Effect of torrefaction on the density and volume changes of coarse biomass particles

This work provides preliminary data on the effect of torrefaction on the apparent density of biomass. It also examines how the shape of wood is affected by torrefaction. Experiments conducted on cylinders of poplar wood showed that torrefaction reduced both density and volume of the wood, and the extent of reduction increased with increase in severity of torrefaction. The shape of the wood appears to have some effect on the extent of density change. The shrinkage in radial direction was 3–4%, while reduction in longitudinal direction was 6.5–8.8%. The mass yield decreased with torrefaction severity. © 2013 Canadian Society for Chemical Engineering     

A Review on Waterborne Thermosetting Polyurethane Coatings Based on Castor Oil: Synthesis,Characterization, and Application

Waterborne polyurethane coatings made from castor oil as polyol resource, replacing oil from fossil fuels are attracting lot of recognition during recent decades. In this review, castor oil and its modifications to synthesize various biobased waterborne polyurethane and their nanocomposite systems have been addressed. Various synthesis procedures for waterborne polyurethane dispersions and their applications as a coating material have been described. This review will be helpful to the green research community for selection of monomer and further development of biobased waterborne polyurethane utilizing advanced technology.     

Recent Developments on Epoxy-Based Thermally Conductive Adhesives (TCA): A Review

The development of new polymer-based conductive adhesives with specific performances and improved conductivity are increasingly critical for thermally interface material (TIM). Epoxy resins have been widely used as a common interface material for conductive adhesives due to its well-known ability to accept wide range of fillers possibly derived from carbon, metallic or ceramic sources. These conductive fillers with high inherent thermal conductivity, together with a possibility to characterize and manipulate the system, leads to the production of thermally conductive adhesives with higher knowledge content for a number of electronics applications.     

Application of Cocultures of Fungal Mycelium during Solid-State Fermentation of Canola Meal for Potential Feed Application

In this study, the mono-, bi-, and tri-cultivation of Aureobasidium pullulans, Neurospora crassa, and Trichoderma reesei in solid-state fermentation were applied to improve the nutritional values of hexane extracted canola meal (HECM) along with the reduction of antinutritional factors for animal feed applications. Static fermentation trials of 50% moisture content HECM were conducted in 500 mL Erlenmeyer flasks for 168 hours at 30 °C. The results showed that fungal cultivation had positive effects on the level of protein, fiber, and, glucosinolates (GLS). Monoculture of N. crassa exhibited the highest protein level of 49%. The combination of A. pullulans and N. crassa provided the highest reduction of crude fiber, acid detergent fiber and neutral detergent fiber by 21.9%, 1.7%, and 9.1%, respectively. Bi-culture of A. pullulans and T. reesei resulted in the best GLS reduction by 81.3% (0.3 vs. 1.6 μM g⁻¹ GLS of uninoculated control). These results indicate that each fungal strain possesses different enzymatic ability and selectively can work with other fungi in synergistic relationship for better fungal conversion of canola meal.     

Thiophene‐Bridged Donor–Acceptor sp2‐Carbon‐Linked 2D Conjugated Polymers as Photocathodes for Water Reduction

Photoelectrochemical (PEC) water reduction, converting solar energy into environmentally friendly hydrogen fuel, requires delicate design and synthesis of semiconductors with appropriate bandgaps, suitable energy levels of the frontier orbitals, and high intrinsic charge mobility. In this work, the synthesis of a novel bithiophene‐bridged donor–acceptor‐based 2D sp²‐carbon‐linked conjugated polymer (2D CCP) is demonstrated. The Knoevenagel polymerization between the electron‐accepting building block 2,3,8,9,14,15‐hexa(4‐formylphenyl) diquinoxalino[2,3‐a:2′,3′‐c]phenazine (HATN‐6CHO) and the first electron‐donating linker 2,2′‐([2,2′‐bithiophene]‐5,5′‐diyl)diacetonitrile (ThDAN) provides the 2D CCP‐HATNThDAN (2D CCP‐Th). Compared with the corresponding biphenyl‐bridged 2D CCP‐HATN‐BDAN (2D CCP‐BD), the bithiophene‐based 2D CCP‐Th exhibits a wide light‐harvesting range (up to 674 nm), a optical energy gap (2.04 eV), and highest energy occupied molecular orbital–lowest unoccupied molecular orbital distributions for facilitated charge transfer, which make 2D CCP‐Th a promising candidate for PEC water reduction. As a result, 2D CCP‐Th presents a superb H₂‐evolution photocurrent density up to ≈7.9 µA cm^?2 at 0 V versus reversible hydrogen electrode, which is superior to the reported 2D covalent organic frameworks and most carbon nitride materials (0.09–6.0 µA cm^?2). Density functional theory calculations identify the thiophene units and cyano substituents at the vinylene linkage as active sites for the evolution of H₂.     

Using spine decompositions to efficiently solve the length-constrained heaviest path problem for trees

The length-constrained heaviest path (LCHP) in a weighted tree T, where each edge is assigned a weight and a length, is the path P in T with maximum total path weight and total path length bounded by a given value B. This paper presents an O(nlogn) time LCHP algorithm which utilizes a data structure constructed from the spine decomposition of the input tree. This is an improvement over the existing algorithm by Wu et al. (1999), which runs in O(nlog²n) time. Our method also improves on a previous O(nlogn) time algorithm by Kim (2005) for the special case of finding a longest nonnegative path in a constant degree tree in that we can handle trees of arbitrary degree within the same time bounds.     

Simple algorithms for partial point set pattern matching under rigid motion

This paper presents simple and deterministic algorithms for partial point set pattern matching in 2D. Given a set P of n points, called sample set, and a query set Q of k points (n?k), the problem is to find a matching of Q with a subset of P under rigid motion. The match may be of two types: exact and approximate. If an exact matching exists, then each point in Q coincides with the corresponding point in P under some translation and/or rotation. For an approximate match, some translation and/or rotation may be allowed such that each point in Q lies in a predefined ε-neighborhood region around some point in P. The proposed algorithm for the exact matching needs O(n²) space and preprocessing time. The existence of a match for a given query set Q can be checked in time in the worst-case, where α is the maximum number of equidistant pairs of point in P. For a set of n points, α may be O(n^4/3) in the worst-case. Some applications of the partial point set pattern matching are then illustrated. Experimental results on random point sets and some fingerprint databases show that, in practice, the computation time is much smaller than the worst-case requirement. The algorithm is then extended for checking the exact match of a set of k line segments in the query set with a k-subset of n line segments in the sample set under rigid motion in time. Next, a simple version of the approximate matching problem is studied where one point of Q exactly matches with a point of P, and each of the other points of Q lie in the ε-neighborhood of some point of P. The worst-case time and space complexities of the proposed algorithm are and O(n), respectively. The proposed algorithms will find many applications to fingerprint matching, image registration, and object recognition.     

Euler vector for search and retrieval of gray-tone images.

A new combinatorial characterization of a gray-tone image called Euler Vector is proposed. The Euler number of a binary image is a well-known topological feature, which remains invariant under translation, rotation, scaling, and rubber-sheet transformation of the image. The Euler vector comprises a 4-tuple, where each element is an integer representing the Euler number of the partial binary image formed by the gray-code representation of the four most significant bit planes of the gray-tone image. Computation of Euler vector requires only integer and Boolean operations. The Euler vector is experimentally observed to be robust against noise and compression. For efficient image indexing, storage and retrieval from an image database using this vector, a bucket searching technique based on a simple modification of Kd-tree, is employed successfully. The Euler vector can also be used to perform an efficient four-dimensional range query. The set of retrieved images are finally ranked on the basis of Mahalanobis distance measure. Experiments are performed on the COIL database and results are reported. The retrieval success can be improved significantly by augmentiong the Euler vector by a few additional simple shape features. Since Euler vector can be computed very fast, the proposed technique is likely to find many applications to content-based image retrieval.     

Software cost estimation based on modified <Emphasis Type="Italic">K</Emphasis>-Modes clustering Algorithm

Unsupervised technique like clustering may be used for software cost estimation in situations where parametric models are difficult to develop. This paper presents a software cost estimation model based on a modified K-Modes clustering algorithm. The aims of this paper are: first, the modified K-Modes clustering which is an enhancement over the simple K-Modes algorithm using a proper dissimilarity measure for mixed data types, is presented and second, the proposed K-Modes algorithm is applied for software cost estimation. We have compared our modified K-Modes algorithm with existing algorithms on different software cost estimation datasets, and results showed the effectiveness of our proposed algorithm.