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The purpose of this research is to investigate speech sound disorders in Urdu-English bilingual children, with a focus on the generalization of phonological knowledge across languages during treatment. Carlos D. Nye's (2019) study on young non-native bilinguals found that there was concurrent growth across phonological systems while treatment was administered in the native language (Spanish) of the bilinguals. This study aims to answer the question of whether it is possible to facilitate cross-linguistic generalization for "targets with shared phonetic features" in young Urdu-English bilinguals who are struggling with speech sound disorders. It is expected that shared phonetic features in Urdu (L1) would generalize into English (L2), despite differences in shared and unshared sounds between these languages and others in which the researcher is fluent as a native speaker. The findings of this study can be used to inform clinical procedures and approaches for bilingual clinicians and speech-language pathologists and support the interdependent structure of the phonological organization in young bilinguals. It is worth noting that there is a shortage of bilingual clinicians and SLPs, with only around 8% of current SLPs speaking more than one language and an increasing number of bilinguals suffering from communication disorders. The results of this study have the potential to provide much-needed assistance to bilinguals who have been struggling with these issues.

The concern to reduce global carbon emissions has significantly improved the development of efficient solid sorbents such as activated carbon (AC). In this study, AC is developed from date stones which is one of the abundantly found agricultural waste material in gulf region. The AC was completely characterized in terms of pore volume, surface area, stability test, volatile carbon and fixed carbon contents. Impregnation of AC was performed by three different alkanolamines, namely Diethylene triamine (DETA), Pentaethylene hexamine (PEHA) and Di-ethanol amine (DEA). The alkanolamine impregnated sorbents were utilized for CO2adsorption at temperatures of 25, 30, 40, 50, 60, 70 and 100 °C and carbon dioxide (CO2) concentrations of 10, 30, 50, 70 and 92% in helium. The adsorption phenomenon was evaluated by Langmuir isotherms for all the studied adsorbents. The AC developed from date stones provided high adsorption loading capacity of CO2 i.e., 89.79 mg/g of AC at 25 °C. Thermodynamic parameters showed that the adsorption was endothermic and spontaneous in nature. Moreover, desorption profiles reveal that DETA-AC samples provided most favorable characteristics with respect to the value of desorption constant.

In this study, the densification of three agriculture waste biomasses (corn cobs, cotton stalks, and sunflower) is investigated using the torrefaction technique. The samples were pyrolyzed under mild temperature conditions (200–320 °C) and at different residence times (10 min–60 min). The thermal properties of the obtained bio-char samples were analyzed via thermo-gravimetric analysis (TGA). Compositional analysis of the torrefied samples was also carried out to determine the presence of hemicellulose, cellulose, and lignin contents. According to the results of this study, optimum temperature conditions were found to be 260 °C–300 °C along with a residence time of 20 min–30 min. Based on the composition analysis, it was found that biochar contains more lignin and celluloses and lower hemicellulose contents than do the original samples. The removal of volatile hemicelluloses broke the interlocking of biomass building blocks, rendering biochar brittle, grindable, and less reactive. The results of this study would be helpful in bettering our understanding of the conversion of agricultural waste residues into valuable, solid biofuels for use in energy recovery schemes. The optimum temperature condition, residence time, and GCV for torrefied corn cobs were found to be 290 °C, 20 min, and 5444 kcal/kg, respectively. The optimum temperature condition, residence time, and GCV for torrefied cotton balls were found to be 270 °C, 30 min, and 4481 Kcal/kg, respectively. In the case of sunflower samples, the mass yield of the torrefied sample decreased from 85% to 71% by increasing the residence time from 10 min to 60 min, respectively.

Well-designed 1D/2D composite, consisting of carbon nanotubes modified protonated carbon nitrides (CNTs/pCN) embedded with Cu-NPs were synthesized by a facile sonicated assisted chemical method. The performance of catalysts towards dynamic CO2 reduction to selective fuels was conducted under UV/visible light irradiations in a continuous flow photoreactor. Photo-activity of g-C3N4 for CO production was increased by 2.38 folds after surface charge modification due to faster charge carrier separation. Loading 3 wt% Cu and 0.5 wt% CNTs into pCN gave highest activity for the production of CO, CH4 and CH3OH under visible light. The highest CO yield as the main product over Cu-CNTs/pCN composite was 560 μmole g-cat−1 h−1, a 1.21, 1.36, 3.78 and 9.03 folds higher than using Cu/pCN, CNTs/pCN, pCN and g-C3N4 samples, respectively. This significantly enhanced photo-activity can be attributed to visible light absorption and multi-stage charges separation in the presence of Cu/CNTs. More interestingly, CO obtained under visible light was 4 times higher than using UV-light, while performance for CH4 production was 14 folds higher with visible light than using UV-light under the same operating conditions. Among the different catalyst loadings, 150 mg gave highest productivity, evidently due to limitations in exposed catalyst active surface area. Additionally, Cu-CNTs/pCN photocatalyst prevailed excellent stability in cyclic runs for continuous CO2 reduction. The findings of this work would be attractive for the development of CO2 conversion systems with renewable fuels production under solar energy.

Conversion of carbon dioxide (CO2) and methane (CH4) to fuels using photo-technology is a cleaner pathway compared to thermal reforming, since its uses only light irradiations, while producing valuable chemicals. In this study, structured nickel (Ni) and montmorillonite (MMT) supported TiO2 composite, synthesized by a sol-gel method, was tested for photocatalytic reduction of CO2 using fixed-bed and monolith photoreactors. The performance of structured nanocatalyst was evaluated using CO2-H2 system via photocatalytic reverse water gas shift (RWGS) reaction and CO2-CH4 system via photocatalytic dry reforming of methane (DRM). Using photocatalytic RWGS, CO was detected as the main products, while the performance of Ni-MMT/TiO2 composite was expressively higher than using MMT/TiO2 and TiO2 catalysts. This was obviously due to larger surface area by MMT dispersion and hindered charges recombination rate by Ni. Similarly, using DRM, H2 and CO were the main products, while their selectivity was greatly dependent on the initial CH4/CO2 molar feed ratios. At a lower CH4/CO2 ratio, more CO was produced, while a higher feed ratio promoted H2 production. This shows, composite catalyst was more favorable for CO2 adsorption, while CH4 was competitively adsorbed during photo-catalysis process. Comparatively, Ni-MMT/TiO2 catalyst reveals higher photo-activity and selectivity in a monolith photoreactor than using fixed-bed reactor under the same operating conditions. This enhanced photoactivity was due to higher photonic flux with enlarged active surface area due to monolithic support and efficient sorption process. The stability of Ni/TiO2 dispersed MMT for CO and H2 production via DRM process sustained in cyclic runs using monolithic support. Hence, using Ni/MMT modified TiO2 catalyst in a monolith photoreactor, CO2 and CH4 can efficiently be converted to renewable fuels under light irradiations and would be a great benefit to the environment.

Chromium(III)-based metal-organic framework was prepared by using a tritopic bridging 1,3,5-Tris(4-carboxyphenyl) benzene ligand as a linker and chromium as metal that forms a secondary building unit, by solvothermal method. Continuous weight loss of Cr-MOF sample in the entire temperature range was related to loss of desorption of adsorbed gases from pores and cavities, removal of guest molecules such as N,N-dimethyl formamide, and framework disintegration. Specific surface area was found to be 420 m2/g and significant steep raise in the isotherm at partial pressure >0.2 indicates microporous character of the sample. The CO2 adsorption capacity of Cr-MOF sample measured at 298 K and partial pressure of 0.9 atm was found to be 3.5 wt.%. Temperature elevation from 298 to 343 K decreases adsorption capacity according to the Le-Chatelier's Principle. The CO2 adsorption increases linearly as the pressure increases from 0 to 0.9 atm is due to relatively weak adsorption sites and homogeneity.

This study is aimed to investigate the electro-catalytic activity of Au supported on both CeO2 and activated carbon (AC) to convert CO2 to mixture of C1-C4 hydrocarbons in the presence of ionic liquid (IL) 1-butyl-3-methylimidazolium methylsulfonate. The studied catalyst samples were prepared by using simultaneous wet impregnation method. The sample containing 0.6 % Au showed higher electro-catalytic activity than the sample contained 0.3 % Au. Both, the average Au particles size and the transformation of layered non-uniformed semi-oval structure to flaked tiny circular like-structure were mainly responsible for the higher catalytic activity of 0.6Au-CeO2-AC sample. In addition, the overall electro-catalytic activity depends upon the applied reaction voltage. Overall, the presence of IL, the surface morphology, and average Au particles size had played a key role in the electro-catalytic conversion of CO2 to hydrocarbons.

Photocatalytic CO2 methanation using H2O vapors and/or H2 reductants over nickel (Ni) and indium (In) promoted TiO2 nanocatalysts has been investigated. The physical–chemical characteristics of the catalysts, prepared through a sol–gel method with different Ni and In doping levels, were characterized by XRD, FESEM, TEM, FTIR, XPS, N2 adsorption–desorption, UV–vis diffuse reflectance, Raman and photoluminescence spectroscopy. The controlled crystallites growth with increased specific surface area and reduced pore diameter were observed by NiO and In2O3 loading into TiO2. In and Ni metals present in TiO2, oxidized as In2O3 and NiO, promoted efficient separation of photo-generated charges (e−/h+). Using H2O as a reductant, CO2 was efficiently converted to CH4 over co-loaded TiO2 catalysts and the optimal loading amount was determined to be 1 wt.% NiO and 3 wt.% In2O3, giving a CH4 production rate of 240 μmole g−1 h−1 at selectivity 80%. This photoactivity of NiO and In2O3 loaded TiO2 catalyst for CO2 methanation was 2 fold more than the yield rate over In2O3/TiO2 and 6.5 times more the amount produced over the pure TiO2. The enhancement was attributed to charge transfer property and efficient suppressed recombination rate by Ni and In metals. In the presence of H2 reductant, both CO and CH4 were produced in significant amount and the maximum yield rates detected were 243 and 208 μmole g−1 h−1, respectively. Therefore, H2O reductant found to be more efficient for CH4 production, yet the CO2 reduction process was more favorable with H2, where the total amounts of products were considerably enhanced. In addition, a photocatalytic reaction mechanism is proposed to understand experimental results over the NiO and In2O3 loaded TiO2 catalysts.

Dwindling fossil fuel reserves require the efficient usage until sustainable alternatives fully replace them. Overall efficiency and output is used to rank the stationary combined cycle gas turbines. Efficient gas turbines require high combustion chamber temperature resulting in NO x generation. Furthermore, low-quality fuel increases the fraction of acidic gases in the exhaust. In this work a novel modification in combined cycle gas turbine cycle is presented, increasing the overall efficiency and decreasing acidic gases production along their capture, before rejection to stack. The modification is implemented on simulated General Electric 9HA.02 turbine using ASPEN HYSYS ® v8.6. Applying efficiency and exhaust temperature limit (constraints), bounds the discrepancies in simulated and real gas turbine parameters. A rise of 0.77% in efficiency and a considerable decrease in acidic gases (exhaust) is observed. Different gas turbine operational features pertinent to overall efficiency have been studied. An unprecedented control technique is presented as an addition to the proposed modification to achieve higher efficiencies under part load conditions.

Magnesium hydride (MgH 2 )–carbon nanotubes (CNT) composite has been prepared by high-energy ball milling method and their experimental and kinetic hydrogen adsorption studies was assessed. Hydrogen adsorption studies were performed by Sievert’s volumetric apparatus and kinetic evaluation was conducted by surface chemistry and Langmuir–Hinshelwood–Hougen–Watson (LHHW) type mode. Powder X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) were performed. Hydrogen adsorption capacity of commercial MgH 2 , milled MgH 2 , and MgH 2 /CNT composite are found to be 0.04, 0.057, and 0.059 g (H 2 )/g (MgH 2 ) at 673 K and hydrogen pressure of 4.6 MPa. Addition of 5 wt% of CNTs to MgH 2 proved to be very critical to enhance hydrogen adsorption as well as to improve its kinetics. It was observed that hydrogen adsorption is not in quasi-state equilibrium and is modeled using kinetic rate laws.

The impurities CO2 and H2S in natural gas (NG) are recognized as major contaminants that exacerbate economic, operational, and environmental losses. Generally, these undesirable impurities are removed using well-established amine-based absorption methods. However, typical methods in this category are cost-intensive, primarily due to their high operating and maintenance costs. The ionic liquids (ILs) are emerging as alternative solvents owing to their lower regeneration costs and non-flammable nature. However, ILs could not attain a significant attention from practitioners due to the lack of effective communication between industry and academia. In this context, a comprehensive review and analysis of specific ILs that can simultaneously remove H2S and CO2 is proposed. This article highlights the major challenges and issues associated with various acid gases removal approaches, particularly IL-based absorption techniques. Recent developments toward solving the major issues associated with absorption using ILs are assessed to highlight areas for further improvement. The acid gas solubility data for ILs are analyzed to evaluate the feasibility and associated major constraints for large-scale process designs using commercial process simulators. Furthermore, the fundamentals for the process systems engineering-based investigations using ILs are also highlighted and evaluated. This study concludes that ILs have the potential to completely replace conventional solvents, have synergistic effects in terms of energy savings, and provide feasible solutions to maintenance-related issues.

Template-free fabrication of graphitic carbon nitride nanotubes modified with lanthanum (La/g-CNT) for dynamic photo-catalytic CO2 reduction with CH4 has been investigated. Successful fabrication of g-C3N4 nanosheets and nanotubes were obtained with enhanced photo-activity under visible-light. Using 5 wt% La/g-CNT, CO yield of 491 µmole g-cat−1 h−1 was obtained which is 3.6 and 5.9 folds higher than g-CNS and g-CN samples. Similarly, production of H2 was highest over La/g-CNT which was 2.95 folds more than g-CNT and 5.1 times higher than using g-CN. Although, pristine g-CN has more basic sites and larger BET surface area but enhanced photo-activity over La/g-CNT can be attributed to efficient transfer of electrons over 1D structure and separation of charge carriers by La. More interestingly, effect of CH4/CO2 feed ratios was obvious, whereas, highest CO was produced at CH4/CO2 ratio of 1.0 but H2 was maximum with ratio of 2.0. Among the different reaction systems, highest CO was obtained using DRM, while CO2 reduction by H2/H2O promoted both CO and CH4 production. This was obviously due to basic characteristics, sorption competition over the catalyst surface and favorable reverse water gas shift (RWSG) reaction. The stability test further confirmed the suitability of this material which prevailed until three cycles without obvious deactivation. This work will open new opportunities to develop structured nanocalaysts for solar energy based reutilization of CO2 and CH4 for the production of renewable fuels.

All syncopal patients who present to the emergency department should be considered for pulmonary embolism (PE) as part of their differential diagnosis. PE presenting as a syncopal episode and associated with occult uterine malignancy is uncommon. Review of the literature indicates that up to 10% of patients with unprovoked venous thromboembolism (VTE) are diagnosed with cancer in the year following that first episode of VTE. In patients suspected of having a PE who do not manifest any source of an embolism require eventual workup to screen for an occult malignancy. Here, we report a 74-year-old female who presented to the emergency department following an unexplained sudden loss of consciousness and eventually was found to have a massive saddle embolus caused by a uterine malignancy-induced VTE.

There are various theoretical approaches to design, improve and optimize CO 2 capture from natural gas sweetening units through chemical absorption. The aim objective of the present review is to explore various theoretical approaches developed by process and research engineers to improve the design and operation of chemical absorption sweetening units. Therefore, this review is divided into four parts. The first part discusses the basic thermodynamic and kinetic principles that represent the main core of any process simulation research. The second part is devoted to designing and improving the main columns i.e., the absorber and the stripper. The third part reviews previous research aiming at designing or optimizing the whole sweetening unit. The last part briefly discusses computational chemistry techniques used by chemists and chemical engineers to design novel solvents at the molecular level. The review ends with conclusions and a brief discussion about future perspectives to improve the process and areas that require further research effort.

Natural gas with high acid gas contents represents a challenge in process engineering and energy industry. Exploring the alternative solutions requires correlating additional costs accompanying the process scale-up to treat high acid-gas contents. This work estimates this relation and validates it against various conditions in amine sweetening plants. An amine sweetening process was simulated using Aspen Hysys to treat a natural gas (25 MMSCFD, 1.7 mol% H 2 S and 4.13 mol% CO 2 ). Amine circulation rate, lean amine temperature, re-boiler temperature and amine concentration were chosen as the main input variables to optimize the process total cost using the central composite experimental design model. The process was scaled-up to handle a sour gas up to (25 mol% CO 2 and 3 mol% H 2 S) by scaling up the amine circulation rate. The capital and operating costs showed a linear relationship with the increase of CO 2 percentage in natural gas. Moreover the utility requirements, regenerator column diameter and the surface area of the re-boiler, the lean-rich amine heat exchanger and the lean amine cooler showed a strong linear increase correlation. There was no statistical difference using either Li–Mather or Kent–Eisenberg thermodynamic models. Low feed gas pressure yielded a similar linear relationship irrespective of the costs for purchasing and operating the inlet compressor and air cooler. No statistical difference found between cost regressions lines of different tray efficiency of the distillation tower. For various partial pressures of CO 2 and H 2 S, assuming no other sulphur compounds, the economics scaled up as a second order polynomial.

In this research work, biodiesel production by trans-esterification of three raw materials including virgin and used edible oil and non edible oil has been presented. A two step method following acidic and alkali catalyst was used for non edible oil due to the unsuitability of using the straight alkaline-catalyzed trans-esterification of high FFA present in rice bran oil. The acid value after processing for rice bran, cottonseed and waste cooking oil was found to be 0.95, 0.12 and 0.87 respectively. The influence of three variables on percentage yield i.e., methanol to oil molar ratio, reaction temperature and reaction time were studied at this stage. Cottonseed oil, waste cooking oil and rice bran oil showed a maximum yield of 91.7%, 84.1% and 87.1% under optimum conditions. Fuel properties of the three biodiesel satisfied standard biodiesel fuel results.

Nobel metals free MW/SW supported TiO2 nanocatalysts were prepared via wet impregnation assisted sol-gel method and tested for photocatalytic H2 evolution. The photoactivity of TiO2 mediated by MW/SW was considerably improved due to superior charges separation. More importantly, hydrogen production depends on wall numbers such as multiwall or single wall carbon nanotubes, works as electrons acceptor and promoted charges separation. The maximum H2 evolution rate of 11,060 ppm h−1g-cat−1 was achieved over MW/TiO2/SW, 1.24 folds higher than SW/TiO2 and 1.42 times higher than MW/TiO2 composites. This improved productivity was due to synergistic effects between SW/MW, which greatly promoted charge carriers separations and enables absorption of visible light. Besides, more H2 production with SW/TiO2 compared to MW/TiO2 was due to more trapping of electrons by single wall than using multi-walls. The activity of composite further enhanced with methanol as hole-scavenger, higher in order of methanol > ethanol > propanol due to presence of α-hydrogen atoms bonded with C-atoms. Response surface methodology (RSM) approach of full factorial design applied to investigate significance and influence of reaction time, loading of catalyst and methanol-water concentration on H2 yield. The interaction between parameters reveals that catalyst loading has more influence on H2 evolution compared to other factors. Therefore, this study provides a new approach for noble-metals free synthesis of composite with enhanced visible light H2 evolution and optimization of parameters for maximum photo-catalytic H2 production.

Not long ago, it was thought that only software applications and general purpose digital systems i.e. computers were prone to various types of attacks against their security. The underlying hardware, hardware implementations of these software applications, embedded systems, and hardware devices were considered to be secure and out of reach of these attacks. However, during the previous few years, it has been demonstrated that novel attacks against the hardware and embedded systems can also be mounted. Not only viruses, but worms and Trojan horses have been developed for them, and they have also been demonstrated to be effective. Whereas a lot of research has already been done in the area of security of general purpose computers and software applications, hardware and embedded systems security is a relatively new and emerging area of research. This chapter provides details of various types of existing attacks against hardware devices and embedded systems, analyzes existing design methodologies for their vulnerability to new types of attacks, and along the way describes solutions and countermeasures against them for the design and development of secure systems.

Revolution in the area of information technology has brought about changes in many spheres of life. Today, information systems are being used in very sensitive areas such as defence and missile control systems, nuclear plants, etc. Not only has it changed how business is conducted, it has also brought about entirely new paradigms like that of information and cyber warfare. Similarly, one of the many impacts that it has made, is how wars are fought. For all what it has contributed, the information stored on digital devices and computers has become a precious resource and special measures are taken to guard it against attacks from malicious users. These special measures are needed by any enterprise be it a business firm, a commercial entity, a government agency or a military organization. However, requirements and specifications for information security and assurance for a military organization are essentially different from those of commercial or business applications. This paper highlights and discusses various aspects related to the security of information resources of military importance and outlines certain parameters that should be taken into consideration when talking about the security of military information resources. W also describe the role satellite reconnaissance can play in cyber war. Authors proclaim that this paper is first such attempt to correlate cyber war with satellite reconnaissance.

A wireless sensor network comprises of small sensor nodes each of which consists of a processing device, small amount of memory, battery and radio transceiver for communication. The sensor nodes are autonomous and spatially distributed in an area of investigation. Certain applications and protocols of wireless sensor networks require that the sensor nodes should be aware of their position relative to the sensor network. For it to be significant and to be of value, the data such as temperature, humidity and pressure, gathered by sensor nodes must be ascribed to the relative position from where it was collected. For this to happen, the sensor nodes must be aware of their relative positions. Traditional location finding solutions, such as Global Positioning System, are not feasible for wireless sensor nodes due to multiple reasons. Therefore, new methods, techniques and algorithms need to be developed to solve the problem of location and position estimation of wireless sensor nodes. A number of algorithms and techniques based upon different characteristics and properties of sensor nodes have already been proposed for this purpose. This chapter discusses the basic principles and techniques used in the localization algorithms, categories of these algorithms and also takes a more closer look at a few of the representative localization schemes.

The growing interest in exploring the physical properties of ionic liquids (ILs) could be attributed towards the design of industrial processes based on ILs (nonvolatile) to replace organic solvents (highly volatile). The densities and viscosities of imidazolium based ILs have been measured and reported by a number of researchers at ambient pressure. However, the experimental physical property data for most of the ILs at high pressure is quite scarce due to the difficulties involved in the treatment of natural gas to remove carbon dioxide (CO2) at high pressures. Therefore, there is an immense need to apply correlations and thermodynamic Equation Of State (EOS) models to predict or estimate physical properties. The main objective of this work is to investigate the application of Gardas and Coutinho method and Modified Tait equation to estimate the densities and viscosities of two ILs: 1-hexyl-3-methyl imidazolium tetrafluoroborate; (C6mim) (BF4) and 1-hexyl-3-methyl imidazolium hexafluorophosphate; (C6mim) (PF6) at pressures up to 100 bar and at temperatures (298.15, 308.15, 318.15) K. The results show that these methods could be applied satisfactorily for estimating the density and viscosity of ionic liquids. The densities and viscosities of both ILs increased with the increase in pressure at all the studied temperatures. However, the effect of anion appeared to be significant on both physical properties for the studied ILs and found to be in decreasing order of (PF6) >(BF

This study explores the possible use of ionic liquids as a solvent in a commercial high-pressure CO2 removal process, to gain environmental and energy benefits. There are two main constraints in realizing this: ionic liquids can be corrosive, specifically when mixed with a water/amine solution with dissolved O2 & CO2; and CO2 absorption within this process is not very well understood. Therefore, scavenging CO2 to ppm levels from process gas comes with several risks. We used 1-butyl-3-methylimidazoium methane sulphonate [bmim][MS] as an ionic liquid because of its high corrosiveness (due to its acidic nature) to estimate the ranges of expected corrosion in the process. TAFEL technique was used to determine these rates. Further, the process was simulated based on the conventional absorption–desorption process using ASPEN HYSYS v 8.6. After preliminary model validation with the amine solution, [bmim][MS] was modeled based on the properties found in the literature. The energy comparison was then provided and the optimum ratio of the ionic liquid/amine solution was calculated.

In the present work, thermophysical properties such as density (ρ), dynamic viscosity (η), refractive index (nD), and surface tension (σ) of aqueous piperazine (PZ) solutions with mass fractions (100w = 1.74, 5.16, 10.35) have been measured from temperatures (298.15 to 338.15) K. All of these properties have also been measured for the aqueous blends of N-methyldiethanolamine (MDEA) and piperazine (PZ) with mass fractions {100(w1/w2) = 32.28/1.74, 32.28/5.16, 32.28/10.35, 48.80/1.74, 48.80/5.16, 48.80/10.35)} for the entire temperature range. The limit of PZ solubility in water was measured by the addition of a known quantity of anhydrous PZ (solid crystals) in 20 mL of distilled water at temperatures (278 to 343) K with a regular interval of 5 K. The experimental values of the studied physical properties have been compared with the literature and also correlated as a function of temperature. The coefficients of thermal expansion (αp) values have been calculated from their experimental density data using a...

In batch process scheduling, the introduction of intermediate storage tanks between process stages result in increasing the efficiency and productivity of the process. The main purpose of this is to minimize the process completion time, i.e. makespan. However, it is important to determine the right number and respective locations of the intermediate storage to ensure optimal investment and operational cost. The generally adopted transfer policies for handling intermediate storage tanks in batch processes are unlimited intermediate storage (UIS) and finite intermediate storage (FIS). In this work, new completion time algorithms for UIS and FIS transfer policies are proposed using matrix representation. The objective of the proposed approach is to calculate the makespan for all possible production sequences for given batch product recipes while at the same time determining the number and location of intermediate storage tanks required. With the assumptions that the intermediate storage could be used to store any intermediate product, the method is verified against the Gantt chart method and the results agreed well. A number of different product recipes are analyzed using a developed computer code. This enables the proposed algorithms to produce solution options for large size batch scheduling problems.

Scheduling of batch processes involves various parameters such as batch process recipes, sequence of production and transfer policy for product intermediates. All these parameters directly or indirectly affect the makespan, i.e. completion time of a batch process. The scheduling approaches reported in past literatures mostly refer to the use of complex mathematical models for determining makespan. These models require good understanding in formulating the problem using programming techniques to find the optimal solution. The current work proposes new completion time algorithms for multiproduct batch process with two commonly used transfer policies namely zero wait (ZW) and no intermediate storage (NIS). The batch process recipes are presented in the form of a matrix which is then used to solve for the completion time using developed algorithms. Rearrangement of the matrix rows reflects the changes in production sequences possible for the specified batch process recipes which then enable the makespan to be determined accordingly for the different sequences. Designer is then provided with the production sequence options with their corresponding makespan from which a selection could be made.

In this paper, a comparative study of the treatment of raw and biotreated (upflow anaerobic sludge blanket, UASB) textile dye bath effluent using advanced oxidation processes (AOPs) is presented. The AOPs applied on raw and biotreated textile dye bath effluent, after characterization in terms of COD, colour, BOD and pH, were ozone, UV, UV/H2O2 and photo-Fenton. The decolorization of raw dye bath effluent was 58% in the case of ozonation. However it was 98% in the case of biotreated dye bath effluent when exposed to UV/H2O2. It is, therefore, suggested that a combination of biotreatment and AOPs be adopted to decolorize dye bath effluent in order to make the process more viable and effective. Biodegradability was also improved by applying AOPs after biotreatment of dye bath effluent.

The thermophysical properties of 1-hexyl-3-methyl imidazolium based hydrophobic room temperature ionic liquids (RTILs); with tetrafluoroborate (BF4), hexafluorophosphate (PF6), and bis(trifluoromethylsulfonyl)imide (Tf2N) anions, namely density ρ (298.15 to 348.15) K, dynamic viscosity η (288.2 to 348.2) K, surface tension σ (298.15 to 338) K, and refractive index nD (302.95 to 332.95) K have been measured. The coefficients of thermal expansion αp values were calculated from the experimental density data using an empirical correlation. The thermal stability of all ILs is also investigated at two different heating rates (10 and 20) °C · min−1) using thermogravimetric analyzer (TGA). The experimental results presented in this study reveal that the choice of anion type shows the most significant effect on the properties of ILs. The chloride and water contents of ILs (as impurities) are also investigated and reported in the present work.

Densities (ρ) of pure and aqueous N-methyldiethanolamine (MDEA) solutions (wMDEA = 0.3228 or 4 mol·kg−1 and wMDEA = 0.4880 or 8 mol·kg−1) at (298.15 to 338.15) K were measured at atmospheric pressu...

In this work, physical properties such as dynamic viscosity at (298.15 to 338.15) K, surface tension, and refractive index at temperatures (303.15 to 333.15) K of pure and aqueous N-methyldiethanol...

Different vegetable oil based biodiesel (FAMES) were prepared by alkaline transesterification using refined oils as well as waste frying oil (WFO). Methanol and sodium hydroxide are used as catalyst under similar reaction conditions. To ensure the quality of biodiesel produced, a series of different ASTM Standard tests were carried out. In this context, various testwere done including viscosity, carbon residue, specific gravity, corrosion test, flash point, cloud point and pour point. Results revealed that characteristics of biodiesel depend on the feedstock and it is far better than petroleum diesel., {"references":["B. K. Barnwal and M. P. Sharma, \"Prospects of biodiesel production from vegetable oils in India,\" Renewable and Sustainable Energy Reviews, vol. 9, pp. 363-378, 2005.","F. Qiu, et al., \"Biodiesel production from mixed soybean oil and rapeseed oil,\" Applied Energy, vol. 88, pp. 2050-2055, 2011.","Y. Zhang, et al., \"Biodiesel production from waste cooking oil: Economic assessment and sensitivity analysis,\" Bioresource Technology, vol. 90, pp. 229-240, 2003.","A. E. Atabani, et al., \"A comprehensive review on biodiesel as an alternative energy resource and its characteristics,\" Renewable and Sustainable Energy Reviews, vol. 16, pp. 2070-2093, 2012.","G. Huang, et al., \"Biodiesel production by microalgal biotechnology,\" Applied Energy, vol. 87, pp. 38-46, 2010.","Y. C. Sharma and B. Singh, \"Development of biodiesel: Current scenario,\" Renewable and Sustainable Energy Reviews, vol. 13, pp. 1646-1651, 2009.","F. Ma and M. A. Hanna, \"Biodiesel production: a review,\" Bioresource Technology, vol. 70, pp. 1-15, 1999.","P. Felizardo, et al., \"Production of biodiesel from waste frying oils,\" Waste Management, vol. 26, pp. 487-494, 2006."]}

This paper investigates the effect of variable reflux ratio on final product composition in a laboratory scale distillation column. The findings of this study include a minimum reflux ratio at which the highest purity of the product could be achieved. The experimental setup is a Technovate Distillation Column with five sieve plates, a feed tank, a reboiler, and a condenser. The feed and reflux ratio was varied with the help of flow meters associated with two centrifugal pumps. The feed composition was set to 45 percent ethanol-water mixture. The final composition obtained was 95% ethanol in the distillate. The minimum reflux ratio was found to be 60 percent of maximum flow.

The solubility*of carbon dioxide (CO 2 ) in fresh and recycled ionic liquid (IL); 1-hexyl-3-methyl imidazolium tetrafluoroborate [C 6 mim][BF 4 ] was experimentally measured at three different temperatures i.e., 303.15 K, 318.15 K, 333.15 K and pressures up to 60 bar. The solubility of CO 2 and Methane (CH 4 ) in fresh IL; [C 6 mim][BF 4 ] was also measured using binary mixtures of CO 2 and CH 4 i.e., 60/40 (B 64 ) and 40/60 (B 46 ) volume percent at temperatures (303.15 K, 318.15 K, 333.15 K) and pressures up to 60 bar. The solubility measurements for both gases were performed in a specifically designed high pressure miniature gas solubility cell. The solubility of CO 2 and CH 4 in the studied IL increased almost linearly with an increase in pressure and decreased with an increase in temperature and no significant difference was observed for the amount of CO 2 absorbed in fresh and recycled IL at the studied range of operating conditions. It was observed that the presence of CH 4 significantly reduced the solubility of CO 2 in the studied IL.