Selective Removal of Lipophilic Wood Extractives from Paper Mill Water Circulations by Ozonation

Circulation waters from paper mills and TMP production were treated by selective ozonation to remove lipophilic wood extractives (LWE's). In the reaction model, ozone was assumed to react with overall organic matter measured as COD with one global reaction rate coefficient. The target compounds, LWE's, are a part of the overall organic matter and they react with ozone with a specific reaction rate coefficient. Reaction selectivity, defined as the ratio of reaction rate coefficients of the reactions of ozone with the LWE's and COD, describes how efficiently ozone is used to remove the LWE's compared to removal of COD. The reaction selectivity was determined from experimental results and it was found to vary from 3 to 20 for different sets of water and for different fractions of LWE's. However, the ozone dose needed for removal of extractives was found to be rather high, about 100–300 mg/dm³ for 50% removal. The reason is the high concentration of organic matter in the waters leading to excessive usage of ozone despite the high selectivity of the reaction. A reactor model was developed to predict the behavior of industrial ozonation reactors. The reactor model takes into account the variation in the rate coefficient with respect to the reaction extent.     

Effects of Ozone on Resin Acids in Thermomechanical Pulp and Paper Mill Circulation Waters

The present study investigated ozonation as means to remove resin acids from pulp and paper mill circulation waters. Ozone selectively oxidizes resin acids in debarking, thermomechanical pulping (TMP), and newsprint machine (PM) circulation waters. The relative ozone dose of 0.2 mgO₃/initial mgCOD eliminated over 90% of total resin acid concentration in all tested waters, despite the initial resin acid or organic matter concentration. With that ozone dose, the removal of organic material (measured as COD) was only about 30%. Because of the different COD concentrations of tested waters, the absolute amount of ozone needed for over 90% resin acid reduction was 2000 mg/1 for debarking water, 600 mg/1 for TMP water, and 300 mg/1 for PM water, when initial COD concentrations were 10,000, 3000, and 1500 mg/1, respectively. In theory, abietane type resin acids should be more susceptible to ozone attack than pimarane type resin acids, because of their conjugated double bond structure. In the experiments, a high oxidizability of pimarane type resin acids, as compared to abietane type resin acids, was found.     

Reactions of lead-free solders with CuNi metallizations

We have done experimental research on the dissolution rate and intermetallic growth on Cu, Ni, and CuNi-alloy substrates as a function of time and Cu/Ni ratio of the substrate. Reactions that occur when CuNi metallizations are soldered with lead-free solders were investigated. The experiments were performed using Sn-3.5Ag and Sn-3.8Ag-0.7Cu solders and different CuNi alloys. To determine the rate of dissolution of the substrate material into the solder, CuNi foils of different concentrations were immersed in Sn-3.5Ag and Sn-3.8Ag-0.7Cu solder baths for soldering times ranging from 15 sec to 5 min at 250°C. In addition, reflows of solder balls were made on top of bulk substrates to study the reaction when there is a practically infinite amount of CuNi available compared to the amount of solder. Thin film experiments were also done, where Ni containing under bump metallizations (UBMs) were fabricated and reflowed with eutectic SnAg solder balls. The nickel slows down the dissolution of the UBM into the solder and the formation of intermetallics during reflow compared to Cu metallizations. The solder/UBM interfaces were analyzed with SEM to find out how Ni concentration affects the reaction, and how much Ni is needed to obtain a sufficiently slow reaction rate.     

Hydrophobic nanocellulose aerogels as floating, sustainable, reusable, and recyclable oil absorbents

Highly porous nanocellulose aerogels can be prepared by vacuum freeze-drying from microfibrillated cellulose hydrogels. Here we show that by functionalizing the native cellulose nanofibrils of the aerogel with a hydrophobic but oleophilic coating, such as titanium dioxide, a selectively oil-absorbing material capable of floating on water is achieved. Because of the low density and the ability to absorb nonpolar liquids and oils up to nearly all of its initial volume, the surface modified aerogels allow to collect organic contaminants from the water surface. The materials can be reused after washing, recycled, or incinerated with the absorbed oil. The cellulose is renewable and titanium dioxide is not environmentally hazardous, thus promoting potential in environmental applications.     

Chromatoid body and small RNAs in male germ cells

The chromatoid body (CB) is a germ granule in the cytoplasm of postmeiotic haploid round spermatids that is loaded with RNA and RNA-binding proteins. Following the discovery of small non-coding RNA-mediated gene regulation and the identification of PIWI-interacting RNAs (piRNAs) that have crucial roles in germ line development, the function of the CB has slowly begun to be revealed. Male germ cells utilise small RNAs to control the complex and specialised process of sperm production. Several microRNAs have been identified during spermatogenesis. In addition, a high number of piRNAs are present both in embryonic and postnatal male germ cells, with their expression being impressively induced in late meiotic cells and haploid round spermatids. At postmeiotic stage of germ cell differentiation, the CB accumulates piRNAs and proteins of piRNA machinery, as well as several other proteins involved in distinct RNA regulation pathways. All existing evidence suggests a role for the CB in mRNA regulation and small RNA-mediated gene control, but the mechanisms remain uncharacterised. In this review, we summarise the current knowledge of the CB and its association with small RNA pathways.     

Noise performance of optical receivers: comparison of directional coupler and resistive feedback based front ends

Noise properties of a directional-coupler-based optical receiver (DCOR) and the resistive-feedback optical receiver (RFOR) topologies are compared. For the DCOR the authors have both simulated and subsequently measured an input equivalent noise current of 3 pA/ square root (Hz) for a bandwidth of up to 2.5 GHz. By using the same noise modelling approach the simulation results for the RFOR topology gave a noise current of 10 pA/ square root (Hz) over the same bandwidth thus verifying the superiority of the DCOR over the resistive feedback optical receiver.<>     

Interactions between Saos-2 cells and microtextured amorphous diamond or amorphous diamond hybrid coated surfaces with different wettability properties

Amorphous diamond (AD) has been shown to be a potential coating material for biomedical devices, such as hip prostheses. In the current study, we have investigated the adhesion and contact guidance of human primary osteogenic sarcoma cells (Saos-2) on AD, AD-titanium-hybrid (AD-Ti-h) and AD-polydimethylsiloxane-hybrid (AD-PDMS-h) with different water contact angles i.e. 72.4°, 81.9° and 100.0°. Microtextured arrays were fabricated onto silicon wafers by using ultraviolet lithography and ultra short pulsed laser deposition (USPLD) of AD coatings. The surface energy parameters were calculated in order to understand the influence of Ti or PDMS on wettability of AD. Saos-2 cells were cultured on the arrays for 24 and 48 h. Environmental scanning electron microscope (ESEM), confocal laser scanning microscopy and MTT assays were used to analyze cell attachment. The results suggest that AD and its hybrids are good coating material candidates with respect to their interactions with osteoblast-like cells. The efficiency of microtexturing in contact guidance was also demonstrated. MTT staining revealed that AD-PDMS-h had the lowest proliferation rate of osteoblast-like cells compared to AD (p < 0.01) or AD-Ti-h (p < 0.05). Pure AD evoked the highest proliferation rate of cells, though it was not significantly different from AD-Ti-h coating.     

Technology options for new nutritional concepts

Recent advances in the food and nutrition sciences support the concept that the diet has a significant role in the modulation of various functions in the body. The diet and/or its components may contribute to an improved state of well-being, a reduction of risks related to certain diseases and even an improvement in the quality of life. These new concepts have led to the introduction of a new category of health-promoting foodstuffs, i.e. functional foods.
The concern about health embraces a number of driving issues, needs and opportunities which may be approached by designing specific diets from various food raw materials. These tailor-made products provide physiological benefits that are targeted at particular consumer groups.
The functionality of functional foods is based on bioactive components, which may be contained naturally in the product but usually require formulation by appropriate technologies in order to optimise the desired beneficial properties. To this end, it is often necessary to develop and apply novel technologies, e.g. membrane separation, high hydrostatic pressure and supercritical fluid extraction techniques. Also the minimal processing concept could be employed in this context.
This review discusses the current technological options available and the future challenges faced in the area. Particular attention is paid to the exploitation of bovine colostrum and milk-derived bioactive compounds for the development of functional foods.     

Improved adherence and spreading of Saos-2 cells on polypropylene surfaces achieved by surface texturing and carbon nitride coating

The adhesion and contact guidance of human primary osteogenic sarcoma cells (Saos-2) were characterized on smooth, microstructured (MST) and micro- and nano-structured (MNST) polypropylene (PP) and on the same samples with a silicon-doped carbon nitride (C₃N₄-Si) coating. Injection molding was used to pattern the PP surfaces and the coating was obtained by using ultra-short pulsed laser deposition (USPLD). Surfaces were characterized using atomic force microscopy and surface energy components were calculated according to the Owens-Wendt model. The results showed C₃N₄-Si coated surfaces to be significantly more hydrophilic than uncoated ones. In addition, there were 86% more cells in the smooth C₃N₄-Si coated PP compared to smooth uncoated PP and 551%/476% more cells with MST/MNST C₃N₄-Si coated PP than could be obtained with MST/MNST uncoated PP. Thus the adhesion, spreading and contact guidance of osteoblast-like cells was effectively improved by combining surface texturing and deposition of osteocompatible C₃N₄-Si coating.