Fabrication of high efficiency and radiation resistant GaAs solar cells

Systematic improvements in fabrication yield were obtained by appropriate control of the liquid phase epitaxial growth process, contact fabrication and surface preparation. To improve radiation hardness, the junction depth was decreased while overcoming the penalty in decreased solar cell efficiency which tends to go hand-in-hand with the reduction of junction depth in (AlGa) As-GaAs solar cells. Cells were made with an AMO efficiency of 18% and a junction depth of 0.5 micrometers, as compared to junction depths on the order of 1.0 micrometers. With respect to the damage caused by proton irradiation, the nature of the observed damage was correlated to the energy and penetration depth of the damaging protons

A study of superficial surgical site infections in a tertiary care hospital at Bangalore

Background: All postoperative surgical infections occurring in an operative site are termed surgical site infections (SSI). Superficial incisional surgical site infection occurs within 30 days after the operation and infection involves only skin or subcutaneous tissue of the incision and represents a substantial burden of disease for patients and health services. The study was conducted to know the incidence of surgical site infection in our hospital, risk factors associated with it and the antibiotic susceptibility pattern of the pathogens.Methods:This prospective study was carried out in the Department of Microbiology at Dr B R AMC for a period of 1 year from Jan 2013to Jan 2014. Samples of SSI received in the Microbiology laboratory were processed and Data collected.Results:The overall surgical site infection rate in our hospital during the study period is 4.3%. Staphylococcus aureus (S. aureus) was the most common isolate obtained followed by Escherichia coli (E. coli) and Coagulase negative Staphylococcus (CONS). Other organisms isolated were Pseudomonas aeruginosa, Enterococcus, Klebsiella pneumoniae and Proteus mirabilis. Among them, 88.8% of S. aureus and 50% of CONS isolates were methicillin-resistant strains. 80% of E. coli and 100% of Klebsiella species were ESBL producers. 50% of Enterococci were Vancomycin resistant. Risk factors like diabetes mellitus and duration plays a significant role in causing surgical site infection.Conclusion:Implementation of an effective infection control programme and judicious use of antibiotic prophylaxis reduces the incidence of SSI in the hospital.

A study of biofilm production in clinical isolates of Staphylococci at a tertiary care hospital, Bangalore

Background: The Biofilms are densely packed communities of microorganisms consisting of layers of cell clusters embedded in a matrix of extracellular polysaccharide called polysaccharide intercellular adhesin. This layer impedes the delivery of antibiotics to the biofilm forming microbial cells leading to emergence of drug resistance. Staphylococci are commensal bacteria on the human skin and mucous membranes. So it may be easily introduced as a contaminant during the surgical intervention. So, this study was conducted to identify the Biofilm producing strains from clinical isolates of Staphylococci.Methods: A total of 182 non-repetitive clinical strains of Staphylococci isolated from various clinical samples from Feb 2014 to Oct 2014 were included in the study. All the isolates were identified using standard microbiological procedures. All the samples were tested for biofilm production by modified Congo-red agar method and tube method.Results: Out of 182 samples that were included in the study, a total of 90 (49.45%) samples showed biofilm formation of which 58 (75.32%) were methicillin resistant and 32 (30.47%) were methicillin sensitive. Also these strains were resistant to other antibiotics.  Conclusion: Our study showed biofilm production by methicillin resistant strains which were also multidrug resistant. Treatment of methicillin resistant strains of Staphylococci is one of the most challenging task for the clinicians and the microbiologists. So they should be routinely screened for biofilm formation in order to prevent emergence and spread of multidrug resistant strains.

An Evaluation of the sliding Wear Behaviour of SiC Particles Reinforced Copper Alloy Composite Materials

The present paper aims at evaluation of the sliding wear behaviour of SiC particles reinforced copper (phosphor-bronze) alloy composite materials studied as a function of sliding speed and applied loads under unlubricated conditions. The content of SiC particles in the composites was varied from 1-5% in steps of 2% by weight. A pin-on-disc wear testing machine was used to evaluate the wear rate, in which EN24 steel disc was used as the counterface. Loads of 20-160 N in steps of 20 N and speeds of 1.25, 1.56, 1.87 m/s were employed. The results indicated that the wear rate of both the composites and the matrix alloy increased with increase in load and sliding speed. However, the composites exhibited lower wear rate than the alloys.It was found that above a critical applied load, there exists a transition from mild to severe wear both in the unreinforced alloy and in the composites. But the transition loads for the composites were much higher than that of the unreinforced alloy. The transition loads increase with the increase in weight % of SiC particles, but decrease with the increase in sliding speeds. SEM analysis of the wear surfaces as well as the sub-surfaces are used to explain the observations made

Speciation of clinically significant coagulase negative staphylococci and their antibiotic resistant patterns in a tertiary care hospital

Background: Coagulase negative Staphylococci (CONS) are normal human microbiota and sometimes cause infections, often associated with implanted devices, such as joint prosthesis, shunts and intravascular catheters, especially in very young, old and immunocompromised patients. These infections are difficult to treat because of the risk factors and the multiple drug resistant nature of the organisms. The study is undertaken to speculate CONS isolates from various clinical samples and to determine antibiotic susceptibility pattern of CONS by Kirby Bauer disc diffusion method.Methods: A total of 134 clinically significant CONS isolated from pus, urine, blood, fluid, sputum, ear swabs, endotracheal tube, ophthalmic, semen and nail samples. These isolates initially identified by colony morphology, Gram staining, catalase test, slide coagulase test, tube coagulase test and mannitol fermentation.Speciation of CONS was done by novobiocin resistance test, urease activity, ornithine decarboxylase and aerobic acid production from mannose.Results: S. epidermidis is the most frequent isolate 62 (46.3%) followed by S. saprophyticus 38(28.4%), S. haemolyticus 27(20.1%), S. lugdunensis 3(2.2%). S. warneri 3(2.2%), S. cohinii 1(0.7%). Antibiotic susceptibility testing of the isolates showed maximum resistance to penicillin 128 (95.5%) and ampicillin118 (88%) followed by erythromycin 96 (71.6%), cefoxitin 89 (66.4%), gentamicin 33(24.6%), piperacillin & tazobactam 31(23.8%), amoxicillin & clavulanic acid 25 (18.7%), linezolid 23 (17.2%), levofloxacin 9 (6.7%), vancomycin & teicoplanin 2 (1.5%), tigecycline 1 (0.7%).Conclusion: S. epidermidis is the more common isolate identified and CONS are often resistant to multiple antibiotics (Penicillin, ampicillin) & glycopeptides have been considered as the drugs of choice for the management of infections caused by these organisms.  

Multi-axial correction system in the treatment of radial club hand

Radial club hand is a well-recognized congenital malformation characterized by hypoplasia of bone and soft tissue on the radial aspect of the forearm and hand. The modalities of treatment have traditionally varied from stretching casts with soft-tissue procedures to the use of multiple corrective osteotomies. These osteotomies can be stabilized by a variety of methods, including external fixators that allow the possibility of gradual distraction with neohistiogenesis. This current study outlines the usage of one such device (multi-axial correction system [MAC]) in the management of deformity associated with severe radial club hand. Three consecutive cases of unilateral or bilateral severe (Bayne type IV) congenital radial club hand were corrected using MAC fixation in the last 5 years. This is a retrospective review of all three cases. Data parameters included: patient demographics, presentation findings, degree of deformity, amount of correction/lengthening, length of procedure, length of treatment, and associated complications. The surgical technique is described in detail for the benefit of the readership. The three patients with severe congenital radial club hand had a total of four limb involvements that underwent correction using osteotomies and usage of the MAC device for external fixation. All three patients underwent successful correction of deformity with the restoration of alignment, lengthening of forearm for improvement of function, and stabilization of the wrist (mean duration, mean lengthening, mean time to consolidation). The MAC system was well tolerated in all patients and associated complications were limited. The MAC fixator seems to be a good alternative modality of stabilization and correction for severe congenital radial club hand deformities. Its usage is fairly simple and it provides the ease of application of a mono-lateral fixator with far superior three-dimensional control, like the circular external fixator. We recommend that clinicians should add this modality to their armamentarium for the deformity correction of severe radial club hand and others in general

Design and Development of Network Monitoring and Controlling Tool for Department of Computer Studies CSIBER

In most of the organizations it is highly desirable to perform different tasks on different machines based on their configuration and permissions assigned to the machines for execution of different tasks. This can be achieved by performing a user-machine mapping by stating clearing the list of tasks that can be performed by a particular user on a particular machine. This kind of discipline further enables traffic control, prevents internal DOS (Denial Of Service) attacks for legitimate users and helps in fair resource sharing. The intent of this research is to enable the end user performing only the tasks permissible to him/her. In this paper we have developed a network monitor and control tool for monitoring the tasks on a medium sized local area network. To facilitate this, task permissions are assigned to different machines which is stored in XML configuration file which is then parsed using JDOM (Java Document Object Model) Parser. The configuration file contains the details such as machine name, and the list of tasks not permitted on that machine. The list of machines and the list of tasks denied on that machine is configurable by an end user. A background thread will continuously monitor the execution of illegal task on a machine and will abort and report the same in a database. This also facilitates the control of network traffic thereby improving the network performance by aborting illegal tasks. Network monitoring tool is tested for local area network of department of computer studies at SIBER by setting up specific monitors to check status and to carry out specific operations. The tool developed by us requires a small amount of system resources, and it is an open source tool. Presently, the tool generates a report comprising of a list of illegal tasks in a specified time period, which enables network administrator to take corrective measures for the smooth operation of the network. DOI: 10.17762/ijritcc2321-8169.15037

The energy-momentum tensor,the trace identity and the Casimir effect

The trace identity associated with the scale transformation x^\mu\tox'{}^\mu = e^{-\rho}x^\mu on the Lagrangian density for the noninteracting electromagnetic field in the covariant gauge is shown to be violated on a single plate on which the Dirichlet boundary condition $A^\mu(t,x^1,x^2,x^3=-a) = 0$ is imposed.It is however respected in free space,i.e. in the absence of the plate; these results reinforce our assertions in an earlier paper where the same exercise was carried out using the Lagrangian density for the free,massive,real scalar field in 2 + 1 dimensions.Comment: 22 page