The use of seismic techniques to identify hazardous ground conditions associated with cavities

The identification of civil engineering hazards such as cavities, mine shafts, etc., is an integral part of site investigations carried out prior to the construction of roads, tunnels and other civil engineering structures. The use of geophysical methods to identify these hazards is becoming increasingly important. An investigation into the effectiveness of three seismic methods to delineate the possible anomalous ground conditions associated with the presence of cavities has been evaluated. The three methods are: surface, interborehole and a single hole method. The surface seismic method (refraction) was used successfully over a disused railway tunnel to identify the presence of a cavity, and a technique was developed to generate images of a theoretical model, which can be compared to a field survey. The interborehole seismic method was used across a disused railway tunnel to study the effect of a cavity on changes in seismic parameters, such as compressional wave velocity and attenuation. Both of these parameters were sensitive to the presence of a large cavity, and the successful application of the technique is demonstrated in the Maidstone survey, where the presence of loosely packed sand (due to sinkholes in the vicinity) was located under a house. The use of the single hole method for detecting cavities is a new technique (ACDER) in seismics, and it is analogous to methods of radar detection. A sparker source, directional receiver and associated instrumentation were developed in the laboratory before field trials at East Fleet. Of the three methods, the interborehole technique was the most successful, followed by the surface method. The single hole method looks promising but requires further work in the design of directional receiving transducers, followed by more field trials

Jednadžbe stanja, energije vezanja, volumni moduli i Gruneisenove konstante 3d, 4d i 5d prijelaznih metala

A model pseudopotential, depending on an effective core radius but otherwise parameter-free, is proposed to study the equation of state by incorporating the s-d hybridization effects. A new criterion for the selection of the exchange and correlation effects is also put forward. The equations of state for Cu, Ta, Mo, W and Pt have been studied up to the pressure of 1000 GPa. The binding energy, pressure, bulk modulus and frequency-independent Grüneisen constant as functions of volume for transition metals are calculated. The theoretical results are compared with available experimental results. The successful application to 27 metals has confirmed our formalism.Uvodimo model potencijala koji ovisi o polumjeru efektivne sredice a ne o drugim parametrima radi proučavanja jednadžbe stanja s uključenim s-d efektima hibridizacije. Postavljamo također nov kriterij za odabir efekata izmjena i korelacija. Proučavamo jednadžbu stanja Cu, Ta, Mo, W i Pt za tlakove do 1000 GPa. Izračunavamo energije vezanja, tlak, volumne module i frekventno-neovisne Gruneisenove konstante. Ishodi računa uspoređuju se s eksperimentalnima za sve poznate podatke. Uspješna primjena našeg formalizma za 27 metala ga potvrđuje

Formulation, evaluation and optimization of stomach specific in situ gel of clarithromycin and metronidazole benzoate

The present investigation deals with the formulation, optimization and evaluation of sodium alginate based In situ gel of Clarithromycin and Metronidazole Benzoate. Sodium alginate used as a polymer and CaCO3 was used as a cross-linking agent. The In situ formulation exhibited well, viscosity, drug content and sustained drug release; this study reports that oral administration of aqueous solutions containing sodium alginate results in formation of In situ gel, such formulations are homogenous liquid when administered orally and become gel at the contact site. The results of a 32 full factorial design revealed that the concentration of sodium alginate and concentration of CaCO3 significantly affected the dependent variables Q1, Q12 and T80. These In situ gels are, thus, suitable for oral sustained release of Clarithromycin and Metronidazole Benzoate.Keywords: In situ gel; Stomach specific; Gastric residence time

Formulation, evaluation and optimization of stomach specific in situ gel of clarithromycin and metronidazole benzoate

The present investigation deals with the formulation, optimization and evaluation of sodium alginate based In situ gel of Clarithromycin and Metronidazole Benzoate. Sodium alginate used as a polymer and CaCO3 was used as a cross-linking agent. The In situ formulation exhibited well, viscosity, drug content and sustained drug release; this study reports that oral administration of aqueous solutions containing sodium alginate results in formation of In situ gel, such formulations are homogenous liquid when administered orally and become gel at the contact site. The results of a 32 full factorial design revealed that the concentration of sodium alginate and concentration of CaCO3 significantly affected the dependent variables Q1, Q12 and T80. These In situ gels are, thus, suitable for oral sustained release of Clarithromycin and Metronidazole Benzoate.Keywords: In situ gel; Stomach specific; Gastric residence time

Sonographically Guided Knee Meniscus Injections: Feasibility, Techniques, and Validation

BackgroundThere is a growing interest in the use of biologic agents such as platelet‐rich plasma and mesenchymal stem/stromal cells to treat musculoskeletal injuries, including meniscal tears. Although previous research has documented the role of diagnostic ultrasound to evaluate meniscal tears, sonographically guided (SG) techniques to specifically deliver therapeutic agents into the meniscus have not been described.ObjectiveTo describe and validate SG injection techniques for the body and posterior horn of the medial and lateral meniscus.DesignProspective, cadaveric laboratory investigation.SettingAcademic institution procedural skills laboratory.SubjectsFive unenbalmed cadaveric knee‐ankle‐foot specimens from 5 donors (3 female and 2 male) ages 33‐92 years (mean age 74 years) with body mass indices of 21.1‐32.4 kg/m2 (mean 24.1 kg/m2).MethodsA single, experienced operator completed SG injections into the bodies and posterior horns of the medial and lateral menisci of 5 unenbalmed cadaveric knees using colored latex and a 22‐gauge, 38‐mm needle. After injection, coinvestigators dissected each specimen to assess latex distribution within the menisci and identify injury to intra‐articular and periarticular structures.Main Outcome MeasuresLatex location within the target region of meniscus (accurate/inaccurate), and iatrogenic injury to “at risk” intra‐ and periarticular structures (present/absent).ResultsSeventeen of 20 injections were accurate. Two of 3 inaccurate injections infiltrated the posterior horn of the medial meniscus instead of the targeted meniscal body. One inaccurate lateral meniscus injection did not contain latex despite sonographically accurate needle placement. No specimen exhibited injury to regional neurovascular structures or intra‐articular hyaline cartilage.ConclusionsSG meniscus injections are feasible and can accurately and safely deliver injectates such as regenerative agents into bodies and posterior horns of the medial and lateral menisci. The role of SG intrameniscal injections in the treatment of patients with degenerative and traumatic meniscal disorders warrants further exploration.Level of EvidenceNot applicable.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147070/1/pmr2998.pd

Closing the circle: is it feasible to rehabilitate reefs with sexually propagated corals?

Sexual propagation of corals specifically for reef rehabilitation remains largely experimental. In this study, we refined low technology culture and transplantation approaches and assessed the role of colony size and age, at time of transfer from nursery to reef, on subsequent survival. Larvae from Acropora millepora were reared from gametes and settled on engineered substrates, called coral plug-ins, that were designed to simplify transplantation to areas of degraded reef. Plug-ins, with laboratory spawned and settled coral recruits attached, were maintained in nurseries until they were at least 7 months old before being transplanted to replicate coral limestone outcrops within a marine protected area until they were 31 months old. Survival rates of transplanted corals that remained at the protected in situ nursery the longest were 3.9–5.6 times higher than corals transplanted to the reef earlier, demonstrating that an intermediate ocean nursery stage is critical in the sexual propagation of corals for reef rehabilitation. 3 years post-settlement, colonies were reproductively mature, making this one of few published studies to date to rear a broadcasting scleractinian from eggs to spawning adults. While our data show that it is technically feasible to transplant sexually propagated corals and rear them until maturity, producing a single 2.5-year-old coral on the reef cost at least US$60. ‘What if’ scenarios indicate that the cost per transplantable coral could be reduced by almost 80 %, nevertheless, it is likely that the high cost per coral using sexual propagation methods would constrain delivery of new corals to relatively small scales in many countries with coral reefs.Published versio

Microseismicity and permeability enhancement of hydrogeologic structures during massive fluid injections into granite at 3 km depth at the Soultz HDR site

A high-rate injection of 20 000 m3 of water into granite between 2.8 and 3.4 km depth at the Soultz hot dry rock (HDR) test site in France in 1993 September led to a 200-fold increase in borehole transmissivity and produced a subvertical cloud of microseismicity of dimensions 0.5 km wide, 1.2 km long, 1.5 km high and oriented 25°NW. The resulting data set is unusually complete and well suited to studying permeability creation/enhancement processes in crystalline rock and the utility of microseismic data for revealing them. Although the microseismic cloud defined using joint hypocentre determination (JHD) locations was diffuse and showed little structure, application of the collapsing method showed it to be composed largely of discrete tubes and planes that propagated coherently. One prominent structure that extended 350 m downwards from the vicinity of a flow inlet early in the injection and that appears to contain a major flow path was subjected to detailed investigation to establish its hydrogeologic nature and the mechanisms underpinning its inferred permeability enhancement. High-resolution microseismic mapping techniques (i.e. multiplets and clustering) showed it to be a subvertical, NNW-SSE striking, fracture zone of width 10-20 m. The strike and scale of the structure identifies it as a member of a family of hydrothermally altered, cataclastic shear structures that constitute the primary permeable paths for fluid migration within the rock mass, both under ambient and forced fluid flow conditions. The microseismicity occurred on subvertical, small-scale fractures within the cataclastic shear zone whose azimuths scatter within 22° of parallel to the parent structure. Although the structure is likely to have been naturally permeable to some degree, its permeability appears to have been significantly enhanced as a consequence of the injection. The most likely mechanism of permeability enhancement, which is in accord with the strong preference for the microseismicity to grow downwards, involves strike-slip shearing, which produced the opening of vertical tubes at along-strike jogs in the fault (the so-called Hill mesh). Seismic moment release averaged over the structure suggests shear displacements of at least 0.3 mm occurred, which are sufficient to generate aperture changes that are hydraulically significant. The preponderance of discrete structures within the microseismic cloud after collapsing suggests that significant flow and permeability enhancement (i.e. stimulation) within the rock mass is largely confined to the interiors of shear zones that appear to have a spacing of approximately 100

Analysis of ectopic pregnancy at a tertiary care hospital: one year study

Background: Ectopic gestation is the leading cause of maternal mortality and morbidity in first trimester and is a major cause of reduced child bearing potential. The aims of our study were to understand the clinical profile, risk factors, sites and management modalities of ectopic pregnancy at tertiary care hospital.Methods: This is a retrospective study carried out for one year at the department of Obstetrics and Gynaecology of our institute. Data of the women admitted for management of ectopic pregnancy during January to December, 2010 was collected and analysed.Results: The proportion of ectopic pregnancy was 0.7 % at our institute. Majority of women 45(83.2%) were between the age group of 21-30 years. Pelvic inflammatory disease (PID) contributed to ectopic pregnancy in 16(29.6%) women. The most common symptom was lower abdominal pain, in 50(92.6%) women. Marked pallor was present in 25(46.3%) women and 38(70.4%) women had cervical motion tenderness. Out of all women, 10(18.5%), 18(33.3%) and 26(48.1%) women were managed successfully with methotrexate, laparoscopy and laparotomy respectively. The success rate was 83.3%, 90% and 100% with methotrexate, laparoscopy and laparotomy respectively. Blood and blood products were given to 25(46.3%) women. Conclusion: Ectopic pregnancy is a growing problem of reproductive age group. Women should be encouraged regarding early reporting of missed periods and made aware of complications of ectopic pregnancy and necessity of seeking urgent medical help as early as possible so that early diagnosis and prompt conservative surgical or medical management of ectopic pregnancy can be done