Innovative Polyelectrolyte Treatment to Flame-Retard Wood

Fire protection has been a major challenge in wood construction for many years, mainly due to the high flame spread risk associated with wood flooring. Wood fire-retardancy is framed by two main axes: coating and bulk impregnation. There is a growing need for economically and environmentally friendly alternatives. The study of polyelectrolyte complexes (PECs) for wood substrates is in its infancy, but PECs’ versatility and eco-friendly character are already recognized for fabric fire-retardancy fabrics. In this study, a new approach to PEC characterization is proposed. First, PECs, which consist of polyethyleneimine and sodium phytate, were chemically and thermally characterized to select the most promising systems. Then, yellow birch (Betula alleghaniensis Britt.) was surface-impregnated under reduced pressure with the two PECs identified as the best options. Overall, wood fire-retardancy was improved with a low weight gain of 2 wt.% without increasing water uptake.

Association of polycyclic aromatic hydrocarbons in moss with blood biomarker among nearby residents in Portland, Oregon

Polycyclic aromatic hydrocarbons (PAHs) are a component of air pollutants that are costly to measure using traditional air-quality monitoring methods. We used an epiphytic bio-indicator (moss genus: Orthotrichum) to cost-effectively evaluate atmospheric deposition of PAHs in Portland, Oregon in May 2013. However, it is unclear if measurements derived from these bioindicators are good proxies for human exposure. To address this question, we simultaneously, measured PAH-DNA adducts in blood samples of non-smokers residing close to the sites of moss measurements. We accounted for individual determinants of PAH uptake that are not related to environmental air quality through questionnaires, e.g., wood fires, consumption of barbecued and fried meats. Correlation and linear regression (to control for confounders from the lifestyle factors) evaluated the associations. We did not observe evidence of an association between PAH levels in moss and PAH-DNA adducts in blood of nearby residents, but higher level of adduct were evident in those who used wood fire in their houses in the last 48 hours. It remains to be determined whether bio-indicators in moss can be used for human health risk assessment.

Chemical Composition of PM2.5 in Wood Fire and LPG Cookstove Homes of Nepali Brick Workers

Household air pollution is a major cause of morbidity and mortality worldwide, largely due to particles ≤ 2.5 µm (PM2.5). The toxicity of PM2.5, however, depends on its physical properties and chemical composition. In this cross-sectional study, we compared the chemical composition of PM2.5 in brick workers’ homes (n = 16) based on use of wood cooking fire or liquefied petroleum gas (LPG) cookstoves. We collected samples using RTI International particulate matter (PM) exposure monitors (MicroPEMs). We analyzed filters for 33 elements using energy-dispersive X-ray fluorescence and, for black (BC) and brown carbon (BrC), integrating sphere optical transmittance. Wood fire homes had significantly higher concentrations of BC (349 µg/m3) than LPG homes (6.27 µg/m3, p < 0.0001) or outdoor air (5.36 µg/m3, p = 0.002). Indoor chlorine in wood fire homes averaged 5.86 µg/m3, which was approximately 34 times the average level in LPG homes (0.17 µg/m3, p = 0.0006). Similarly, potassium in wood fire homes (4.17 µg/m3) was approximately four times the level in LPG homes (0.98 µg/m3, p = 0.001). In all locations, we found aluminum, calcium, copper, iron, silicon, and titanium in concentrations exceeding those shown to cause respiratory effects in other studies. Our findings suggest the need for multi-faceted interventions to improve air quality for brick workers in Nepal.

Study on the local know-how of the use of beef hides in western Cameroon meals

The current study was conducted in four localities in the West region of Cameroon from May to September 2019, to know the pre-treatments made on given to beef hides before their use in different dishes, as well as the ingredients used in the preparation of pepper soup beef hides through household surveys. A total of 307 housewives were surveyed interviewed. The data was collected using a questionnaire and further analyzed using Sphinx Plus2 V5 software. Results showed that 54.6 to 71% participants consumed beef hides monthly. More than 50% participants purchased their beef hides at the butchery at a price varying between XAF 1,000 for 1Kg of uncleaned smoked beef hides and XAF 3,000 for 2Kg of clean smoked beef hides. The results also showed that there were five main stages in the preparation of beef hides and housewives had a greater preference of beef hides from the head and buttocks. The pre-cooking of beef hides was done between 180 and 240 minutes, with a quantity of water varying between 4 and 5 liters for 1 to 2Kg of beef hides, on the wood fire. “Eru” and “Yellow achu sauce” were cited as the main sauces in which beef hides were used at 95.40% and 85% respectively. Besides, more than 70% of housewives used a maximum of five ingredients for the preparation of pepper soup beef hides. Our findings revealed, interesting insights on the steps and ingredients used when preparing pepper soup beef hides that will be of great importance in the development of better formulation for pepper soup beef hides preparation

Fire Detection Tendency through Combustion Products Generated during UL 268 Wood Flame Fire and Smoldering Fire Test

This experiment analyzes the tendency of fire detection through combustion products generated during UL 268 wood flame fires and smoldering tests. Fire detection tendency was measured using a particle matter sencor (PMS), combustion gas analyzer (CGA), and gas analyzer (GA). The combustion products were matched and analyzed at 5 %/m (non-operation), 10 %/m, and 15 %/m of the smoke sensitivity measured by the smoke detector. In the case of wood flaming fire, PMS PM 10, CGA CO, SO₂, GA HCHO, and TVOC, the trend was observed because of the continuous increase in the measured value according to the smoke generation. In the case of smoldering, PM 10, CO, and HCHO were adaptable to the tendency to be observed. Finally, in the case of wood fire accompanied by flame fire and smoldering to PM 10, CO and HCHO were considered to be the optimal fire detection factors.

Compliance of fire-protective cellulose-containing materials with environmental safety

Search for new highly efficient agents for wood fire retardant treatment in the construction has been conducted more and more intensively. But fire retardant treatment nowadays should not only ensure specified fire resistance of wood but preserve its performance as well as ensure its environmental safety and durability. Therefore a significant problem of ensuring vital activities and safe functioning of building facilities lies in the development of intumescent coatings for building structures taking into consideration economical, processing and environmental aspects; these coatings shall be used not only on a par with existing similar ones but be highly efficient in special spheres of construction which makes it possible to prevent occurrence of man-caused accidents. The paper shows results of the studies purposed at raising efficiency of the facilities protection by conversion of the cellulose containing materials used at them to the group of hardly combustible materials; it was revealed that application of appropriate composition converted the wood into hardly combustible material that did not spread flame across its surface and had moderate smoke production ability. Taking into account these fire hazard indices the wood having been subjected to fire retardant treatment as construction material could be allowed for application for the internal lining of rooms including those at the escape routes.

Technical Sheet of the Preparation of Traditional Cassava Starters Used for Attieke Production in Côte d'Ivoire

Aims: The aim of this study was to identify the different methods of preparing the traditional cassava starters used for attiéké production in Côte d'Ivoire, allowed the recounting of five different production methods. Study Design: Sampling of cassava starters were collected from attiéké producers de four areas of south of Côte d’Ivoire. The cassava starters obtained with the braised cassava were collected from attiéké women producers of Grand-Lahou, those obtained directly from fresh cassava were collected from attiéké producers in the region of Bonoua, and those obtained with the cassava cooked at water were collected from attiéké women producers of Abidjan and Jacqueville. Place and Duration of Study: University of Nangui Abrogoua, Abidjan, Côte d’Ivoire (between March 2018 and June 2019). Methodology: Traditional cassava starters are produced with the bitter or sweet variety of cassava, either freshly preserved without cooking until fermented, boiled in boiling water or braised over a wood fire. Conclusion: This study highlighted five methods of preparing traditional cassava starters used in Côte d'Ivoire for the preparation of attiéké, a food derived from cassava. This is the starters from fresh preserved uncooked cassava that derived from fresh braised cassava and those (three) from fresh cassava cooked with boiling water either with the casing or without the casing after cooking and without the shell during cooking.