An analytical and experimental study of the behavior of semi-infinite metal targets under hypervelocity impact

The material strength and strain rate effects associated with the hypervelocity impact problem were considered. A yield criterion involving the second and third invariants of the stress deviator and a strain rate sensitive constitutive equation were developed. The part of total deformation which represents change in shape is attributable to the stress deviator. Constitutive equation is a means for analytically describing the mechanical response of a continuum under study. The accuracy of the yield criterion was verified utilizing the published two and three dimensional experimental data. The constants associated with the constitutive equation were determined from one dimensional quasistatic and dynamic experiments. Hypervelocity impact experiments were conducted on semi-infinite targets of 1100 aluminum, 6061 aluminum alloy, mild steel, and commercially pure lead using spherically shaped and normally incident pyrex projectiles

Early removal versus expectant management of central venous catheters in neonates with bloodstream infection

BACKGROUND: Uncertainty exists regarding the management of newborn infants with a bloodstream infection and a central venous catheter in place. The central venous catheter may act as a nidus for infecting organisms and observational studies have suggested that early removal of the catheter is associated with a lower incidence of persistent or complicated infection. However, since central venous catheters provide secure vascular access to deliver nutrition and medications, the possible harms of early removal versus expectant management also need to be considered. OBJECTIVES: To determine the effect of early removal versus expectant management of central venous catheters on morbidity and mortality in newborn infants with bloodstream infections. SEARCH METHODS: We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL 2015, Issue 11), MEDLINE (1966 to October 2015), EMBASE (1980 to October 2015), CINAHL (1982 to October 2015), conference proceedings and previous reviews. SELECTION CRITERIA: Randomised and quasi-randomised controlled trials that compared early removal versus expectant management of central venous catheters in neonates with bloodstream infections. DATA COLLECTION AND ANALYSIS: We used the standard methods of the Cochrane Neonatal Review Group. MAIN RESULTS: We did not identify any eligible randomised controlled trials. AUTHORS' CONCLUSIONS: There are no trial data to guide practice regarding early removal versus expectant management of central venous catheters in newborn infants with bloodstream infections. A simple and pragmatic randomised controlled trial is needed to resolve the uncertainty about optimal management in this common and important clinical scenario

Inspection and evaluation of dry fibers in thick composites

This paper presents the investigation of dry fibers in thick composites. Dry fibers can be defined as lack of epoxy in localized regions. These local regions act as potential defects in thick composites under compressive loads and act as an initiation point for defects such as matrix cracking and delamination. Detection and characterization of dryness in glass/epoxy composites, with thickness greater than one inch, is presented in this paper. One inch samples with dry fibers were fabricated and tested. Detection is carried out with the help of air coupled ultrasonics in both through transmission and singled sided inspection. To characterize the amount of epoxy, time of flight data was correlated with density and fiber volume fraction. Based on the observations a technique was developed for characterization of dryness

Effect of cissus quadrangularis linn and zingiber officinale rosc in osteoarthritis patients

Background: To evaluate the efficacy of Cissus quadrangularis Linn. or Zingiber officinalis Rosc. or in combination treatment of osteoarthritis which reduces joint pain, joint swelling and tenderness without risk of side effects.Methods: Total 60 patients were selected and divided into 3 groups (each group consist of 20 patients); data were collected before and after treatment of following groups: Group A-Cissus quadrangularis linn-5gm; Group B- Zingiber officinale rosc-5gm; Group C-Treatment of Cissus quadrangularis linn combined with Zingiber officinale rosc-5 gm/dose twice a day with luke warm water.Results: 60 % cases of joint pain were relieved at the end of the treatment in group B & C, in group A 50%, reduction in joint pain extremely significant in all groups A, B, C (p<0.0001). ‘C’ 80%, ‘A’ 15% and ‘B’5% reduction in symptom of Joint swelling and which is very significant in group A, and group B (p<0.001) and extremely significant in group C (p<0.0001). Symptom of tenderness ‘C’ 90%, ‘A’ 85%, and ‘B’ 10% cases were relived from the complaint. The difference in tenderness is statistically extremely significant when compared between groups (p<0.0001).Conclusions: Present study reveals that, significant reduction of joint pain, joint swelling and tenderness after treatment of Cissus quadrangularis Linn. or Zingiber officinalis Rosc. and extremely significant reduction of joint swelling and tenderness in combination therapy

Clinical and socio-demographic profile of treatment on osteoarthritis patients in Tirupathi, Andhra Pradesh, India

Background: Osteoarthritis is a chronic degenerative joint disease and it is slowly progressive with signs and symptoms being pain. It is a common cause of disability affecting 60-70% of the population in the age of 60 years. It usually affects the hand, large weight bearing joints, often the knee and the hip.Methods: A prospective study was carried out in S.V Ayurvedic Medical College and Hospital. Collected the data of Socio-demographic and risk factors (age, diet, history, marital status, religion, occupation etc.) during the treatment of osteoarthritis among the patients in hospital.Results: The data reveals that majority of the patients belongs to the age group of 51-60 (43.33%) and 41-50 years (33.33%) followed by 61-70years (16.66%), 31-40 years (6.66%), and 70 % of females, 30% patients were Males in present study. 90% were married 10% were widows. 63.33% of Hindu, 23.33 % were Muslims and only 13.33% were Christians. 40%, of labour, 33.33% Businessmen, 13.33% Servicemen and 13.33% House wives. 53.33% rural, 46.66% urban area. 50% were belonging to middle class while 23.33% were very poor status, 16.66% Rich only 10 % patients were from upper middle class families. 43.33% were Primary level education, 36.66% were illiterates, 10% up to Graduation, 6.66% Post-Graduation and 3.33% up to Matriculation. 63.33% mixed diet, 36.66% vegetarian.Conclusions: Present study reveals that, incidence of osteoarthritis was very high especially in elder female, married, Hindu, labour, rural area, middle class with very poor, primary education, mixed diet (vegetarian with non-vegetarian) patients.

Inspection of helicopter rotor blades with the help of guided waves and turning modes : Experimental and finite element analysis

Modern helicopter rotor blades constructed of composite materials offer significant inspection challenges, particularly at inner structures, where geometry and differing material properties and anisotropy make placement of the probing energy difficult. This paper presents an application of Lamb waves to these structures, where mode conversion occurs at internal geometric discontinuities. These additional modes were found to successfully propagate to the targeted regions inside the rotor and back out, allowing evaluation of the structure. A finite element model was developed to simulate wave propagation and mode conversion in the structure and aid in identifying the signals received in the laboratory experiment. A good correlation between numerical and experimental results was observed

Review of ultrasonic testing for NDE of composite wind turbine blades

This paper will present a review of the use of Air coupled ultrasonics for nondestructive evaluation of wind turbine blades carried out at the CNDE, Iowa State University. Results will show the use of air coupled ultrasonics to scan thick composite sections of 40m wind turbine blades including the spar cap, the leading and trailing edges. Detection of defects such as slots, holes, fiber waviness (both in-plane and out-of-plane waviness), delaminations and dry fibers will be presented. Other features like adhesive thickness and length estimation in spar cap/shear web section and the trailing edge section will also be presented. The use of air coupled UT is not limited to just detection, but also characterization of the detected defects. Results highlighting the use of ultrasonic velocity to characterize defects will be presented. This includes defining damage index in terms of velocity, as well as development of stiffness maps to show reduction in structural stiffness based on the defect. Additionally, the challenges of NDT of wind turbine blades using conventional ultrasonics will also be presented