Harnessing the potential of cells as complex biosensors promises the potential to create sensitive and selective detectors for discrimination of biodefense agents. Here we present toxin detection and suggest discrimination using cells in a multianalyte microphysiometer (MMP) that is capable of simultaneously measuring flux changes in four extracellular analytes (acidification rate, glucose uptake, oxygen uptake, and lactate production) in real-time. Differential short-term cellular responses were observed between botulinum neurotoxin A and ricin toxin with neuroblastoma cells, alamethicin and anthrax protective antigen with RAW macrophages, and cholera toxin, muscarine, 2,4-dinitro-phenol, and NaF with CHO cells. These results and the post exposure dynamics and metabolic recovery observed in each case suggest the usefulness of cell-based detectors to discriminate between specific analytes and classes of compounds in a complex matrix, and furthermore to make metabolic inferences on the cellular effects of the agents. This may be particularly valuable for classifying unknown toxins.

Microstructural damage induced by sulfate attack in concrete is a cause of primary concern in building foundations and other structures. Most research focuses on prevention. In contrast, the concept of damage recovery has not received significant attention. Studies were conducted using alumina-coated-silica nanoparticles to facilitate an electrochemical recovery of strength. Treatments were applied to extract sulfates while the nanoparticles were being injected. Initial sodium sulfate exposure on cylindrical concrete specimens was conducted for a period of 30 days. This exposure induced body cracking and microstructural damage. The specimens were subjected to electrokinetic treatment using a constant current density of 1 A/m2 for 7 days. Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR) analysis revealed significant sulfate content in the sulfate-exposed specimens that was not detected in the treated cases. Raman spectroscopy also indicated a higher C-S-H among the treated specimens, ...

Electrokinetic nanoparticle (EN) treatments were employed to mitigate corrosion in reinforced concrete. In this approach an electric field was used to drive pozzolanic nanoparticles through the capillary pores of concrete and directly to the reinforcement. The intent was to use the nanoparticles as pore-blocking agents to prevent the ingress of chlorides. Treatment effectiveness was examined for both freshly batched and relatively mature concrete. Cylindrical reinforced concrete specimens were subjected to EN treatment immediately after batching and then exposed to chlorides for a period of two years. The EN-treated specimens exhibited a reduction in corrosion rates by a factor of 74 as compared to the untreated controls. Another set of specimens was subjected to chlorides for a period of two years prior to EN treatment application. Electrochemical chloride extraction and EN treatments were performed on these mature specimens for one week. These specimens were placed back into saltwater exposure for an additional year. The mature controls exhibited severe corrosion cracking as compared with the mature treated specimens after 1 year of saltwater exposure. The corrosion rates were 8 times that of the treated specimens. Microstructural and chemical analysis was conducted using scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. This study demonstrated that microstructural changes attributable to treatment were effective in mitigating reinforcement corrosion in both young and mature concrete.

Cured-in-place pipe (CIPP) is one of the most popular in situ rehabilitation techniques to repair sewer and water pipes. While there are multiple approaches to curing CIPP, steam-curing of styrene-based resins has been found to be associated with air-borne chemical emissions. Health officials, utilities and industry representatives have recognized the need to know more about these emissions, especially styrene. Such concern has led to multiple studies investigating the concentrations of volatile organic compounds on CIPP installation sites. This study expands upon previous effort by modeling worst-case, steam-cured CIPP emissions over a 5-year weather record. The effort also includes calibration of the model to emissions averages over the work day rather than instantaneous field measurements. Dispersion modelling software, AERMOD, was utilized to model the styrene component of CIPP emissions on two CIPP installation sites in the US. Based on the analysis results, it was found that the styrene emitted from stacks dissipates rapidly with styrene concentrations only exceeding minimum health and safety threshold levels at distances close to the stack (2 m or less). The values predicted by the model analysis are comparable with the field measured styrene concentrations from other studies. Current safety guidelines in the US recommend a 4.6-m (15-ft) safety perimeter for stack emission points. The results of this study indicate that significant and lasting health impacts are unlikely outside recommended safety perimeter. The results also validate the importance of enforcing recommended safety guidance on steam-cured CIPP sites.

At present, many secondary agricultural residues are landfilled or burned in the open field, leading to the loss of the valuable nutrients they contain. The valorization of agricultural biomass provides a promising route for resource recovery and circular bioeconomy development, allowing for symmetry in their reuse. Hydrothermal carbonization (HTC) offers a sustainable method for converting agricultural waste to both solid and liquid carbon-containing products. Since the liquid product is highly dilute, it is a challenge to apply it at large scales. In this work, a low-energy separation process, direct contact membrane distillation (DCMD), has been used to concentrate the liquid product from HTC of rice husks while recovering water from it. The effect of feed temperature on DCMD performance in terms of water recovery percentage and concentration factors for the fermentable sugars xylose and glucose was investigated at feed temperatures of 50 °C, 65 °C, and 80 °C. DCMD conducted at a feed temperature of 80 °C yielded the highest value for average water flux at 3.4 L/m²·h. DCMD at 80 °C also showed the highest water recovery (56.9%) compared to the lower temperatures, and concentrated xylose and glucose by 2.06 and 3.20 times, respectively³. Incremental flux measurements revealed evidence of limiting mechanisms, such as temperature and concentration polarization, with prolonged operation time. The results from this study thus establish an integrated HTC–DCMD system for efficient water recovery and the concentration of HTC liquor, thereby enhancing its potential for commercial use.