Energy conditions in f(R) gravity and Brans-Dicke theories

The equivalence between f(R) gravity and scalar-tensor theories is invoked to study the null, strong, weak and dominant energy conditions in Brans-Dicke theory. We consider the validity of the energy conditions in Brans-Dicke theory by invoking the energy conditions derived from a generic f(R) theory. The parameters involved are shown to be consistent with an accelerated expanding universe.Comment: 9 pages, 1 figure, to appear in IJMP

Effects of Gas Cross-over through the Membrane on Water Management in the Cathode and Anode Sides of PEM Fuel Cell

Water management in a proton exchange membrane fuel cell (PEMFC) is numerically modeled by considering the 2D, non-isothermal steady flow assumptions. Governing equations are solved in all cell layers including cathode and anode electrodes by finite volume method using a single-region approach. The effect of gas cross-over through the membrane is studied on cell performance. This consideration, not only improves the general accuracy of modeling but also makes it possible to model energy losses due to direct reaction of reactant gases. The effect of some key variables such as liquid water diffusivity, current density, membrane thickness, etc. on PEMFC conditions such as the amount of saturated liquid water, power density, cell temperature, cross-over efficiency and so on are examined. It was observed that the amount of saturated liquid water on the anode side is considerably important. This observation addresses needs for further investigation of liquid water behavior in the anode electrode. The amount of liquid water saturation in both the cathode and anode electrodes is increased with increasing the current density. The results showed that at the current density of 0.2 A/cm2, cross-over effect causes about 10% reduction in cell efficiency and by decreasing the current density this effect is enhanced

Microarray analysis revealed different gene expression patterns in HepG2 cells treated with low and high concentrations of the extracts of Anacardium occidentale shoots

In this study, the effects of low and high concentrations of the Anacardium occidentale shoot extracts on gene expression in liver HepG2 cells were investigated. From MTT assays, the concentration of the shoot extracts that maintained 50% cell viability (IC50) was 1.7 mg/ml. Cell viability was kept above 90% at both 0.4 mg/ml and 0.6 mg/ml of the extracts. The three concentrations were subsequently used for the gene expression analysis using Affymetrix Human Genome 1.0 S.T arrays. The microarray data were validated using real-time qRT–PCR. A total of 246, 696 and 4503 genes were significantly regulated (P < 0.01) by at least 1.5-fold in response to 0.4, 0.6 and 1.7 mg/ml of the extracts, respectively. Mutually regulated genes in response to the three concentrations included CDKN3, LOC100289612, DHFR, VRK1, CDC6, AURKB and GABRE. Genes like CYP24A1, BRCA1, AURKA, CDC2, CDK2, CDK4 and INSR were significantly regulated at 0.6 mg/ml and 1.7 mg but not at 0.4 mg/ml. However, the expression of genes including LGR5, IGFBP3, RB1, IDE, LDLR, MTTP, APOB, MTIX, SOD2 and SOD3 were exclusively regulated at the IC50 concentration. In conclusion, low concentrations of the extracts were able to significantly regulate a sizable number of genes. The type of genes that were expressed was highly dependent on the concentration of the extracts used

Evaluating mechanism and severity of injuries among trauma patients admitted to Sina Hospital, the National Trauma Registry of Iran

Purpose: Injuries are one of the leading causes of death and lead to a high social and financial burden. Injury patterns can vary significantly among different age groups and body regions. This study aimed to evaluate the relationship between mechanism of injury, patient comorbidities and severity of injuries. Methods: The study included trauma patients from July 2016 to June 2018, who were admitted to Sina Hospital, Tehran, Iran. The inclusion criteria were all injured patients who had at least one of the following: hospital length of stay more than 24 h, death in hospital, and transfer from the intensive care unit of another hospital. Data collection was performed using the National Trauma Registry of Iran minimum dataset. Results: The most common injury mechanism was road traffic injuries (49.0), followed by falls (25.5). The mean age of those who fell was significantly higher in comparison with other mechanisms (p < 0.001). Severe extremity injuries occurred more often in the fall group than in the vehicle collision group (69.0 vs. 43.5, p < 0.001). Moreover, cases of severe multiple trauma were higher amongst vehicle collisions than injuries caused by falls (27.8 vs. 12.9, p = 0.003). Conclusion: Comparing falls with motor vehicle collisions, patients who fell were older and sustained more extremity injuries. Patients injured by motor vehicle collision were more likely to have sustained multiple trauma than those presenting with falls. Recognition of the relationship between mechanisms and consequences of injuries may lead to more effective interventions. © 2021 Chinese Medical Associatio

Covalent modification of reduced graphene oxide with piperazine as a novel nanoadsorbent for removal of H2S gas

In the present research, piperazine grafted-reduced graphene oxide RGO-N-(piperazine) was synthesized through a three-step reaction and employed as a highly efficient nanoadsorbent for H2S gas removal. Temperature optimization within the range of 30–90 °C was set which significantly improved the adsorption capacity of the nanoadsorbent. The operational conditions including the initial concentration of H2S (60,000 ppm) with CH4 (15 vol%), H2O (10 vol%), O2 (3 vol%) and the rest by helium gas and gas hour space velocity (GHSV) 4000–6000 h−1 were examined on adsorption capacity. The results of the removal of H2S after 180 min by RGO-N-(piperazine), reduced graphene oxide (RGO), and graphene oxide (GO) were reported as 99.71, 99.18, and 99.38, respectively. Also, the output concentration of H2S after 180 min by RGO-N-(piperazine), RGO, and GO was found to be 170, 488, and 369 ppm, respectively. Both chemisorption and physisorption are suggested as mechanism in which the chemisorption is based on an acid–base reaction between H2S and amine, epoxy, hydroxyl functional groups on the surface of RGO-N-(piperazine), GO, and RGO. The piperazine augmentation of removal percentage can be attributed to the presence of amine functional groups in the case of RGO-N-(piperazine) versus RGO and GO. Finally, analyses of the equilibrium models used to describe the experimental data showed that the three-parameter isotherm equations Toth and Sips provided slightly better fits compared to the three-parameter isotherms

Evaluating Satisfaction of Participants within the Outreach and Engagement Program of MECCA

The present study aimed to provide literature on community-based programs and correlated participant satisfaction, to examine the factors that contribute to participant satisfaction within community-based programs, and to evaluate outcomes of participant satisfaction for MECCA’s O&E program, as well as reflection on components of the O&E program that produce satisfaction ratings. The primary research question of the present study was: Were participants satisfied with their participant in MECCA’s O&E program for both fiscal years and if so, what factors may have contributed to their satisfaction? Through use of description analyses on outcomes of the Participant Satisfaction Survey from MECCA’s six community-based agencies, findings indicate that MECCA provided culturally-responsive and linguistically congruent services. Additionally, participants were satisfied overall with the O&E services and would elect to obtain services from the O&E program again. O&E’s success can be attributed to MECCA’s foundation in cultural responsiveness, diversity empowerment, destigmatizing mental health services, and collaboration with the communities to create and provide community-based programs

Video game market segmentation based on user behavior

Games excited generations in various societies: from the very simple physical form - to the latest generation of digital games - in the world where we are living. They always played an important role in every aspect of human life. The initial forces behind games where means as social interaction, pure entertainment, edutainment, or simply to have fun. However, from the initial forces, games emerged towards a tool for empowering creativity and the game industry turned into a largely profitable industry. Within the scope of this paper, we describe the key findings that are indicating the common trends in gaming industry, we evaluate key technologies contributing to the game industry, and try to understand game preferences of game players and the specifics of behavioral patterns in different game genres. © 2012 ACM

Generation of Cherenkov radiation in the soft x-ray region by 10-MeV electron accelerator

Cherenkov radiation is generated when relativistic charged particles move in a medium with refractive index larger than unity. Although, the refractive index is generally smaller than unity in X-ray region, in the vicinity of atomic absorption edges, the refractive index may exceed unity and Cherenkov radiation can be generated in soft X-ray region with a narrow band width. In this paper, the spectral-angular distribution of X-ray Cherenkov Radiation (XCR) and its properties are analyzed. It is shown that, by using electron accelerators which can produce 10 MeV electrons, with average current density 20 mA/mm2, and choosing different &micro;m-thick foils, one can produce soft X-ray Cherenkov radiation source with intensity about 10-4 ph/el, and X-ray photon energy from 50 eV up to 1 keV. Some unique properties of XCR, such as narrow band width and high brightness, make XCR a novel soft X-ray source for applications in soft X-ray microscopy, photoelectron spectroscopy, analysis of trace elements and other research areas. &nbsp; &nbsp