Presence Of Organic Matter Research Articles

Effectiveness of a Novel Rechargeable Polycationic N-Halamine Antibacterial Coating on Listeria monocytogenes Survival in Food Processing Environments

The goal of this research was to evaluate the efficacy of a novel rechargeable nonleaching polycationic N-halamine coating applied to stainless steel food contact surfaces to reduce Listeria monocytogenes contamination on ready-to-eat (RTE) foods. Four L. monocytogenes strains were inoculated onto the charged (C; chlorine activated) or noncharged (NC) N-halamine-coated steel coupon surfaces that were either intact or scratched. After inoculation, test surfaces were incubated at 2, 10, and 25°C for 0, 48, and 72 h. L. monocytogenes transfer from coated adulterated surfaces to RTE meat (beef sausages and roast beef) was also tested at 2°C. L. monocytogenes on both intact-C and scratched-C surfaces was significantly reduced at all temperatures; however, in the presence of organic material, these coatings were more effective for reducing L. monocytogenes at 2 and 10°C than at 25°C (P < 0.05). In contrast, on NC intact and scratched surfaces, reduction at 25°C increased (P < 0.05), decreasing the difference in L. monocytogenes levels between charged and noncharged intact and scratched surfaces at this temperature. Overall, greater L. monocytogenes reduction was achieved on intact-C and scratched-C (4.1 ± 0.19 log CFU/cm2) than on intact-NC and scratched-NC (2.3 ± 0.19 log CFU/cm2) surfaces at all temperatures (P < 0.05). The combination of surface condition and chlorine with coupons exposed for 2 h at 2°C in the presence of an organic load (50% meat purge) did not significantly affect the bactericidal efficacy of the N-halamine coating. Regarding transfer to RTE meat, an overall 3.7-log reduction in L. monocytogenes was observed in sausages and roast beef. These findings suggest that a novel rechargeable N-halamine coating on stainless steel surfaces can inactivate L. monocytogenes.

Germinación y bioestimulación en Acacia farnesiana (L.) Willd y Ebenopsis ebano (Berl.) Barneby para la remoción de As, Cd y Zn de lodos residuales por extracción de gas shale en Tamaulipas

Introducción: En la actualidad, existe una creciente demanda de hidrocarburos, lo que ha provocado el empleo de tecnologías no convencionales como la fracturación hidráulica. Sin embargo, esta técnica ocasiona daños ambientales a los ecosistemas por la generación de lodos residuales, como es el caso del matorral espinoso tamaulipeco que se encuentra dentro de la Cuenca de Burgos, zona de relevancia económica para la explotación de gas convencional. El objetivo del estudio fue evaluar la germinación de Acacia farnesiana (L.) Willd y Ebenopsis ebano (Berl.) Barneby y su uso potencial con bioestimulación, en la remoción de As, Cd y Zn en lodos residuales provenientes de la extracción de gas shale. Método: Se colectaron semillas de Acacia farnesiana (L.) Willd y Ebenopsis ebano (Berl.) Barneby en el ejido El Zaus, municipio de Hidalgo, Tamaulipas. Se evaluó el índice de germinación (IG) de acuerdo con Zucconi. Los tratamientos fueron 23, considerando los sustratos (dos tipos de lodo, suelo y una mezcla de ambos sustratos), las dos especies de plántulas (Acacia y Ebenopsis) y la bioestimulación donde se utilizó una solución de urea al 46 %. Se utilizaron macetas de tres kilogramos como unidades experimentales, donde se sembraron tres plántulas con tres repeticiones por tratamiento. Se realizó un muestreo final de cada tratamiento para las determinaciones correspondientes de As, Cd, Zn, P y K, las cuales se realizaron por extracción de (DTPA), y posteriormente se llevaron a espectroscopia de emisión atómica de inducción por plasma (ICP-OES Varian modelo 725-ES, Agilent Mulgrave, Australia). El Nitrógeno total, en plántulas y sustratos, se realizó por el método micro Kjeldahl, y la materia orgánica (MO) por Walkely Black.Resultados: Se observaron diferencias en IG (P = 0.02374). Los resultados indican que las características estructurales (tamaño) y fisiológicas (viabilidad del embrión) de las semillas están relacionadas con la capacidad de germinación de estas especies en sustratos contaminados. Se encontraron diferencias significativas en la concentración de As, Cd, y Zn, a través del tratamiento (P &lt; 0.0001). La acumulación de As, Cd y Zn, fue determinada por la estructura de la planta (raíz &gt; tallo &gt;hoja).Conclusión: El índice de germinación de Acacia farnesiana (L.) Willd y Ebenopsis ebano (Berl.) Barneby, en sustratos acuosos de lodos residuales provenientes de la extracción de gas shale, se sustenta en las características estructurales y fisiológicas de cada especie. La remoción de As, Cd y Zn, estuvo influenciada por la especie, el sustrato, la bioestimulación con la urea y la presencia de MO que confiere el efecto tapón que controló la alcalinidad de los sustratos y, por ende, la movilidad de los metales.

Sustainability of SARS-CoV-2 in aerosols: should we worry about airborne transmission?

Sustainability of SARS-CoV-2 in aerosols: should we worry about airborne transmission?

Disulfide polymer grafted polypropylene/polyethylene filter media for selective cadmium removal

Heavy metal pollution caused by stormwater runoff has triggered a demand for effective heavy metal sorbents. Effective heavy metal removal using conventional stormwater runoff treatment processes that employ filtration mechanisms as primary removal mechanisms is difficult. Therefore, we attempt to improve cadmium removal performance by attaching disulfide polymer (DiS−COP) containing soft bases, thiols, onto the surface of polypropylene/polyethylene (PP/PE) fiber media, which is widely used for stormwater runoff treatment. Material characterization demonstrated that DiS−COP was successfully grafted and grown on the surface of PP/PE (Dis-PP/PE). The batch and continuous flow adsorption capacities of Dis-PP/PE were 81.1 mg/g and 2.33 mg/g, respectively, which is 40 times higher than those of pristine PP/PE. Applicability of DiS-PP/PE at pH 6–8 was demonstrated, and effects of calcium and humic acid on cadmium adsorption were investigated. Calcium marginally affected cadmium adsorption, which can be explained using the Hard and soft (Lewis) acids and bases theory (HSAB), but cadmium removal efficiency decreased owing to humic acid (HA)-Cd complex formation and agglomeration in the presence of organic material. In a breakthrough test, the adsorption column exhibited complete cadmium uptake over 24 h until it reached the breakthrough point. Therefore, heavy metal adsorption performance of PP/PE was successfully enhanced by grafting DiS−COP on its surface.

Advanced Oxidation Process as a Postharvest Decontamination Technology To Improve Microbial Safety of Fresh Produce.

Fresh produce is frequently associated with outbreaks of foodborne diseases; thus, there is a need to develop effective intervention technologies and antimicrobial treatments to improve the microbial safety of fresh produce. Washing with chemical sanitizers, commonly used by the industry, is limited in its effectiveness and is viewed as a possible cross-contamination opportunity. This review discuses the advanced oxidation process (AOP), which involves generating highly reactive hydroxyl radicals to inactivate human pathogens. Ionizing irradiation, ultraviolet (UV) light, and cold plasma can be regarded as AOP; however, AOPs employing combinations of UV, H2O2, cold plasma, and ozone may be more promising because higher amounts of hydroxyl radicals are produced in comparison to the individual treatments and the combinative AOPs may be more consumer friendly than ionizing irradiation. When applied as a gaseous/aerosolized treatment, AOPs may have advantages over immersion treatments, considering the reactivity of hydroxyl radicals and presence of organic materials in wash water. Gaseous/aerosolized AOPs achieve up to 5 log reductions of pathogenic bacteria on fresh produce compared to reductions of 1-2 logs with aqueous sanitizers. Further research needs to be conducted on specific AOPs before being considered for commercialization, such as reduced formation of undesirable chemical byproducts, impact on quality, and scaled up studies.

Photochemiresistor Sensor Development Based on a Bismuth Vanadate Type Semiconductor for Determination of Chemical Oxygen Demand.

The present paper describes the development of a novel photochemiresistor sensor for the determination of chemical oxygen demand (COD). A chemiresistive device was produced by a thin film of the monoclinic phase of bismuth vanadate deposited on an FTO glass surface. The resistive properties of the photosensor were carried out by electrochemical impedance spectroscopy (EIS). The electrical resistance of the platform was dependent on the presence of organic material in aqueous solution and the incidence of light. The decrease in resistance can be explained by considering that by increasing the amount of organic material, the amount of charge transferred to BiVO4 increases, as does the amount of the photogenerated conduction band on the film. This behavior is not observed when carrying out the same measurements in the absence of light. Under the optimal experimental conditions, the linear response of the chemiresistor sensor is between 0.20 and 19.9 mg L-1 COD at a fixed AC frequency of 0.1 Hz. There is a good correlation between the charge transfer resistance and COD concentration in the electrolyte solution. Quantification of COD in waste and lake waters was successfully performed using the novel photochemiresistor sensor. The results achieved in the analysis with the sensor are in accordance with the conventional method.

Characterization of aerosol particles at Cabo Verde close to sea level and at the cloud level – Part 1: Particle number size distribution, cloud condensation nuclei and their origins

Abstract. In the framework of the MarParCloud (Marine biological production, organic aerosol particles and marine clouds: a Process Chain) project, measurements were carried out on the islands of Cabo Verde (a.k.a. Cape Verde) to investigate the abundance, properties and sources of aerosol particles in general, and cloud condensation nuclei (CCN) in particular, both close to sea level and at the cloud level. A thorough comparison of particle number concentration (PNC), particle number size distribution (PNSD) and CCN number concentration (NCCN) at the Cape Verde Atmospheric Observatory (CVAO, sea-level station) and Monte Verde (MV, cloud-level station) reveals that during times without clouds the aerosols at CVAO and MV are similar and the boundary layer is generally well mixed. Therefore, data obtained at CVAO can be used to describe the aerosol particles at cloud level. Cloud events were observed at MV during roughly 58 % of the time, and during these events a large fraction of particles was activated to cloud droplets. A trimodal parameterization method was deployed to characterize PNC at CVAO. Based on number concentrations in different aerosol modes, four well-separable types of PNSDs were found, which were named the marine type, mixture type, dust type1 and dust type2. Aerosol particles differ depending on their origins. When the air masses came from the Atlantic Ocean, sea spray can be assumed to be one source for particles besides new particle formation. For these air masses, PNSDs featured the lowest number concentration in Aitken, accumulation and coarse modes. Particle number concentrations for sea spray aerosol (SSA, i.e., the coarse mode for these air masses) accounted for about 3.7 % of NCCN,0.30 % (CCN number concentration at 0.30 % supersaturation) and about 1.1 % to 4.4 % of Ntotal (total particle number concentration). When the air masses came from the Sahara, we observed enhanced Aitken, accumulation and coarse mode particle number concentrations and overall increased NCCN; NCCN,0.30 % during the strongest observed dust periods is about 2.5 times higher than that during marine periods. However, the particle hygroscopicity parameter κ for these two most different periods shows no significant difference and is generally similar, independent of air mass. Overall, κ averaged 0.28, suggesting the presence of organic material in particles. This is consistent with previous model work and field measurements. There is a slight increase in κ with increasing particle size, indicating the addition of soluble, likely inorganic, material during cloud processing.

Hydrogeochemical Properties Providing Links to Methanogenesis in Deep Aquifer of Bhola Island, Bangladesh

This paper compares the hydrogeochemical signatures between naturally flowing wells with methane (FWs) and non-flowing wells (require pumping) without methane (NFWs) by analyzing a total of 59 groundwater samples to find possible links for methane gas generation. Relatively higher concentration of HCO3 ⁻ indicates oxidation of organic matter (OM) for both the cases which is corroborated by the dominance of Na-Mg-HCO3 and Na- Mg-HCO3-Cl water type. Low concentrations of redox sensitive parameters i.e., NO3 ⁻, SO4 2⁻, Fe2+ and Mn2+ are indicating prevalence of extremely reducing condition and relatively lower concentrations of SO₄²⁻ in FWs suggest microbial sulphate reduction reaching final stage of redox ladder i.e., methanogenesis. Comparatively higher temperature and subsequent higher electrical conductivity (EC) in FWs possibly attributed by the chemical reactions of methane generation or vice versa. Low geothermal gradient, presence of OM and distribution of the FWs over a paleo valley in the deep confined aquifer zone refer to the existence of favourable environment for biogenic methane production rather than the upward migration or leakage of thermogenic gas from the reservoir below.&#x0D; Asiat. Soc. Bangladesh, Sci. 45(2): 217-228, December 2019

THE EFFECT OF CHANGE IN WATER LEVEL ON THE ABUNDANCE OF LIPTINITE AND VITRINITE MACERALS IN UPPER KELESA FORMATION SHALE IN KUBURAN PANJANG, RIAU

Research on changes in water levels to the abundance of liptnite and vitrinite maceral has focused on Kuburan Panjang area of the Sumai sub-Basin, Central Sumatra Basin. The subject of this research is shale rock from the Eocene-Oligocene Kelesa Formation. Series of rocks from bottom to top shows repetition between shale, sandstone and mudstone strata bounded by conglomerates at the top and bottom. The composition of organic material consists of vitrinite ranging from 0.20 - 5.0%, liptinite 0.60 - 4.70%, pyrite 0.20 - 16.00%, carbonate maceral 0.20 - 24.2%, and clay mineral which is the most dominant component, ranging from 71.60 - 98.00%. Based on the results of TOC analysis, the abundant organic material of the Kelesa Formation shale has a TOC value of 1.18% to 7.17% indicating the ability of shale as a source rock is very good. The presence of organic material in the study area shows that there is a cycle of enrichment of organic material from bottom to top. The smaller the ratio of pristane/phytane (anoxic condition, high water level), the smaller the content of liptinite and the higher the content of vitrinite. Otherwise, the greater the ratio (oxic condition, low water level), the higher the content of liptinite and the lower the content of vitrinite. Change in water level during sedimentation has effect on the quality of shale as a source of unconventional hydrocarbon energy in the Kuburan Panjang area.

Quantification of the Fate of Aminocyclopyrachlor in Soil Amended with Organic Residues from a Sugarcane System

Aminocyclopyrachlor is a persistent herbicide in soil; in the presence of organic matter, this persistence can be increased and can contribute to environmental contamination. The objective of this study was to verify the effects of organic materials derived from the sugarcane cultivation system on the mineralization and degradation of aminocyclopyrachlor in the soil. 14C-aminocyclopyrachlor was applied to soil with organic residues (sugarcane straw, filter cake and vinasse) and evaluated for 112 days of incubation. Mineralization was quantified by the weekly evolution of 14CO2, and the extracted, bound residues and the formation of metabolites of aminocyclopyrachlor were quantified. The mineralization was lower than 45% in all treatments. The degradation half-life (DT50) is being 187 days for unamended soil and > 240 days for soils amended with organic materials. For 90% of the herbicide to be degraded (DT90), between 622 and 921 days was required in all soils. Bound residues were formed in the soil (30% of the total applied in all treatments). No metabolites were formed during the whole incubation period, regardless of the treatment. The presence of organic materials in the soil increased the persistence of aminocyclopyrachlor in the soil, so that persistence of the herbicide may promote a residual effect on weeds and carryover in subsequent crops.

Seasonality of riverine macroplastic transport

Marine plastic pollution is an increasing environmental threat. Although it is assumed that most marine plastics are transported from land to the ocean through rivers, only limited data on riverine plastic transport exists. Recently, new methods have been introduced to characterize riverine plastics consistently through time and space. For example, combining visual counting observations and plastic debris sampling can provide order of magnitude estimations of plastic transport through a river. In this paper, we present findings from multi-season measurement campaign in the Saigon River, Vietnam. For the first time, we demonstrate that macroplastic transport exhibits strong temporal variation. The monthly averaged plastic transport changes up to a factor five within the measurement period. As it is unclear what drives the variation in plastic transport, relations between rainfall, river discharge, presence of organic material and plastic transport have been explored. Furthermore, we present new findings on the cross-sectional and vertical distribution of riverine plastic transport. With this paper we present new insights in the origin and fate of riverine plastic transport, emphasizing the severity of the emerging thread of plastic pollution on riverine ecosystems.

The fate of silver nanoparticles in riverbank filtration systems — The role of biological components and flow velocity

Riverbank filtration is a natural process that may ensure the cleaning of surface water for producing drinking water. For silver nanoparticles (AgNP), physico-chemical interaction with sediment surfaces is one major retention mechanism. However, the effect of flow velocity and the importance of biological retention, such as AgNP attachment to biomass, are not well understood, yet.We investigated AgNP (c = 0.6 mg L−1) transport at different spatial and temporal scales in pristine and previously pond water-aged sediment columns. Transport of AgNP under near-natural conditions was studied in a long-term riverbank filtration experiment over the course of one month with changing flow scenarios (i.e. transport at 0.7 m d−1, stagnation, and remobilization at 1.7 m d−1). To elucidate retention processes, we conducted small-scale lab column experiments at low (0.2 m d−1) and high (0.7 m d−1) flow rate using pristine and aged sediments.Overall, AgNP accumulated in the upper centimeters of the sediment both in lab and outdoor experiments. In the lab study, retention of AgNP by attachment to biological components was very effective under high and low flow rate with nearly complete NP accumulation in the upper 2 mm. When organic material was absent, abiotic filtration mechanisms led to NP retention in the upper 5 to 7 cm of the column. In the long-term study, AgNP were transported up to a depth of 25 cm. For the pristine sediment in the lab study and the outdoor experiments only erratic particle breakthrough was detected in a depth of 15 cm.We conclude that physico-chemical interactions of AgNP with sediment surfaces are efficient in retaining AgNP. The presence of organic material provides additional retention sites which increase the filtration capacity of the system. Nevertheless, erratic breakthrough events might transport NP into deeper sediment layers.

Bactericidal and virucidal efficacies of food additive grade calcium hydroxide under various concentrations, organic material conditions, exposure duration, and its stability.

Aim:This study aimed to evaluate the bactericidal and virucidal activity of food additive grade calcium hydroxide (FdCa(OH)2) under various concentrations, organic material conditions, and exposure duration including its stability.Materials and Methods:The FdCa(OH)2 powder as well as the 0.17% and 3% solutions were evaluated for bacteria and virus inactivating efficacies against Salmonella infantis (SI), Escherichia coli, Newcastle disease virus (NDV), and avian influenza virus (AIV), in the absence or presence of organic materials. In addition, the stability of FdCa(OH)2, was also examined using wet-dry conditions and under sunlight.Results:The FdCa(OH)2 powder could inactivate both NDV and AIV in the absence and presence of organic materials within a 3 min exposure period. The bactericidal efficacy using solution form revealed that 0.17% and 3% of FdCa(OH)2 could inactivate SI in the absence and presence of organic materials within 3 min of exposure. However, 3% of FdCa(OH)2 inactivated E. coli both with and without organic materials within 3min, while 0.17% required 5 min to be efficacious. The virucidal efficacy also showed that 0.17% FdCa(OH)2 could inactivate NDV in the absence and presence of organic materials within 10 min and 30 min, respectively. However, AIV inactivation was achieved within 30 sec under all conditions. In addition, under wet and dry conditions, FdCa(OH)2 powder demonstrated high efficacy when re-suspended at least 16 times for NDV and 7 times for AIV. Simultaneously, the FdCa(OH)2 powder retained its efficacy under the sunlight during up to 4 months for NDV and at least 6 months for AIV.Conclusion:The present study indicates that FdCa(OH)2 powder and solutions could inactivate SI, E. coli, NDV, and AIV while retaining good stability under challenging environmental conditions. Finally, the FdCa(OH)2 is safe for consumers because it is of food additive grade and can be useful as an alternative disinfectant, especially for biosecurity enhancement on and around poultry farms.

Characterization of aerosol properties at Cyprus, focusing on cloud condensation nuclei and ice-nucleating particles

Abstract. As part of the A-LIFE (Absorbing aerosol layers in a changing climate: aging, LIFEtime and dynamics) campaign, ground-based measurements were carried out in Paphos, Cyprus, to characterize the abundance, properties, and sources of aerosol particles in general and cloud condensation nuclei (CCN) and ice-nucleating particles (INP) in particular. New particle formation (NPF) events with subsequent growth of the particles into the CCN size range were observed. Aitken mode particles featured κ values of 0.21 to 0.29, indicating the presence of organic materials. Accumulation mode particles featured a higher hygroscopicity parameter, with a median κ value of 0.57, suggesting the presence of sulfate and maybe sea salt particles mixed with organic carbon. A clear downward trend of κ with increasing supersaturation and decreasing dcrit was found. Super-micron particles originated mainly from sea-spray aerosol (SSA) and partly from mineral dust. INP concentrations (NINP) were measured in the temperature range from −6.5 to −26.5 ∘C, using two freezing array-type instruments. NINP at a particular temperature span around 1 order of magnitude below −20 ∘C and about 2 orders of magnitude at warmer temperatures (T&gt;-18 ∘C). Few samples showed elevated concentrations at temperatures &gt;-15 ∘C, which suggests a significant contribution of biological particles to the INP population, which possibly could originate from Cyprus. Both measured temperature spectra and NINP probability density functions (PDFs) indicate that the observed INP (ice active in the temperature range between −15 and −20 ∘C) mainly originate from long-range transport. There was no correlation between NINP and particle number concentration in the size range &gt;500 nm (N&gt;500 nm). Parameterizations based on N&gt;500 nm were found to overestimate NINP by about 1 to 2 orders of magnitude. There was also no correlation between NINP and particle surface area concentration. The ice active surface site density (ns) for the polluted aerosol encountered in the eastern Mediterranean in this study is about 1 to 3 orders of magnitude lower than the ns found for dust aerosol particles in previous studies. This suggests that observed NINP PDFs such as those derived here could be a better choice for modeling NINP if the aerosol particle composition is unknown or uncertain.

Succession of Microbial Community in Gray Forest Soil during the Decomposition of Different Organic Compounds

In a model laboratory experiment on gray forest soil, the succession of microbial communities during the decomposition of proteins, lipids, and polysaccharides was studied. Proteins were mineralized during the first three months; active decomposition of lipids started two months after the beginning of the experiment. Differences in the functional diversity of microbial communities during the succession were revealed using the method of multisubstrate testing of respiration activity. Microbial respiratory responses to introduction of nitrogen-containing compounds (amino acids) were the highest in variants with decomposition of nitrogen-free compounds and low in protein variants. The ratio of respiratory responses of microbial communities to introduction of carboxylic acids to that of amino acids characterized the nitrogen supply in the soil. This parameter may be useful for reconstruction of initial presence of organic materials in various archaeological contexts.

Cleaning diamond surfaces using boiling acid treatment in a standard laboratory chemical hood

Diamond is the basis for numerous applications in optics, electronics, and quantum science due to its desirable material properties and the existence of optically active spins such as the nitrogen-vacancy (NV) center. For some applications, pristine diamond surfaces are required. However, treatments such as irradiation and high-temperature annealing used to create NV centers produce unwanted graphitic and pyrolytic domains of carbon that are difficult to remove using most chemical treatments. A boiling mixture of nitric, perchloric, and sulfuric acids is known to selectively etch graphitic carbon and is commonly used in the research community to restore a clean diamond surface. The risks associated with using these acids, in the presence of organic material, are explosion due to the potential creation of perchlorate salts, as well as ignition due to the presence of an oxygen source from all three acids and a fuel source from the organic material. In this paper, we will discuss a method that mitigates these risks of the cleaning process without requiring a special laboratory chemical hood with a wash-down feature. This method was brought to the attention of health and safety staff after a research group at The University of Pennsylvania requested information about the safety of the procedure and preventative controls.

Stability and virucidal efficacies using powder and liquid forms of fresh charcoal ash and slaked lime against Newcastle disease virus and Avian influenza virus.

Aim:The present study was examined the virucidal activity comparison between fresh charcoal ash (FCA) and slaked lime (SL) against avian influenza virus (AIV) and Newcastle disease virus (NDV), using powder and liquid forms, either in the absence or presence of organic materials. In addition, both FCA and SL were evaluated for the persistence of virucidal activity in wet and dry conditions and stability of the solution.Materials and Methods:Two hundred milligrams of FCA or SL powders were mixed with 100 µl of AIV or NDV in the absence of organic material or 33% of organic materials. In the same time, 400 µl of 1%, 5%, or 10% solution samples were mixed with 100 µl of each virus and then incubated at room temperature for an indicated time. After that, the mixed solution was stop activity of sample using 500 µl of 1M Tris-HCl pH 7.2. Each treatment was titrated onto Madin-Darby canine kidney cells or chicken embryo fibroblasts for AIV or NDV, respectively, for determining the efficacy of viral inactivation. In addition, the stability of powder under the wet-dry condition and solution stability under room temperature was examined.Results:The results demonstrated that the FCA and SL in powder form could inactivate AIV and NDV even in the absence or presence of organic materials. In the liquid form, 5% and 10% of FCA could inactivate AIV and NDV either in the absence or presence of organic materials. Alongside, 1%, 5%, and 10% of SL could inactivate both viruses. 10% of FCA solution could inactivate virus at a shortest time when compared with other concentrations. In addition, the efficacy of wet-dry conditions of FCA was limited when compared with SL. On the other hand, it is demonstrated that the FCA solution was more stable and kept at room temperature longer than SL.Conclusion:The FCA may, hence, be used as an alternative virucide, while applying it to prevent spreading of poultry disease on commercial chicken farms and also backyard chickens, especially in developing countries, including in rural areas of Thailand.

Preliminary view of geotechnical properties of soft rocks of Semanggol formation at Pokok Sena, Kedah

The research was inspired by series of geological studies on Semanggol formation found exposed at North Perak, South Kedah and North Kedah. The chert unit comprised interbedded chert-shale rocks are the main lithologies sampled in a small-scale outcrop of Pokok Sena area. Black shale materials were also observed associated with these sedimentary rocks. The well-known characteristics of shale that may swell when absorb water and leave shrinkage when dried make the formation weaker when load is applied on it. The presence of organic materials may worsen the condition apart from the other factors such as the history of geological processes and depositional environment. Thus, this research is important to find the preliminary relations of the geotechnical properties of soft rocks and the geological reasoning behind it. Series of basic soil tests and 1-D compression tests were carried out to obtain the soil parameters. The results obtained gave some preliminary insight to mechanical behaviour of these two samples. The black shale and weathered interbedded chert-shale were classified as sandy-clayey-SILT and clayey-silty-SAND respectively. The range of specific gravity of black shale and interbedded chert/shale 2.3 – 2.6 and fall in the common range of shale and chert specific gravity value. In terms of degree of plasticity, the interbedded chert/shale samples exhibit higher plastic degree compared to the black shale samples. Results from oedometer tests showed that black shale samples had higher overburden pressure (Pc) throughout its lifetime compare to weathered interbedded chert-shale, however the compression index (Cc) of black shale were 0.15 – 0.185 which was higher than that found in interbedded chert-shale. The geotechnical properties of these two samples were explained in correlation with their provenance and their history of geological processes involved which predominantly dictated the mechanical behaviour of these two samples.

Sorption of Pb(II) by Nanosized Ferrihydrite Organo-Mineral Composites Formed by Adsorption versus Coprecipitation

Nanosized iron hydroxides and organic matter (OM) are important scavengers of nutrient elements and dissolved trace-metals in geologic systems. Despite this, little is known about the sorption characteristics of metals to the iron–OM nanocomposites formed by adsorption (adsorption of OM on presynthesis ferrihydrite) versus coprecipitation (formation of ferrihydrite in the presence of OM). This study investigates lead (Pb) sorption behaviors on ferrihydrite–humic acid (Fh–HA) composites through batch sorption coupled with Pb-LIII EXAFS. We report that composites formed by coprecipitation have a higher carbon content, smaller specific surface area, and faster Pb sorption rate compared to the equivalent composites formed by adsorption of HA to preformed Fh. Pb sorption on the composites is enhanced at pH < 5 than that on pure Fh, and coprecipitated and adsorbed composites sorb almost equivalent amount of Pb. We identify a bidentate edge-sharing Pb complex on the ferrihydrite surface with a Pb—Fe bond length ...

Painting the Palace of Apries I: ancient binding media and coatings of the reliefs from the Palace of Apries, Lower Egypt

This study gives an account of the organic components (binders and coatings) found in the polychromy of some fragmented architectural reliefs from the Palace of Apries in Memphis, Egypt (26th Dynasty, ca. 589-568 BCE). A column capital and five relief fragments from the collections of the Ny Carlsberg Glyptotek in Copenhagen were chosen for examination, selected because of their well-preserved polychromy. Samples from the fragments were first investigated using Fourier transform infrared (FTIR) spectroscopy to screen for the presence of organic materials and to identify the chemical family to which these materials belong (proteinaceous, polysaccharides or lipid). Only the samples showing the potential presence of organic binder residues were further investigated using gas chromatography with mass spectrometry detection (GC–MS) targeting the analysis towards the detection and identification of compounds belonging to the chemical families identified by FTIR. The detection of polysaccharides in the paint layers on the capital and on two of the fragments indicates the use of plant gums as binding media. The interpretation of the sugar profiles was not straightforward so botanical classification was only possible for one fragment where the results of analysis seem to point to gum arabic. The sample from the same fragment was found to contain animal glue and a second protein material (possibly egg). While the presence of animal glue is probably ascribable to the binder used for the ground layer, the second protein indicates that either the paint layer was bound in a mixture of different binding materials or that the paint layer, bound in a plant gum, was then coated with a proteinaceous material. The surface of two of the investigated samples was partially covered by translucent waxy materials that were identified as a synthetic wax (applied during old conservation treatments) and as beeswax, respectively. It is possible that the beeswax is of ancient origin, selectively applied on yellow areas in order to create a certain glossiness or highlight specific elements.