Microwave technique for reflector antenna profile measurement

A method for microwave measurement of the reflector antenna surface profile is described. The technique uses a focused monostatic secondary reflector located on axis at approximately two focal lenths from the reflector under test. Measurement of the two-ways phase change provides profile error information over a set of annular sections. Practical results are provided to illustrate the spatial resolution and sensitivity of the technique.     

Coherent imaging with two-dimensional focal-plane arrays: design and applications

Scanned, single-channel optical heterodyne detection has been used in a variety of lidar applications from ranging and velocity measurements to differential absorption spectroscopy. We describe the design of a coherent camera system that is based on a two-dimensional staring array of heterodyne receivers for coherent imaging applications. Experimental results with a single HgCdTe detector translated in the image plane to form a synthetic two-dimensional array demonstrate the ability to obtain passive heterodyne images of chemical vapor plumes that are invisible to normal video infrared cameras. We describe active heterodyne imaging experiments with use of focal-plane arrays that yield hard-body Doppler lidar images and also demonstrate spatial averaging to reduce speckle effects in static coherent images.     

Integration of Radioactive Material with Microcalorimeter Detectors

Microcalorimeter detectors with embedded radioactive material offer many possibilities for new types of measurements and applications. We will discuss the designs and methods that we are developing for precise deposition of radioactive material and its encapsulation in the absorber of transition-edge sensor (TES) microcalorimeter detectors for two specific applications. The first application is total nuclear reaction energy (Q) spectroscopy for nuclear forensics measurements of trace actinide samples, where the goal is determination of ratios of isotopes with Q values in the range of 5–7 MeV. Simplified, rapid sample preparation and detector assembly is necessary for practical measurements, while maintaining good energy resolution. The second application is electron capture spectroscopy of isotopes with low Q values, such as \(^{163}\) Ho, for measurement of neutrino mass. Detectors for electron capture spectroscopy are designed for measuring energies up to approximately 6 keV. Their smaller heat capacity and physical size present unique challenges. Both applications require precise deposition of radioactive material and encapsulation in an absorber with optimized thermal properties and coupling to the TES. We have made detectors for both applications with a variety of designs and assembly methods, and will present their development.     

Profiling selected phytochemicals and nutrients in different tissues of the multipurpose tree Moringa oleifera L., grown in Ghana

The purpose of this new study was to determine the types and levels of major phytochemicals (non-nutrients) and nutrients in the different tissues from vegetative and flowering Moringa oleifera L. an important multipurpose crop. Rhamnose and acetyl-rhamnose-substituted glucosinolates were found in all of the M. oleifera tissues with different profiles depending on the tissue. In addition the tissues of M. oleifera had a relatively complex flavonoid profile consisting of glucosides, rutinosides, malonylglucosides and traces of acetylglucosides of kaempferol, quercetin and isorhamnetin. Fatty acid profiling of the different tissues showed that leaves were rich in palmitic (16:0) and linolenic (18:3) acid whereas seeds were predominated by oleic acid (18:1). Roots were rich in palmitic and oleic acid, whereas stems and twigs predominately contained palmitic acid. Potassium, magnesium and calcium were the predominant minerals in all of the tissues. Low levels of selenium were detected only in whole seeds.     

Influence of denaturation and aggregation of β-lactoglobulin on rennet coagulation properties of skim milk and ultrafiltered milk

Skim milk and ultrafiltered milk were heated at temperatures in the range 80–140 °C for 4s in a UHT plate heat exchanger. The extent of denaturation of β-lactoglobulin and its association with the casein micelles increased with increase in heating temperature; the extent of association was markedly less than the amount that denatured. There was no noticeable difference in the extent of denaturation and association of β-lactoglobulin between skim milk and the corresponding ultrafiltered milk. The coagulation properties of renneted heated milks were measured by dynamic oscillation rheometry. Gelation times and storage modulus (G′) could be related to the extent of denaturation of β-lactoglobulin and its association with the casein micelles. Denaturation of β-lactoglobulin up to 60% had no effect on the gelation time, but additional denaturation markedly increased the gelation times. In contrast, G' decreased gradually with increase in the extent of denaturation of β-lactoglobulin and its association with casein micelles. The effects of β-lactoglobulin denaturation and association on coagulation properties were less pronounced in ultrafiltered milk. G' values for ultrafiltered milk were markedly higher than the corresponding skim milks under all heating conditions.     

Responses of cells of posterior lateral line lobe to activation of electroreceptors in a mormyrid fish

Activity of neurons in the lateral line lobe was studied by intracellular recording of responses to stimulation of the lateral line nerves and of electroreceptors on the skin surface. Two modes of activation occur for cells responding to inputs from medium receptors. There is a direct monosynaptic input mediated by a single fiber. Short latency of response and antidromic spread from cell to afferent fiber indicate that the mediating synapse is electrotonic. The second input is from a number of additional fibers and is relayed, presumably by the granule cells. At shortest latency this input is disynaptic, probably involving at least one electrotonic synapse. A relay is indicated by heterosynaptic facilitation of the PSP and by pronounced depression with repetitive stimulation. The monosynaptic input may be on the axon. Disynaptic inputs are distributed over the dendrites, and impulses can arise in the dendrites. What appear to be spikes restricted to dendritic regions are often recorded as small brief potentials in the cell body. There is a somatotopic projection of the electroreceptors to the lateral line lobe. The monosynaptic input comes from a specific receptor in the periphery. Strong disynaptic inputs come from a group of receptors generally found anterior, but less commonly posterior or lateral, to the receptor giving rise to the monosynaptic input. Additional inputs that are inhibitory come from surrounding receptors. The inhibition only affects responses to the disynaptic input. The different inputs and multiple sites of impulse initiation must modify the cell's response as compared with the input-output relations that would be obtained with inputs acting on a single summation point. Cells responding to activation of large receptors are infrequent. They are characterized by low threshold, little latency change near threshold, and ability to follow high frequencies of stimulation.     

Transnasal hypophysectomy

A transnasal trans-sphenoidal surgical approach to the pituitary gland is described. The operative and post-operative experiences with the use of this technique on 21 patients with hormone-dependent malignant disease are reported. In 2 patients the procedure was abandoned because of intrasellar haemorrhage and in 1 an empty sella was found. Fifteen patients developed diabetes insipidus and 1 patient died in the postoperative period.     

Aminoglutethimide in the treatment of Cushing's syndrome

The efficacy and tolerability of aminoglutethimide for the treatment of Cushing's syndrome was assessed in 66 cases three of which are described in the present paper. Aminoglutethimide provided palliation from the signs and symptoms of hypercorticism in 13 of 21 patients with metastatic adrenocortical carcinoma and four of six patients with ectopic ACTH production due to metastatic carcinomas. All six of the patients with adrenal adenomas showed clinical and biochemical improvement, while 14 of the 33 patients with bilateral adrenal hyperplasia of pituitary origin improved. Adverse reactions attributed to aminoglutethimide such as drowsiness, rash, and nausea occurred in 58 per cent of cases. These data suggest that aminoglutethimide has a place in controlling the signs and symptoms of adrenocorticoid excess in patients with Cushing's syndrome due to malignancy and is effective preoperative therapy for patients with adrenal adenomas and bilateral hyperplasia.