The increasing generation of saline wastewater through various industrial activities is becoming a global concern for activated sludge (AS) based biological treatment which is widely applied in wastewater treatment plants (WWTPs). As for the AS process, an increase in wastewater salinity has negative impact on its overall performance. The advent of conventional aerobic granular sludge (AGS) or bacterial AGS biotechnology has gained much attention because of its superior performance. The development of algal-bacterial AGS could enhance better nutrients removal, potentially reduce aeration cost through symbiotic algae-bacterial activity, and thus, can also reduce overall treatment cost. Nonetheless, the potential of salt stress to decrease biomass growth, microbial activity and nutrient removal exist. Up to the present, little information is available on saline wastewater treatment by algal-bacterial AGS. To the authors’ best knowledge, a comparison of the two AGS systems has not been done to evaluate nutrients removal capacity in the context of salinity increase. This study sought to figure out the impact of salinity on the algal-bacterial AGS system in comparison to bacterial AGS one, contributing to the application of AGS technology in the real world of saline wastewater treatment. In this study, the salt concentrations tested were 0 g/L, 1 g/L, 5 g/L, 10 g/L and 15 g/L of NaCl with 24-hr artificial illuminance of approximately 97.2 μmol m ̄2s ̄1, and mature bacterial and algal-bacterial AGS were used for the operation of two identical sequencing batch reactors (SBRs) with a working volume of 0.9 L each, respectively. The results showed that salinity increase caused no apparent change in the color of bacterial AGS; while for algal-bacterial AGS, its color was progressively changed from green to dark green. A consequent increase in granule diameter and fluffiness was observed in the bacterial AGS reactor with the increase of salinity in comparison to a decrease in algal-bacterial AGS diameter. However, nitrite accumulation peaked from 1.0 mg/L and 0.4 mg/L at 1 g/L NaCl in the bacterial and algal-bacterial AGS systems, respectively to 9.8 mg/L in both systems when NaCl concentration varied from 5 g/L to 15 g/L. Almost no ammonia nitrogen was detected in the effluent except at 10 g/L NaCl concentration, where it averaged 4.2 mg/L and 2.4 mg/L, respectively, in the bacterial and algal-bacterial AGS systems. Nutrients removal in the algal-bacterial system was relatively higher than the bacterial AGS in terms of nitrogen and phosphorus removals. Nonetheless, the nutrient removal rate was almost 50% or lower. Results show that algal-bacterial AGS is more adaptable to salinity increase and could be more suitable for saline wastewater treatment. Optimization of operation conditions for algal-bacterial AGS system would be Philip Semaha, Ziwen Zhao, Sen Liu, Zhenya Zhang, and Kazuya Shimizu are with the Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan (e-mail: macmensah125@yahoo.com, tsukubazhaoziwen@outlook.com, liusen.china@outlook.com, zhang.zhenya.fu@u.tsukuba.ac.jp, shimizu.kazuya.fn@u.tsukuba.ac.jp). Zhongfang Lei is with the Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan, (corresponding author, phone: +81 298536703; fax: +81 298536703; e-mail: lei.zhongfang.gu@u.tsukuba.ac.jp). important to ensure its stably high efficiency in practice. Keywords—Algal-bacterial aerobic granular sludge, bacterial aerobic granular sludge, nutrients removal, saline wastewater, sequencing batch reactor.
Concussions represent an increasing economic burden to society. Motor vehicle collisions (MVCs) are of the leading causes for sustaining a concussion, potentially due to high head accelerations. The change in velocity (i.e., delta-V) of a vehicle in a MVC is an established metric for impact severity. Accordingly, the purpose of this paper is to analyze findings from previous research to determine the relation between delta-V and linear head acceleration, including occupant parameters. Data was collected from previous research papers comprising both linear head acceleration and delta-V at the time of incident, head position of the occupant, awareness of the occupant prior to impact, as well as gender, age, height, and weight. Statistical analysis revealed the following significant power relation between delta-V and head acceleration: head acceleration=0.465delta‐V1.3231 (R2=0.5913, p<0.001). Further analysis revealed that alongside delta-V, the occupant’s gender and head position prior to impact were significant predictors of head acceleration (p=0.022 and p=0.001, respectively). The strongest model developed in this paper is considered physiologically implausible as the delta-V corresponding to a theoretical concussion threshold of 80 g exceeds the delta-V associated with probability of fatality. Future research should be aimed at providing a more thorough data set of the occupant head kinematics in MVCs to help develop a stronger predictive model for the relation between delta-V and head linear and angular acceleration.
Local strain engineering is an exciting approach to tune optoelectronic properties of materials. Two‐dimensional (2D) materials such as 2D transition metal dichalcogenides (TMDs) are particularly well‐suited for this purpose due to their high flexibility and deformability. Local strain engineering in 2D TMDs is typically achieved via strained wrinkles. Wrinkles on thick TMD layers have been reported to show interesting photoluminescence enhancement due to bandgap modulation and funneling effect. However, the wrinkles in ultrathin TMDs are not investigated because they can easily fall down to form folds. Both wrinkles and folds are achieved simultaneously in 1–3L tungsten disulfide (WS 2 ) using a new fabrication technique. A layer‐dependent reduction in surface potential is found for both folded layers and perfect packed layers due to the dominant interlayer screening effect. The strain produced from the wrinkles modulates the semiconductive junction properties significantly. Thermoionic modeling suggests that strained (1.6%) wrinkles can lower the Schottky barrier height (SBH) by 20%. Upon illumination, SBH reduces significantly due to photogenerated carriers. This is an important advance toward controlling the optoelectronic properties of 2D TMDs via strain engineering, with applications for electronics and optoelectronics devices.
We hypothesized that differences in the microbiome could be a cause of the substantial differences in the symptoms of and treatment options for adult and pediatric patients with chronic rhinosinusitis (CRS). First, we characterized the differences in the nasal microbiomes of pediatric and adult CRS patients. Swabs were obtained from 19 patients with chronic rhinosinusitis (9 children and 10 adults). The bacterial 16S rRNA gene was pyrosequenced to compare the microbiota of the middle meatus. No significant differences were found in species richness and alpha-diversity indices between the two groups. However, in the comparison of diversity between groups using the unweighted pair group method with arithmetic mean (UPGMA) clustering of microbiome taxonomic profiles, we observed a relatively clear separation between the adult and pediatric groups. Actinobacteria had a significantly higher relative abundance in the adult group than in the pediatric group at the phylum level. At the genus level, Corynebacterium showed significantly higher relative abundance in the adult group than in the pediatric group. This is a comparative study between the microbiomes of adult and pediatric CRS patients. We expect this study to be the first step in understanding the pathogenesis of CRS in adults and children using microbiome analysis.
In this work, sequential optimization strategy, based on statistical designs, was employed to enhance the degradation of PHB by Trichoderma asperellum through the measurement of PHB depolymerase specific activity.For PHB degradation screening, two-level Plackett-Burman design was used.Result of study revealed that fermentation medium composition significantly influencing the PHB depolymerase specific activity.Further, it was reported that time of incubation, levels of PHB and concentration of glucose were found to be the major factors influencing the enzyme specific activity.A second threelevel Box-Behnken design was applied to acquire the best process conditions for PHB depolymerase specific activity.In this study, the initial basal medium showed a PHB depolymerase specific activity of 40 ng / l / hr / g dry wt and through the two successive statistical design, the final level of PHB depolymerase specific activity was 3230 ng / l / hr / g drywt, this means a nearly of 80 fold increase.
