High density polyethylene matrix syntactic foams: Industrial scale fabrication and mechanical properties

Thermoplastic resins are widely used in consumer goods and structural components. Use of syntactic foams to replace some of the existing parts can help in saving weight in these structures and also help in reducing the consumption of thermoplastic resins. The present work describes development of high density (HDPE) matrix syntactic foams having fly ash cenosphere fillers using an industrial scale injection molding machine. Process optimization is conducted to minimize the microballoon fracture during processing. The fabricated syntactic foams are characterized for particle breakage, mechanical properties and thermal properties. The results show that the optimized process is capable of producing high quality syntactic foams. The tensile, quasi-static and high strain rate compressive and dynamic mechanical properties of the fabricated syntactic foams are presented. Theoretical models are used to predict the properties and these models are validated with the experimental results. The presentation also describes a new calculation method that can be used to extract modulus of resin and syntactic foams over a wide range of strain rates (Fig. 1) from testing of only one specimen on dynamic mechanical analyzer. This method can significantly reduce the experimental testing requirements to obtain the characteristic behavior of the material. Please click Additional Files below to see the full abstract

Coronal Hole Oscillations as inferred from SDO/AIA data

With high temporal resolution (12 s) of about two hours duration, data of a coronal hole structure in 171 à , 193 à and 211 à taken from SDO/AIA images is considered for examination of oscillations. After estimating the total DN counts of a whole coronal hole structure in three wavelength bands, the resulting time series are subjected to FFT and wavelet analysis. Significant periods in all the three wavelength bands are detected that are mainly concentrated around 500 s as a fundamental mode and its odd (167, 100, 71, 56, 46, 39, 33, 29, 26, 24 s) harmonics. Computed phases in all the three wavelengths band are estimated to be constant. © 2014 COSPAR

Analytical assessment of Akika Pishti based on Ancient and Modern Parameters

Pishti Kalpana is one of the Kharaliya Kalpanas of Rasashastra which brings the heat sensitive substances to micro particle level without applying the heat for better therapeutic efficacy and is considered as Sukshma as Bhasma. In Rasa texts it is said that Marana of Ratna and Uparatna are not worthwhile hence, Pishti Kalpana is advocated. There is no direct reference for the Siddhilakshana of Pishti, but our Acharyas has mentioned that Pishti is a Anagnisidhdha Bhasma i.e. Pishti should be Bhasmavat, so the parameters mentioned for quality control of Bhasma in ancient text are applicable for assessing the Siddhilaxanas of Pishti. So an attempt has been made to study analytically Siddhilaxana of Pishti by both ancient and modern parameters with special reference to Akika Pishti. Akika is one of the semiprecious gem grouped under the Paradadi Varga, Uparatna Varga and Spatika Varga Ratna. In present study Pishti was prepared as per pharmacopeial standards and subjected to both ancient and modern tests to analyze viz. Pishtivarna, Mrudutva and Slakshanatva, Rekhapurnata, Varitara, Nirdhooma, Unama and Nischandratva tests according to classics and according to modern parameters like organoleptic tests, physio-chemical like LOD, pH, ash values, instrumental analysis like XRD , SEM-EDAX and particle size

Brief Review of literature on Puti Lohas

Rasashastra is a science which deals with the pharmaceuticals of medicines out of mercury, minerals, metals, gem stones and animal products etc. Loha and Dhatu are consider as one and the same. Puti Lohas are those drugs which emits bad smell while they are melting. Many references of Puti Lohas is available in Ayurvedic classics since Vedakala to modern texts. Puti Lohas cannot be degraded since they are having their own identity in mineralogy and clinical practice of Ayurveda

Maternal and perinatal outcome in placenta previa in atertiary care centre: a record based retrospective case series study

Background: Placenta previa occurs when the placenta is situated wholly or partially in the lower uterine segment. It is one of the leading causes for maternal and perinatal morbidity and mortality. It occurs in 4 to 5 cases out of 1000 pregnancies and remains a significant cause for maternal and perinatal morbidity and mortality. Objective of this study is to know the maternal and perinatal outcome in placenta previa. Methods: It is a retrospective case series study. Data of 51 pregnant women diagnosed with placenta previa managed at SNMC and HSK hospital between January 21 to December 22 were retrieved and analyzed. Results: Incidence of placenta previa was found to be 1.6% of 3135 deliveries at the given time. Among 51 cases of placenta previa, 7.84% delivered vaginally, 92.16% underwent caesarean section. 45.10% were early preterm, 29.41% had late preterm delivery, 25.49% had term deliver, 49.02% had h/o previous LSCS, 7.8% had history of d and e, 17.65% had h/o abortion, 11.76 % still born. Blood transfusion was done for 27.45% of women, post-partum haemorrhage was documented in 21.56%, 7.84% needed ICU admission and there were no documented peri-partum hysterectomy upon any of these women. Conclusions: The availability of advanced emergency obstetric care across greater number of referral hospitals has been responsible to decrease the morbidity and mortality associated with many complicated obstetric conditions. However the challenge is that as this condition is confirmed by ultrasound, women should take regular antenatal check-ups, should be counselled and made aware of the complications associated with this condition so that adequate and appropriate management can be planned and executed for better maternal and perinatal outcome also with on time referral to tertiary care centre where there is required multidisciplinary team, adequate availability of blood and blood products, NICU and ICU facilities where these high risk caesarean be managed efficiently the potential to limit maternal and perinatal mortality and morbidity caused due to placenta previa can be greatly reduced

Fracture analysis of AA6061-graphite composite for the application of helicopter rotor blade

The main objective of the work is to study the fracture behavior of AA6061-graphite material using both experimental technique and finite element simulation by considering helicopter rotor blade as a case study. From the case study, it has been observed that the helicopter rotor blade, made of AA6061, has been failed at the threaded portion of the hole. Experimental fracture toughness is carried out using the compact tension specimens as per ASTM standard testing procedure. Modeling of compact tension specimens and the threaded portion of the bolt hole was utilized to analyze the fracture toughness using a simulation tool. From the results and the comparison, it is recommended to use AA6061-9wt% graphite material as a replacement of AA6061 in the application of main rotor blades of the helicopter

Salinity Tolerance of Forage Range Legumes during Germination and Early Seedling Growth

Salinity is one of the rising problems causing tremendous yield losses in many regions of the world especially in arid and semiarid regions. In India, about 5.95M ha areas were affected by salinity. Five states viz. Haryana, Punjab, Rajasthan, Gujarat and Andhra Pradesh accounts for 48% of the total salt affected soils of the country. Establishment of seedlings at early growth stages of crop plants as one of the most important determinants of high yield is severely affected by soil salinity. Increasing salinity levels significantly decreased germination parameters, shoot and root length, shoot and root fresh and dry weights of some forage sorghum cultivars (Kandil et al., 2012). Therefore, in the present investigation three forage range legumes namely centro, clitoria and siratro were tested for their relative salt tolerance to increasing levels of salinity in those combinations of salts which nearly exist in the natural salt affected soils

Investigation of Impact Energy Absorption of AA6061 and Composites: Role of Post-Aging Cooling Methods

Al6061 and its composites are widely employed in applications requiring high strength and impact resistance. Heat treatment, particularly ageing, is a well-established method for enhancing the mechanical properties of these composites. However, the influence of post-ageing cooling methods on the impact energy absorption capacity of Al6061 and its composites remains inadequately understood. This investigation aims to examine the impact energy absorption of Al6061 and its composites after ageing at 460°C for 2 hours, employing different cooling methods, including furnace cooling, air cooling, and water cooling. The composites were produced using the stir casting technique with varying weight fractions of graphite and SiC particles based on Taguchi's design of experiments. Charpy impact tests were conducted using a specialised testing machine. The results reveal that the impact energy absorption capacity of the composites is influenced by the cooling method employed after the ageing treatment. Furnace cooling demonstrated the highest impact energy absorption capacity compared to the other cooling methods, exhibiting a 28% increase compared to the monolithic aluminium alloy. Furthermore, it was observed that the impact energy absorption capacity of the composites did not improve with an increase in the weight fraction of SiC particles, while the addition of graphite negatively impacted the absorption capacity