Removal of mercury (II) from aqueous solution by using rice residues

Sorption potential of rice residues for Hg(II) removal from aqueous solution was investigated. Rice husk (RH) and rice straw (RS) were selected and treated with sodium hydroxide (NaOH). The raw and modified adsorbents were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and BET surface area measurements. The effects of pH, initial ion concentration, and agitation time on the removal process were studied in batch adsorption experiments. Two simple kinetic models, which are pseudo-first-order and pseudo-second-order, were tested to investigate the adsorption mechanisms. The kinetic data fits to pseudo second order model with correlation coefficients greater than 0.99 for all adsorbents. The equilibrium data fitted well with the Langmuir compared to Freundlich isotherm models. Alkali-treated adsorbent obtained larger surface area and RH-NaOH showed highest adsorption capacity followed by RS-Pure > RH-Pure > RS-NaOH. The maximum removal efficiency obtained by RH-NaOH and RS-Pure was 42 mg/l (80%) at pH 6.5 and with 2 days contact time (for 50 mg/l initial concentration and 25 mg adsorbents)

Charge and momentum transfer in supercooled melts: Why should their relaxation times differ?

The steady state values of the viscosity and the intrinsic ionic-conductivity of quenched melts are computed, in terms of independently measurable quantities. The frequency dependence of the ac dielectric response is estimated. The discrepancy between the corresponding characteristic relaxation times is only apparent; it does not imply distinct mechanisms, but stems from the intrinsic barrier distribution for $\alpha$-relaxation in supercooled fluids and glasses. This type of intrinsic ``decoupling'' is argued not to exceed four orders in magnitude, for known glassformers. We explain the origin of the discrepancy between the stretching exponent $\beta$, as extracted from $\epsilon(\omega)$ and the dielectric modulus data. The actual width of the barrier distribution always grows with lowering the temperature. The contrary is an artifact of the large contribution of the dc-conductivity component to the modulus data. The methodology allows one to single out other contributions to the conductivity, as in ``superionic'' liquids or when charge carriers are delocalized, implying that in those systems, charge transfer does not require structural reconfiguration.Comment: submitted to J Chem Phy

Guidelines for Process Safety Hazard Assessment Based on Process Information

In any new chemical process development and design, process safety is a critical aspect to be considered besides economic and technical feasibility of the manufacture of the product. A lack of proper hazard assessment during the design phase may later result in accidents with disastrous consequences to workers, the public as well as the environment. Many methods have been introduced to qualitatively and quantitatively assess the safety level of processes. Despite the availability of a large amount of methods, a systematic framework that details guidelines for hazard identification, risk assessment, safety measure design, and safe critical decision-making is still missing. To address this issue, the main objective of this study was to propose a systematic framework that outlines comprehensive guidelines for assessing the safety performance of processes based on information from the piping and instrumentation diagram (P&ID). Apart from proposing the framework, appropriate strategies for minimizing safety hazards and risks are also recommended. In addition, the user is assisted in selecting the most appropriate assessment method according to his or her needs and the scope and constraints of the assessment. A case study is presented to illustrate the application of the proposed framework

Thermal Sweet Taste Machine for Multisensory Internet

This paper presents a new taste interface for multisensory communication called "Thermal Sweet Taste Machine". We developed this interface in order to create sweet sensations, by manipulating the temperature on the tongue, without using chemicals. This device device changes the temperature on the surface of the tongue (from 20°C to 40°C) within a short period of time using a computer controlled circuit. Our preliminary user studies suggested that this device would be effective in two ways; producing the sweet sensations without the aid of chemicals, and enhancing the sweetness of the food and drinks. Here we discuss our concept, development of the interface, and some preliminary studies that has been carried out. We believe our technology would enhance the experiences and capabilities in future multisensory communication in different disciplines such as Human-Computer Interaction, human robot interactions, gaming and interacting with artificial agents

Anti-inflammatory activity of Nigella sativa oil in rats

Nigella sativa (N. sativa), commonly known as black seed, has been a well known herb since ancient times with a wide range of healing properties. The aim of this study was to investigate anti-inflammatory activity of N. sativa seed oil at three dosages on carrageenan-induced paw oedema, total white blood cell (TWBC) count and plasma protein in rats. Acute inflammation was induced by subplantar injection of carrageenan (0.1 ml, 1 % w/v) into the rat hind paw. 500 mglkg, 1000 mg/kg and 1500 mg/kg of N. sativa oil were administrated orally. Paw oedema, total white blood cell count and plasma protein were assessed. N. sativa seed oil exerted significant inhibition of paw oedema at the dosage of 1500 mg/kg at second hour and plasma protein at a dosage of 1000 mg/kg at third hour (p< 0.05). No significant inhibition ofTWBC count was exerted by N. sativa seed oil at third hour after treatment at dosages used in this study. There was also dose-dependent correlation of N. sativa seed oil on inhibition of paw oedema. These results support the traditional use of N. sativa seed oil for the treatment of inflammatory diseases

New Thermal Taste Actuation Technology for Future Multisensory Virtual Reality and Internet

Today’s virtual reality (VR) applications are mainly based on audio, visual, and haptic interactions between human and virtual world. Integrating the sense of taste into VR is difficult since we are dependent on chemical-based taste delivery systems. Therefore, developing a proper non-chemical digital taste actuation technology can unlock taste experiences in VR applications such as gaming, multisensory entertainment, remote dining, and online shopping. This paper presents the ‘Thermal Taste Machine’, a new digital taste actuation technology that can effectively produce and modify thermal taste sensations on the tongue. This device changes the temperature of the surface of the tongue within a short period of time (from 25 ◦ C to 40 ◦ C while heating and from 25 ◦ C to 10 ◦ C while cooling). We tested this device on human subjects and described the experience of thermal taste using 20 known (taste and non-taste) sensations. Our results suggested that rapidly heating the tongue produce sweetness, fatty/oiliness, electric taste, warmness, and reduced the sensibility for metallic taste. Similarly, participants reported that the cooling the tongue produced mint taste, pleasantness, and coldness. By conducting an another user study on the perceived sweetness of sucrose solutions after the thermal stimulation, we found that heating the tongue significantly enhanced the intensity of sweetness for both thermal tasters and non-thermal tasters. Also, we found that faster temperature rise on the tongue produce more intense sweet sensations for thermal tasters. We believe that this technology will be useful in two ways: First, it can produce taste sensations without using chemicals for the individuals who are sensitive to thermal taste. Second, the temperature rise of the device can be used as a way to enhance the intensity of sweetness. We believe that this technology can be used to digitally produce and enhance taste sensations in future virtual reality applications. The key novelties of this paper are as follows: 1. Development of a thermal taste actuation technology for stimulating the human taste receptors, 2. Characterization of the thermal taste produced by the device based on a set of taste related sensations and non-taste related sensations, 3. Research on enhancing the intensity for sucrose using thermal stimulation, 4. Research on how different speeds of heating affect the intensity of sweetness produced by thermal stimulation