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Objective: The objective was to investigate the effects of dietary benzoic acid (BA) on nitrogen (N) balance, urinary pH, slurry pH, and odorous compounds in feces and slurry of pigs. Methods: Twelve barrows with an initial body weight of 56.2±2.6 kg were individually housed in metabolism crates. The animals were allocated to a replicated 6×4 incomplete Latin square design with 12 animals, 6 experimental diets, and 4 periods, resulting in 8 observations per treatment. The basal diet consisted mainly of corn, soybean meal, and rapeseed meal. Benzoic acid was supplemented to the basal diet at 0.5%, 1.0%, 1.5%, 2.0%, or 2.5% at the expense of corn starch. Each period consisted of a 4-day adaptation period and a 24-h collection period for slurry, followed by a 4-day collection period for feces and urine. On day 5, feces and urine were collected for 24 h and mixed to obtain slurry samples. Results: The daily digested N linearly increased (p<0.05) with increasing BA supplementation. Supplemental BA lowered urinary pH (p<0.001) and slurry pH (p<0.05) in a linear and quadratic manner. In the fecal samples, the concentrations of acetate, propionate, butyrate, and skatole linearly decreased (p<0.05) with supplemental BA. In the slurry samples, the concentrations of butyrate, isovalerate, and skatole linearly decreased (p<0.05) by supplemental BA. Conclusion: In conclusion, supplemental benzoic acid has the potential to improve nitrogen digestion in a dose-dependent manner for pigs. Additionally, dietary benzoic acid lowers urinary pH, slurry pH, and concentrations of odorous compounds in pig feces and slurry. [ABSTRACT FROM AUTHOR]

Simple Summary: Ammonia gases are produced from urea in the urine and slurry due to the action of urease. Odorous compounds are produced by microbial fermentation that utilizes an undigested nutrient in pig slurry. Various additives have been researched to mitigate ammonia emissions or odorous compound production. These studies involve inducing acidic conditions in urine or slurry, enhancing nitrogen utilization, inhibiting urease, or absorbing odorous compounds in pig slurry. However, information about the comparison of these additives is lacking. In this study, we evaluate and compare the effects of each additive on nitrogen utilization, urinary pH, slurry pH, and odorous compound concentrations. The five experimental diets were (1) a control diet, (2) the control diet with 1% benzoic acid, (3) the control diet with 1% adipic acid, (4) the control diet with 1% bromelain, and (5) the control diet with 1% humic substances. Fecal dry matter and nitrogen output were greatest in pigs fed the humic substances diet. Daily retained nitrogen and the nitrogen retention rate tended to be lowest in pigs fed an adipic acid diet. Urinary pH was lowest in pigs fed the adipic acid diet. In addition, slurry pH did not affect odorous compound concentrations, and some odorous compounds tended to be lowest in pigs fed the humic substances diet. The objective was to evaluate the effects of benzoic acid, bromelain, adipic acid, and humic substance supplementation on nitrogen balance, urinary pH, slurry pH, and manure odorous compounds in pigs. Fifteen castrated male pigs with an initial body weight of 37.9 kg (standard deviation = 4.1) were individually housed in metabolism crates. The animals were allocated to a triplicated 5 × 2 incomplete Latin square design with 15 animals, 5 experimental diets, and 2 periods. The basal diet mainly consisted of corn, soybean meal, and rapeseed meal. Four experimental diets were prepared by supplementing each additive at a concentration of 10 g/kg at the expense of corn starch to the basal diet. Each period consisted of a 4-day adaptation period, a 24 h collection period for slurry sampling, and a 4-day collection period for feces and urine. The feces and urine collected for 24 h on day 5 were mixed at a ratio of fecal weight and urine weight to obtain slurry samples. The apparent total tract digestibility N in pigs fed the humic substance diet was the least (p < 0.05) compared to the other groups. The daily retained N and N retention as % ingested tended (p < 0.10) to be the lowest in the adipic acid group among the treatments. The urinary pH in pigs fed the adipic acid diet was less (p < 0.05) than that in other groups except the benzoic acid group. The slurry pH tended to differ among the treatment groups (p = 0.074) with the lowest value in the pigs fed the adipic acid diet. The concentrations of indole in slurry (p = 0.084) and isovalerate in feces (p = 0.062) tended to differ among the groups with the lowest values in the pigs fed the humic substance diet. In conclusion, adipic acid supplementation in pig diets can decrease urinary pH and slurry pH. Although benzoic acid and adipic acid have limited effects in reducing odorous compounds, humic substances have the potential to reduce some odorous compounds. [ABSTRACT FROM AUTHOR]

Biogas is one of the renewable energy resources produced from the anaerobic fermentation of biomass. About 60% of Pakistan population live in rural areas that demand energy source for domestic and commercial use. Therefore, biogas plants can be used as one of the renewable energy sources in Pakistan. This paper described the development and performance evaluation of small size household portable biogas plant. The lightweight double-ply polypropylene material is used to fabricate the biogas plant, which is durable and easily portable. The volume of the digester was 2.15 m3, and the gasholder volume was 0.84 m3. The performance of the developed plant and biogas production is verified by three different treatments of feeding materials, i.e., buffalo dung (BD), buffalo dung plus sheep waste (BD + SW), and buffalo dung plus chicken droppings (BD + CD). The maximum biogas productions for treatments BD, BD + CD and BD + SW were recorded 0.59 m3/kg-VS, 0.61 m3/kg-VS, and 0.79 m3/kg-VS, respectively. The AMPTS was also conducted to compare total methane production. The nutrient analysis performed for both substrate and slurry showed improved nutrient quantity in the slurry. The cost estimation cleared that fixed biogas plants have 1.27 times more costly than that of portable biogas plants. The developed biogas plant is favorable for its light in weight and low cost, and it can produce enough methane gas to fulfill the domestic requirements. [ABSTRACT FROM AUTHOR]

During transportation and stockpiling, coal is in contact with air for periods of time that may exceed 6 months. During this time, reaction with oxygen in the presence of water, sunlight, and possibly elevated temperatures may take place. The resulting weathered coal suffers some alteration in its physical and chemical properties. This article describes weathering with reference to coking coal, and its importance in understanding the weathering of coal. In this article, the effect of weathering on coal quality is discussed. Two Indian coals were kept for a period of 2 months, and different coal properties such as free swelling index (FSI), ash, and slurry pH were monitored at different intervals. This article suggests pH determination of coal slurry technique is more reliable for monitoring weathering of the Indian coal. [ABSTRACT FROM AUTHOR]

The objective of the current work was to study an observed incompatibility between croscarmellose sodium and basic excipients in a tablet formulation. Significant dissolution slowdown was observed for alkaline tablet compositions of an acid-labile drug containing croscarmellose sodium (CCS) as a disintegrant. The severity of the dissolution slowdown was directly proportional to both the degree of alkalinity and the level of CCS in the tablet formulation. It is postulated that the ester cross-links in CCS were partially or fully hydrolyzed under basic conditions (pH values >9) forming by-products of increased water solubility. This increase in the level of water-soluble polymer can lead to the formation of a viscous barrier in the tablet upon moisture uptake, thus slowing down its dissolution. The dissolution slowdown was not observed for a similar alkaline tablet preparation containing crospovidone as a disintegrant. [ABSTRACT FROM AUTHOR]

Abstract: In our previous paper we found that the particles in the slurry can agglomerate by adding larger amount of polyelectrolyte dispersant compared to that needed to attain well dispersion. Thus, the dependency of initial particle concentration on the agglomeration and its mechanism in slurry prepared by adding excess polyelectrolytes was experimentally discussed. It was shown that agglomeration behavior strongly depends on the additive amount of polyelectrolytes, not on the polyelectrolyte concentration in the solution. It was also found that the dominant factor of agglomeration in slurry prepared by adding extra polyelectrolytes should be the compression of the electrical double layer by the increased counter ion concentration, not by the so called depletion effect or by pH change. Interestingly, the final sediment had a relatively high packing fraction and good flowability in the case of the agglomerated slurry with extra polyelectrolytes compared to that of the agglomerated slurry with an additional NaCl solution. [Copyright &y& Elsevier]

[Display omitted] • Material removal mechanisms under different slurry pH are revealed. • More abrasives act on YAG surface under acidic conditions than alkaline conditions. • Preferred slurry pH is about six according to the surface quality and MRR. Yttrium aluminum garnet (YAG) single crystal has become a promising substrate for the high-power solid-state laser. It needs to be processed into a defect-free surface by chemical mechanical polishing (CMP). The preparation of polishing slurry is critical for the material removal efficiency and surface quality, which relies on understanding the removal mechanism of polished materials. In this study, the impacts of slurry pH on the chemical and mechanical actions of YAG in CMP process are investigated. Chemical reaction mechanisms are revealed by X-ray photoelectron spectroscopy analysis. And mechanical actions of abrasives are analyzed by the theory of Derjaguin–Landau–Verwey–Overbeek and the measured coefficient of friction. The results indicate that the material removal depends on the formation of bridge bonds at the interface and the dissociation of work surface bonds when the slurry pH is below 12. In comparison, it is based on forming a softer reaction layer and removed mechanically at pH 13. More abrasives interact with YAG under the acidic condition and it contributes to elevating the material removal rate. The colloidal silica at pH 6 is preferred for CMP of YAG. This study helps to understand the material removal mechanism and optimize the polishing process. [ABSTRACT FROM AUTHOR]

The slurry pH shows significant effects on flotation, but the root cause of pH affecting flotation in the presence of clay is still not fully understood. In this work, the mechanisms of protonation and deprotonation reactions of clays at weakly acidic (pH = 4.5) and alkalescent (pH = 9.0) environment affecting pyrite flotation were investigated. The pyrite flotation in the presence of clays (montmorillonite (Mt), kaolinite (Kaol) and illite (I)) was improved with the deprotonation reactions at pH 9.0 compared with the protonation at pH 4.5. The protonation reactions made the edge surfaces of all the clays and the O basal surface of Kaol positively charged. Hence, the "house-of-cards" structure of Mt and the slime coating of Mt and Kaol occurred, which depressed the pyrite flotation. However, the deprotonation of clay took place at pH 9.0, and thus the face-to-face associations of clay were clearly observed by scanning electron microscopy (SEM). In addition, the negative potential of clay also increased with the deprotonation of clay, which affected the DLVO total interaction energy, making the attraction turning into the repulsive tendency between pyrite and clay. However, pyrite grade showed a little or no increase in the presence of I, which was ascribed to the 2:1 structure and non-swelling nature of I. Such findings can not only help understand the protonation and deprotonation of clay on regulating flotation in the presence of clay, but are expected to provide guidance for mitigating the negative effects of clay during the flotation in the future work. [ABSTRACT FROM AUTHOR]