Non-overshooting PD and PID controllers design

This paper involves the design of non-overshooting PD and PID controllers for some special plants. The PID controller parameters are determined to reach a stable closed-loop system with monotonically decreasing frequency response. Thus specific regions in the controller parameters space are obtained. Gain crossover frequency and phase isodamping property are employed to choose an appropriate solution among the obtained solutions. The performance of the proposed PD and PID controllers in position and velocity control of a laboratory DC servomechanism system is investigated through experimental tests

Coupled Lattice Boltzmann Modeling Framework for Pore-Scale Fluid Flow and Reactive Transport

In this paper, we propose a modeling framework for pore-scale fluid flow and reactive transport based on a coupled lattice Boltzmann model (LBM). We develop a modeling interface to integrate the LBM modeling code parallel lattice Boltzmann solver and the PHREEQC reaction solver using multiple flow and reaction cell mapping schemes. The major advantage of the proposed workflow is the high modeling flexibility obtained by coupling the geochemical model with the LBM fluid flow model. Consequently, the model is capable of executing one or more complex reactions within desired cells while preserving the high data communication efficiency between the two codes. Meanwhile, the developed mapping mechanism enables the flow, diffusion, and reactions in complex pore-scale geometries. We validate the coupled code in a series of benchmark numerical experiments, including 2D single-phase Poiseuille flow and diffusion, 2D reactive transport with calcite dissolution, as well as surface complexation reactions. The simulation results show good agreement with analytical solutions, experimental data, and multiple other simulation codes. In addition, we design an AI-based optimization workflow and implement it on the surface complexation model to enable increased capacity of the coupled modeling framework. Compared to the manual tuning results proposed in the literature, our workflow demonstrates fast and reliable model optimization results without incorporating pre-existing domain knowledge

Psychological Distress Model Among Iranian Pre-Hospital Personnel in Disasters: A Grounded Theory Study

Objective: Pre-hospital personnels (PHPs) who work in disasters under extreme pressure, uncertainty, and complex situations are victims of disasters themselves, and there is a link between experiencing such incidents andmental health problems. Because most studies focus on the injured and less on the psychological issues of PHPs, the present study aimed to develop a model to provide relief for PHPs in disasters from a psychological perspective. Methods: A grounded theorymethodology recommended by Corbin and Strauss (2015) was employed. PHPs (n = 24) participated in a semi-structured interview between July 2018 to May 2020. Results: In the analysis of the pre-hospital staff interviews, three main themes were extracted, namely, providing relief with struggle (complexity of incident scenes, command-organizational and occupational challenges), psychological distress (psychological regression and psychological empowerment), and consequences (resilience and job burnout). Seven categories and 22 subcategories were explored from our data via the grounded theory approach Conclusions: The PHPs managed psychological distress with two approaches: psychological self-empowerment and regression, which resulted in resilience and burnout, respectively. Due to the lack of enough support, the resilience of the PHPs was short-term, turned into burnout over time, and affected the structural factors again as a cycle

Considerable increase in Poly(3-hydroxybutyrate) production via phbC gene overexpression in Ralstonia eutropha PTCC 1615

Introduction: Poly(3-hydroxybutyrate) (PHB) is a well-known biodegradable polymer produced by some microorganisms and can be a suitable alternative for petrochemical plastics. PHB synthase encoded by phbC gene is the main enzyme in PHB biosynthesis pathway in Ralstonia eutropha. The aim of current study was the transformation of R. eutropha PTCC 1615 with its own phbC gene and evaluation of the overexpression effect on PHB accumulation. Methods: DNA fragment including phbC gene and its promoter and terminator regions, was isolated from R. eutropha PTCC 1615, inserted into pET28a(+) vector, and transferred to the competent bacteria using calcium chloride and heat shock method. The effect of the cloned gene expression on PHB production was investigated with absorption of crotonic acid produced through PHB dehydration. Statistical analyses were carried out by SPSS software. Results: PHB content of cells of the engineered strain was 1.4 times more than that of the native bacteria. This significant difference can be an important finding for improvement of biopolymer production. Conclusion: Overexpression of phbC, the critical gene in PHB biosynthesis pathway, in R. eutropha PTCC 1615 had considerable effect on PHB accumulation

Spatial modeling of cutaneous leishmaniasis in Iranian army units during 2014-2017 using a hierarchical Bayesian method and the spatial scan statistic

OBJECTIVES This study aimed to map the incidence of cutaneous leishmaniasis (CL) in Iranian army units (IAUs) and to identify possible spatial clusters. METHODS This ecological study investigated incident cases of CL between 2014 and 2017. CL data were extracted from the CL registry maintained by the deputy of health of AJA University of Medical Sciences. The standardized incidence ratio (SIR) of CL was computed with a Besag, York, and Mollié model. The purely spatial scan statistic was employed to detect the most likely high-and low-rate clusters and to obtain the observed-to-expected (O/E) ratio for each detected cluster. The statistical significance of the clusters was assessed using the log likelihood ratio (LLR) test and Monte Carlo hypothesis testing. RESULTS A total of 1,144 new CL cases occurred in IAUs from 2014 to 2017, with an incidence rate of 260 per 100,000. Isfahan and Khuzestan Provinces were found to have more CL cases than expected in all studied years (SIR>1), while Kermanshah, Kerman, and Fars Provinces were observed to have been high-risk areas in only some years of the study period. The most significant CL cluster was in Kermanshah Province (O/E, 67.88; LLR, 1,200.62; p<0.001), followed by clusters in Isfahan Province (O/E, 6.02; LLR, 513.24; p<0.001) and Khuzestan Province (O/E, 2.35; LLR, 73.71; p<0.001), while low-rate clusters were located in the northeast areas, including Razavi Khorasan, North Khorasan, Semnan, and Golestan Provinces (O/E, 0.03; LLR, 95.11; p<0.001). CONCLUSIONS This study identified high-risk areas for CL. These findings have public health implications and should be considered when planning control interventions among IAUs

Did Iranians change their eating behavior following COVID-19 outbreak?

Background: Significant lifestyle changes have been reported after COVID-19 outbreak. The present study aimed at investigating changes in dietary habits in response to the COVID-19 outbreak in an Iranian population sample. Materials and Methods: In this cross-sectional study, the dietary habits of Iranian adults were assessed before and during the COVID-19 outbreak. Consumption of different food groups such as meats, dairy, fruits, vegetables, seeds, and nuts was assessed using a digital questionnaire which was shared on social media platforms. For the statistical analysis, the Wilcoxon signed-rank test was used. Results: In this online survey, 1553 questionnaires were completed. The results showed that the reported consumption of protein-rich foods increased (P < 0.05), but fish and dairy consumption showed a significant reduction (P = 0.006 and <0.001, respectively). There was a significant reduction in reported fast-food consumption (P < 0.001). Fruits and vegetables (P < 0.001), natural fruit juices (P < 0.001), and water (P < 0.001) were consumed more frequently. Individuals also consumed more vitamin and mineral supplements (P < 0.001) including those containing Vitamin D. Conclusion: During the COVID-19 pandemic, participants reported a significant change in their dietary habits and intake of supplements. Higher intakes of meats, protein-rich foods, fruits, vegetables, and nutritional supplements and lower intakes of fish, dairy, and fast foods were reported

Detection of Sea, Seb, Sec, Seq genes in staphylococcus aureus isolated from nasal carriers in Tehran province, Iran; by multiplex PCR

Staphylococcus(S.) aureus  produces different extra-cellular protein toxins and virulence factors. One of the most important extra-cellular proteins is an enterotoxin which causes staphylococcal food poisoning (SFP) due to their enterotoxins. Different methods have been used to detect this toxin, each of which has advantages and disadvantages. DNA amplification methods, however, can show the presence of enterotoxigenic strains of S. aureus before the expression of enterotoxins on the basis of specific gene sequences. In this study, 150 S. aureus strains isolated from nasal carriers were confirmed by biochemical testing. PCR was used to amplify the staphylococcal enterotoxin A, B, C and Q genes, as well as the staphylococcal nuclease gene.  Among the 150 healthy human isolates from the nasal carrier, 95 were confirmed as S. aureus.  Only 58.9% of the isolates were diagnosed as sea, b, c, q positive. There were 24 (25.3%) isolates associated with the sea gene, 15.8% isolates associated with the seb gene, 9.5% of the isolates were associated with the sec gene, and 8.4% of the isolates associated with the seq gene. Of these isolates, 41% might be possessing additional se genes but they were not see (178 bp) and sed (319 bp) genes.  The nuc gene, which encodes thermo nuclease, was used as a target DNA to identify S. aureus. Additionally, one of these enterotoxigenic isolates carried more than one toxin gene

2,2′-[(E,E)-1,1′-(2,2-Dimethyl­propane-1,3-diyldinitrilo)diethyl­idyne]diphenol

The title Schiff base, C21H26N2O2, contains two intra­molecular O—H⋯N hydrogen bonds between the hydroxyl groups and the nearest imine N atoms, each leading to a six-membered ring. Weak C—H⋯O hydrogen bonds result in a ladder network running along the a axis. In addition, inter­molecular C—H⋯π inter­actions serve to stabilize the extended structure

Survey on white spot virus infection in wild shrimps and crabs in Bushehr province coastal waters

After severe mortality due to white spot disease incidence in cultured shrimps of Helleh grows out farms, disease spread to Delvar,Mond, Boeyrat and Bandar Rig sites in Bushehr province during 2005. Many crustaceans keep this virus in the body, act as a carrier, and can spread of the infection. In order to investigate status of contamination of wild shrimp and crab's population to white spot virus in Bushehr province waters (north of Persian Gulf), samples were collected and tested by Nested PCR for detection of WSV from estuaries and input and output channels water around the Helleh, Shif and Mond sites during 2007 and 2008. Total tested shrimps were 401 peaces, includes green tiger shrimp (Penaeus semisulcatus) 220 pieces, white shrimp (Metapenaeus affinis) 181 pieces, also total tested crabs were 292 pieces includes Ocypode rotundata 68 pieces and Portunus pelagicus 224 pieces. All the samples showed negative results of WSV contamination. However, it can never be sure that the population is free from WSV unless we collect a random sample of 300 pieces from each species and test them individually for WSV. Therefore, we will be confident up to 95% that the wild sources in that area have no prevalence of 1% or upper WSV contamination