Corrosion Characteristics of Copper-Added Austempered Gray Cast Iron (AGCI).

The aim of this investigation was to assess the corrosion behavior of gray cast iron (GCI) alloyed with copper. Alloyed GCI specimens were austempered isothermally at varying temperatures. After austenitizing at 927 °C, the samples were austempered at different temperatures ranging from 260 to 385 °C with an interval of 25 °C for 60 minutes. As a result, these samples developed an ausferrite matrix with different percentages of austenite. The resulting microstructures were evaluated and characterized by optical microscope (OM), scanning electron microscope (SEM), and X-ray diffraction (XRD). The corrosion characteristics were determined using potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) of these samples. These tests were carried out in a medium of 0.5 M H2SO4 and 3.5% NaCl solution. It was observed from the potentiodynamic polarization results that with increasing austempering temperature, the corrosion rate decreased. All results of the EIS were in accordance with a constant phase element (CPE) model. It was found that with an increase in austempering temperature, the polarization resistance (Rp) increased. The austenite content was also found to influence the corrosion behavior of the austempered gray cast iron (AGCI).

Microstructure characterization and corrosion resistance properties of Pb-Sb alloys for lead acid battery spine produced by different casting methods.

The aim of this study is to find out the microstructure, hardness, and corrosion resistance of Pb-5%Sb spine alloy. The alloy has been produced by high pressure die casting (HPDC), medium pressure die casting (AS) and low pressure die casting (GS) methods, respectively. The microstructure was characterized by using optical microscopy and scanning electron microscopy (SEM). The hardness was also reported. The corrosion resistance of the spines in 0.5M H2SO4 solution has been analyzed by measuring the weight loss, impedance spectroscopy and the potentiodynamic polarization techniques. It has been found that the spine produced by HPDC has defect-free fine grain structure resulting improvement in hardness and excellent corrosion resistance.

Acute fulminant fungal sinusitis: clinical presentation, radiological findings and treatment.

Acute fulminant fungal sinusitis is characterized by acute symptoms and rapid progress with a mortality rate of 60-80%. A large number of survivors have permanent neurological, visual and cosmetic disabilities. This clearly underscores the need of early recognition of this disease in at risk population in order to start urgent treatment. The at-risk population of diabetics, AIDS and other immunosuppressed is likely to increase, as will the incidence of acute fulminant fungal sinusitis. In the present study we have reviewed nine cases of acute fulminant fungal sinusitis to determine clinical presentation, related radiological picture and optimum treatment. Most common presenting features were fever, headache, facial swelling and proptosis. Many patients presented with blindness, facial paralysis and meningitis. Predisposing causes were uncontrolled diabetes with ketoacidosis in four out of six cases, post renal transplant immunosuppression and leukemia. All patients were treated with amphotericin B or liposomal amphotericin B (AmBisome). Diagnosis was confirmed by biopsy and culture of sinus mucosa, soft tissues of cheek, or orbit. Mucor (Zygomycetes) was identified on culture or histopathology in all cases. Surgical debridement was performed in seven cases. Six out of nine patients survived but morbidity was high: only two patients survived without any permanent disability.

Nasopharyngeal cyst of branchiogenic origin: report of a case and review of the literature.

To date, only 22 cases of nasopharyngeal cyst of branchiogenic origin have been reported in the literature. In this article, we report a new case in a 35-year-old woman. We also present a review of the literature and a discussion of the sites of origin, histopathology, and treatment modalities.

Mediastinal emphysema associated with functional endoscopic sinus surgery. A case report.

A case of mediastinal emphysema after functional endoscopic sinus surgery (FESS) is presented. Mediastinal emphysema is a rare and previously unreported complication after FESS. The possible aetiologies are discussed.

Granulomatous osteomyelitis of the maxillary sinus.

A case of granulomatous osteomyelitis of the maxilla, probably due to tuberculosis is reported, and the literature reviewed. Excision of the diseased tissue with antitubercular treatment forms the most effective line of treatment.

Amino acid requirements of the breeding sow. 2. The dietary lysine requirement of the lactating sow.

1. Two experiments, involving six lactating Landacre x (Landrace x Large White) sows were undertaken to study the lysine requirement of the lactating sow and to identify the second limiting amino acid by means of interpretation of plasma amino acid and blood urea levels. 2. A basal diet composed mainly of equal amounts of ground barley and ground wheat supplemented with mineral and vitamin mixtures was used. This diet was supplemented with synthetic amino acids (lysine threonine, tryptophan, methionine and isoleucine). 3. Plasma amino acid and blood urea values showed a close agreement and indicated that lysine intake above 38.4 g/d was in excess of the requirement level. 4. Plasma amino acid values suggested tryptophan to be the second limiting amino acid whereas blood urea values suggested threonine to be the second limiting amino acids.

Amino acid requirements of the breeding sow: the dietary lysine requirement during pregnancy.

1. Four pregnant sows were used to study lysine requirements by means of the interpretation of values for plasma amino acid and blood urea. Diets containing graded levels of dietary lysine were fed at the rate of 1.82 kg/d. 2. Plasma lysine remained at a low level up to 6.4 g dietary lysine/kg (dry matter basis) and then increased sharply with further increases in lysine intake. 3. Blood urea levels decreased when the dietary lysine content was increased to 6.4 g/kg and then increased at higher dietary lysine concentrations. 4. Both criteria of response indicated that the lysine requirement of the pregnant sow given 1.82 kg diet/d during the later stages of pregnancy does not exceed 10.00 g/d.

Embryonal rhabdosarcoma of the middle ear and mastoid.

Two cases of embryonal rhabdomyosarcoma, arising from the middle ear, are described. It is a rare mesenchymal tumour of childhood, with a very poor prognosis. The literature is briefly reviewed and the difficulties encountered in diagnosis are outlined.

Hamartomas of the nose.

Three cases of hamartomas of the nose, very rare conditions in otolaryngology are reported. According to the Willis (1953) classification two of these cases, belonged to the angiomatous, and the third one to the lipomatous, group of hamartomas.

The variation in the concentration of plasma amino acids and blood urea in pregnant sows.

Two pregnant sows were fed on a basal diet consisting of equal amounts of ground barley and ground wheat with or without addition of L-lysine hydrochloride. Plasma amino acid and blood urea levels varied according to the time after feeding. Almost all the essential amino acids reached a maximum level after one hour and then declined at four hours after feeding. The results suggested that samples taken at between one and four hours after feeding were responsive to changes in dietary composition and could provide a measure to evaluate the amino acid pattern in relation to feeding. Both plasma amino acid and blood urea data suggested that lysine was the first limiting amino acid in the basal diet.