Biohydrogen Production from Organic Waste – A Review

Hydrogen fuel is a promising alternative to fossil fuels because of its energy content, clean nature, and fuel efficiency. However, it is not readily available. Most current producion processes are very energy intensive and emit carbon dioxide. Therefore, this article reviews technological options for hydrogen production that are eco-friendly and generate clean hydrogen fuel. Biological methods, such different fermentation processes and photolysis are discussed together with the required substrates and the process efficiency.     

RBF neural networks for solving the inverse problem of backscattering spectra

This paper investigates a new method to solve the inverse problem of Rutherford backscattering (RBS) data. The inverse problem is to determine the sample structure information from measured spectra, which can be defined as a function approximation problem. We propose using radial basis function (RBF) neural networks to approximate an inverse function. Each RBS spectrum, which may contain up to 128 data points, is compressed by the principal component analysis, so that the dimensionality of input data and complexity of the network are reduced significantly. Our theoretical consideration is tested by numerical experiments with the example of the SiGe thin film sample and corresponding backscattering spectra. A comparison of the RBF method with multilayer perceptrons reveals that the former has better performance in extracting structural information from spectra. Furthermore, the proposed method can handle redundancies properly, which are caused by the constraint of output variables. This study is the first method based on RBF to deal with the inverse RBS data analysis problem.     

Calcific mitral stenosis in the hemodialysis patient

The dialysis patient is prone to elevations in the calcium phosphorus product and hyperparathyroidism, which contributes to valvular and vascular calcification. We present the case of a young lady on chronic dialysis that developed mitral calcification complicated by severe mitral stenosis, caseous calcification and retinal embolization. She subsequently required mitral valve replacement.     

Inactivation efficacy of plasma-activated water: influence of plasma treatment time,exposure time and bacterial species

This study aimed to evaluate the influence of plasma treatment time, bacterial exposure time to PAW and bacterial species on the inactivation efficacy of plasma-activated water (PAW), with additional investigation of the inactivation mechanisms of PAW. Six bacterial species, including Listeria innocua, Staphyloccus aureus, Escherichia coli, Pseudomonas fluorescens, Shewanella putrefaciens and Aeromonas hydrophila were selected as the representative bacteria. The initial bacterial concentration was around 7 log CFU ml⁻¹ after mixing with PAW, and the inactivation efficacy was measured after different exposure times during the 4 °C storage. Scanning electron microscopy (SEM) images of the bacteria after PAW treatment were carried out to inspect the cell structure damage, and physicochemical properties of PAW, including pH, conductivity and long-living reactive species of H₂O₂, , and , were examined. The results showed that the inactivation efficacy of PAW was positively correlated with plasma treatment time and bacterial exposure time, and for the species examined in this study, the Gram-negative species were more sensitive to PAW than the Gram-positive species. Cell structure damage, including shrinkage, distortion, or holes, was observed after PAW treatment. The pH of PAW was acidified to 2.5–2.9, and conductivity was significantly increased to 518.0 μs cm⁻¹. and H₂O₂ were reduced during the 48 h storage, while an increased concentration was observed for . This study demonstrated that the processing parameters of plasma treatment time, exposure time and characteristics of bacteria can significantly affect the inactivation efficacy of PAW.     

Deriving real-time action systems in a sampling logic

Action systems have been shown to be applicable for modelling and constructing systems in both discrete and hybrid domains. We present a novel semantics for action systems using a sampling logic that facilitates reasoning about the truly concurrent behaviour between an action system and its environment. By reasoning over the apparent states, the sampling logic allows one to determine whether a state predicate is definitely or possibly true over an interval. We present a semantics for action systems that allows the time taken to sample inputs and evaluate expressions (and hence guards) into account. We develop a temporal logic based on the sampling logic that facilitates formalisation of safety, progress, timing and transient properties. Then, we incorporate this logic to the method of enforced properties, which facilitates stepwise refinement of action systems.     

Building regulations are a barrier to affordable housing in Indian cities: the case of Ahmedabad

Cities in developing countries seldom consider the cost increases that regulations impose on development. To build legal housing, developers must meet a high minimum cost threshold established by mandatory standards. Many standards impose costs on building construction, make them less affordable to low-income households, deprive them access to legally built housing, and fuel the formation of slums. This study analyses the impact of relaxing a few mandatory building and site planning regulations on the cost of small two-room homes in Ahmedabad by developing two alternative layouts for the same site, one in accordance with prevalent regulations, and another after modifying a few regulations. It shows that rationalizing regulations can reduce housing cost by 34% and increase supply by as much as 75% without significantly lowering quality or compromising safety. It also shows that for a large portion of poor households, the costs imposed by mandatory standards are not trivial and have a high impact on the affordability of legally built housing. It recommends that if municipal authorities are interested in tackling the rapid growth of slums by expanding the supply of affordable housing, they should critically examine their building regulations and modify them to address the housing needs of their low-income residents.     

Bioactive Carbohydrates and Peptides in Foods: An Overview of Sources,Downstream Processing Steps and Associated Bioactivities

Bioactive peptides and carbohydrates are sourced from a myriad of plant, animal and insects and have huge potential for use as food ingredients and pharmaceuticals. However, downstream processing bottlenecks hinder the potential use of these natural bioactive compounds and add cost to production processes. This review discusses the health benefits and bioactivities associated with peptides and carbohydrates of natural origin and downstream processing methodologies and novel processes which may be used to overcome these.     

Identification of copy–paste regions in digital image

In recent technocrat world, an alteration of a digital image is more ubiquitous amongst techno‐savvy professionals, which has also been proved recurrent even for laymen. This has been popularized on account of a lucid access of different types of image‐editing software. Copying a particular region from a digital image to selective location within the same image is one of the good citations of image doctoring. Usually, the bitmap pictures are represented in the form of three‐channel color image, in which the algorithm identifies the similar areas with an assumption of image acquisition in 24 bits Bitmap format. In the present article, an exclusive procedure was applied to produce an output image, pinpointing the copy–paste area with more than 90% accuracy. The resultant image was depicting a forgery operation presumed to be performed, which determined two areas of similarity. A novel approach of 1‐connected graph was applied, as the forgery is not believed to be done in the form of a petite point‐like area. Finally, the forgery area was exposed with an aid of discerning color value, commonly as a black color for an apparent visibility of an image. The present application will be a tool in image forensics that can be applicable to identify the copy–paste regions in a single bitmap image. This article refers to a new approach for detecting the image portions which are copied from another image. Besides, the present investigation discusses an algorithm effectively implemented to determine the areas formed by copy–paste operation in an image. © 2010 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 20, 367–369, 2010     

A boundary element model of microbubble sticking and sliding in the microcirculation

A pressure driven 2D channel flow at very low Reynolds numbers (Stokes flow) with a bubble sticking and sliding along one of the walls is studied computationally using the boundary element method (BEM). The moving three phase contact lines are modeled using a Tanner law wherein the contact line speed is linearly proportional to the deviation of the contact angle from its equilibrium value. Results are presented with and without the effect of contact angle hysteresis. Including contact angle hysteresis allows us to predict the stick-slide behavior of bubbles, which in turn affects the long term evolution and dynamics of the bubbles. It is shown that the initial rapid contraction or expansion of the bubbles to achieve local equilibrium with the surrounding pressure field results in cusps and bulges in the wall normal stress profiles. The wall shear stress also increases (with opposite signs upstream and downstream of the bubble) as the fluid rushes in or out of the channel inlet and outlet. In the long term, bubbles slowly expand as they slide along the channel wall. Contact lines are found to correspond to peaks in the wall normal and shear stress profiles at all times. The effectiveness of bubbles in occluding flow through the channel is also examined.     

Physical Model Based Method to Generate Channel Coefficients for Nakagami-m Distribution

In this paper, we discuss physical model based method to generate channel coefficients for Nakagami-m distribution. We consider the phase envelope joint distribution so that the phase of the faded signal is also considered. Mainly, the coefficients are generated by exploring the physical model that relates the Nakagami-m fading distribution with Gaussian and gamma distributions for which generation of coefficients is available in commonly used simulation tools. The empirical probability density function (PDF) of generated coefficients are compared with the theoretical values and they are found in excellent agreements. The empirical PDFs for envelope and phase of the generated coefficients are validated using the Kolmogorov–Smirnov test.