Computer-aided Reverse Engineering for Rapid Replacement of Parts

Indigenous product development using conventional means involves a relatively long leadtime and cost, especially for replacing worn out and broken parts. This paper presentsmethodologies and technologies for computer-aided reverse engineering, illustrated by a reallifecase study of an aluminium alloy separator body of a hydraulic filter assembly for the specialarmy vehicle. It involved reconstruction of part geometry using 3-D scanning, materialidentification using spectrometry, casting process optimisation using simulation software, andfabrication of prototype and tooling using rapid prototyping systems. It was found that thefabrication of wax patterns directly from reverse-engineered CAD data in a suitable rapidprototyping system (such as thermojet), followed by conventional investment casting, gives areliable and economic route for rapid development of one-off intricate parts for the replacementpurpose

Infrared & Mossbauer Spectral Studies on Organic Base Hydroferrocyanides

523-52

Strengthening of heat damaged reinforced concrete cylinders

The purpose of this study is to investigate the effectiveness of various strengthening techniques in restoring heat damaged reinforced concrete. A series of 40 reinforced concrete cylinders were tested under concentric compression after being jacketed externally with high strength fiber reinforced concrete (HSFRC), Ferrocement (FC) and Glass fiber reinforced polymer (GFRP) jackets. Concrete specimens were exposed to elevated temperatures ranging from room temperature to 900 ºC. The overall response of strengthened specimens was investigated vis-à-vis un-strengthened specimens in terms of axial compression, axial displacement and axial stress strain behaviour. The results indicate that important gains in strength and ductility can be achieved by strengthening heat – damaged R.C cylinders by HSFRC, FC and GFRP external Jacketing. GFRP jacketing was found to be the most effective method of strengthening fire or heat damaged concrete structures

Soft X-ray and FUV observations of Nova Her 2021 (V1674 Her) with AstroSat

Nova Her 2021 or V1674 Her was one of the fastest novae to be observed so far. We report here the results from our timing and spectral studies of the source observed at multiple epochs with AstroSat. We report the detection of a periodicity in the source in soft X-rays at a period of 501.4–501.5 s which was detected with high significance after the peak of the super-soft phase, but was not detected in the far ultraviolet (FUV) band of AstroSat. The shape of the phase-folded X-ray light curves has varied significantly as the nova evolved. The phase-resolved spectral studies reveal the likely presence of various absorption features in the soft X-ray band of 0.5–2 keV, and suggest that the optical depth of these absorption features may be marginally dependent on the pulse phase. Strong emission lines from Si, N, and O are detected in the FUV, and their strength declined continuously as the nova evolved and went through a bright X-ray state.Fil: Bhargava, Yash. No especifíca;Fil: Dewangan, Gulab Chand. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; EspañaFil: Anupama, G. C.. No especifíca;Fil: Kamath, U. S.. No especifíca;Fil: Sonith, L. S.. No especifíca;Fil: Pal Singh, Kulinder. ndian Institute of Science Education and Research Mohali; IndiaFil: Drake, J. J.. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Beardmore, A. University of Leicester; Reino UnidoFil: Luna, Gerardo Juan Manuel. Secretaria de Investigacion ; Universidad Nacional de Hurlingham; . Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Orio, M.. Istituto Nazionale di Astrofisica; ItaliaFil: Page, K. L.. University of Leicester; Reino Unid

Malignant melanoma presenting as an isolated pleural effusion

Isolated pleural effusion is a very rare presentation of malignant melanoma. A 46 year-old male patient presented to us with complaints of shortness of breath during the previous month. A contrast enhanced computed tomography (CECT) imaging scan of his thorax showed right-sided pleural effusion with the absence of any mass lesion or mediastinal lymphadenopathy. Cytology of his pleural fluid showed pigmented cells suggestive of malignant melanoma. Staining of the pleural fluid cells with immunohistological markers for melanoma (HMB 45 and S 100) were positive. An examination of his skin did not reveal any pigmented lesion, nor was there a past history of malignant melanoma for this patient. The patient responded well to therapy for malignant melanoma and has remained asymptomatic for the last year. This patient was diagnosed with a rare case of primary malignant melanoma of the pleura presenting as isolated pleural effusion

Response of stone wool-insulated building barriers under severe heating exposures

This article presents the experimental results of stone wool-layered sandwich constructions, with either steel or gypsum claddings, tested under four different heating exposures: 7kW/m(2) incident radiant heat flux exposure, 60kW/m(2) incident radiant heat flux exposure, parametric time-temperature curve exposure and ISO 834 standard time-temperature exposure. The test apparatus used were a movable radiant panel system, a mid-scale furnace (1.5m(3)) and a large-scale furnace (15m(3)). The results show that reduced-scale tests are capable of reproducing the heat transferred through the construction at large scale provided there is limited mechanical degradation. The results indicate that the availability of oxygen is fundamental to the fire behaviour of the sandwich composites tested. Reactions occurring in stone wool micro-scale testing, such as oxidative combustion of the binder or crystallisation of the fibres, have a limited effect on the temperature increase when wool is protected from air entrainment

Titanium based cranial reconstruction using incremental sheet forming

In this paper, we report recent work in cranial plate manufacturing using incremental sheet forming (ISF) process. With a typical cranial shape, the ISF process was used to manufacture the titanium cranial shape by using different ISF tooling solutions with and without backing plates. Detailed evaluation of the ISF process including material deformation and thinning, geometric accuracy and surface finish was conducted by using a combination of experimental testing and Finite Element (FE) simulation. The results show that satisfactory cranial shape can be achieved with sufficient accuracy and surface finish by using a feature based tool path generation method and new ISF tooling design. The results also demonstrate that the ISF based cranial reconstruction has the potential to achieve considerable lead time reduction as compared to conventional methods for cranial plate manufacturing. This outcome indicates that there is a potential for the ISF process to achieve technological advances and economic benefits as well as improvement to quality of life

Maternal Low-Protein Diet or Hypercholesterolemia Reduces Circulating Essential Amino Acids and Leads to Intrauterine Growth Restriction

OBJECTIVE—We have examined maternal mechanisms for adult-onset glucose intolerance, increased adiposity, and atherosclerosis using two mouse models for intrauterine growth restriction (IUGR): maternal protein restriction and hypercholesterolemia