Study the spectroscopic characteristics of Rhodamine B Dye in Ethanol and Methanol mixture and Calculation the Quantum Efficiency

The effect of ethanol and methanol solvent, and their mixture has been studied on the absorption and fluorescence spectra of laser dye Rhodamine B at concentration of (10-4) Molar at room temperature. The molar absorption coefficient has been determined for mixture which was (3.223) at wave number (18181.8 cm-1), Also the Quantum Efficiency of the two solvents (ethanol and methanol) and their mixture have been calculated ,which was for mixture spectrum (38.94%) and it was larger comparing with other and solvents. The characteristics of spectrum has been determined by calculating (??) of absorption spectrum for the solvents and its mixture at maximum wave number ( ) cm-1 depending on solvent polarity and the transitions between molecular energy levels in each solvent of Rhodamine B dye

Mechanical Properties of High Strength Concrete Containing Different Cementitious Materials

High strength concrete hasstrength significantly beyond what is used in normal practice. According to American Concrete Institute (ACI), high strength concrete revised the definition to cover mixtures with specified design strength of 55 MPa or more. The main objective of this investigation isto study the effect of using different supplementary cementitious materials in binary blends on mechanical properties of high strength concrete. The experimental work includes threestages: firstly, preparation of cementitious materials (metakaolin and pumice) from local materials,second involves conducting several trial mixes to choose the best of superplasticizer that satisfies the required properties and to specify the optimum water content which is designed in laboratory by 0.3 W/Cm ratio, to achieve workability with (60-80mm) slump and the best compressive strength which was 64.6 at 28 days. Thirdly carrying out tests to find out the compressive strength, splitting tensile strength, modulus of rupture, on binary concretes including mixes containing silica fume as cement replacement at percentages of 8%, 10% and 15%, mixes containing metakaolin as cement replacement levels of 10%, 15%, and20% and mixes containing pumice at cement replacement of 10%, 15%, and 20%.These properieswere measured at ages ranging from7days to 180 days. The resultsindicate that the silica fume performs better than other supplementary cementitious materials(metakaolin or pumice) in terms of the compressive strength, splitting tensile strength and modulus of rupture development at ages of 7,28,60,90and180 days where the average percentage of increase when using 8%,10% and 15% ofsilica fume was about(19%,23% and 18.7%) ,respectively, while when using 10%,15% and 20%metakaolin the average percentage of increase was (10%,12.6% and 4%) respectively, also when using 10%,15% and 20% of pumice the average percentage of increase was (2.6%, 6% and 1.5%), respectively

Design and Performance Analysis of 250 kW Grid-Connected Photovoltaic System in Iraqi Environment Using PVsyst Software

A 250 kW grid-connected photovoltaic (PV) plant systems have been installed at the Ministry of Electricity in Baghdad and penetrated to the Iraqi national grid since November 2017. This is the first high power grid-connected PV system that has been installed in Iraq and it’s one of the four parts 1MW large-scale PV systems that should be completed in early of 2019. This paper presents the design and performance analysis of this system using a PVsyst software package. The performance ratio and different losses that occurred in the system are also calculated. The results show that the performance ratio is 75% using 1428 photovoltaic panels type (Sharp 175Wp) spread over an area of 1858 m². The total energy injected into the grid is (346692 kWh/year) .Based on the simulation results that developed in this paper, the practical PV grid-tied system has been implemented in Baghdad site

An Optimal Current Controller Design for a Grid Connected Inverter to Improve Power Quality and Test Commercial PV Inverters

Grid connected inverters play a crucial role in generating energy to be fed to the grid. A filter is commonly used to suppress the switching frequency harmonics produced by the inverter, this being passive, and either an L- or LCL-filter. The latter is smaller in size compared to the L-filter. But choosing the optimal values of the LCL-filter is challenging due to resonance, which can affect stability. This paper presents a simple inverter controller design with an L-filter. The control topology is simple and applied easily using traditional control theory. Fast Fourier Transform analysis is used to compare different grid connected inverter control topologies. The modelled grid connected inverter with the proposed controller complies with the IEEE-1547 standard, and total harmonic distortion of the output current of the modelled inverter has been just 0.25% with an improved output waveform. Experimental work on a commercial PV inverter is then presented, including the effect of strong and weak grid connection. Inverter effects on the resistive load connected at the point of common coupling are presented. Results show that the voltage and current of resistive load, when the grid is interrupted, are increased, which may cause failure or damage for connecting appliances

Energizing the thermophysical properties of phase change material using carbon-based nano additives for sustainable thermal energy storage application in photovoltaic thermal systems

As solar energy are intermittent in nature and not predictable, researchers and scientists are actively developing efficient thermal energy storage (TES) systems intending to maximize the utilization of solar energy. Phase change materials (PCM) are potential materials that are largely accessed towards TES. However, the notable drawback of PCM is their lower thermal conductivity, leading to slower heat transfer rates and reduced thermal energy storage density. Thus, the current study focuses on developing and exploring a PCM composite by embedding paraffin wax and graphene to enhance the heat transfer mechanisms, making it a promising option for TES applications. Various aspects of the composite's performance were examined, including its microstructural behaviour, chemical stability, thermal stability, thermal conductivity, thermal reliability, and heat transfer characteristics. The findings revealed that the inclusion of graphene led to a substantial increase of up to 75.09 % in thermal conductivity while preserving the melting enthalpy of the material. The newly developed nanocomposite also demonstrated chemically and thermally stable up to a temperature of 210 °C, and the thermal stability was slightly enhanced by adding nanoparticles. This nanocomposite also exhibited improved optical absorptance and reduced transmittance, enhancing its potential for solar energy absorption. It further demonstrated durability, maintaining stability even after undergoing 500 thermal cycles. Notably, the overall efficiency of the nano-enhanced PCM integrated photovoltaic-thermal system (PVT) enhanced by 29 % and 49 % greater than the PVT system and conventional PV system. Given these exceptional characteristics and performance enhancements, this nanocomposite material holds promise for significantly advancing future sustainable TES technologies

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

Investigating principal working memory features in generalized, panic and social anxiety spectrum disorders

Anxiety spectrum disorders are characterized by excessive and uncontrollable worrying about potential negative events in the short- and long-term future. Various reports linked anxiety spectrum disorders with working memory (WM) deficits despite conflicting results stemming from different study approaches. It remains unclear, however, how different anxiety spectrum disorders such as generalized anxiety disorder (GAD), social anxiety disorder (SAD), and panic disorder (PD), differ in WM function. In this study, we utilized verbal, numerical, and sequential evaluations of WM to cover most possible facets of the WM data space. We used principal component analysis to extract the uncorrelated/whitened components of WM based on these measures. We evaluated medication-free patients with GAD, SAD, and PD patients as well as matched healthy individuals using a battery that measures WM duration and load. We found that patients with GAD and SAD, but not PD, exhibited poor performance only in the WM principal component that represents maintenance. There were no other significant differences between the four groups. Further, different WM components significantly predicted the severity of anxiety symptoms in the groups. We explored the clinical utility of WM components for differentiating patients with anxiety spectrum disorders from healthy individuals. By only using the WM components that represent maintenance and encoding, we managed to differentiate patients from controls in 84% of cases. For the first time, we present multiple novel approaches to examine cognitive function and design cognitive screening, and potentially diagnostics, for psychiatric disorders

Posterior auricular artery

Introduction: The posterior auricular artery (PAA) is the preterminal branch of the external carotid artery (ECA), arising superiorly to the occipital artery (OA). The PAA has quite a few anatomical variations and established neurosurgical applications. We conducted this study as an overview to illustrate all neurosurgical aspects regarding this artery, its reconstructive uses, and anatomical variation. Method:  We performed a literature review in Google Scholar and PubMed medical databases for studies discussing the PAA, its anatomical variations, and neurosurgical applications. Results: We identified 30 articles that discuss the anatomical variations and neurosurgical applications of the PAA. While reviewing the available articles and original works regarding PAA. Conclusion: The PAA has considerable anatomical variations regarding its origin, course, branches, and length. The related neurosurgical applications of PAA include bypass, embolization, aneurysm, AVM, and reconstruction flaps

Generalized anxiety disorder and social anxiety disorder, but not panic anxiety disorder, are associated with higher sensitivity to learning from negative feedback : behavioral and computational investigation

Anxiety disorders, including generalized anxiety disorder (GAD), social anxiety disorder (SAD), and panic anxiety disorder (PAD), are a group of common psychiatric conditions. They are characterized by excessive worrying, uneasiness, and fear of future events, such that they affect social and occupational functioning. Anxiety disorders can alter behaviour and cognition as well, yet little is known about the particular domains they affect. In this study, we tested the cognitive correlates of medication-free patients with GAD, SAD, and PAD, along with matched healthy participants using a probabilistic category-learning task that allows the dissociation between positive and negative feedback learning. We also fitted all participants’ data to a Q-learning model and various actor-critic models that examine learning rate parameters from positive and negative feedback to investigate effects of valence vs. action on performance. SAD and GAD patients were more sensitive to negative feedback than either PAD patients or healthy participants. PAD, SAD, and GAD patients did not differ in positive-feedback learning compared to healthy participants. We found that Q-learning models provide the simplest fit of the data in comparison to other models. However, computational analysis revealed that groups did not differ in terms of learning rate or exploration values. These findings argue that (a) not all anxiety spectrum disorders share similar cognitive correlates, but are rather different in ways that do not link them to the hallmark of anxiety (higher sensitivity to negative feedback); and (b) perception of negative consequences is the core feature of GAD and SAD, but not Pad. Further research is needed to examine the similarities and differences between anxiety spectrum disorders in other cognitive domains and potential implementation of behavioural therapy to remediate cognitive deficits