On T-duality of R 2-corrections to DBI action at all orders of gauge field

Recently, it has been observed that in a T-duality invariant world-volume theory in flat spacetime, all orders of gauge field strength and all orders of the D-brane velocity appear in two specific matrices. Using these two matrices, we construct the world-volume couplings of two massless NSNS states at order $\alpha'^2$ and all orders of the velocity and the gauge field strength, by requiring them to be invariant under the linear T-duality. The standard extension $F\rightarrow F+P[B]$, then produces all orders of the pull-back of B-field into the action. We compare the resulting couplings for zero velocity and gauge field strength, with the $\alpha'^2$ terms of the disk-level S-matrix element of two massless NSNS vertex operators in the presence of a constant background B-field. We have found an exact agreement.Comment: 13 page

Prediction of braid pattern on mandrels with constant non-circular cross-sections

In this study, a new useful mathematical model has been developed to predict the braid pattern for every point onto themandrel surface with non-circular cross-sections. The Reza-Jalil-Mohammad (RJM) equation thus obtained has beenproposed for the braid angle. The implementation and validation of this mathematical model has been discussed for acylindrical mandrel. It is observed that using RJM equation, one can get the arrangement of strands in circular braidingmachine for each mandrel with different cross-sections

Prevalence of and Some Factors Relating with Unwanted Pregnancy, in Ahwaz City, Iran, 2010

We aimed to find the prevalence and some factors relating with unwanted pregnancy. Methods. It was a cross-sectional study on 400 randomly pregnant women, who were referring to different health centers in Ahwaz city during 2010. Data was conducted based on questionnaire, and all the analysis was performed using SPSS (version 17) statistical analysis software. Results. The prevalence of unwanted pregnancy was 26%. The percentage of unwanted pregnancy in ages more than 35 years was approximately three times more than the intended pregnancy. There were significant relationship between unwanted pregnancy and some variables such as age, number of pregnancy, number of childbirth, education status, economic status, husband's occupation, and the relationship with the spouse and contraceptive methods (P < 0.0001). Conclusion. The prevalence of unwanted pregnancy was high. To prevent unwanted pregnancy using consultation services before planning to be pregnancy, it is necessary to identify the factors relating with unwanted pregnancy

Towards purification of antibodies with light

One of the most common method to purify a particular antibody is done by affinity chromatography. Antibody binding proteins such as Protein A are used to purify antibody from the mixture of proteins and antibodies. The main objective of my project is to design a new method that utilizes light-responsive (LR) affinity-capture ligands for antibody purification. This would vastly improve the quality of purification of the antibodies. Using the LR affinity-capture ligands to purify the antibody can be widely applied to many fields related to biotechnology, life science industry, and pharmaceutical industry. To achieve this, we designed the LR cyclic peptide as affinity ligand that recognizes the constant region (Fc) of the antibody we want to purify. We began with octapeptide sequences that was known to have an affinity to the Fc region of IGg antibody. The octapeptide was attempted to react with the LR azobenzene linker 3,3’-bis(sulfonato)- 4,4’-bis(chloroacetamido)-azobenzene (BSBCA) to create a macrocyclic product, LR-macrocycle peptide. We hypothesized that the LR-macrocycle peptide will have two&nbsp; geometric isomers: one isomer with higher affinity and one isomer with lower affinity towards the Fc region. The peptides were immobilized on paper for observing the affinity difference of&nbsp; two isomers towards the Fc region of the antibody. The data obtained from preliminary study suggested that the LR-macrocycle peptides had different affinities between the two isomers. To further understanding the system, we will be validating the affinity differences of those ligands and will be optimizing the peptide sequences to increase the efficiency of the technique. *Indicates faculty mentor

Evaluation of photoionization detector performance for measuring the airborne toluene

Background and aims: In the field of chemical agents at workplaces, traditional measurement method for assessing the volatile organic compounds (VOCs) concentration is using a gas chromatograph generally equipped with a flame ionization detector (GC-FID). However, there are some limitations in working with this equipment including equipment accessibility, necessity of highly trained operators, and the high cost of sample analysis. The aim of this study was to evaluate the performance of photoionization detector (PID) as a substitution for GC-FID in the measurement of toluene as a representative of the VOCs in experimental studies. Methods: This study was carried out by an experimental set up for generating toluene known concentrations at 5, 20, 50, 100, 200, 500 and 1000 ppm with relative humidity 13 ±2. The concentration values were measured with PID as well as the National Institute of Occupational Safety and Health (NIOSH) 1501 reference method and results were compared. Results: The results showed a significant difference between the two methods at concentrations higher than 50 ppm while there was no significant difference at 5 ppm and 20 ppm. The correlation coefficient of the toluene concentrations at 5 to 1000 ppm was 0.999. The correction factor for the PID was 1.05 at the studied concentration range. Conclusion: Although the results presented by PID were different from those extracted from the NIOSH reference method, the response was linear. Thus, in studies of measuring airborne concentrations of toluene using this type of detector; the reading values must be corrected by the calculated correction factor

Study On The Acoustic Characteristics Of Natural Date Palm Fibres: Experimental And Theoretical Approaches

The present study deals with the acoustic performance of natural fibres originated from the date palm empty fruit (DPEFB) fibres which is mainly considered as agricultural waste. The fibres were processed and fabricated to be sound absorber samples with two different densities of 100 kg/m3 and 200 kg/m3 and with thicknesses of 10–40 mm. The normal incidence absorption coefficients of the sound absorbers were measured using an impedance tube based on ISO 10534-2. The effects of fibre density and sample thickness are discussed. The findings reveal that for density of 100 kg/m3 the absorption coefficient is 0.6–0.8 above 1.5 kHz for the samples with the thickness of 20 mm and 30 mm. For the thickness of 40 mm, the values even reached the value of 0.9. The values can reach 0.7–0.8 above 1 kHz for the density of 200 kg/m3. Mathematical model using the optimized Delaney-Bazley model with Nelder-Mead simplex method is shown to successfully predict the sound absorption coefficient of the fibre samples. The Johnson-Champoux-Allard model follows the trend of the absorption coefficient, but underestimates the measured data at high frequencies above 2.5 kHz

Impact of hybrid heat transfer enhancement techniques in shell and tube heat exchanger design

Despite the advantages of shell and tube heat exchangers, one of their major problems is low thermal efficiency. This problem can be improved by using heat transfer enhancement techniques such as adding nanoparticles to the hot or cold fluids, and/or using tube inserts as turbulators on tube side as well as changing baffles to a helical or twisted profile on the shell side. Although all of these techniques increase the thermal efficiency; however, engineers still need a quantitative approach to assess the impact of these technologies on the shell and tube heat exchangers. This study attempts to provide a combination of such techniques to increase the impact of these improvements quantitatively. For this purpose, at first stage the thermal and hydraulic characteristics of pure fluid, Al₂O₃/water nanofluid in a plain tube equipped with and without twisted tape turbulator is evaluated based on a developed rapid design algorithm. Therefore, the impact of using enhanced techniques either in form of individual or in hybrid format and the increase of nanoparticle concentration in base fluid have been studied. The results show that using turbulators individually and in hybrid format with nanofluid can be effected on design parameters of a typical heat exchanger by reducing the required heat transfer area up to 10 %

Global, regional, and national burden of chronic kidney disease, 1990–2017 : a systematic analysis for the Global Burden of Disease Study 2017

Background Health system planning requires careful assessment of chronic kidney disease (CKD) epidemiology, but data for morbidity and mortality of this disease are scarce or non-existent in many countries. We estimated the global, regional, and national burden of CKD, as well as the burden of cardiovascular disease and gout attributable to impaired kidney function, for the Global Burden of Diseases, Injuries, and Risk Factors Study 2017. We use the term CKD to refer to the morbidity and mortality that can be directly attributed to all stages of CKD, and we use the term impaired kidney function to refer to the additional risk of CKD from cardiovascular disease and gout. Methods The main data sources we used were published literature, vital registration systems, end-stage kidney disease registries, and household surveys. Estimates of CKD burden were produced using a Cause of Death Ensemble model and a Bayesian meta-regression analytical tool, and included incidence, prevalence, years lived with disability, mortality, years of life lost, and disability-adjusted life-years (DALYs). A comparative risk assessment approach was used to estimate the proportion of cardiovascular diseases and gout burden attributable to impaired kidney function. Findings Globally, in 2017, 1·2 million (95% uncertainty interval [UI] 1·2 to 1·3) people died from CKD. The global all-age mortality rate from CKD increased 41·5% (95% UI 35·2 to 46·5) between 1990 and 2017, although there was no significant change in the age-standardised mortality rate (2·8%, −1·5 to 6·3). In 2017, 697·5 million (95% UI 649·2 to 752·0) cases of all-stage CKD were recorded, for a global prevalence of 9·1% (8·5 to 9·8). The global all-age prevalence of CKD increased 29·3% (95% UI 26·4 to 32·6) since 1990, whereas the age-standardised prevalence remained stable (1·2%, −1·1 to 3·5). CKD resulted in 35·8 million (95% UI 33·7 to 38·0) DALYs in 2017, with diabetic nephropathy accounting for almost a third of DALYs. Most of the burden of CKD was concentrated in the three lowest quintiles of Socio-demographic Index (SDI). In several regions, particularly Oceania, sub-Saharan Africa, and Latin America, the burden of CKD was much higher than expected for the level of development, whereas the disease burden in western, eastern, and central sub-Saharan Africa, east Asia, south Asia, central and eastern Europe, Australasia, and western Europe was lower than expected. 1·4 million (95% UI 1·2 to 1·6) cardiovascular disease-related deaths and 25·3 million (22·2 to 28·9) cardiovascular disease DALYs were attributable to impaired kidney function. Interpretation Kidney disease has a major effect on global health, both as a direct cause of global morbidity and mortality and as an important risk factor for cardiovascular disease. CKD is largely preventable and treatable and deserves greater attention in global health policy decision making, particularly in locations with low and middle SDI