Hamiltonian approach to QCD in Coulomb gauge - a survey of recent results

I report on recent results obtained within the Hamiltonian approach to QCD in Coulomb gauge. Furthermore this approach is compared to recent lattice data, which were obtained by an alternative gauge fixing method and which show an improved agreement with the continuum results. By relating the Gribov confinement scenario to the center vortex picture of confinement it is shown that the Coulomb string tension is tied to the spatial string tension. For the quark sector a vacuum wave functional is used which explicitly contains the coupling of the quarks to the transverse gluons and which results in variational equations which are free of ultraviolet divergences. The variational approach is extended to finite temperatures by compactifying a spatial dimension. The effective potential of the Polyakov loop is evaluated from the zero-temperature variational solution. For pure Yang--Mills theory, the deconfinement phase transition is found to be second order for SU(2) and first order for SU(3), in agreement with the lattice results. The corresponding critical temperatures are found to be $275 \, \mathrm{MeV}$ and $280 \, \mathrm{MeV}$, respectively. When quarks are included, the deconfinement transition turns into a cross-over. From the dual and chiral quark condensate one finds pseudo-critical temperatures of $198 \, \mathrm{MeV}$ and $170 \, \mathrm{MeV}$, respectively, for the deconfinement and chiral transition.Comment: Talk given by H. Reinhardt at "5th Winter Workshop on Non-Perturbative Quantum Field Theory", 22-24 March 2017, Sophia-Antipolis, France. arXiv admin note: text overlap with arXiv:1609.09370, arXiv:1510.03286, arXiv:1607.0814

Challenges of polymer‐based pH sensing in soil

OnlinePublIt is well established that plants need a range of soil nutrients to grow. In farming, these nutrients are generally added to the soil in the form of fertilizers. However, depending on the soil conditions (such as temperature, water content, pH, and soil type), nutrients may not be in the right form for plant uptake. Determining the availability of nutrients in the soil for plant growth is therefore critical for the yield and productivity of modern farming. A considerable amount of research and knowledge has been developed that shows the importance of the soil pH on the availability (or not) of nutrients. Furthermore, pH plays a crucial role in controlling the availability of potential toxic elements, such as aluminum and manganese. This review article discusses recent research aimed at real‐time and continuous soil pH measurement in‐situ. More specifically, it focuses on the development of polymer materials that will ultimately enable pH measurements for the specific application of in‐ground pH sensing. Given the breadth of the polymeric sensor research field, this review has a narrowed focus on optical and electrochemical transduction methods.Esmat Ebadati, Eliza Switalska, Enzo Lombi, Stephen C. Warren-Smith, Drew Evan

Study of Serum level of Chrome in Bladder Cancer Patients

ABSTRACT Introduction & Objective: Chrome (Cr) is one of the carcinogen trace elements that its role in cancer induction is documented in many studies. In spite o this, there are limited studies about the relationship between chrome and bladder cancer. So we decided to study the serum concentration of Cr in patients with bladder cancer in comparison with healthy individuals. Materials & method: During this case control study, 51 patients with bladder cancer and 58 normal subjects, after matching in age, sex and smoking habits with case group, were selected. Blood samples were collected from each cases. Serum level of Cr was measured in all samples by using the Flameless Atomic Absorption Spectrophotometer. Finally data were analyzed, using student t test. Results: Mean age of participants was 62.74 ± 14.63 years in control group and 58.2 ± 9.8 years in case group. Mean of serum Cr concentration was 128.82 ± 16.99 µg/L in bladder cancer patients and 121.93 ± 16.67 µg/L in control group. The difference in Cr level of serum was significant between two groups (p < 0.05). Conclusion: Results of this study indicated the high level of Cr in the serum of bladder cancer patients. Performing of some strategies in reduction of environmental contaminations, finding the contaminated sources and modifying them, can be useful, for reduction of serum level of Cr, especially in high risk groups

Collapse analysis of Al 6061 alloy conical shells with circular cutouts under axial loading: experiment and simulation

The current research is conducted to investigate the experimental and numerical study of crushing behavior and buckling modes of thin-walled truncated conical shells with or without cutouts and discontinuities under axial loading. In this regard, Instron 8802 servohydraulic machine is used to perform the experiments. Additionally, the buckling modes, derived from the axial collapse phenomenon, are simulated with Finite Element (FE) software. The force-displacement diagrams extracted numerically are compared with experimental results. Various factors, including maximum force, energy absorption, specific energy, and failure modes of each case, are also discussed. The results indicate that the increasing cutout cause a decrease in the maximum force and energy absorption. Moreover, with cutouts reduction, the failure modes of the samples changed from the diamond asymmetric mode and single-lobe mode to multi-lobes, and with removing cutouts, the failure mode is observed to be completely symmetric. © IMechE 2022

Hamiltonian approach to QCD in Coulomb gauge: Gribov’s confinement scenario at work*

I will review essential features of the Hamiltonian approach to QCD in Coulomb gauge showing that Gribov's confinement scenario is realized in this gauge. For this purpose I will discuss in detail the emergence of the horizon condition and the Coulomb string tension. I will show that both are induced by center vortex gauge field configurations, which establish the connection between Gribov’s confinement scenario and the center vortex picture of confinement. I will then extend the Hamiltonian approach to QCD in Coulomb gauge to finite temperatures, first by the usual grand canonical ensemble and second by the compactification of a spatial dimension. I will present results for the pressure, energy density and interaction measure as well as for the Polyakov loop

Hamiltonian approach to QCD in Coulomb gauge: Gribov’s confinement scenario at work

I will review essential features of the Hamiltonian approach to QCD in Coulomb gauge showing that Gribov's confinement scenario is realized in this gauge. For this purpose I will discuss in detail the emergence of the horizon condition and the Coulomb string tension. I will show that both are induced by center vortex gauge field configurations, which establish the connection between Gribov’s confinement scenario and the center vortex picture of confinement. I will then extend the Hamiltonian approach to QCD in Coulomb gauge to finite temperatures, first by the usual grand canonical ensemble and second by the compactification of a spatial dimension. I will present results for the pressure, energy density and interaction measure as well as for the Polyakov loop

Hamiltonian approach to QCD in Coulomb gauge at zero and finite temperature

I report on recent results obtained within the Hamiltonian approach to QCD in Coulomb gauge. By relating the Gribov confinement scenario to the center vortex picture of confinement it is shown that the Coulomb string tension is tied to the spatial string tension. For the quark sector a vacuum wave functional is used which results in variational equations which are free of ultraviolet divergences. The variational approach is extended to finite temperatures by compactifying a spatial dimension. For the chiral and deconfinement phase transition pseudo-critical temperatures of 170MeV and 198 MeV, respectively, are obtained