ADAPTIVE BEHAVIOR AND THE PROXEMIC STUDY OF A SMALL GROUP OF SEVERELY MENTALLY RETARDED CHILDREN

The study sought to develop a method for recording and analyzing some of the patterns of the proxemic behavior of a small group of retarded children. It further sought to determine whether or not there were reliably measurable proxemic group behavior and individual differences in the proxemic behavior of mentally retarded subjects who were not significantly different in behavior patterns measured by an adaptive behavior scale. The four subjects used in this study were observed in a small rectangular room. A photographic record was made at two minute intervals of the positions of the subjects in the room. From this record measurements of the distancing behavior between subjects was made. The results have shown that subjects who had no significant differences in adaptive behavior, as measured by an adaptive behavior scale, exhibited significant differences in proxemic behavior. Not only did individual differences become apparent, but also reliably measurable proxemic patterms emerged for the group

Environmental education : a quest for the future : inaugural lecture delivered at Rhodes University

Inaugural lecture delivered at Rhodes UniversityRhodes University Libraries (Digitisation

Conservation awareness amongst white adolescents in South Africa: a study of senior secondary pupils in Natal.

Masters Degree. University of KwaZulu-Natal, Pietermaritzburg.Abstract available PDF

The etiology of bacterial soft rot of onions and identification of the causal organisms

Observations of bacterial soft rot of onions in the Lake Labish area in the Willamette Valley of western Oregon showed that two distinct symptom types occur during the growing season. The most prevalent symptom type appears in infected plants as a wilting and chlorosis of two or more lower leaves which is followed closely by appearance of elongated lesions emerging from the neck and extending up the adaxial side of one or more young leaves. Although most infected plants showing these symptoms usually decay quickly, some plants may appear to partially recover if conditions unfavorable for disease development return. A second symptom type is evident in those infected plants in which the collapse of all emerged leaves occurs simultaneously. During leaf collapse, foliar color changes from dark green to grey-green and finally, with desiccation, to light tan. Two kinds of soft rot also occur commonly in stored onions. One kind of decay, commonly called "slippery skin, " is characterized by the progression of soft rot down through one or two of the outer fleshy scales. These scales turn yellowish, soft, and are foul smelling. A second kind of soft rot is characterized by the interior of the bulb being totally macerated and putrid, but only slightly discolored. Only one or two of the outer fleshy scales remain firm. This decay is commonly called "stinking rot" because of its very offensive odor. Initial appearance of bacterial soft rot in the third week of June is directly related to occurrence of rain and cool, cloudy weather in the previous week. Occurrence of such periods of inclement weather are found to be predictable when past records of local climatological conditions are analyzed. Area-wide outbreaks throughout the remainder of the growing season also are related to such periods of inclement weather. The relationship between weather and disease suggests that outbreaks of bacterial soft rot can be forecast by occurrence of such periods of inclement weather. Irrigation of onions with contaminated surface waters significantly increases the amount of bacterial soft rot in the field, at harvest time, and in storage, over that found when uncontaminated well water is used. Varying the frequency of irrigations, the rates of application, and the size of sprinkler nozzles affect the amount of soft rot in the field and in storage somewhat less than does the source of water. Longer and more frequent periods of irrigation increase the incidence of bacterial soft rot. Much of the decay seen at harvest is either soft rot which has totally decayed the bulbs and will not go into storage, or is fungal in origin. Including storage rots which are fungal in origin under the general grouping of "soft rots" inflates the estimation of losses due to bacterial soft rot. Three isolates of seventeen unknown isolates capable of decaying inoculated onion bulbs were identified as Pseudomonas cepacia. Five isolates which lack ability to produce a water-soluble fluorescent pigment and possess a nitrate reductase system were otherwise virtually identical to P. cepacia. Two additional isolates were identified as P. cichorii on the basis of physiological tests. Three other isolates were provisionally identified as members of the genus Erwinia on the basis of cell shape, flagellation, and pathogenicity. The remaining four isolates were not identified

Experimental study of the filling of thin-walled investment Castings in 17-4PH stainless steel

The global requirements on lower fuel consumption and emissions are increasing the demand for lowering the weight of cast components. Reducing the wall thickness of cast components is one way of achieving this. The aim of this work was to investigate castability of 17-4PH stainless steel in thin-walled test geometries (less than 2mm). The casting trials were performed to investigate the fluidity as a function of casting temperature, mold preheat temperature and filling systems in thin-walled sections. It was observed that fluidityin a top-gated configuration is strongly affected by casting temperature, however, effect of mold pre heat temperature on fluidity was not significant. On the other hand, castings made in bottom-gated configuration were more stable and fluidity was not significantly affected by variation in casting temperature and mold preheat temperature. Less porosityand flow-related defects were observed in the bottom-gated system as compared to top-gated system

The Status of Ethics in Technology Education

Ethics is not a new concept within technology education. The inclusion of ethics evolved naturally from the progression of technological activity in the latter part of the twentieth century. During this shift to a postindustrial society, people started to look at technology from a more humanistic view than they previously had. To keep pace with these changes, a new ethic was suggested to help advance technological literacy by highlighting the relationship between humans, the environment, and technology (DeVore, 1980, 1991). How far have we come? This chapter reviews the current state of ethics within technology education. In the first two sections, materials for classroom instruction, including textbooks and modular materials, are examined. The third section discusses and recommends resources and practices that appear in professional literature. A survey of international technology education and ethics constitutes the fourth section. The chapter concludes with a look at professional ethics as they relate to technology teachers, teacher educators, and administrators

EXCEDE Technology Development III: First Vacuum Tests

This paper is the third in the series on the technology development for the EXCEDE (EXoplanetary Circumstellar Environments and Disk Explorer) mission concept, which in 2011 was selected by NASA's Explorer program for technology development (Category III). EXCEDE is a 0.7m space telescope concept designed to achieve raw contrasts of 1e6 at an inner working angle of 1.2 l/D and 1e7 at 2 l/D and beyond. This will allow it to directly detect and spatially resolve low surface brightness circumstellar debris disks as well as image giant planets as close as in the habitable zones of their host stars. In addition to doing fundamental science on debris disks, EXCEDE will also serve as a technological and scientific precursor for any future exo-Earth imaging mission. EXCEDE uses a Starlight Suppression System (SSS) based on the PIAA coronagraph, enabling aggressive performance. We report on our continuing progress of developing the SSS for EXCEDE, and in particular (a) the reconfiguration of our system into a more flight-like layout, with an upstream deformable mirror and an inverse PIAA system, as well as a LOWFS, and (b) testing this system in a vacuum chamber, including IWA, contrast, and stability performance. The results achieved so far are 2.9e-7 contrast between 1.2-2.0 l/D and 9.7e-8 contrast between 2.0-6.0 l/D in monochromatic light; as well as 1.4e-6 between 2.0-6.0 l/D in a 10% band, all with a PIAA coronagraph operating at an inner working angle of 1.2 l/D. This constitutes better contrast than EXCEDE requirements (in those regions) in monochromatic light, and progress towards requirements in broadband light. Even though this technology development is primarily targeted towards EXCEDE, it is also germane to any exoplanet direct imaging space-based telescopes because of the many challenges common to different coronagraph architectures and mission requirements.Comment: 12 pages, 12 figures, to be published in proceedings of SPIE Astronomical Telescopes + Instrumentation (2014

Prototype finline-coupled TES bolometers for CLOVER

CLOVER is an experiment which aims to detect the signature of gravitational waves from inflation by measuring the B-mode polarization of the cosmic microwave background. CLOVER consists of three telescopes operating at 97, 150, and 220 GHz. The 97-GHz telescope has 160 feedhorns in its focal plane while the 150 and 220-GHz telescopes have 256 horns each. The horns are arranged in a hexagonal array and feed a polarimeter which uses finline-coupled TES bolometers as detectors. To detect the two polarizations the 97-GHz telescope has 320 detectors while the 150 and 220-GHz telescopes have 512 detectors each. To achieve the target NEPs (1.5, 2.5, and 4.5x10^-17 W/rtHz) the detectors are cooled to 100 mK for the 97 and 150-GHz polarimeters and 230 mK for the 220-GHz polarimeter. Each detector is fabricated as a single chip to ensure a 100% operational focal plane. The detectors are contained in linear modules made of copper which form split-block waveguides. The detector modules contain 16 or 20 detectors each for compatibility with the hexagonal arrays of horns in the telescopes' focal planes. Each detector module contains a time-division SQUID multiplexer to read out the detectors. Further amplification of the multiplexed signals is provided by SQUID series arrays. The first prototype detectors for CLOVER operate with a bath temperature of 230 mK and are used to validate the detector design as well as the polarimeter technology. We describe the design of the CLOVER detectors, detector blocks, and readout, and present preliminary measurements of the prototype detectors performance.Comment: 4 pages, 6 figures; to appear in the Proceedings of the 17th International Symposium on Space Terahertz Technology, held 10-12 May 2006 in Pari

Radio and X-ray observations of SN 2006jd: Another strongly interacting Type IIn supernova

We report four years of radio and X-ray monitoring of the Type IIn supernova SN 2006jd at radio wavelengths with the Very Large Array, Giant Metrewave Radio Telescope and Expanded Very Large Array; at X-ray wavelengths with {\em Chandra}, {\em XMM-Newton} and {\em Swift}-XRT. We assume that the radio and X-ray emitting particles are produced by shock interaction with a dense circumstellar medium. The radio emission shows an initial rise that can be attributed to free-free absorption by cool gas mixed into the nonthermal emitting region; external free-free absorption is disfavored because of the shape of the rising light curves and the low gas column density inferred along the line of sight to the emission region. The X-ray luminosity implies a preshock circumstellar density $\sim 10^6$ cm$^{-3}$ at a radius $r\sim 2\times 10^{16}$ cm, but the column density inferred from the photoabsorption of X-rays along the line of sight suggests a significantly lower density. The implication may be an asymmetry in the interaction. The X-ray spectrum shows Fe line emission at 6.9 keV that is stronger than is expected for the conditions in the X-ray emitting gas. We suggest that cool gas mixed into the hot gas plays a role in the line emission. Our radio and X-ray data both suggest the density profile is flatter than $r^{-2}$ because of the slow evolution of the unabsorbed emission.Comment: Accepted for publication in ApJ without any change

Pointing control for the SPIDER balloon-borne telescope

We present the technology and control methods developed for the pointing system of the SPIDER experiment. SPIDER is a balloon-borne polarimeter designed to detect the imprint of primordial gravitational waves in the polarization of the Cosmic Microwave Background radiation. We describe the two main components of the telescope's azimuth drive: the reaction wheel and the motorized pivot. A 13 kHz PI control loop runs on a digital signal processor, with feedback from fibre optic rate gyroscopes. This system can control azimuthal speed with < 0.02 deg/s RMS error. To control elevation, SPIDER uses stepper-motor-driven linear actuators to rotate the cryostat, which houses the optical instruments, relative to the outer frame. With the velocity in each axis controlled in this way, higher-level control loops on the onboard flight computers can implement the pointing and scanning observation modes required for the experiment. We have accomplished the non-trivial task of scanning a 5000 lb payload sinusoidally in azimuth at a peak acceleration of 0.8 deg/s$^2$, and a peak speed of 6 deg/s. We can do so while reliably achieving sub-arcminute pointing control accuracy.Comment: 20 pages, 12 figures, Presented at SPIE Ground-based and Airborne Telescopes V, June 23, 2014. To be published in Proceedings of SPIE Volume 914