Characteristics of wood pellets from over-dry sawdust waste

Wood pellets are renewable fuels from biomass which can be an alternative substitute for petroleum fuels. One of the raw materials for making wood pellets is sawdust from the sawmill industry or other wood craftsmen. Sawdust waste that dumped for a long time will reduce its moisture content (over-dry) and will be difficult to form into pellets. In this paper, we studied the effect of adding liquid solution ie. water, tapioca starch solution, pure molasses solution and dilute molasses solution on over-dry sawdust to the characteristic properties of wood pellet torrefaction. The sawdust material was collected from the wood sawmill in the Bogor District. There were five treatments i.e sawdust (control), sawdust + 10% water, sawdust + 10% tapioca starch solution, sawdust + 10% pure molasses solution, sawdust + 10% diluted molasses solution. The wood pellet torrefaction properties were investigated using a manual hot press at the temperature of 210°C. The results showed that the addition of pure molasses solution produced better pellets than other treatments, with properties i.e water content of 2.65%, the ash content of 1.45%, volatile matter 76.72%, fixed carbon 19.18%, the calorific value of 19.56 MJkg−1, density 0.84 gcm−3, and compressive strength 52.22 kgcm−2.

Effect of Lactobacillus acidophilus added to a starch coating related to the microbiological contamination, quality and acceptability of fresh cheese

The fresh cheese produced in the province of Manabí is an Ecuadorian artisan cheese. The processing conditions commonly do not comply Ecuadorian regulations, resulting in the presence of pathogenic microorganisms such as Salmonella. The high number of cases of Salmonellosis in the province of Manabí justifies the need to identify and control the possible sources of this pathogenic microorganism. In the present work, the effect of the addition of Lactobacillus acidophilus to fresh cheese was studied, by immersing it in a starch solution with 1x108 CFU mL-1 of L. acidophilus with further storage for 30 days at 4 °C. The pH, acidity, weight loss, instrumental firmness, number of CFU of mesophilic aerobic bacteria and acceptability of fresh cheese were analyzed. At the same time, a duo-trio analysis was carried out, followed by a satisfaction analysis with the participation of semi-trained panelists. The presence of L. acidophilus reduced the pH and acidity in the fresh cheese in relation to the control sample. Satisfaction results, on a five-point hedonic scale, which ranged from 1 (I dislike it very much) to 5 (I like it very much), showed that the cheese treated with L. acidophilus and the control sample received a rating between “I neither like nor dislike” and “I like it moderately”, with values of 3.63 for the treated sample and 3.50 for the control. The application of L. acidophilus did not affect the organoleptic acceptability of cheese and produced less changes in pH, acidity and weight loss during storage for 30 days at 4 °C in relation to the control sample.

Valorization of Aquatic Weed and Agricultural Residues for Innovative Biopolymer Production and Their Biodegradation

In this work, water hyacinths, bagasse and rice straw were valorized to produce an innovative biopolymer. Serial steps of extraction, bleaching and conversion of cellulose to be carboxymethylcellulose (CMC) as well as the last steps of blending and molding were performed. The CMC was mixed with tapioca starch solution by a ratio of 9:18, and a plastic sizer of glycerol was varied at 2%, 4% and 6% by volume. In addition, bioplastic sheets were further determined in their properties and biodegradation. The results revealed that bioplastics with 6% glycerol showed a high moisture content of 23% and water solubility was increased by about 47.94% over 24 h. The effect of temperature on bioplastic stability was found in the ranges of 146.28–169.25 °C. Furthermore, bioplastic sheets with 2% glycerol could maintain their shape. Moreover, for texture analysis, the highest elastic texture in the range of 33.74–38.68% with 6% glycerol was used. Moreover, bioplastics were then tested for their biodegradation by landfill method. Under natural conditions, they degraded at about 10.75% by weight over 24 h after burying in 10 cm soil depth. After 144 h, bioplastics were completely decomposed. Successfully, the application of water, weed and agricultural wastes as raw materials to produce innovative bioplastic showed maximum benefits for an environmentally friendly product, which could also be a guideline for an alternative to replace synthetic plastics derived from petroleum.

Starch Solutions Prepared under Different Conditions as Modifiers of Chitosan/Poly(aspartic acid)-Based Hydrogels

Recently, there has been great interest in the application of polysaccharides in the preparation of diverse biomaterials which result from their biocompatibility, biodegradability and biological activity. In this work, the investigations on chitosan/poly(aspartic acid)-based hydrogels modified with starch were described. Firstly, a series of hydrogel matrices was prepared and investigated to characterize their swelling properties, structure via FT-IR spectroscopy, elasticity and tensile strength using the Brookfield texture analyzer as well as their impact on simulated physiological liquids. Hydrogels consisting of chitosan and poly(aspartic acid) in a 2:1 volume ratio were elastic (9% elongation), did not degrade after 30-day incubation in simulated physiological liquids, exhibited a relative biocompatibility towards these liquids and similar swelling in each absorbed medium. This hydrogel matrix was modified with starch wherein two of its form were applied—a solution obtained at an elevated temperature and a suspension obtained at room temperature. Hydrogels modified with hot starch solution showed higher sorption that unmodified materials. This was probably due to the higher starch inclusion (i.e., a larger number of hydrophilic groups able to interact with the adsorbed liquid) when this polysaccharide was given in the form of a hot solution. Hydrogels modified with a cold starch suspension had visible heterogeneous inequalities on their surfaces and this modification led to the obtainment materials with unrepeatable structures which made the analysis of their properties difficult and may have led to misleading conclusions.

Study of acute toxicity of GIZh-298

Assessment of acute toxicity is a necessary stage of preclinical research of the substance GIZh-298. The aim of present research is study of acute toxicity GIZh-298. Methods. GIZh-298 was administered once intraperitoneally to mice at doses 200-330 mg/kg. Equivalent volume of 1 % starch solution was administered to animals of the control groups. Periods of intoxication and death of animals with a detailed description of the observed clinical picture were registered. Euthanasia and pathoanatomical dissection were performed 14 days after drug administration. Results. The median lethal doses were identified: LD50 = 299,6 (279,7 – 320,8) mg/kg in female mice, LD50 = 302,3 (281,5 – 324,6) mg/kg in male mice at intraperitoneal introduction. The morphological view of the internal organs, detected during pathoanatomical dissection of all surviving experimental animals, did not differ from that observed in control animals. Conclusion. It was determined that GIZh-298 at intraperitoneal introduction concerns to low-toxic substances. According to classification Sidorov K.K. GIZh-298 may be related to 4th toxicity class.

STUDYING THE INFLUENCE OF THE TEMPERATURE ON MORPHOLOGY OF CONGLOMERATES FROM COPPER NANOPARTICLES OBTAINED BY ELECTROEROSION DISPERSION

Aim. To obtain conglomerates from copper nanoparticles by the method of electroerosive dispersion in various liquid media (in 1% starch solution, ethanol, acetone, kerosene, petroleum ether) at two different temperatures (negative and room). Assessment of the influence of this factor on the size and shape of the resulting conglomerates. Methods. Methods based on visual observation of the obtained particles using a digital microscope at a magnification of 600x. Results. The results are presented in the form of micrographs of the obtained particles. Conclusions. Conclusions are drawn on the study of the influence of the temperature factor on the morphology (size, shape and ordering) of the resulting conglomerates.

Assessment of Cymoxanil in Soil, Water and Vegetable Samples

The present work describes a newly developed method for the spectrophotometric determination of cymoxanil in soil, water and vegetable samples. The detection of the target chemical substance is based on the reaction of cyanide released from the hydrolysed product of cymoxanil with potassium iodide-potassium iodate to form a blue-coloured complex in the presence of starch solution. This complex is water-soluble and shows maximum absorbance at 580 nm. For this complex, Beer's law is obeyed over the concentration range of 2-50 μg mL−1 with molar absorptivity 1.2×105 L mol-1cm-1 and Sandell’s sensitivity 1.0×10-3 µg cm-2. The reproducibility was assessed by carrying out seven days replicate analysis of a solution containing 10 µgmL-1 of cymoxanil in a final solution of a volume of 10 mL. The standard deviation and relative standard deviation for the absorbance value were found to be ± 2.9×10-3 and 1.6% respectively. The proposed method is free from the interference of other toxicants. The analytical parameters were optimized and the method was applied to the determination of cymoxanil in water, soil, and vegetable samples.

Experimental comparison of two methods to study barley responses to partial submergence

Background Crop yield is dependent on climate conditions, which are becoming both more variable and extreme in some areas of the world as a consequence of global climate change. Increased precipitation and flooding events are the cause of important yield losses due to waterlogging or (partial) submergence of crops in the field. Our ability to screen efficiently and quickly for varieties that have increased tolerance to waterlogging or (partial) submergence is important. Barley, a staple crop worldwide, is particularly sensitive to waterlogging. Screening for waterlogging tolerant barley varieties has been ongoing for many years, but methods used to screen vary greatly, from the type of soil used to the time at which the treatment is applied. This variation makes it difficult to cross-compare results. Results Here, we have devised a scoring system to assess barley tolerance to waterlogging and compare two different methods when partial submergence is applied with either water or a starch solution at an early developmental stage, which is particularly sensitive to waterlogging or partial submergence. The use of a starch solution has been previously shown to result in more reducing soil conditions and has been used to screen for waterlogging tolerance. Conclusions Our results show that the two methods provide similar results to qualitatively rank varieties as tolerant or sensitive, while also affecting plants differently, in that application of a starch solution results in stronger and earlier symptoms than applying partial submergence with water.

Evaluation of the effects of additives on the properties of starch-based bioplastic film

The adverse environmental effects of petroleum-based packaging plastics have necessitated the need for eco-friendly bioplastics. Most bioplastics are starch-based and are not without drawbacks, hence there is the need for their properties to be improved. In this study, the effect of varying concentrations of dialdehyde starch and silica solutions on the physical, mechanical, biodegradable, surface topology, and thermal properties of the bioplastic films was examined. The additive concentrations were varied from 60 to 100%. The bioplastic films produced with dialdehyde starch solution recorded better moisture content (6.62–11.85%), bioplastic film solubility (4.23–7.90%), and tensile strength (1.63–3.06 MPa), against (11.24–14.26%), (7.77–19.27%) and (0.53–0.73 MPa) respectively for bioplastic films produced with silica solution. The atomic force microscopy analysis; root-mean-square roughness, kurtosis, and skewness revealed better miscibility and compatibility between the starch matrix and the dialdehyde solution than between the starch matrix and the silica solution. Bioplastic with added dialdehyde starch solution has better tensile strength and long biodegradability than that with silica solution. The research has demonstrated that bioplastic film produced with starch and dialdehyde starch solution has better properties than the one produced with starch and silica solution. The properties evaluation results of the bioplastic films thus demonstrated their aptness for food packaging applications. Graphic abstract