Topics in vacuum decay

If a theory has more than one classically stable vacuum, quantum tunneling and thermal jumps make the transition between the vacua possible. The transition happens through a first order phase transition started by nucleation of a bubble of the new vacuum. The outward pressure of the truer vacuum makes the bubble expand and consequently eat away more of the old phase. In the presence of gravity this phenomenon gets more complicated and meanwhile more interesting. It can potentially have important cosmological consequences. Some aspects of this decay are studied in this thesis. Solutions with different symmetry than the generically used O(4) symmetry are studied and their actions calculated. Vacuum decay in a spatial vector field is studied and novel features like kinky domain walls are presented. The question of stability of vacua in a landscape of potentials is studied and the possible instability in large dimension of fields is shown. Finally a compactification of the Einstein-Maxwell theory is studied which can be a good lab to understand the decay rates in compactification models of arbitrary dimensions

A Third Location and the Territory of Pedestrians in Thirty-Three Bridge Urban Plaza Design with an Emphasis on the Importance of Pedestrians

A third location is a context that civil life is currently in it, events, incidents take place, events and incidents that led to the formation of memories, and space lasts in people's minds. Third place can be called "pedestrians' territory" for this reason. These places must be created in today's cities and must be flourished. The urban should invite people to these places to strengthen the sense of belonging to place in their own citizens. Increased presence of pedestrians depends on user diversity, participation, recognition and interaction with others in the attractive and varied environment. However, without security, traffic safety, accessibility, comfort and creating facilities for pedestrians, streets and third locations turn into a place for necessary, quickly and without feeling passage and pedestrian are willing to stay and gather in those places. The study was based on analytical methods and procedure of documentation, library and field are used. By using analytical Hierarchy Process techniques, and Super Decisions software, problems are identified, actions and strategies are prioritized and according to the most important criteria, a square on Isfahan framework, Chahar Bagh Street intersection and thirty-three bridge was designed, that the square is the most important square of tourism-leisure in Isfahan city and it is a third place for pedestrians' interaction with each other. The most important result of this research is the role of pedestrians in the formation of vibrant and dynamic urban spaces; including the current presence of pedestrians in this space is the most important need for establishment of thirty-three bridge municipal square

Geomechanical model for surface excavation in tropically weathered granite

Mass heterogeneity, abrupt changes in weathering state and presence of boulders in tropically weathered granite lead to uncertainties in predicting the surface excavation performance. This study proposed a new geomechanical model for prediction of surface excavation rate by considering the complex characteristics and effective parameters of weathered granite. Beside the new model, a typical mass weathering profile of granite was proposed with details of rock mass characteristics including typical appearance, discontinuities characteristics, shape and size of boulder, homogeneity and rock to soil ratio in each mass weathering grade. Based on extensive study of fourty panels from four granite quarries, the effect of weathering on the mentioned parameters were established. Practical excavation was performed in excavable zones in the quarries. Statistical analysis using multiply linear regression was performed on the relation of the parameters and practical excavation rate to investigate effective parameters of rock mass and rock material in surface excavation. Then after, the correlation of each parameter with practical excavation rate was obtain utilizing Pearson Correlation Coefficient (PCC). Based on PCC and the results of laboratory tests and site investigation, a rating system in a chart know as Excavation Index in Granite (EIG) was proposed. EIG value was calculated for each weathering zone in each panel of the quarries. The correlation between the results of practical excavation and the values of EIG was obtain and then used to propose a chart of excavability classification in granite. The chart consists of excavation classes, the range of excavation rates and the excavability conditions. Finally, the applicability of the proposed model was verified by comparing the predicted ranges of surface excavation rate using the model and the results of practical excavation rate at another site. The proposed model contributes to the field of surface excavation in tropically weathered granite

Bispiraloconulus serbicus Schlagintweit, Bucur & Sudar, 2019 (arborescentni Bentoski foraminifer) i Torremiroella hispanica Brun & Canérot,1979 iz gornjobaremskog sedimentnog basena Kopet-Dag (SI Iran) i njihove paleobiogeografske revizije

During micropaleontological investigations on the Lower Cretaceous successions of the Tirgan Formation in Kopet-Dagh sedimentary basin, some new achievements are yielded. In this regards, the first occurrence of Bispiraloconulus serbicus Schlagintweit, Bucur & Sudar in close association with Torremiroella hispanica Brun & Canérot is reported for the first time from the Upper Barremian of Kopet-Dagh sedimentary basin (NE Iran). The biostratigraphic investigations were carried out on a 197.5 m thick Gelian stratigraphic succession cropping out along the Tirgan Formation located 35 km southwest of Shirvan town. This study reviews the palaeogeographical distribution and age of Bispiraloconulus serbicus Schlagintweit, Bucur& Sudar and Torremiroella hispanica Brun & Canérot along the northern Tethyan margins and extends its palaeobiogeographical existence.Mikropaleontološka istraživanja donjokredne sukcesije formacije Tirgan u Kopet-Dag sedimentacionom basenu (SI Iran) su pružila nove podatke. S tim u vezi, prvi put je u sedimentima Gornjeg Barema dokumentovan Bispiraloconulus serbicus Schlagintweit, Bucur& Sudar u asocijaciji sa Torremiroella hispanica Brun & Canérot. Biostratigrafska istraživanja su obavljena na stratigrafskom profilu Gelian (Formacija Tirgan) ukupne debljine 197,5 m koji je otkriven 35 km jugozapadno od grada Shirvan. U radu je data revizija paleogeografskog rasprostranjenja i starosti foraminifera Bispiraloconulus serbicus Schlagintweit, Bucur & Sudar i Torremiroella hispanica Brun & Canérot duž severnogo boda Tetisa

Calpionellid biostratigraphy and microfacies of the Upper Tithonian pelagic carbonates in northeastern Serbia (Carpatho-Balkanides)

The occurrence of microfossil assemblage represented by calpionellids in close association with benthic foraminifera and encrusting Crescentiella morronensis is reported for the first time from the Upper Tithonian of NE Serbia. The biostratigraphic and sedimentological investigations were carried out on a 250 m thick carbonate succession in Jelenska Stena quarry cropping out along the Danube River Gorge in the border area of Serbian Carpatho-Balkanides and Romanian Southern Carphatians. On the basis of determined benthic foraminiferal taxa Textularia sp. cf. T bettenstaedti and Everticyclammina praekelleri in the lower part of the succession and calpionellid association dominated by the representatives of calpionellid genera Tintinnopsella, Crassicollaria and Calpionella the carbonate succession is assigned to the Upper Tithonian. The scarcity of calpionellid zonal species prevents the nominal zones being recognized. Petrographic analysis of thin-sections led to the recognition of three basin microfacies types: bioclastic wackestone, bioclastic peloidal wackestone/packstone and mudstone. These microfacies characterize the SMF 3 and SMF 4 which indicate deposition in slope and toe-of-slope environments. This study extends the palaeogeographical distribution of Upper Tithonian calpionellids along the northern Tethyan margins. The investigated carbonate succession is compared with coeval strata from other northern Tethyan regions

Developing a serocorrelate of protection against invasive group B streptococcus disease in pregnant women: a feasibility study.

BACKGROUND: Group B streptococcus is the leading cause of infection in infants. Currently, intrapartum antibiotic prophylaxis is the major strategy to prevent invasive group B streptococcus disease. However, intrapartum antibiotic prophylaxis does not prevent maternal sepsis, premature births, stillbirths or late-onset disease. Maternal vaccination may offer an alternative strategy. Multivalent polysaccharide protein conjugate vaccine development is under way and a serocorrelate of protection is needed to expedite vaccine licensure. OBJECTIVES: The ultimate aim of this work is to determine the correlate of protection against the major group B streptococcus disease-causing serotypes in infants in the UK. The aim of this feasibility study is to test key operational aspects of the study design. DESIGN: Prospective cohort study of pregnant women and their infants in a 6-month period (1 July to 31 December 2018). SETTING: Five secondary and tertiary hospitals from London and South England. National iGBS disease surveillance was conducted in all trusts in England and Wales. PARTICIPANTS: Pregnant women aged ≥ 18 years who were delivering at one of the selected hospitals and who provided consent during the study period. There were no exclusion criteria. INTERVENTIONS: No interventions were performed. MAIN OUTCOME MEASURES: (1) To test the feasibility of collecting serum at delivery from a large cohort of pregnant women. (2) To test the key operational aspects for a proposed large serocorrelates study. (3) To test the feasibility of collecting samples from those with invasive group B streptococcus. RESULTS: A total of 1823 women were recruited during the study period. Overall, 85% of serum samples were collected at three sites collecting only cord blood. At the two sites collecting maternal, cord and infant blood samples, the collection rate was 60%. A total of 614 women were screened for group B streptococcus with a colonisation rate of 22% (serotype distribution: 30% III, 25% Ia, 16% II, 14% Ib, 14% V and 1% IV). A blood sample was collected from 34 infants who were born to colonised women. Maternal and infant blood and the bacterial isolates for 15 newborns who developed invasive group B streptococcal disease during the study period were collected (serotype distribution: 29% III, 29% II, 21% Ia, 7% Ib, 7% IV and 7% V). LIMITATIONS: Recruitment and sample collection were dependent on the presence of research midwives rather than the whole clinical team. In addition, individualised consent limited the number of women who could be approached each day, and site set-up for the national surveillance study and the limited time period of this feasibility study limited recruitment of all eligible participants. CONCLUSIONS: We have verified the feasibility of collecting and processing rectovaginal swabs and blood samples in pregnant women, as well as samples from those with invasive group B streptococcal disease. We have made recommendations for the recruitment of cases within the proposed GBS3 study and for controls both within GBS3 and as an extension of this feasibility study. FUTURE WORK: A large case-control study comparing specific immunoglobulin G levels in mothers whose infants develop invasive group B streptococcal disease with those in colonised mothers whose infants do not develop invasive group B streptococcal disease is recommended. TRIAL REGISTRATION: Current Controlled Trials ISRCTN49326091; IRAS project identification number 246149/REC reference number 18/WM/0147. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 67. See the NIHR Journals Library website for further project information

The First Record of Microcodium from Maastrichtian Kalat Formation, Kopet-Dagh Sedimentary Basin, NE Iran: Biostratigraphy and Microfacies

This paper is to present the biostratigraphy of the Maastrichtian Kalat Formation in Karnaveh area of the northeastern Iranian Kopet-Dagh sedimentary basin. Micropaleontological studies have led to the determination of micro-calcite structures, having Microcodium deposited in the stratigraphic section due to transgression and regression of the sea. On the basis of determined benthic foraminiferal taxa Laffitteina mengaudi (Astre), Lepidorbitoides socialis (Leymerie), Omphalocyclus macroporus (Lamarck), Orbitoides apiculata Schlumberger, Orbitoides media (d’Archiac), Rotalia skourensis Pfender, Siderolites calcitrapoides Lamarck, Sirtina orbitoidiformis Brönnimann & Wirz, Sulcoperculina cosdeni Applin & Jordan, Sulcoperculina globosa Cizancourt and Sulcoperculina vermunti (Thiadens), Kalat Formation in the studied stratigraphic section is assigned to the Maastrichtian. The current study represents the first record of Microcodium occurrence in Kopet-Dagh sedimentary basin in northeast Iran, expanding the current knowledge on its palaeogeographical distribution in Tethyan Realm

Pregled i mogućnosti zaštite nekih transgraničnih (istočna Srbija-zapadna Bugarska) stratigrafsko-paleontoloških geoobjekata

Stratigraphic/palaeontological geosites of Stara Planina Mountain in east Serbia are well developed in the area of Serbian/Bulgarian state border, where with this occassion, three sections of exeptional geological and scientific interest are selected: Jelovica, Rosomač and Senokos. These geosites represent the important localities for study of Triassic and Jurassic terrigene-carbonate deposits, for which the scientific value from the domains of palaeontology, stratigraphy and sedimentology is widely known. The aim of this work is to represent the main scientific arguments for inventory and protection of detached transborder geological sites that are unique according to their composition and content.Stratigrafsko-paleontološki geoobjekti Stare planine istočne Srbije su dobro razvijeni na području srpsko-bugarske državne granice gde su ovom prilikom izdvojena tri profila od izuzetnog geološkog i naučnog značaja: Jelovica, Rosomač i Senokos. Ovi geološki objekti predstavljaju značajne lokalitete za proučavanje trijaskih i jurskih terigeno-karbonatnih sedimenata čiji je naučni značaj iz domena paleontologije, stratigrafije i sedimentologije široko poznat. Cilj ovog rada je reprezentovanje glavnih naučnih argumenata za inventarisanje i zaštitu izdvojenih transgraničnih geoloških objekata koji su jedinstveni po svom sastavu i sadržaju

Pregled i mogućnosti zaštite nekih transgraničnih (istočna Srbija-zapadna Bugarska) stratigrafsko-paleontoloških geoobjekata

Stratigraphic/palaeontological geosites of Stara Planina Mountain in east Serbia are well developed in the area of Serbian/Bulgarian state border, where with this occassion, three sections of exeptional geological and scientific interest are selected: Jelovica, Rosomač and Senokos. These geosites represent the important localities for study of Triassic and Jurassic terrigene-carbonate deposits, for which the scientific value from the domains of palaeontology, stratigraphy and sedimentology is widely known. The aim of this work is to represent the main scientific arguments for inventory and protection of detached transborder geological sites that are unique according to their composition and content.Stratigrafsko-paleontološki geoobjekti Stare planine istočne Srbije su dobro razvijeni na području srpsko-bugarske državne granice gde su ovom prilikom izdvojena tri profila od izuzetnog geološkog i naučnog značaja: Jelovica, Rosomač i Senokos. Ovi geološki objekti predstavljaju značajne lokalitete za proučavanje trijaskih i jurskih terigeno-karbonatnih sedimenata čiji je naučni značaj iz domena paleontologije, stratigrafije i sedimentologije široko poznat. Cilj ovog rada je reprezentovanje glavnih naučnih argumenata za inventarisanje i zaštitu izdvojenih transgraničnih geoloških objekata koji su jedinstveni po svom sastavu i sadržaju

The First Record of Microcodium from Maastrichtian Kalat Formation, Kopet-Dagh Sedimentary Basin, NE Iran: Biostratigraphy and Microfacies

This paper is to present the biostratigraphy of the Maastrichtian Kalat Formation in Karnaveh area of the northeastern Iranian Kopet-Dagh sedimentary basin. Micropaleontological studies have led to the determination of micro-calcite structures, having Microcodium deposited in the stratigraphic section due to transgression and regression of the sea. On the basis of determined benthic foraminiferal taxa Laffitteina mengaudi (Astre), Lepidorbitoides socialis (Leymerie), Omphalocyclus macroporus (Lamarck), Orbitoides apiculata Schlumberger, Orbitoides media (d’Archiac), Rotalia skourensis Pfender, Siderolites calcitrapoides Lamarck, Sirtina orbitoidiformis Brönnimann & Wirz, Sulcoperculina cosdeni Applin & Jordan, Sulcoperculina globosa Cizancourt and Sulcoperculina vermunti (Thiadens), Kalat Formation in the studied stratigraphic section is assigned to the Maastrichtian. The current study represents the first record of Microcodium occurrence in Kopet-Dagh sedimentary basin in northeast Iran, expanding the current knowledge on its palaeogeographical distribution in Tethyan Realm