Numerical investigations of the three-dimensional proton-proton screened Coulomb t-matrix

We demonstrate behaviour of the momentum space screened Coulomb t-matrix, obtained by a numerical solution of the three-dimensional Lippmann-Schwinger equation. Examples are given for different types of screening. They prove that it is possible to obtain numerically a reliable three-dimensional screened Coulomb t-matrix, what is important in view of its application in few-body calculations.Comment: 23 pages, 2 tables, 13 figures in 65 eps file

Calculations of three-nucleon reactions with N3LO chiral forces: achievements and challenges

We discuss the application of the chiral N3LO forces to three-nucleon reactions and point to the challenges which will have to be addressed. Present approaches to solve three-nucleon Faddeev equations are based on a partial-wave decomposition. A rapid increase of the number of terms contributing to the chiral three-nucleon force when increasing the order of the chiral expansion from N2LO to N3LO forced us to develop a fast and effective method of automatized partial wave decomposition. At low energies of the incoming nucleon below about 20MeV, where only a limited number of partial waves is required, this method allowed us to perform calculations of reactions in the three-nucleon continuum using N3LO two- and three-nucleon forces. It turns out that inclusion of consistent chiral interactions, with relativistic 1/m corrections and short-range 2pi-contact term omitted in the N3LO three-nucleon force, does not explain the long standing low energy Ay-puzzle. We discuss problems arising when chiral forces are applied at higher energies, where large three-nucleon force effects are expected. It seems plausible that at higher energies, due to a rapid increase of a number of partial waves required to reach convergent results, a three-dimensional formulation of the Faddeev equations which avoids partial-wave decomposition is desirable.Comment: 31 pages, 13 figure

The Evolution of the Chief Technology Officer and the Modernization of Technology in Education

The role of technology in education has changed dramatically over the past 20 years. From the advent of individual workstations to networked labs to one-to-one technologies, computers have transformed how teachers and students consume information. School districts today support hundreds if not thousands of devices and end users. Technology supports mission critical systems like financial, human resources, library, and student information systems and ensures they are integrating rostering information to numerous third-party programs like Clever, Classlink or textbook specific websites. They also support the district operations as well by assisting in or managing building automation controls which can include lighting, heating and cooling along with physical security which includes security cameras and access control systems. With this rapid change of technology’s usage, the rise in the individuals who support these systems and maintaining them have rapidly grown as well. Gone is the position that began as a part-time teacher who knew a little bit about computers. Now this person is a visionary leader for the school district. A pillar to any administrative team today is the Chief Technology Officer (CTO) who is tasked with being a leader, a bridge between technology, operations and instruction, is collaborative and has a wide, diverse skill set. Today’s CTO is paving the way forward integrating new technologies in the classroom, onsite and virtually, while ensuring that it is done in the safest and most secure ways. CTOs are looked upon as experts in their field who constantly research new opportunities, stay on top of trends and whose department has a hand in working with every employee in a school district. With the rapid rise of cloud computing and more student data residing in the cloud, CTOs have been susceptible to third-party vendors data breaches or malware attacks. This is in addition to similar attacks that can happen internally with DDoS, ransomware or malware attacks on a school’s internal systems. CTOs must have a balance on understanding the needs of the present, looking at new future trends, and improving from the past

Liposome Synthesis and Evaluation in the HEK-293 Cell Line

Liposomes were synthesized using the thin film method. A lyophilized power of egg-derived phosphatidylcholine, stearylamine, and cholesterol were added to ethanol and dried under argon to form a lipid cake. The lipid cake was rehydrated with dPBS and sonicated at 60°C forming a heterogenous batch of liposomes. Our results revealed the average size of the liposomes, determined by Dynamic Light Scattering, was approximately 223.1nm, while demonstrating a weakly positive zeta-potential of 1.9± 8.07mv. Next, we tested the antitumor action of the liposomes in the HEK-293 cell line via an MTT assay. We observed that the liposomes were able to inhibit cell proliferation in the HEK-293 cell line in comparison to controls. Future studies will focus on encapsulating hydrophobic and hydrophilic molecules within the liposome formulation to improve delivery to cancer cells

Swimming pool water treatment with conventional and alternative water treatment technologies

To mitigate microbial activity in swimming pools and to assure hygienic safety for bathers, pool systems have a re-circulating water system ensuring continuous water treatment and disinfection by chlorination. A major drawback associated with the use of chlorine as disinfectant is its potential to react with organic matter (OM) present in pool water to form potentially harmful disinfection by-products (DBP). In this thesis, the treatment performance of different combinations of conventional and novel treatment processes was compared using a pilot scale swimming pool model that was operated under reproducible and fully controlled conditions. The quality of the pool water was determined in means of volatile DBPs and the concentration and composition of dissolved organic carbon (DOC). Further, overall apparent reaction rates for the removal of monochloramine (MCA), a DBP found in pool water, in granular activated carbon (GAC) beds were determined using a fixed-bed reactor system operated under conditions typical for swimming pool water treatment. The reaction rates as well as the type of reaction products formed were correlated with physico-chemical properties of the tested GACs

Efficient calculation of chiral three-nucleon forces up to N3LO for ab initio studies

We present a novel framework to decompose three-nucleon forces in a momentum space partial-wave basis. The new approach is computationally much more efficient than previous methods and opens the way to ab initio studies of few-nucleon scattering processes, nuclei and nuclear matter based on higher-order chiral 3N forces. We use the new framework to calculate matrix elements of chiral three-nucleon forces at N2LO and N3LO in large basis spaces and carry out benchmark calculations for neutron matter and symmetric nuclear matter. We also study the size of the individual three-nucleon force contributions for $^3$H. For nonlocal regulators, we find that the sub-leading terms, which have been neglected in most calculations so far, provide important contributions. All matrix elements are calculated and stored in a user-friendly way, such that values of low-energy constants as well as the form of regulator functions can be chosen freely.Comment: 10 pages, 4 figure

Theoretical uncertainties of the elastic nucleon-deuteron scattering observables

Theoretical uncertainties of various types are discussed for the nucleon-deuteron elastic scattering observables at the incoming nucleon laboratory energies up to 200 MeV. We are especially interested in the statistical errors arising from uncertainties of parameters of a nucleon-nucleon interaction. The obtained uncertainties of the differential cross section and numerous scattering observables are in general small, grow with the reaction energy and amount up to a few percent at 200 MeV. We compare these uncertainties with the other types of theoretical errors like truncation errors, numerical uncertainties and uncertainties arising from using the various models of nuclear interaction. We find the latter ones to be dominant source of uncertainties of modern predictions for the three-nucleon scattering observables. To perform above mentioned studies we use the One-Pion-Exchange Gaussian potential derived by the Granada group, for which the covariance matrix of its parameters is known, and solve the Faddeev equation for the nucleon-deuteron elastic scattering. Thus beside studying theoretical uncertainties we also show a description of the nucleon-deuteron elastic scattering data by the One-Pion-Exchange Gaussian model and compare it with results obtained with other nucleon-nucleon potentials, including chiral N$^4$LO forces from the Bochum-Bonn and Moscow(Idaho)-Salamanca groups. In this way we confirm the usefulness and high quality of the One-Pion-Exchange Gaussian force.Comment: 23 pages, 15 figures in 64 eps file

Proteomic analysis of F1 hybrids and intermediate variants in a littorina saxatilis hybrid zone

Proteomic analysis was carried out on the Crab (upper-shore) and Wave (lower-shore) ecotypes ofLittorina saxatilis from a hybrid zone at Silleiro Cape, Spain. Proteome profiles of individual snailswere obtained. Protein expression in F1 hybrid snails bred in the laboratory and snails with intermediate shell phenotypes collected from the mid-shore were compared with Crab and Wave ecotypes using analytical approaches used to study dominance. Multivariate analysis over many proteinspots showed that the F1 snails are distinct from both ecotypes but closer to the Wave ecotype. Theintermediate snails are highly variable, some closer to the Crab and others to the Wave ecotype.Considered on a protein by protein basis, some proteins are significantly closer in expression to theCrab and others to the Wave ecotype for both F1 and intermediate snails. Furthermore, a significantmajority of proteins were closer in expression to the Wave ecotype for the F1, consistent with themultivariate analysis. No such significant majority toward either the Crab or Wave ecotype wasobserved for the intermediate snails. The closer similarity of F1 and Wave ecotype expression patterns could be the result of similar selective pressures in the similar mid-shore and low-shore environments. For a significantly larger number of proteins, intermediate snails were closer in expressionto the ecotype having the lower expression, for both Crab and Wave ecotypes. This is somewhat unexpected as lower expression might be expected to be an indication of impairment of function andlower fitness. Proteomic analysis could be important for the identification of candidate proteins useful for gaining improved understanding of adaptation and barriers to gene flow in hybrid zones