A Reliable Communication Model Based on IEEE802.15.4 for WSANs in Smart Grids

Creating cyber-physical systems (CPSs) based on wireless sensor and actuator networks (WSANs) has great potential to improve the performance of Smart Grid. In addition, IEEE802.15.4 has widely been regarded as an appropriate standard for WSANs, due to some striking and unique features. WSANs require provisioning strict quality of service (QoS) due to noisy harsh environments in Smart Grid applications. Although analytical models have been studied in the literature, they have not provided a full-fledged model for Smart Grid. In this paper, we have added a MAC-level buffer, and a novel Markov chain model has been also proposed. By comparison with previous studies, retransmission confines, acknowledgment, packet length variation, saturated traffic, and degenerate distribution of packet generation are accounted for. The algorithm has been experimentally implemented and appraised on a platform with self-designed WSAN. The analytical model predicts well our exhaustive experiments. Further, Monte Carlo simulations validate mathematical results

Conceptualization of Addiction to Romantic Relationships: A Conceptual Model

Introduction: Addiction to romantic relationship is one of the prevalent disorders in the field of psychology. The objective of the present study is to formulate a qualitative model of addiction to romantic relationships. Methods: The research is an applied study using discovery manner, in which, qualitative research method and grounded theory were utilized. The population was the entire people who were addicted to romantic relationships, selecting purposefully 100 samples for interview process. To collect data, in-depth interview was used, and then, after the implementation of the data, they prepared for analysis. The process of data analysis was deductive. In the other hand, there was no previous conceptual framework for coding and categorizing; rather, it was analyzed freely by coding technique of grounded theory. Results: Regarding the results, the final model of the study comprised eight different concepts, including: affective mental, family, emotional, needs, critics, consequences factors, and the factors related to relationship. Discussion: The results addressed the different context and dimensions of vulnerability to romantic relationships addiction, thus, considering the results of the present study, practitioners particularly psychologists can adopt appropriate intervention either in treatment or prevention of romantic relationship addiction

Magnesiothermic Reduction of Silica: A Machine Learning Study

undamental studies have been carried out experimentally and theoretically on the magnesiothermic reduction of silica with different Mg/SiO2 molar ratios (1–4) in the temperature range of 1073 to 1373 K with different reaction times (10–240 min). Due to the kinetic barriers occurring in metallothermic reductions, the equilibrium relations calculated by the well-known thermochemical software FactSage (version 8.2) and its databanks are not adequate to describe the experimental observations. The unreacted silica core encapsulated by the reduction products can be found in some parts of laboratory samples. However, other parts of samples show that the metallothermic reduction disappears almost completely. Some quartz particles are broken into fine pieces and form many tiny cracks. Magnesium reactants are able to infiltrate the core of silica particles via tiny fracture pathways, thereby enabling the reaction to occur almost completely. The traditional unreacted core model is thus inadequate to represent such complicated reaction schemes. In the present work, an attempt is made to apply a machine learning approach using hybrid datasets in order to describe complex magnesiothermic reductions. In addition to the experimental laboratory data, equilibrium relations calculated by the thermochemical database are also introduced as boundary conditions for the magnesiothermic reductions, assuming a sufficiently long reaction time. The physics-informed Gaussian process machine (GPM) is then developed and used to describe hybrid data, given its advantages when describing small datasets. A composite kernel for the GPM is specifically developed to mitigate the overfitting problems commonly encountered when using generic kernels. Training the physics-informed Gaussian process machine (GPM) with the hybrid dataset results in a regression score of 0.9665. The trained GPM is thus used to predict the effects of Mg-SiO2 mixtures, temperatures, and reaction times on the products of a magnesiothermic reduction, that have not been covered by experiments. Additional experimental validation indicates that the GPM works well for the interpolates of the observations.publishedVersio

Kinetics of Magnesiothermic Reduction of Natural Quartz

In this work, the kinetics of natural quartz reduction by Mg to produce either Si or Mg2Si was studied through quantitative phase analysis. Reduction reaction experiments were performed at various temperatures, reaction times and Mg to SiO2 mole ratios of 2 and 4. Rietveld refinement of X-ray diffraction patterns was used to obtain phase distributions in the reacted samples. SEM and EPMA examinations were performed to evaluate the microstructural change during reduction. The results indicated that the reduction reaction rate was slower at a mole ratio of 2 than 4 at the same temperature, as illustrated by the total amount of Si formed (the percent of Si that is reduced to either Si or Mg2Si to total amount of Si) being 59% and 75%, respectively, after 240 min reaction time for mole ratios of 2 and 4. At the mole ratio of 4, the reaction rate was strongly dependent on the reaction temperature, where SiO2 was completely reduced after 20 min at 1273 K. At the lower temperatures of 1173 and 1073 K, total Si formed was 75% and 39%, respectively, after 240 min reaction time. The results of the current work show that Mg2Si can be produced through the magnesiothermic reduction of natural quartz with high yield. The obtained Mg2Si can be processed further to produce silane gas as a precursor to high purity Si. The combination of these two processes offers the potential for a more direct and low carbon method to produce Si with high purity

Kinetics of Magnesiothermic Reduction of Natural Quartz

In this work, the kinetics of natural quartz reduction by Mg to produce either Si or Mg2Si was studied through quantitative phase analysis. Reduction reaction experiments were performed at various temperatures, reaction times and Mg to SiO2 mole ratios of 2 and 4. Rietveld refinement of X-ray diffraction patterns was used to obtain phase distributions in the reacted samples. SEM and EPMA examinations were performed to evaluate the microstructural change during reduction. The results indicated that the reduction reaction rate was slower at a mole ratio of 2 than 4 at the same temperature, as illustrated by the total amount of Si formed (the percent of Si that is reduced to either Si or Mg2Si to total amount of Si) being 59% and 75%, respectively, after 240 min reaction time for mole ratios of 2 and 4. At the mole ratio of 4, the reaction rate was strongly dependent on the reaction temperature, where SiO2 was completely reduced after 20 min at 1273 K. At the lower temperatures of 1173 and 1073 K, total Si formed was 75% and 39%, respectively, after 240 min reaction time. The results of the current work show that Mg2Si can be produced through the magnesiothermic reduction of natural quartz with high yield. The obtained Mg2Si can be processed further to produce silane gas as a precursor to high purity Si. The combination of these two processes offers the potential for a more direct and low carbon method to produce Si with high purity

Magnesiothermic Reduction of Natural Quartz

In the current work, the metallothermic reduction of natural quartz by magnesium has been studied at 1373 K under different reaction conditions, i.e. quartz type, quartz particle size, Mg:SiO2 mole ratio and reaction time. The microstructure of reaction products was studied to illustrate the reaction progression through scanning and transmission electron microscopy techniques. X-ray diffraction analysis with Rietveld phase quantification was used to calculate the change in the amount of phases at different reaction conditions. The results showed that the Mg:SiO2 mole ratio strongly affects reaction mechanism and product characteristics such as phase content and microstructure. At lower Mg:SiO2 mole ratios, the reaction rate is fast at the beginning and the formation of a product layer consisting of different phases such as MgO, Si, Mg2Si, Mg2SiO4 and MgSiO3 around quartz particles limits the Mg diffusion. This phenomenon is more noticeable for larger quartz particle sizes where Mg should diffuse longer distance towards the quartz core to react with it. At higher Mg:SiO2 mole ratios, a significant amount of Si–Mg liquid alloy is formed during reaction where the high mobility of Mg in this liquid phase and cracking of quartz particles result in significantly higher reaction rate. Here the formation of intermediate phases is not significant and the products would be the mixture of MgO, Mg2Si, and either Si or Mg phases

Magnesiothermic Reduction of Natural Quartz

In the current work, the metallothermic reduction of natural quartz by magnesium has been studied at 1373 K under different reaction conditions, i.e. quartz type, quartz particle size, Mg:SiO2 mole ratio and reaction time. The microstructure of reaction products was studied to illustrate the reaction progression through scanning and transmission electron microscopy techniques. X-ray diffraction analysis with Rietveld phase quantification was used to calculate the change in the amount of phases at different reaction conditions. The results showed that the Mg:SiO2 mole ratio strongly affects reaction mechanism and product characteristics such as phase content and microstructure. At lower Mg:SiO2 mole ratios, the reaction rate is fast at the beginning and the formation of a product layer consisting of different phases such as MgO, Si, Mg2Si, Mg2SiO4 and MgSiO3 around quartz particles limits the Mg diffusion. This phenomenon is more noticeable for larger quartz particle sizes where Mg should diffuse longer distance towards the quartz core to react with it. At higher Mg:SiO2 mole ratios, a significant amount of Si–Mg liquid alloy is formed during reaction where the high mobility of Mg in this liquid phase and cracking of quartz particles result in significantly higher reaction rate. Here the formation of intermediate phases is not significant and the products would be the mixture of MgO, Mg2Si, and either Si or Mg phases.publishedVersio

Magnesiothermic Reduction of Natural Quartz

In the current work, the metallothermic reduction of natural quartz by magnesium has been studied at 1373 K under different reaction conditions, i.e. quartz type, quartz particle size, Mg:SiO2 mole ratio and reaction time. The microstructure of reaction products was studied to illustrate the reaction progression through scanning and transmission electron microscopy techniques. X-ray diffraction analysis with Rietveld phase quantification was used to calculate the change in the amount of phases at different reaction conditions. The results showed that the Mg:SiO2 mole ratio strongly affects reaction mechanism and product characteristics such as phase content and microstructure. At lower Mg:SiO2 mole ratios, the reaction rate is fast at the beginning and the formation of a product layer consisting of different phases such as MgO, Si, Mg2Si, Mg2SiO4 and MgSiO3 around quartz particles limits the Mg diffusion. This phenomenon is more noticeable for larger quartz particle sizes where Mg should diffuse longer distance towards the quartz core to react with it. At higher Mg:SiO2 mole ratios, a significant amount of Si–Mg liquid alloy is formed during reaction where the high mobility of Mg in this liquid phase and cracking of quartz particles result in significantly higher reaction rate. Here the formation of intermediate phases is not significant and the products would be the mixture of MgO, Mg2Si, and either Si or Mg phases

Evaluation of antibacterial properties of alcoholic extract of pine on bacteria isolated from urine of patients with urinary tract infection � genital

Introduction: Urinary tract infection is one of the most common infections and the second cause of infection in human body. The main cause of this infection is gram negative bacteria such as E coli. The base of treatment for urinary tract infection is administrating an appropriate antibiotic. Today, antibiotic resistance is considered as an important challenge in treating infections. High and unnecessary use of antibiotics especially in urinary infections resulted in resistance to some antibioticsThis study aimed to evaluate the antibacterial effect of alcoholic extract of Escherichia coli took over the pine leaves.Methods: In this experimental study the Alcoholic extract was extracted using. its antimicrobial activity agar disk diffusion method for determination of bacterial sensitivity and dilution method for determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) is used separately.Results: Also the results of MIC and MBC tests indicated that the inhibition of E.coli and Staphilococci aureus bacterial growth by Alcoholic extract of pine had a direct relationship with the amount of available alcoholic extract of pine. with increasing of Alcoholic extract of pine in each dilution, reduced the number of cultured bacterial colonies and no bacterial growth was observed in the dilution equivalent to MBC of Alcoholic extract of pine.Conclusion: The results suggest that Alcoholic extract of pine can be used as a source of cheap and accessible replacing chemical drugs to treat some bacterial infections

Nano Conjugated PLGA-Chlorambucil: Synthesis In Vitro Anti Non-Hodgkin's Lymphoma Cellular Assay

Background: In spite of increasing number of chemotherapeutic drugs, achieving chemotherapy drug with minimal side effects in cancer treatment is still a major challenge. Chemotherapy has an important role in the treatment of non- Hodgkin's lymphoma cancer. Chlorambucil (CBL) is a lipophilic DNA alkylating drug having been administrated in many cancers like leukemia but its use has been limited because of chemical instability, low permeability of the cells and high toxicity. Objective: The main aim of this study is improving in vitro anticancer activity of CBL through conjugating CBL with Poly (DL-lactide-co-glycolide) (PLGA). The characterization of physiochemical structure of PLGA-CBL conjugation was determined by different techniques such as dynamic light scattering (DLS), Scanning electron microscopy (SEM), Atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), and HNMR Spectrometry. Moreover, therapeutic effect of new PLGA-CBL conjugated was evaluated, after which, the cell viability was determined by MTT assay and the numbers of apoptotic/necrotic cells were calculated by flowcytometry using Annexin V/PIkit on a non- Hodgkin's lymphoma cell line. Results and Conclusion: The results of in vitro cytotoxicity showed significantly greater conjugated PLGA-CBL on the non-Hodgkin's lymphoma compared to CBL alon