Showing papers by "Clemson University published in 1974"

Thermally enhanced radioresponse of cultured Chinese hamster cells: inhibition of repair of sublethal damage and enhancement of lethal damage.

Abstract: X-irradiation of Chinese hamster cells at temperatures above 37°C results in enhanced killing response. The magnitude of this thermal effect increases with increasing temperature and varies inversely with dose rate during the exposure of the cells to the combined effects of elevated temperature and ionizing radiation. Postirradiation incubation at an elevated temperature is also effective in enhancing the response but not preirradiation hyperthermia. Split-dose experiments demonstrate that hyperthermia also inhibits the repair of sublethal damage for temperatures up to ∼41°C. Above 41°C, lethal damage expression is enhanced as well. Fluctuations in the age-response structure of cells x-irradiated at 42°C are reduced, a result consistent with a reduced capacity for sublethal damage when cells are hyperthermic during irradiation.

Derivatives of Eigenvalues and Eigenvectors for a General Matrix

Abstract: Expressions are obtained for the derivatives of the eigenvalues and eigenvectors which are expressions of only one left-hand and one right-hand eigenvector. The approach described makes use of a Choleski decomposition or some other decomposition method. The method may be extended to find any order of derivative of the eigenvalue and eigenvector. The expressions obtained for finding the derivatives of eigenvalues and eigenvectors for nonself-adjoint systems may be applied to self-adjoint systems.

Effect of meat particle size and casing diameter on summer sausage properties during drying1

Abstract: Drying characteristics were evaluated for summer sausages (50% beef, 50% pork) prepared with three meat particle sizes obtained through grinding variations. Increases of chemical components (protein, fat, ash, salt, lactic acid) during 45 days of drying were dependent on the rate of moisture removal from sausages. Summer sausage produced with a 9-mm grinder plate for the pork and a 6-mm plate for beef (9-6 grinding combination) had a 34% shrinkage at 45 days, whereas sausages of a 3–6 and a 6-6 grind combination had shrinkages of 37% and 40%, respectively. The rate of moisture removal for an all beef summer sausage was lower for larger diameter sausage when 52, 62, and 73 mm sizes were compared. Moisture content of the outer one-third radius portion of the sausages was 5 to 7% lower than the moisture content of the inner two-thirds radius portion from 5 days through 45 days of drying. Both types of summer sausages (beef-pork and all beef) having greater than 1.2 kg/cm2 of shearing force were generally of ...

Defect analysis and yield degradation of integrated circuits

Abstract: Various attempts have been made to analyze the yield of integrated circuits in the presence of point defects. This paper analyzes the yield considering both radial and angular variation in the defect density. The effect of statistical variations in the average defect density from slice to slice is also included. Different types of defects which affect the yield are reviewed. The degradation in yield due to point defects, line defects, area defects, and defect clusters is considered in detail. A method of optimum chip placement is described, and the results of computer calculations showing yield as a function of chip size are given assuming different defect density distributions. The results are primarily applicable to large integrated circuit chips.

The role of porous polymeric materials in prosthesis attachment

Abstract: Polymeric materials are becoming increasingly popular as prosthetic materials in orthopedic surgery. One of these materials, polyethylene, is capable of being fabricated in a porous form suitable for tissue ingrowth. Porous polyethylene appears to be well suited for prosthesis attachment when bonded to its solid form of other prosthetic materials. Extensive bone growth into porous cylindrical specimens implanted in the canine femur has occurred as early as four weeks. Ingrown tissues appear normal and there is minimal inflammatory response. Mechanical strength of the porous material, though not as great as that of the solid material, does appear to be sufficient for certain orthopedic applications. Current research is directed toward determining interfacial strengths and the mechanical properties of the porous polyethylene-bone composite.

A Survey of Railway Vehicle Dynamics Research

Abstract: Presents a survey of the research concerned with the dynamics of single, conventional railway vehicles. Attention is concentrated on analytical research and only that experimental research that has been performed in conjunction with analytical efforts. The often conflicting objectives for railway vehicle suspension design and the research done to understand the design implications of these objectives are discussed.

Effect of stress on tissue ingrowth into porous aluminum oxide.

Abstract: A study of the tissue compatibility of aluminum oxide implants under different stress conditions in rabbits was performed over four- and eight-week implantation periods. The specific objectives were to examine endosteal bone ingrowth into aluminum oxide coneshaped plugs in amputated tibiae, while additional pellet-shaped implants in the tibiae and femora of rabbits with amputated and nonamputated limbs were studied to determine: (1) if the degree of loading placed on the amputated limb was sufficient to promote bone activity, (2) the degree of inertness and/or toxicity of the aluminum oxide implants, and (3) a possible cause of bone spurs. The results of the radiographic, histologic and microradiographic analyses of the in vivo implants demonstrated that there was little mineralized bone ingrowth into the coneshaped aluminum oxide implants in the amputated tibiae. The study also showed that the aluminum oxide pellet implants in the tibiae and femora of the nonamputated limbs demonstrated excellent mineralized bone ingrowth into surface and internal pores. By comparing these results with the incomplete ingrowth into corresponding pellet implants in the tibiae and femora of amputated limbs, it was determined that a lack of weight bearing and damage to the musculature and vascularity following amputation were interfering with the normal bone activity and therefore bone ingrowth. Angiographs and radiographs of the amputated tibiae demonstrated that bone spurs were present and that they originated at the site of the periosteal damage. Their cause was believed to be associated with an increase in the vascularity of the adjacent tissues.

Ghost neutrinos in general relativity

Abstract: An exact solution to the Einstein-Dirac equations is presented for a static, plane-symmetric spacetime generated by neutrinos. We find the neutrino field to be nonzero and correspond to a neutrino current along the symmetry axis of the space. The neutrinos yield a zero energy-momentum tensor and therefore the gravitational field is exactly the same as for the vacuum case. A comparison with other solutions is presented along with a discussion of the possible physical significance of this "ghost neutrino" field.

Analysis of the Piedmont in Northwest South Carolina

Abstract: Two major autochthonous nappes and a deep synformal structure occur in the Piedmont of northwest South Carolina. The cataclastic Brevard zone, which borders the Blue Ridge geologic belt on the southeast, is associated with the synformal belt of partially cataclastic and retrograded rocks at low amphibolite facies grade. This Non-migmatitic belt contains tight cylindroidal isoclines and tectonic slides with a northwest vergence. Refolded isoclines in the Non-migmatitic belt occur near the Brevard zone as a result of recurring displacements there. Immediately southeast lies the Walhalla nappe, which contains kyanite-grade rocks complexly folded into a northeast-plunging conical system. The migmatite front lies within this nappe and in places is coincident with the major slide boundary between the Walhalla nappe and the underlying synformal Non-migmatitic belt. The major slide that separates the overlying Six Mile nappe from the Walhalla nappe is subhorizontal; however, in the broad root zone of both nappes in the southeast part of the area, northwest dips and steep dips represent the attitudes of s-surfaces in many locations. The autochthonous nappe complex probably formed in a continental rise assemblage subjected to intense thermal effects in the early Paleozoic. Sedimentary and (or) volcanic-volcaniclastic assemblages sited along the continental margin were squeezed as a detachment zone between the northwest-driving Piedmont nappes and the activated craton margin. These assemblages became tectonically related to a detachment zone overlying the rising infrastructural nappes, which is now eroded away with the overlying supra-structure. Annealed textures indicate that metamorphism outlasted penetrative deformation, except along the Brevard zone, which continued as a zone of dislocation while thermal metamorphism waned. Late Paleozoic Alleghanian movements may be recorded as microbreccia zones within the Brevard zone and Inner Piedmont belt. This event was not penetrative; instead, it was one of vertical en bloc uplift primarily centered in the Inner Piedmont, and perhaps it accompanied a weak retrogressive metamorphism.

Nucleosynthesis in white-dwarf atmospheres

Abstract: Consideration of events by which both s- and r-process nucleosynthesis may occur on the surfaces of white-dwarf stars. The main requirement is that the accreted hydrogen be mixed with comparable numbers of C-12 (or other alpha nuclei) before a runaway capture of protons takes place. Subsequent events offer many possibilities for nucleosynthesis and stars of peculiar composition. A new mechanism for a surface s-process due to few-MeV protons is also described. Concluding comments concern cosmic gamma-ray bursts and the origin of anomalous low-energy galactic cosmic rays.

PROPERTIES OF A FERMENTED, SEMIDRY TURKEY SAUSAGE DURING PRODUCTION WITH LYOPHILIZED AND FROZEN CONCENTRATES OF Pediococcus cerevisiae

Abstract: Turkey sausage mixes utilizing breast, thigh and skin tissues were inoculated with either lyophilized or frozen concentrate starter cultures of Pediococcus cerevisiae. Main phases of production were examined to determine where and at what rate compositional, microbial and physical changes occur. Fermentation of the sausages was more rapid with the frozen concentrate (6–8 hr lag phase) than with the lyophilized culture (12–14 hr lag phase), as determined by the rates of pH reduction and lactic acid production. The sausage meat waterholding capacity during fermentation using either culture form showed a minimum at pH 5.0, the approximate isoelectric point of major muscle proteins. During heat processing to 71°C internally, counts of total viable bacteria and lactic acid bacteria were reduced by 5 log cycles. Changes in concentrations of chemical components (protein, fat, moisture, salt) and shear force values during the drying phase were highly correlated with the amount of shrinkage and moisture removed. A semidry product was attained in 10–12 days.

Responses and competition of the parasitoids spalangia endius and muscidifurax raptor (hymenoptera: pteromalidae) at different densities of house fly pupae

Abstract: The functional response of Spalangia endius Walker was described by a linear relationship between attack rate and density of house fly pupae. S. endius searched well at higher host densities and in 72 h, appeared capable of attacking more than 80 pupae per female under laboratory conditions. The response of Muscidifurax raptor G. & S. was quadratic as poor searching ability limited this parasitoid’s attack rate at high host densities. Individual parasitoid efficiency of both species was reduced by intraspecific competition when parasitoid density was increased.

EFFECT OF FERMENTED MEAT pH ON SUMMER SAUSAGE PROPERTIES1

Abstract: Beef summer sausages were fermented to pH endpoints ranging from 5.5 to 4.6. A nonfermented sausage of pH 5.9 served as control. Fermentation time requirements using a frozen concentrate of Pediococus cerevisiae ranged from 7–8 h (pH 5.5) to 19–21 h (pH 4.6). Water holding capacities (WHC) of sausage mixes during the fermentation phase rapidly decreased as sausage pH decreased, reaching a minimum at pH 5.2. An increase in WHC from pH 5.2 to pH 4.6 was attributed to the combined effect of pH reduction and remaining functional protein. Bacterial counts (total viable and lactic bacteria) showed a stepwise increase from 2.4 × 108 cells/g (lactics) to 6.6 × 108 cells/g (lactics) during fermentation. Reductions of bacterial counts during heat processing appeared dependent on the sausage pH and phase of bacterial growth. Compositional changes (fat, protein, ash, salt, lactic acid) during the drying phase were significantly correlated to moisture loss of the sausages. Within drying intervals (days), sausages of p...

A quick screening test of biomaterials by means of chick embryo techniques

Abstract: Many types of materials are being used as biomaterials, and there is a continuing search for more and better materials for specific pur poses. In this investigation, a new method was employed in screening materials in an effort to cut costs, save time, and have a worthwhile indication of the prospect of a new material. Samples of twenty gauge wires of stainless steel 316, stainless steel 304, Titanium 40, Vitallium, and copper were introduced into leg or wing muscles of 18-day-old chick embryos. This was accomplished by opening the egg shell with a dental drill, implanting the material, and reclosing the shell. The chicks were allowed to hatch and were later sacrificed after eleven days, giving a total implant time of 14 days. This time period allowed for the acute inflammation that occurred during wound healing to subside. The sections were retrieved, embedded in epon 812, sectioned with a diamond saw, and histologically evaluated. Copper was used for the negative control and showed the greatest adverse tissue response. Titanium 40 showed almost no response and stainless steel 316 showed very little. Stainless steel 304 exhibited a somewhat greater response than the stainless steel 316. All of the materials except wrought Vitallium used in this experiment gave predicted results.

Bacillus thuringiensis investigations for control of Heliothis spp. on cotton.

Abstract: Studies were conducted at Florence, S. C., in 1972 to evaluate commercial preparations of Bacillus thuringiensis Berliner for control of Heliothis spp. on cotton. Dipel,® Thuricide® HPC, Biotrol® XK, and Bactospeine® P.M. were added to a cottonseed oil bait and applied, with the Florence 3-outlet ULV sprayer, to 0.13-acre plots. Dipel was evaluated in various other baits that contained cornmeal, corn oil, Wheast® or some combination of these ingredients. Dipel in cottonseed oil bait produced higher mortality of caged larvae than other preparations of B. thuringiensis . On some occasions, Dipel was as effective as toxaphene + DDT + methyl parathion in killing larvae of H. virescens (F.). Laboratory feeding tests again proved Dipel to be the most effective of the materials tested.

Control of Anaerobic Digestion Process

Abstract: The anaerobic digester is a common biological wastewater treatment process. A recently proposed fifth-order, nonlinear, dynamic model for the anaerobic digester has been shown to be qualitatively correct. Three methods of controlling the anaerobic digester are considered: base addition, organism recycle, and flow control. Feedback and feedforward controllers are designed for each of the control mechanisms, and a discrete adaptive predictive flow control algorithm is proposed. The control studies indicate that feedforward base addition control, in response to organic loading, is more effective and less expensive than feedback proportional base addition control. The predictive controller periodically computes optimum influent flow rate to the digester based on model response. This direct digital control method is adaptable to other wastewater treatment processes and offers flexible control objectives, allowing operational costs and quality of performance to be assigned weight factors, based on operational goals.

Vinylbenzyl ethers of cellulose. Preparation and polymerization

Abstract: Grafting of chain-growth polymerizable monomers onto cellulose has been a thoroughly investigated area. Introduction of polymerizable monomeric species chemically bound to cellulose has been less fruitful. Crotonate esters, methacrylate esters, and allyl and vinyl derivatives are examples where subsequent polymerization to crosslinked species has been described. Reported are the reactions of vinylbenzyl chloride with causticized cotton fabric to give a series of vinylbenzylated celluloses with degrees of substitution from 0.05 to 0.26. Homopolymerization of these or copolymerization with maleic anhydride or dimethyl maleate gave little or no crosslinking under the conditions employed. Vinylbenzyl cellulose acetate proved to be a polymerizable “prepolymer” with diethyl maleate.

Diet Periodicity of Entomophthora gammae in the Soybean Looper

Abstract: The soybean looper, Pseudoplusia includens (Walker), is a common pest of soybeans in South Carolina. Loopers contribute to a group of general defoliators which may reach population levels sufficient to cause economic damage. Working with P. includens in Alabama, Harper and Carner (1973) reported that larval populations often are infected with the fungus, Entomophthora sp., which under certain conditions may reduce or eliminate looper populations. Current opinion (MacLeod, personal communication) regards this pathogen as the same species ( Entomophthora ( Tarichium ) gammae ) described by Weiser (1965) infecting Plusia gamma (L.).