Simplified Production of Large Prototypes using Visible Slicing

Rapid Prototyping (RP) is a totally automatic generative manufacturing technique based on a “divide-and-conquer” strategy called ‘slicing’. Simple slicing used on 2.5-axis kinematics of the existing RP machines is responsible for the staircase error. Although thinner slices will have less error, the slice thickness has practical limits. Visible Slicing overcomes these limitations. A few visible slices exactly represent the object. Each visible slice can be realized using a 3- axis kinematics machine from two opposite directions. Visible slicing is implemented on Segmented Object Manufacturing (SOM) machine under development. SOM can produce soft large prototypes faster and cheaper with accuracy comparable to that of CNC machining.Mechanical Engineerin

Techno-Economic Analysis of Hybrid Layered Manufacturing

Subtractive manufacturing (CNC machining) has high quality of geometric and material properties but is slow, costly and infeasible in some cases; additive manufacturing (RP) is just the opposite. Total automation and hence speed is achieved in RP by compromising on quality. Hybrid Layered Manufacturing (HLM) developed at IIT Bombay combines the best features of both these approaches. It uses arc welding for building near-net shapes which are finish machined to final dimensions. High speed of HLM surpasses all other processes for tool making by eliminating NC programming and rough machining. The techno-economic viability of HLM process has been proved through a real life case study. Time and cost of tool making using HLM promises to be substantially lower than that of CNC machining and other RP methods. Interestingly, the material cost in HLM was also found to be lower. HLM is a cheaper retrofitment to any 3 or 5 axis CNC milling machine or machining center.Mechanical Engineerin

A prospective study on maternal and perinatal outcome of gestational diabetes mellitus

Background: To identify risk factors, study maternal, fetal and perinatal outcome of pregnancy in relation to the glycemic control and different modalities of management in pregnancy complicated by Gestational Diabetes Mellitus (GDM).Methods: Descriptive study conducted in Department of OBG, Government TD Medical College Alappuzha, during the one year period January 2005 to December 2005. Study group comprised of 134 women who are diagnosed to have GDM. The aim was to study the maternal, fetal and perinatal outcome.Results: Despite early diagnosis and treatment the GDM patients in the present study had a statistically significant higher incidence of pregnancy induced hypertension (11.9%) induction of labor about (37.2%), caesarean section (58.96%) preterm delivery (2.99%) macrosomia (2.9%). Incidence of perinatal morbidity was 29.8%, common causes being neonatal hypoglycemia (32.5%), hyperbilirubinemia (12.5%) meconium aspiration syndrome (7.5%). Admission to neonatal unit required in (25%). There were 2 cases of intrauterine deaths, 2 cases of neonatal deaths and no still births. Perinatal mortality was 2.9%.Conclusions: The occurrence of GDM is a high-risk situation. Maternal morbidity, perinatal morbidity and mortality are increased in women with GDM. All pregnant women should be screened for GDM with a 50gm oral glucose load followed by a glucose determination 1 hour later. This helps to detect all GDM cases earlier and so timely intervention can be done which will reduces the complications. Proper management of GDM during the antenatal period will improve pregnancy outcome

Proportion and risk factors of postnatal depression among women delivering in a government tertiary care hospital in Kerala, India

Background: The burden of postpartum depression is significant because it remains unrecognized and it not only affects the mother adversely but also has a negative consequence on the family life and the development of the infant. This research aims to aid the early diagnosis of postnatal depression using Edinburgh postnatal depression scale (EPDS) and the psychosocial and reproductive risk factors of postnatal depression among women delivering in a tertiary hospital in Kerala state, India.Methods: 500 women were subjected to a standard questionnaire for assessing psychosocial and reproductive characteristics. The diagnosis of postnatal depression was made using a pretested and validated Malayalam version of EPDS with a score cut off of 13 or more.Results: The proportion of postnatal depression six weeks after delivery at TD Medical College, Alappuzha was found to be 8.6%. Marital harmony (p value=0.002) was significantly associated with postnatal depression. Diabetes (p value=0.037), hypertensive disorders (p value=0.013), antepartum hemorrhage (p value=0.036), neurological disorders (p value <0.001), type of delivery (p value=0.042), postpartum complications (p value=0.003), mode of infant feeding (p value=0.001), infant illness (p value=0.001), symptoms of maternity blues (p value <0.0001), premenstrual syndromes (p value=0.008) and infertility treatment (p value=0.03) were significantly associated with postnatal depression.Conclusions: Early screening of the women and counselling of women and their family will reduce the maternal morbidity and adverse child outcomes

Bioinformatic Analysis of Chlamydia trachomatis Polymorphic Membrane Proteins PmpE, PmpF, PmpG and PmpH as Potential Vaccine Antigens

Chlamydia trachomatis is the most important infectious cause of infertility in women with important implications in public health and for which a vaccine is urgently needed. Recent immunoproteomic vaccine studies found that four polymorphic membrane proteins (PmpE, PmpF, PmpG and PmpH) are immunodominant, recognized by various MHC class II haplotypes and protective in mouse models. In the present study, we aimed to evaluate genetic and protein features of Pmps (focusing on the N-terminal 600 amino acids where MHC class II epitopes were mapped) in order to understand antigen variation that may emerge following vaccine induced immune selection. We used several bioinformatics platforms to study: i) Pmps' phylogeny and genetic polymorphism; ii) the location and distribution of protein features (GGA(I, L)/FxxN motifs and cysteine residues) that may impact pathogen-host interactions and protein conformation; and iii) the existence of phase variation mechanisms that may impact Pmps' expression. We used a well-characterized collection of 53 fully-sequenced strains that represent the C. trachomatis serovars associated with the three disease groups: ocular (N=8), epithelial-genital (N=25) and lymphogranuloma venereum (LGV) (N=20). We observed that PmpF and PmpE are highly polymorphic between LGV and epithelial-genital strains, and also within populations of the latter. We also found heterogeneous representation among strains for GGA(I, L)/FxxN motifs and cysteine residues, suggesting possible alterations in adhesion properties, tissue specificity and immunogenicity. PmpG and, to a lesser extent, PmpH revealed low polymorphism and high conservation of protein features among the genital strains (including the LGV group). Uniquely among the four Pmps, pmpG has regulatory sequences suggestive of phase variation. In aggregate, the results suggest that PmpG may be the lead vaccine candidate because of sequence conservation but may need to be paired with another protective antigen (like PmpH) in order to prevent immune selection of phase variants.AN is a recipient of a post-doctoral fellowship (SFRH/BPD/75295/2010) from Fundação para a Ciência e a Tecnologia (FCT)

Optimization of a flexible manufacturing system (FMS) for high technology product producing factory via the modularization of production systems

This research is timely because many High Technology Product Producing Factories (HTPPF) are still following the trend of factories that produces the likes of canned food or even cars where all machines are jointed from start to end (Towill, 2010). These HTPPF have not realized that improvements to product must be done everyday to keep market share. And to perform research continuously, buffers in-between production machines is a necessity. The absence of this has caused a number of hard disk manufacturers to close down, especially in Japan and Taiwan (notably Sony, NEC, Matsushita and Trace), which are leaders in joining up production lines from start to end. It is due to this that currently 90% of hard disks are produced by Western Digital and Seagate, with Toshiba having 10% market share

Results of exploratory trawl fishing on the continental slope of the south west coast of India by M.F.V. 'Kalava'

So far, extensive deep sea trawling, in waters beyond 100 fathom depths, has not been attempted in Indian waters except for occasional hauls taken by the INVESTIGATOR (Alcock, 1891-1900) and other Expedition vessels (Gunther, 1887, Max Weber, 1913. Norman, 1939). During March-May 1963 M.F.V. 'Kalava' of the Indo-Norwegian Project, carried out 9 exploratory cruises off Alleppey and Ponnani on the South West Coast of India at depths ranging between 150 to 205 fathoms (274-374 m.). Large quantities of bathypelagic fish were taken during these cruises, in areas on the continental slope (Fig. 1). 24 species belonging to 23 genera and 19 families have already been described by Tholasilingam et al. (1964). Nearly 82% of the catch was represented by about 11 bathypelagic species taken at the rate of up to 496 kg. per hour of trawl, in the richest grounds. Since such occurrence has not been recorded so far, a quantitative assessment of these bathypelagic fishes along with deep sea prawns, lobsters and squids, has been given in the following pape

Additive manufacturing of magnesium alloys

Magnesium alloys are a promising new class of degradable biomaterials that have a similar stiffness to bone, which minimizes the harmful effects of stress shielding. Use of biodegradable magnesium implants eliminates the need for a second surgery for repair or removal. There is a growing interest to capitalize on additive manufacturing\u27s unique design capabilities to advance the frontiers of medicine. However, magnesium alloys are difficult to 3D print due to the high chemical reactivity that poses a combustion risk. Furthermore, the low vaporization temperature of magnesium and common biocompatible alloying elements further increases the difficulty to print fully dense structures that balance strength and corrosion requirements. The purpose of this study is to survey current techniques to 3D print magnesium constructs and provide guidance on best additive practices for these alloys