Process Modeling of Forward Osmosis and Pressure Retarded Osmosis Integration with Seawater Reverse Osmosis

Osmotically driven membrane processes, like forward osmosis and pressure retarded osmosis, may hold key advantages when integrated with reverse osmosis for seawater desalination. The spiral-wound membrane platform in which these processes are applied has inherent disadvantages that need to be explored. Maintaining proper operating pressure in both of the fluid channels of a spiral-wound membrane requires the feed and draw streams to be operated at different flow rates, often as drastic as a 1:10 ratio. This affects the thermodynamic equilibrium of the system and drastically affects potential water and energy recovery. In this work, a model was created to rigorously represent spiral-wound membranes to increase modeling accuracy. A process configuration that features periodic recharging of the stream inside of the envelope is proposed to mitigate the effects of the flow rate difference. The model is used to compare the multi-stage design to single-stage configurations for both forward osmosis and pressure retarded osmosis by testing various feed and draw flow rate ratios, between 1:10 to 1:1, operated by each process as well as important membrane characteristics such as channel height and water and salt permeability. The multi-stage design shows an increase in wastewater utilization from 62.6% to 90% when compared to the single-stage designs for forward osmosis. Additionally, the multi-stage configuration increases the pressure retarded osmosis specific energy recovery from 0.13 kWh/m3 to 0.55 kWh/m3. However, the increased effectiveness of these multi-staged designs comes with a reduction in average water flux and power density, which leads to the requirement of more membrane area and capital investment for potential system implementation

The Form Factors of the Gauge-Invariant Three-Gluon Vertex

The gauge-invariant three-gluon vertex obtained from the pinch technique is characterized by thirteen nonzero form factors, which are given in complete generality for unbroken gauge theory at one loop. The results are given in $d$ dimensions using both dimensional regularization and dimensional reduction, including the effects of massless gluons and arbitrary representations of massive gauge bosons, fermions, and scalars. We find interesting relations between the functional forms of the contributions from gauge bosons, fermions, and scalars. These relations hold only for the gauge-invariant pinch technique vertex and are d-dimensional incarnations of supersymmetric nonrenormalization theorems which include finite terms. The form factors are shown to simplify for $N=1,2$, and 4 supersymmetry in various dimensions. In four-dimensional non-supersymmetric theories, eight of the form factors have the same functional form for massless gluons, quarks, and scalars, when written in a physically motivated tensor basis. For QCD, these include the tree-level tensor structure which has prefactor $\beta_0=(11N_c-2N_f)/3$, another tensor with prefactor $4N_c-N_f$, and six tensors with $N_c-N_f$. In perturbative calculations our results lead naturally to an effective coupling for the three-gluon vertex which depends on three momenta and gives rise to an effective scale which governs the behavior of the vertex. The effects of nonzero internal masses are important and have a complicated threshold and pseudo-threshold structure. The results of this paper are an important part of a gauge-invariant dressed skeleton expansion and a related multi-scale analytic renormalization scheme. In this approach the scale ambiguity problem is resolved since physical kinematic invariants determine the arguments of the couplings.Comment: 53 pages, 10 figures. v2: added reference

The Higgs Boson Mass in Split Supersymmetry at Two-Loops

The mass of the Higgs boson in the Split Supersymmetric Standard Model is calculated, including all one-loop threshold effects and the renormalization group evolution of the Higgs quartic coupling through two-loops. The two-loop corrections are very small (<<1 GeV), while the one-loop threshold corrections generally push the Higgs mass down several GeV.Comment: 17 pages. 4 figures. Improved discussion and notation. Corrected typos. Added references. Added plots. Main results unchange

Probiotics and Gut Microbiota: The Underlying Helpers of Health

As per the amount of time that bacteria spend living and growing in the intestine, we can divide them into two categories: long-term (also called permanent residents) and transitory (also called alien). According to the findings of previous research, a dysbiosis of the microbiota in the gut may be linked to a wide variety of human illnesses. Microorganisms that are considered to be living, such as bacteria, are known as probiotics. When given to a host in adequate quantities, probiotics can be beneficial. There is compelling evidence that probiotics have a positive impact on health, but this area of research has to be expanded

Examination for bias: a content analysis of the Lattimore-McCarthy "Communists in the State Department" case in the Boston dailies.

Thesis (M.S.)--Boston Universit