Physical and numerical investigation of conglomeratic rocks

This thesis investigates the mechanics of clast supported conglomerates, through physical and numerical simulations on idealised specimens with spherical clasts and a homogeneous cement matrix. In the physical experiments synthetic conglomerate specimens were prepared from steel spheres as clasts and Portland cement paste as the cement matrix. The mechanical parameters of these specimens were measured in ISRM standard tests. Numerical specimens were prepared in PFC3D using measured and known micro parameters, and tested in conditions as equivalent as possible to the physical experiments. In order to validate the numerical simulations, the responses of the numerical and synthetic conglomerates were compared. Although the numerical tests reproduced many features of the physical tests, some significant differences were observed which were attributed to the presence of cement matrix in the synthetic conglomerate. After a achieving a reasonable calibration between the physical and numerical conglomerates, the simulations were extended to investigate the sensitivity of the cement matrix and the clast properties, effect of specimen size and size distribution of the clasts in controlling the mechanical response of a clast supported conglomerate. The study showed that the mechanical response is sensitive to the strength and stiffness of the cement matrix in uniaxial conditions only. Similarly, clasts’ strength and stiffness was found to significantly influence the mechanical response in triaxial loading but not in uniaxial loading. The specimen size was found to influence the mechanical response of conglomerates, similar to natural rocks. In the clast size distribution study, the peak strength and stiffness of the conglomerate was observed to decrease as the maximum to minimum clast size ratio is increased. A micro mechanical investigation using PFC2D was conducted to explore the clast-cement interaction by modelling the cement matrix as an aggregate of micro particles. It was observed that the properties of the clast-cement interface significantly affect the failure mechanism and peak strength in various modes of deformation. Similarly, the role of the cement matrix was also investigated. It was found that the cement matrix acts as a stress riser and a relation was proposed to estimate the cement induced stress effect, named, the Cement Wedge Effect

Assessment of Knowledge of Cardiopulmonary Resuscitation among Pharmacy Students of Mirpur, Azad Jammu & Kashmir

Introduction: Cardiopulmonary resuscitation (CPR) is the most important lifesaving technique in several emergency situations such as cardiac arrest. In future, being part of health care professionals, pharmacy students are deemed to possess basic skills and expertise which are required to perform CPR. Objective: To access the knowledge of cardiopulmonary among pharmacy students of Mirpur Azad Jammu & Kashmir. Methods: It was a questionnaire-based, descriptive cross-sectional study, conducted among 4th and 5th year students of two Pharmacy institutes of Mirpur AJ&K from November 2018 to January 2019. A pre-tested questionnaire from previous study was used to collect data. It comprised of 13 dichotomous questions with “Yes/No” options, regarding knowledge of CPR. Descriptive statistics was used to unfold the demographic characteristics. Inferential statistics (Kruskal Wallis and Man Whitney) tests were used for evaluating difference between dependent continuous variables and independent variables and Chi-square was applied to determine difference between grouped variables. P-value of less than 0.05 is considered significant. The data was analyzed using SPSS version 20. Result: Overall, 131 out of 150(response rate= 92%) students participated in current study. Gender distribution among the participants was almost equal with 66 males (50.4%) males and 65 (49.6%) females took part in current study. Participants of the age group 21-23 years (n=88, 67.2%) were dominant. Only few students (n=23, 17.6%) reported to have taken training in CPR previously. Eighty-eight (66.7%) had average knowledge of CPR. No significant differences among male and female, 4th and 5th year students of both the institutes were found. Conclusion: The study revealed that knowledge level of CPR is adequate in most of the students of pharmacy. However, further improvements are required to perform CPR in an efficient manner. Thus, training in CPR should be mandatory in the pharmacy curriculum

Utilizing Seismic and Well Logging Techniques for Locating Hydrocarbon of Kabirwala Area Punjab Platform Pakistan

Nandpur Gas field is situated at a distance of 64 km near District Multan. It lies in Middle Indus Basin Punjab Platform, Pakistan. The structure is dipping at a gentle angle toward the NW-SE. Tectonically the area fall in extensional regime and is dominated by Normal faults, favorable for accumulation of hydrocarbon. The interpretation of Seismic lines, time contour map and depth contour map confirms the Graben structure and stratigraphic traps (Pinchouts) in the study area. The high zone present in the South Eastern part of the contour maps is possible location of hydrocarbon entrapment, which is further confirmed by the presence of the well Nandpur -02.The reservoir quality of the Samana Suk Formation was much better in terms of clean Sandstone, porosity, water saturation and permeability. We use seismic lines, a base map and well data of Nandpur-02 area which was obtained from Landmark Resources, Pakistan. For subsurface mapping, structural interpretation, synthetic seismogram generation of investigated area we used four dip and five strike lines. These seismic lines and well data are in digital format. The reservoir discrimination and modeling is carried out with the help of geophysical parameter. Keywords: Seismic Interpretation, Time and depth contour map, Generating Synthetic Seismogram, 3D view, Reservoir Estimatio

Numerical Verification of Empirically Designed Support for a Headrace Tunnel

In this paper, we used two empirical rock classification systems of rock mass rating (RMR) and rock quality tunnelling index (Q-system) for the support design of a tunnel in District Battagram, Khyber Pakhtunkhwa, Pakistan. Along the tunnel route, the rocks of Precambrian namely Gandaf Formation, Karora Formation and Besham Complex were exposed. During the field investigations, two shear zones were marked in the schist of Karora Formation. The discontinuities parameters collected during the field investigations, results of laboratory testing and material constants determined from RocData version 5.0 software were used during the empirical classification and numerical modelling. The support was designed for the rock mass units from RMR and Q. The quantification of the thickness of plastic zone and total displacement around the tunnel were achieved by the numerical modelling of RS2 9.0 software in both unsupported and supported conditions. The empirically designed support was installed in the model prepared in the RS2 software. According to the results, the empirically designed support when installed in models prepared in RS2 significantly reduced the plastic zone around the tunnel. The reduction in the plastic zone and displacement around the tunnel verified the support design by empirical methods. The present research concludes that empirical designed support can be used for the complex geology of Pakistan

Analysis of the Impacts of Cochlear Implants in the Adults of Sensorineural Hearing Loss: What Is New and Not So New: A Literature Review

PURPOSE: the purpose of this systematic review is to advise on advantages and clinical outcomes of Cochlear implants in adult population with sensorineural hearing loss. Methods: A systematic search of several electronic databases, including PubMed and Embase, was used to identify relevant studies for inclusion. RESULTS: 16 articles were included in our study most of the studies showed better speech recognition, quality of life, speech perception and social interactions. Consistent use of implant showed better results as well as early implantation. CONCLUSION: Early intervention and consistent use of implant is necessary for desired outcome. Sensorineural hearing loss have many different causes from simple infection to genetic mutations. DOI: 10.7176/JHMN/93-05 Publication date:September 30th 202

Epidemiology and Control of Congo Fever in Sacrificial Animals of Pakistan

The cases and deaths due to Crimean-Congo haemorrhagic fever (CCHF) [49] virus commonly known as Congo virus (fatality rate 15%) have been reported throughout Pakistan from the last five years especially during religious occasion, Eid-ul-Azha. The annual increase in death rates due to CCHF demonstrate the importance of awareness of Congo fever at academia as well as public level. The symptoms of Congo fever which appear one to nine days after tick bite, include sudden high fever, muscle aches, abdominal pain, headache, dizziness, sore eyes, jaundice, mood swings, confusion, aggression, and sensitivity to light. The other signs include sore throat, joint pain, vomiting, diarrhea, hemorrhages, and bleeding from skin and large intestine. The Infection has been reported in many species of wild as well as domestic animals including hares, cattle, sheep, goats, dogs, mice and hedgehogs. At least 31 species of Hyalomma, Boophilus, Rhipicephalus, Dermacentor (Ixodidae: hard ticks) act as vector of CCHF in which transovarial, transstadial and venereal transmission occurs. The virus attacks the immune system of the host and influences the immune cells. The Congo fever virus can be isolated from blood, plasma and many body tissues (kidneys, liver, spleen, lungs, brain and bone marrow). Mice inoculation, enzyme-linked immunosorbent assay (ELISA), reverse transcription polymerase chain reaction (RT-PCR) can be used for detection of the infection. Furthermore, IgM and IgG antibodies against CCHFV can also be detected and quantified. Education of general public, tick control with acaricides, use of anti-CCHFV immunoglobulin, usage of approved repellents to prevent tick bites, wearing neutral-coloured garments, application of a permethrin spray to the clothing, avoiding tall grasses and shrubs, applying sunscreen, avoiding direct contact with the blood or tissues of animals are the factors for successful prevention of the infection

Preservation of hearing and facial nerve function with the microsurgical excision of large vestibular schwannomas: Experience with the retrosigmoid approach

Introduction: Vestibular schwannomas (VS) are the most common benign neoplasms of a cerebellopontine angle (CPA), which arise from the Schwann cells of the vestibulocochlear nerve. Eighty percent of CPA tumors are VS followed by meningioma as the second common mass lesion in this critical potential space. Treatment options range from watchful waiting with serial imaging studies to radiosurgery or a microsurgical excision or a combination of surgery and radiation therapy. The primary objective of the study was to assess hearing and facial nerve status before and after the surgery via the retrosigmoid approach.Methods: The database of Aga Khan University Hospital was searched for diagnoses of vestibular schwannomas between 2000 and 2007. A total of 35 patients were identified; among them, 27 were selected for the study who met the inclusion criteria. The variables of the study were age, gender, presenting symptoms, size of the tumor, surgical approach, hearing levels, and facial nerve function. Hearing loss was categorized according to the Gardener-Robertson hearing classification and the House-Brackmann Scale was used for facial nerve assessment.Results: Out of the 27 patients, 18 were male and nine were female. The mean age was 43 years. The most common presenting complaint was hearing loss and tinnitus, seen in 21 patients. Headache was present in six patients, ataxia in five, and vertigo in three. Facial nerve weakness was noticed in six patients. Two patients had Grade-III paralysis, three had Grade-IV paralysis, and one had Grade-V paralysis. The audiogram confirmed the presence of sensorineural hearing loss (SNHL) in all patients. Twelve patients out of 27 had Class II hearing with the threshold between 31 and 50 decibels and a Speech Discrimination Score (SDS) of 50% to 69%. Ten patients had non-serviceable hearing and the remaining five had poor hearing. The audiogram was repeated after surgery for those 12 patients who had Class II hearing and showed that seven out of 12 patients maintained a hearing threshold within the range of Class II at the one-year follow-up (hearing preservation 58%). The facial nerve preservation rate was 56% considering House-Brackmann Grade III or less as acceptable facial nerve function.Conclusion: The optimal treatment for small vestibular schwannomas is a matter of controversy; however, the choice of treatment for large vestibular schwannomas in patients without significant comorbidity is generally microsurgical excision. The surgical excision of a large VS with the retrosigmoid approach is found to be safe consistently. The hearing and facial nerve preservation in our study were found comparable with the literature