A Facile Online Multi-gear Capacitively Coupled Contactless Conductivity Detector for Automatic and Wide Range Monitoring of High Salt in HPLC

Sensing the electrolyte solution or aqueous-organic mixture has great interest to chemical separation, pharmaceutical engineering, bioprocess and biochemical experiments etc. However, rare report was presented on online contactless sensor...

Substantial organic impurities at the surface of synthetic ammonium sulfate particles

Ammonium sulfate (AS) particles are widely used for studying the physical-chemistry processes of aerosols and for instrument calibrations. Small quantities of organic matter can greatly influence the studied properties, as observed by many laboratory studies. In this work, monodisperse particles (from 200 nm to 500 nm) were generated by nebulizing various AS solutions and organic impurities were quantified relative to sulfate using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS). The organic content found in AS solutions was also tentatively identified using a Liquid Chromatography–tandem Mass Spectrometry (LC-MS). The results from both analytical techniques were consistent and demonstrated that the organic impurities contained oxygen, nitrogen and/or sulfur, their molecular masses ranged from m/z 69 to 420, they likely originate from the commercial AS crystals. For AS particle sizes ranging from 200 nm to 500 nm, the total mass fraction of organic (relative to sulfate) ranged from 3.8 % to 1.5 % respectively. An inorganic-organic mixture model suggested that the organic impurities were coated on the AS particle surface with a density of 1.1 × 10−3 g m−2. A series of tests were performed to remove the organic content (using pure N2 in the flow, ultrapure water in the solutions, and very high AS quality), showing that at least 40 % of the organic impurities could be removed. In conclusion, it is recommended to use AS seeds with caution, especially when small particles are used, in terms of AS purity and water purity when aqueous solutions are used for atomization.

Fluorescence Properties of the Air- and Freeze-Drying Treatment on Size-Fractioned Sediment Organic Matter

Sediment humic substance (SHS) is a highly heterogeneous and complex organic mixture with a broad molecular weight range. It is the significant component that associates distribution, transport, and biotoxicity of pollutants in a river environment. Air- and freeze-drying sediment pre-treatment may cause different biological activity and may result in different chemical quantities and sediment organic matter. This study collected sediments that received livestock wastewater discharge. The sediments were air- (AD) and freeze-dried (FD). The dried sediment organic matter was extracted with an alkaline solution and separated into three size-fractioned SHS samples. Size-fractioning is an effective method used to differentiate materials, on a molecular level. The bulk solution (<0.45 μm) was designated as BHS, and size-fractioned solutions were identified as LHS (<1 kDa), MHS (1–10 kDa), and HHS (10 kDa-0.45 μm). The AD SHS had a lower dissolved organic carbon (DOC) concentration than the FD SHS for the bulk and individual size-fractioned SHS, but the AD and FD SHS had a similar distribution of organic carbon in the size-fractioned SHS. The AD SHS had higher aromaticity (SUVA254) and an extent of humification (HIX) than the FD SHS. In addition, the high molecular weight SHS (HHS) had a higher SUVA254 but lower HIX than the MHS and LHS. The HHS had significantly lower fulvic acid but had higher humic acid-like substances than the MHS and LHS. This is possibly the reason the LHS had a higher humification degree but lower aromaticity than HHS. The size-fractioned SHS and optical indicators distinguished the difference between the chemical properties when air- or freeze-dried, due to the different degree of biological activities.

Investigation and Experimentation on Ancient Egyptian Tattooing Methods

Summary The aim of this research is to use experimental archaeology and comparative studies in order to obtain a potential answer to the theory that UC 7790 is a set of tattooing implements. Comparing the tools, methods, and inks of other cultures that practice tattooing is a way to offer some guidance regarding the identification of tattooing tools in the archaeological record. The experiment reproduced the original points using the closest modern metal and tested each one with an organic mixture of charcoal and water, and Indian ink as a control ink. The reproduced needles are tested on pigskin and human skin to test efficacy and healing. The experiment proves that UC 7790 may have been tattoo needles as they successfully tattoo human skin and were probably hafted implements.

Extraction of Organic Volatile Pollutants in Over-Saturated Water by Pervaporation Technique Using a Poly (Dimethylsiloxane)-Based Sealer as a Membrane

SILICONE1200 is an inexpensive domestic poly (dimethylsiloxane)-based sealer that was used in this study to remove volatile organic compounds from over-saturated water using the pervaporation technique. A series of volatile organic liquid compounds representing an important part of polluting organic products released every day in water were chosen for this study. These products were alkyl halides (chloroform), aromatics (toluene), aliphatic hydrocarbons (heptanes), ketones and aldehydes (butanone), and organosulfides (thiophene). The mass transfer of these compounds and their mixtures through the SILICONE1200 membrane was assessed to predict the results of the separation process. The results indicate that the mechanism of diffusion obeyed a Fickian model. Different parameters affecting the pervaporation results, such as the membrane thickness, stirring rate, and temperature, were examined to determine the optimal conditions in terms of the total flux and selectivity. The optimized parameters were then applied to the separation of an organic mixture from polluted water using the dynamic pervaporation process with promising results.

Thermal Behaviour Analysis and Cost-Saving Opportunities of PCM-Integrated Terracotta Brick Buildings

Buildings contribute greatly to global energy use and consumption. The energy consumption of buildings is significant due to the integration of heating, ventilation, and cooling systems. Evidently, the utilization of phase change materials (PCMs) in building design can adequately reduce air-conditioning costs of buildings by diminishing external heat gains and losses. Moreover, the adoption of natural, eco-friendly, and cost-effective materials, such as terracotta bricks, can be valuable from an environmental point of view. This paper intends to assess the air-conditioning cost-saving potential of several PCM stuffed terracotta brick configurations. In that respect, the encapsulated PCMs were filled in the hollows of terracotta bricks. For the aims of this study, five different types of PCMs were considered, in relation to the thermophysical properties of their solid and liquid state (OM18: organic mixture, HS22: hydrated salt, OM29, OM32, and OM37). In addition, three PCM-stuffed terracotta brick configurations were examined with reference to the number of the PCM layers (PCMTB-A with one PCM layer, PCMTB-B with two PCM layers, and PCMTB-C with three PCM layers). Therefore, fifteen PCM-stuffed terracotta brick configurations were analysed numerically, related to environmental conditions that refer to two different scenarios in India (hot dry and composite climates). Results have unveiled that the OM32 PCM assemblies have shown better thermoeconomic performance compared to the other types of PCM. With respect to the most advantageous number of PCM layers, the evidence of this analysis has exposed that the PCMTB-C case has shown the highest annual air-conditioning cost-savings and the highest yearly carbon emission mitigations in both climates (Ahmedabad and Lucknow). In hot-dry climates, the PCMTB-C with OM32 PCM exhibited the highest annual air-conditioning cost-saving ($ 74.7), the highest annual carbon emission mitigation (1.43 ton/kWh), and the moderate payback period (22.5 years) compared to the other cases. To conclude, the findings of this study suggest a suitable way to improve the decision-making process of building design, while bridging the performance gap in terms of energy efficiency and sustainability.

Ultra-dehydration of a reactive epichlorohydrin-containing organic mixture using a defect-free thin carbon molecular sieve composite membrane

A high-performance thin carbon molecular sieve (CMS) composite membrane was prepared using a drop-coating process for dehydration of a ternary mixture (water/IPA/ECH) by a pervaporation process.

Liquid Membranes for Efficient Recovery of Phenolic Compounds Such as Vanillin and Catechol

Investigations were carried out to obtain different lignin monomers such as vanillin and catechol as efficiently as possible, to prevent side reactions e.g., during lignin degradation. Therefore, extraction experiments were performed to determine the influence of parameters such as initial pH in the aqueous phase, organic phases containing alcohols or solvating extractants, and monomer concentrations. Cyanex 923 (Cy923) and tri-n-butyl-phosphat (TBP) diluted in kerosene were the organic phases chosen to evaluate the transport of vanillin because of their high efficiencies (>76.8%) and suitability in membrane technologies. The most efficient vanillin transport was accomplished with Cy923, as > 90% of vanillin was transferred after 5 h. However, the permeability coefficient at carrier concentration of > 0.48 mol/L was influenced not only by the diffusion but also by the organic mixture viscosity. Thus, this concentration was used in the membrane experiment containing a mixture of vanillin and catechol in the feed phase. Catechol was transported about 7% faster to the receiving phase than vanillin, presumably due to its chemical structure. Side reactions were avoided using the current liquid membrane set-up, allowing the further industrial application of an entire process, which, e.g., recovers vanillin from enzymatic lignin conversion by membrane technology.