数中,焙烧温度、硅与锆摩尔比和焙烧时间对材料除氟性能的影响较大。     

New approach of depollution of solid chromium leather waste by the use of organic chelates: Economical and environmental impacts

Herein, we describe an original novel method which allows the decontamination of the chromium-containing leather wastes to simplify the recovery of its considerable protein fractions. Organic salts and acids such as potassium oxalate, potassium tartrate, acetic and citric acids were tested for their efficiency to separate the chromium from the leather waste. Our investigation is based on the research of the total reversibility of the tanning process, in order to decontaminate the waste without its previous degradation or digestion. The effect of several influential parameters on the treatment process was also studied. Therefore, the action of chemical agents used in decontamination process seems very interesting. The optimal yield of chromium extraction about 95% is obtained. The aim of the present study is to define a preliminary processing of solid leather waste with two main impacts: Removing with reusing chromium in the tanning process with simple, ecological and economic treatment process and potential valorization of the organic matrix of waste decontaminated.