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In the present investigations, the density, refractive index and speed of sound for pure organic solvents and binary liquid mixtures of 3,4,4′-Trichlorodiphenylurea between (293.15 and 323.15) K temperatures have been measured up to the solubility limit. From these experimental results, the acoustic impedance, the isentropic compressibility coefficient, the space-filling factor, the specific refraction, the relaxation strength, the intermolecular free length, the surface tension, the solubility and the solvation number of triclocarban in six organic solvents, namely ethyl alcohol, n-Propyl alcohol, n-Butyl alcohol, Tetrahydrofuran, N,N-Dimethylformamide and N,N-Dimethylacetamide have been computed. The studied acoustic and optical parameters and surface tension behavior versus temperature in pure solvents and binary mixtures were useful in understanding the nature and the extent of interaction between the solute and solvent molecules. The results also show the presence of higher degree of interaction between triclocarban and nitrogen-containing solvents in comparison with other solvents. The distribution of triclocarban in water/organic solvent mixtures is frequently encountered in wastewater treatment plants.

In this study, the chemical distribution of triclocarban (TCC), in natural aqueous systems, between water and sediment, with different chemical compositions of the aqueous phase and different percentages of organic carbon (OC%) in the sediments is presented. The influences of the temperature, of the composition of the aqueous matrices of natural waters and (OC%) in the sediment over the solubility of triclocarban, and its distribution coefficient Kd values were studied. log KD at 25 °C varied between 1.94 and 3.27 for a sediment with 5.50% OC and between 3.95 and 5.93% for a sediment with 6.75% OC, in the studied aqueous systems, with different concentrations of OC in the sediment.

Background: Coronary thrombosis is the key pathogenic mechanism of acute heart attack, including non-ST segment elevation (NSTEMI). Given that, the detection of reliable markers of hemostasis disorders is important in the process of optimizing the diagnosis of NSTEMI. Material and methods: The study was conducted on 54 patients with NSTEMI (average age 69.7±1.5 years). In 60% of cases, 3-vessel disease was noted; 56% of patients had ejection fraction >50%, and Killip class I of heart failure was revealed in 78% of patients. With the help of the STA-Liatest (France) equipment, the blood tests determined the following hemostasis markers: fibrin monomers (FM), thrombotic complex activity of factors II, VII and X. Additional markers like Procoag, the coagulation indicator dependent on circulating phospholipids or SPA, D-dimers, as well as factors C, S and antithrombin III were appreciated. The values of these markers determined by the same method in 20 healthy persons (control group) were used as normal values. Results: Circulating level of FM on admission was increased twice, while the values of Procoag and SPA were significantly decreased by 35.3% compared to the control. Factors C, S and antithrombin III were 54-80% of the control value range, and D-dimers were within the permissible values. In the acute phase of the heart attack, a deterioration of hemostasis indicators was noted, excepting the D-dimers. The levels of FM determined 24 and 72 hours after revascularization were consistently increased (up to 3.8 times) compared to the control, while Procoag and SPA decreased by 54-57%. Further reduction of factors C, S and antithrombin III accounted for 42-54% of normal indicators. After 5 days, an improvement in hemostasis markers was observed, but a significant difference still remained comparing to the control group. Conclusions: The hemostasis particularities discovered in patients with NSTEMI indicate the features of an activated prothrombotic status, and FM could be an important diagnostic marker of NSTEMI, due to its most significant deviation from the normal value (>100%). It can reliably reflect the thrombin level, which triggers the last enzymatic phase of thrombus formation.

Water injection in internal combustion engines is mainly used for additional cooling of the combustion chamber and knock suppression. The main advantages of the water injection are the potential for the enhancement of the performance of the engine. Studies conducted so far have aimed to track engine performance at maximum load and fuel consumption (brake-specific fuel consumption BSFC). Specialized literature is less consistent as regards to the injection of water at medium and low loads. This work monitors the effects of water injection at medium loads and the evolution processes of the four-strokes in the engine with and without water injection. A side-valve, air cooled natural aspirated engine with water and fuel injections in the intake manifold was used for this study. The work during expansion was increased, but this trend was reversed by the higher loads required during intake, compression and exhaust strokes, leading to a reduction in the indicated efficiency when water was injected.

The solubility of triclocarban in ultrapure water and in several natural aqueous solutions is influenced by several environmental factors. In this study the variation of temperature, pH, ionic strength and concentration of the organic matter over the solubility of triclocarban was analysed. The results show that the solubility of triclocarban increases by increasing the contact time, longer than the time of equilibrium and the temperature. It is less influenced by the variations of pH and strongly influenced by the variation of ionic strength and by the natural organic matter into the studied aqueous matrices.

The influence of the chemical composition of natural waters on triclocarban (TCC) sorption on pristine and irradiated multi-walled carbon nanotubes (MWCNTs) at different temperatures was studied. Natural waters have been characterized in terms of the concentrations of cations and anions, pH, and electric conductivity. The sorption process of TCC on MWCNTs is influenced by both the chemical composition of natural waters and the variation of the temperature. The adsorption capacity of TCC on pristine and irradiated MWCNTs in the studied natural waters increased by increasing the temperature. The increase of the concentration of monovalent cations (Na+ and K+) in natural waters determined a significant decrease of the adsorption capacity of TCC on both pristine and irradiated MWCNTs while the increase of the bivalent cations (Ca2+ and Mg2+) determined an easy increase adsorption capacity. Freundlich and Langmuir models were selected to describe the steady adsorption of the TCC on the pristine and irradiated MWCNTs.

Nanocomposite materials have seen increased adoption in a wide range of applications, with toxic gas detection, such as carbon monoxide (CO), being of particular interest for this review. Such sensors are usually characterized by the presence of CO absorption sites in their structures, with the Langmuir reaction model offering a good description of the reaction mechanism involved in capturing the gas. Among the reviewed sensors, those that combined polymers with carbonaceous materials showed improvements in their analytical parameters such as increased sensitivities, wider dynamic ranges, and faster response times. Moreover, it was observed that the CO reaction mechanism can differ when measured in mixtures with other gases as opposed to when it is detected in isolation, which leads to lower sensitivities to the target gas. To better understand such changes, we offer a complete description of carbon nanostructure-based chemosensors for the detection of CO from the sensing mechanism of each material to the water solution strategies for the composite nanomaterials and the choice of morphology for enhancing a layers’ conductivity. Then, a series of state-of-the-art resistive chemosensors that make use of nanocomposite materials is analyzed, with performance being assessed based on their detection range and sensitivity.

In this work, fullerene (C60) was selected as a model carbon nanomaterial, humic acid (HA) as the model natural organic matter and bisphenol A (BPA), as a moderate hydrophobic organic contaminant. The effects of ionic strength, concentration of organic matter and of the pH over the adsorption of BPA on C60 were studied, as well as the competition between the BPA and the HA at the active sites of the C60. A possible adsorption mechanism was proposed as well as an attempt to study the sorption process in real environmental samples with characteristics alike to the optimum ones found in the synthetic samples studied.

In this manuscript an improved sorbent based on modified exfoliated carbon nanoplatelets, applied in the removal of ammonium from aqueous samples, is presented. This sorbent showed better efficiency in comparison with the previous one obtained in our group for ammonium removal, the values of the maximum sorption capacity being improved from 10 to 12.04 mg/g. In terms of kinetics and sorption characteristic parameters, their values were also improved. Based on these results, a sorption mechanism was proposed, taking into account ion-exchange and chemisorption processes at the surface of the oxidized exfoliated carbon nanoplatelets. Future applications for simultaneous removal of other positive charged contaminants from natural waters might be possible.

Energy and economic performance of an organic Rankine cycle (ORC) system designed to recycle waste heat of a steam boiler was analysed. Optimisation of ORC system was performed by using the Cycle-Tempo software and the REFPROP program. The selected working fluid was R245fa. For the exhaust gases temperature of 163°C and mass flow rate of 11.83 kg/s, cooling water temperature of 20°C resulted a gross efficiency of 21.02% and a cost of 2987 €/kW, an electricity levelised cost of 102 €/kWh and a payback period of 5.5 years.

A thermodynamics study on exfoliated graphite nanoplatelets dispersed in tetrahydrofuran in comparison with activated carbon dispersed in same solvent was realised. The refractive index, speed of sound, and density of diluted mixed binary solutions of exfoliated graphite nanoplatelets and activated carbon in tetrahydrofuran were measured between 0 and 100 kg·m−3 with composition step of 20 kg·m−3 and at temperatures from 293.15 to 308.15 K and at normal pressure. The isentropic compressibility, acoustic impedance, specific refraction, relaxation strength, and space-filling factor have been evaluated for six concentrations, at four different temperatures for each system. The identified possible molecular interactions between the edges and the surface of exfoliated graphite nanoplatelets and tetrahydrofuran molecules, which include modifications in the structure of exfoliated nanostructured materials in tetrahydrofuran solvent and the influence of the temperature, and of the solute concentration have been calculated based on the obtained experimental values.

The municipal solid wastes (MSW) can be turned into resources through recycling and energy recovery. To obtain the maximum amount of energy, the appropriate technology must be applied to waste treatment. The composition and characteristics of municipal solid wastes are determinant for technologies choice for MSW in a city/region. Municipal authorities from the Galati city proposed a recovery rate of recyclable materials of 60% from MSW and treatment of the post-recycling MSW as follow: biodegradable fraction by anaerobic digestion and the combustible fraction by incineration or gasification. In this study traditional and innovative waste to energy technologies have been analysed and the potential of electrical energy of waste has been estimated. Results show that plasma gasification system of raw MSW coupled with gas turbine engine has almost the same electrical energy production (32.92 GWh/year) as conventional gasification of combustible material from MSW (17.21GWh/year) coupled with anaerobic digestion of organic fraction of MSW (11.65 GWh/year). By recovering and using the landfill gas from the Tirighina landfill, 6.68 GWh of electricity can be produced annually.

The low-enthalpy geothermal sources can be efficiently exploited for heat and power cogeneration by using the KCS-34 Kalina cycle systems. The maximum power for given heat source temperature and cooling temperature is obtained for a certain value of the ammonia-water solution concentration and turbine exit pressure. The Cycle-Tempo simulation software is a very useful tool to investigate variation of some cycle parameters in order to obtain the maximum energy efficiency. In this paper the performance of a KCS-34 Kalina cycle based CHP plant is investigated to exploit a geothermal source with 120°C temperature present in North-West of Romania. It was found that by using the heat and power cogeneration the energy efficiency can be increased from 16.76% to 57.86% in winter and to 33.44% in summer.

This article states the problems with the use of central heating stations, as well as the need to introduce individual heat points. As a result, the authors considered the issue of improving the energy efficiency of heat supply systems in Russian cities while replacing central heating stations with individual heat points. The beneficial effects of the activities are especially noted.

In this work, Sb (III) adsorption on oxidized exfoliated graphite nanoplatelets (ox-xGnP) was evaluated for the first time, to the best of our knowledge. The ox-xGnP were characterized by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), Brunauer⁻Emmet⁻Teller (BET) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM) equipped with energy-dispersive X-ray spectroscopy (EDX), and Zeta potential analysis. The adsorption parameters, such as pH and contact time, were optimized, and the best adsorption capacity obtained was 8.91 mg g−1 at pH = 7.0, 1.0 mg ox-xGnP/100 mL solution, T = 293 K, 1.0 mg L−1, Sb (III), 25 min contact time. The best correlation of the kinetic data was described by a pseudo-first-order kinetic model, with R2 = 0.999. The adsorption isotherms of Sb (III) onto ox-xGnP were best described by the Langmuir isotherm model. The thermodynamic parameters showed that the adsorption process was exothermic and spontaneous.

Agriculture may hold the key to a sustainable future. By efficiently capturing atmospheric CO2, we can simultaneously produce food, feed, biomass, and biofuels. For more eco-friendly soil processing practices, biofuels can replace diesel in agricultural machinery, significantly reducing the carbon footprint of crop production. Thus, biofuel production can be a sustainable solution for a future with a decreasing carbon footprint. This paper examines the possibility of replacing petroleum-based fuels with 100% biofuels to continue powering heavy-duty vehicles, where the use of electric vehicles is not the optimal solution. This study particularly focused on the operating scenario of heavy-duty engines under medium to high loads, typical of transport or soil processing in agriculture. Diesel was used as a benchmark, and each alternative, such as vegetable oil, methyl ester (B100), and methyl ester–ethanol blends (90B10E, 80B20E, and 70B30E), was tested individually. To find a sustainable fuel substitute, the goal was to identify a biofuel with a kinematic viscosity similar to that of diesel for a comparable spray process. Experimental results showed that an 80% methyl ester and 20% ethanol blend had a kinematic viscosity close to that of diesel. In addition to diesel, this blend resulted in a 48.6% reduction in exhaust gas opacity and a 6.54% lower specific fuel consumption (BSEC). The main aim of the tests was to find a 100% biofuel substitute without modifying the fuel injection systems of existing engines. [ABSTRACT FROM AUTHOR]

In the present investigations, the density, refractive index and speed of sound for pure organic solvents and binary liquid mixtures of 3,4,4′-Trichlorodiphenylurea between (293.15 and 323.15) K temperatures have been measured up to the solubility limit. From these experimental results, the acoustic impedance, the isentropic compressibility coefficient, the space-filling factor, the specific refraction, the relaxation strength, the intermolecular free length, the surface tension, the solubility and the solvation number of triclocarban in six organic solvents, namely ethyl alcohol, n-Propyl alcohol, n-Butyl alcohol, Tetrahydrofuran, N,N-Dimethylformamide and N,N-Dimethylacetamide have been computed. The studied acoustic and optical parameters and surface tension behavior versus temperature in pure solvents and binary mixtures were useful in understanding the nature and the extent of interaction between the solute and solvent molecules. The results also show the presence of higher degree of interaction between triclocarban and nitrogen-containing solvents in comparison with other solvents. The distribution of triclocarban in water/organic solvent mixtures is frequently encountered in wastewater treatment plants. [ABSTRACT FROM AUTHOR]

Waste heat recovery from exhaust gas is one of the most convenient methods to save energy in internal combustion engine-driven vehicles. This paper aims to investigate a reduction in waste heat from the exhaust gas of an internal combustion engine of a serial Diesel–electric hybrid bus by recovering part of the heat and converting it into useful power with the help of a split-flow supercritical CO2 (sCO2) recompression Brayton cycle. It can recover 17.01 kW of the total 33.47 kW of waste heat contained in exhaust gas from a 151 kW internal combustion engine. The thermal efficiency of the cycle is 38.51%, and the net power of the cycle is 6.55 kW. The variation in the sCO2 temperature at the shutdown of the internal combustion engine is analyzed, and a slow drop followed by a sudden and then a slow drop is observed. After 80 s from stopping the engine, the temperature drops by (23–33)% depending on the tube thickness of the recovery heat exchanger. The performances (net power, thermal efficiency, and waste heat recovery efficiency) of the split-flow sCO2 recompression Brayton cycle are clearly superior to those of the steam Rankine cycle and the organic Rankine cycle (ORC) with cyclopentane as a working fluid. [ABSTRACT FROM AUTHOR]

The paper analyses the behaviour of cereal straw briquettes in combustion at energy installations equipped with fixed grates for powers below 75 kW, intended for uses in the field of agriculture. A comparison was made with the combustion of sawdust briquettes. A wider involvement of the energy use of cereal straws, which are in large quantities in certain agricultural regimes, is envisaged. The research includes a new production of cereal straw briquettes from the Oltenia area, previous research being carried out with briquettes made in the agricultural area of North-Eastern Moldova. The use of cereal straw for energy purposes, however, collided with the final processes of combustion when the ash becomes adherent to the elements of the combustion plant, so this new approach will contribute to broadening the knowledge about this biofuel that represents a certain future. The work presented experimental combustion tests comparing the two fuels (cereal straw briquettes and wood sawdust respectively) at a 55 kW pilot plant, plant equipped with a fixed grill. [ABSTRACT FROM AUTHOR]