Structure-Property Correlation of Hypoeutectic Al-7.6Si Alloys with and without Al-5Ti-1B Grain Refiner

696-700Hypoeutectic Al-7.6Si alloy has been developed with and without Al-5Ti-1B grain refiner through the gravity casting method. Effects of 2, 4, and 6 wt % master alloy (Al-5Ti-1B) addition on the microstructural morphology, mechanical properties (percentage elongation (%El) and ultimate tensile strength (UTS)), hardness and fracture behaviour of the Al-7.6Si alloy have been investigated. Unmodified hypoeutectic Al-7.6Si alloy consists of needle and rod-like eutectic Si ((Si)E) particles with sharp corners inside the Alα phase. In the grain refined Al-7.6Si alloy, TiB2 is formed and these TiB2 acts as a potential site for nucleation of Alα grains. Therefore, the grain refined alloys have fine globular Alα grains and fibrous (Si)E phase. The bulk hardness, UTS and elongation (%) are increased in the grain refined alloys. Further, fractography show that the cleavage fracture is reduced in the modified alloy and fine dimple formation is increased

Structure-Property Correlation of Hypoeutectic Al-7.6Si Alloys with and without Al-5Ti-1B Grain Refiner

Hypoeutectic Al-7.6Si alloy has been developed with and without Al-5Ti-1B grain refiner through the gravity casting method. Effects of 2, 4, and 6 wt % master alloy (Al-5Ti-1B) addition on the microstructural morphology, mechanical properties (percentage elongation (%El) and ultimate tensile strength (UTS)), hardness and fracture behaviour of the Al-7.6Si alloy have been investigated. Unmodified hypoeutectic Al-7.6Si alloy consists of needle and rod-like eutectic Si ((Si)E) particles with sharp corners inside the Alα phase. In the grain refined Al-7.6Si alloy, TiB2 is formed and these TiB2 acts as a potential site for nucleation of Alα grains. Therefore, the grain refined alloys have fine globular Alα grains and fibrous (Si)E phase. The bulk hardness, UTS and elongation (%) are increased in the grain refined alloys. Further, fractography show that the cleavage fracture is reduced in the modified alloy and fine dimple formation is increased

Demographic and clinico-pathological profile of carcinoma stomach in a tertiary referral centre of Eastern India

Objectives: This prospective study was done to assess the incidence, clinical presentations, histopathological subtypes of gastric adenocarcinoma in a referral institute of Eastern India. Methods: The patients admitted with diagnosis of gastric carcinoma in a tertiary referral hospital in Eastern India between January2006 to December2010 were included in this study. Data were compiled and analyzed with regards to their age, sex, socioeconomic status, their clinical presentations, site of lesion & histopathological subtypes. Results: 150 patients were included in this study of which 50 patients were of ≤50 years age. The median age group was 57 years. The male: female ratio was 2.3:1. Most of the patients were from lower socioeconomic strata (55.33%). Anemia (41.33%) and weight loss (38%) were the predominant presenting features irrespective of age, whereas gastric outlet obstruction due to antral growths was the commonest presentation in patients of ≤50 years age group. The most common histopathological type was adenocarcinoma; patients of≤50 years of age group presented with well differentiated and moderately differentiated adenocarcinoma while those in >50 years age group with poorly differentiated growth. Most (82.66%) of the patients presented with advanced growth(T3/T4). Conclusion: 1) The incidence of gastric carcinoma in patients younger than 50 years was more common than Western world. 2) Patients are presenting more with lesion in distal stomach than Western world. 3) Gastric outlet obstruction and metastatic disease are commoner than abdominal lump and upper GI bleeding. The latter being the commoner presentations in Western world. 4) Regarding the histological type, adenocarcinoma are commoner than in Western world and 5) Patients with signet cell subtype are much less than Western world

Dermoid cyst of the mesentery in an infant

7 months old male child presented with abdominal distension since birth. On examination there was a lobulated, tense cystic mass occupying almost 2/3 of the abdominal cavity. Ultrasonography (USG) revealed a predominantly hypoechoic mass measuring 17cm x 14cm x15cm. CT scan of abdomen showed a multiseptate cystic mass with eccentrically located areas of fat and calcification. Exploration of the abdomen revealed a huge thick walled cyst within the leaves of the mid ileal mesentery which could be enucleated out entirely after careful dissection. Histopathology suggested it to be a benign cystic teratoma (Dermoid cyst)

Primary small gut lymphoma presenting as an incarcerated inguinal hernia in an adult

A 73-year-male presented with features of subacute small gut obstruction of 10 days duration. He also complained of a painless, slowly enlarging swelling in the right groin, which was first noticed 10 years ago. There was a history of weight loss, anorexia, and asthenia but no history of fever, respiratory, or urinary symptoms. He was a smoker and was on medication for hypertension and type 2 diabetes mellitus. The general health of the patient was poor. He appeared pale and dehydrated. No lymphadenopathy was evident on the general survey. The abdomen was distended, tense with hyperactive bowel sounds. Examination of the groin and genitalia revealed right inguinal hernia and an irreducible, firm, solid, nontender, 6 cm × 5 cm scrotal mass separate from the right testis. Digital rectal examination revealed no abnormality. Contrast-enhanced computed tomography of the abdomen showed dilated gut loops, right inguinal hernia, and a gut related endophytic soft-tissue mass in the scrotum. Exploration after resuscitation revealed a firm, endoluminal soft-tissue mass arising from the apex of the herniated loop of the small gut which was obliterating its lumen. The tumor-bearing segment of the gut was resected through a groin incision. We then performed a laparotomy to bring out the ends of the bowel loops as double barrel ileostomy. The hernial defect was then repaired. Postoperative recovery was uneventful. Histopathology of the excised specimen suggested the possibility of Non-Hodgkin's lymphoma of small gut. Immunohistochemistry confirmed it to be low-grade follicular B-cell NHL

Microstructural evolution and hardness property of in situ Al–Mg2Si composites using one-step gravity casting method

In the present investigation, Al–X wt-% Mg2Si (X = 0, 5, 10, 15 and 20) in situ composites are successfully synthesised by one-step gravity casting technique. Commercially pure Al, Mg and Si are used as raw materials. Microstructural evaluation and correlation of micro- and bulk hardness properties have been studied on developing composites. The composites consist of mainly three phases: matrix (α-Al), reinforcing (primary Mg2Si) and binary eutectic (Al–Mg2Si) phase. Primary Mg2Si particles are formed by pseudo-eutectic transformation during solidification and surrounded by matrix and binary eutectic phase. It is found that Mg2Si concentration has a significant impact on morphology and volume per cent of the above-mentioned phases. Primary Mg2Si particles’ size and volume per cent increase with increasing wt-% of Mg2Si. Volume per cent of individual phases and Mg2Si concentration have great impact on hardness properties of composites. Bulk hardness increases with increasing wt-% of Mg2Si concentration, but micro-hardness of primary Mg2Si particle decreases slightly. Mg2Si concentration also has significant impact on micro-hardness of individual phases