Requisite Characteristics Research Articles

Porosity Evolution in Electrosurgical Blade Coatings

AbstractDuring Electrosurgery, Radio Frequency (RF) electrical power is applied to a cutting surface which cauterizes the incision. The desiccation of surrounding tissue results in hemostasis and surgery without bleeding. In the case of localized heavy bleeding, a coagulation process is employed using modulated RF power. However, substantial amounts of desiccated tissue may stick to the blade, undoing the achieved hemostasis, and possibly worsening the situation. To prevent this, various electrosurgical blade coatings have been developed to both permit the flow of RF power through the coating, and prevent desiccated tissue from sticking to it.PolyTetraFluoroEthylene (PTFE) is a commonly used electro- surgical blade coating that undergoes substantial surface morphology changes during use, eventually leading to failure. Highly conductive Diamond-Like Nanocomposite (DLN) electrosurgical coatings have been developed with the requisite non-stick characteristics and enhanced durability.After a brief review of electrosurgical fundamentals, the underlying mechanisms of operation of these two coating materials are compared. In the case of PTFE, establishment and evolution of porosity in the coating is essential to the flow of RF power, yet ultimately leads to long term degradation. Alternate conduction mechanisms for DLN coatings are considered.

On the possibility of producing piston pins for diesel engines from steel 18KhGT with the use of mechanical and chemical heat treatment

At the present time pisto pins of highly loaded diesel engines are produced by mechanical treatment from tube preforms of steel 12KhN3A and carburized by subsequent heat treatment. The high cost of domestic steel and the absence of preforms of the requisite size make it necessary to choose a less scare material and develop a treatment process that would provide the requisite operational characteristics of the parts. The present work is devoted to a study of the possibility of using for the purpose steel 18KhGT in a state of substructural toughening created by cold plastic straining (CPS) and a stabilizing heat treatment with subsequent ion nitriding.

Porosity of heat-resistant glass ceramic coatings based on a nonfritted glass matrix

The porous macrostructure of heat-resistant coatings is described as a function of the content of Al2,O3, Cr2O3, NiO, ZrO2, and Fe2O3 additives. The relationship between the porosity of the coating and its refractoriness is established. The introduction of Cr2O3 and NiO provides the requisite melting characteristics in the coating and the optimum porous macrostructure.

Change in teacher education: There are dragons to slay

Abstract Teacher education programs across the country are responding to calls for reform in the professional preparation of teachers. This article presents a case study of the revision of an elementary teacher education program at a state university. Using a school‐university collaboration, the content and sequence of the program were based on a careful review of literature and the development of a consensus on the requisite characteristics and competencies of excellent elementary teachers. During the university approval process tensions and dilemmas arose related to faculty involvement, power and authority, incentives, and some “sacred cows” of the academy such as academic freedom. Lessons learned about programmatic change within the culture of the university are presented.

Identification and Characterization of All-trans-Retinoic Acid Receptor Transcripts and Receptor Protein in Human Neuroblastoma Cells

Retinoic acid (RA) induces the differentiation of tumor cells of neural origin and may do so by binding to one or more nuclear receptor proteins. We have identified transcripts and nuclear RA receptor (RAR) protein in a clonal line of human neuroblastoma cells that differentiate in response to RA. Prior to any exposure to RA, LA1-15n cells express two transcripts for RARa (3.6 and 2.7 kb) as well as low levels of transcript for RARα (3.4) and RARγ (2.8 kb). Exposure of LA1-15n cells to RA leads to the induction of a 2.9-kb RARβ mRNA, whereas the expression of transcripts for RARs α and γ does not change appreciably. The 2.9-kb RARβ transcript is increased by 4 h (8-fold) and continues to increase for 24-48 h (40- to 60-fold). The RA-associated increase in RARβ mRNA in LA1-15n cells is not diminished by the addition of the protein synthesis inhibitor, cycloheximide, but is abolished by the addition of the RNA synthesis inhibitor, actinomycin D. In addition to RAR transcripts, LA 1-15n cells contain a nuclear protein with the requisite characteristics of a RAR. The nuclear protein binds all-trans-[3H]RA with high affinity (Kd 0.2 nM). The nuclear protein sediments at 4S, which is consistent with the molecular mass deduced from RAR cDNAs (50,000 Da). The nuclear protein is clearly distinguishable from a all-trans-[3H]RA-binding protein found in the cytosolic fraction of LAl-iSa cells. The cytosolic protein sediments at 2S on sucrose density gradients, consistent with the expected molecular mass of the cellular retinoic acid-binding protein (16,000 Da). The nuclear [3H]RA-binding protein binds to DNA-cellulose and to the RARfl response element. These results support the hypothesis that RARs are present in human neuroblastoma cells and may be involved in human neuroblastoma cell differentiation. They also demonstrate that RA markedly influences the expression of steady-state levels of mRNA for one of its own receptors, the RARβ.

Use of anti-peptide antibodies for the design of antigen-specific immune complex assays

A simple and sensitive method is described for the detection of circulating immune complexes (ICs) in an antigen-specific manner. The method is based on the use of anti-peptide antibodies as solid-phase capture reagents to bind antigen which is complexed to serum antibodies. The bound serum antibody is detected with a labelled second antibody. The method requires that the anti-peptide antibodies bind native protein efficiently, and that the anti-peptide antibodies do not compete with antibodies raised against the native protein which are involved in IC formation. Two anti-peptide antibodies specific for the hepatitis B surface antigen (HBsAg) and the hepatitis B e antigen (HBeAg), which possessed the requisite characteristics, were chosen as models for IC assay development. The solid-phase, anti-peptide based assays efficiently detected HBsAg and HBeAg-containing ICs in preformed antigen/antibody mixtures and in the serum of chronically infected hepatitis B patients.

Measurement Characteristics of the Inventory of Parent Experience Scales

Researchers and practitioners increasingly recognize the importance of ecologically valid family-focused assessment tools, especially given the mandates of P.L. 99--457. The present study investigated the measurement integrity of one possible tool, the Inventory of Parent Experiences (IPE) (Crnic & Greenberg, 1981). Subjects were both parents from 66 intact families, half of which included children with handicaps. The results were generally not supportive of an interpretation that subscale or subsubscale scores have requisite measurement characteristics. At best, these scales must be viewed as first-step efforts to begin the development of appropriate item pools and item classification systems. However, the results regarding the use of IPE total scores were more favorable and were also consistent with previous research.

The development of the ‘electronics complex’ and government policies in Brazil

This paper reports some of the results of research conducted at the Instituto de Economia Industrial of the Federal University of Rio de Janeiro on the pattern of development of two industries of the ‘electronics complex’ — electronic data processing equipment (EDPE) and electronic semiconductor components (SCC). The industries were selected because of their technological and economic importance and for their potential inter-relatedness, as well as for policy-related reasons.The research focused on the analysis of the international characteristics of the two industries (based mainly on secondary sources) and an empirical investigation of their pattern of competition in Brazil. Following a brief characterization of the ‘electronics complex,’ the next section of this paper describes the evolution of imports, local production and exports and the pattern of competition in the Brazilian market. The third section analyzes in more detail the inter-relations between consumers, international firms, local producers and Government policies, focusing mainly on the EDPE industry ‘infant-industry’ experience. The last section focuses on the intended policy for the SCC industry, exploring the implications of industrial interdependence and drawing from the experience of the EDPE industry. The article concludes by presenting some requisite characteristics of policy for fostering an ‘electronics complex’, which may be useful not only for Brazil, but for other LDCs as well.

A More Complete Listing of LMC Planetary Nebulae

In an earlier paper by Sanduleak et al. (1978) a listing was given of 102 confirmed and probable planetary nebulae in the Large Magellanic Cloud detected on objective-prism plates taken with the Curtis Schmidt telescope at Cerro Tololo. Subsequently, deeper coverage was obtained on nitrogen-baked Kodak IIIa-J plates plus GG 455 filter exposed for 90 minutes. The thin prism was again used to provide a dispersion of about 1500 Å mm−1 at Hβ and the spectra were unwidened. An additional 25 planetary nebula candidates were found on this new plate material to show the requisite characteristics, i.e. they display (a) a stellar appearance, (b) [OIII] λλ5007, 4959 strongly in emission, and (c) no evidence of a continuum.

Theory of equilibrium copolycondensation

A calculation was made related to equilibrium copolycondensation with and without the substitution effect. It was confirmed that the microstructure of products of any process may be described using a Markoff chain and a method found for finding the dependence of parameters of this chain on equilibrium constants and the composition of the monomer mixture. This makes it possible to calculate all the requisite statistical characteristics of copolymers by a standard method: molecular weight, composition, structure and molecular distribution according to dimension and composition.

Characteristics of Mineral Licks and Behavior of Visiting White-Tailed Deer in Southern Indiana

Characteristics of mineral licks and various facets of their use by whitetailed deer (Odocoileus virginianus) were examined in southern Indiana. Sodium (Na) levels were elevated in all licks, and Na was judged to be the element sought by deer. Use of licks by deer was maximum in early spring and moderated during the summer and early autumn; no winter use occurred. All sexes and ages except spotted fawns visited licks. Much aggressive interaction occurred at licks with no evidence of formation of a dominance hierarchy; only adult males were clearly dominant. It is concluded that the primary role of licks is the provision of Na during periods of Na deficiency. Requisite characteristics for any attractant proposed as an alternative to Na are discussed.

Implications of the reorganizational behavior of condensed phosphates for mitochondrial phosphorylation

The composition of phosphorus-32 labeled polyphosphoric acid ( 32PPA) prepared from, (i) H 3 32PO 4 and (82% w/w) P 2O 5 and, (ii) by incorporation of radioactivity from H 3 32PO 4 into unlabeled polyphosphoric acid (PPA) was examined and found to be the same. The identity of these condensed phosphorate mixtures, as established, argues strongly in favor of a rapid and complete equilibration and provides direct evidence in support of Van Wazer's reorganization theory of condensed phosphates. No evidence for metaphosphates or label exchange in an aqueous environment was found. 32PPA was found to exist in metastable equilibrium with 32PPA as a crystalline solid of different composition. Agreement of hydrolytic rate data from the mixtures of condensed phosphates with literature values for individual species suggests that the hydrolysis of the pyro- and tripolyphosphate species proceeds independently in the presence of other homologs. The rate of hydrolysis of the condensed phosphates (at pH5.0 and 65 °C) was found to be proportional to chain length, increasing about four-fold between pyro- and hexapoly-phosphate. The same correlation is also manifest in the adenosine 5′ polyphosphates. A slight enhancement in the rate of hydrolysis of adenosine diphosphate, increasingly more pronounced in the case of adenosine tri- and tetra-phosphate, was also noted. This effect is attributed to the presence of the adenosine moiety. The most interesting aspect of the rate data is to be found in the similarity of the rates of hydrolysis of the adenosine 5′ polyphosphates, relative to their inorganic polyphosphate counterparts. The significance of these findings is discussed and the viewpoint is presented that the properties of condensed phosphates are compatible with the requisite characteristics that must be predicated of any in situ phosphoryl precursor in mitochondrial phosphorylation.

Spin-wave renormalization in the Heisenberg ferromagnet

The cumulative effects of higher-order correlations and spin-wave interactions are represented in the usual versions of a practical (first-order) Green's-function theory of the Heisenberg ferromagnet by the renormalization of the spin-wave energies. The problem of deriving the appropriate renormalization factor $R$ in a given temperature regime based on a comparison with some exact result is considered. To this end, Dyson's rigorous asymptotic series for the spontaneous magnetization $\ensuremath{\sigma}$ and the free energy at very low temperatures are used as a boundary condition on the theory to derive necessary conditions on $R$. Spectral relations are then used to derive an expression for $R$ of the form ${h}^{\frac{(1+\ensuremath{\xi})}{(2+\ensuremath{\xi})}}$, where $h$ is the average energy $〈\mathcal{H}〉$ of the system measured in units of the ground-state energy; 1, $\ensuremath{\xi}$ are certain relative contributions to the ${T}^{4}$ term in $\ensuremath{\sigma}$ and represent the leading effects of the dynamical interaction of spin waves, respectively, in the Born and in higher orders. The phenomenological second random-phase approximation is a special case of this form, corresponding to the retention of only the Born in the above. The explicit occurrence of $R$ (due to a summation over renormalized spin waves) in the spectral relation for the Hamiltonian is exploited to eliminate $h$ and find a result for $R$ in terms of the customary parameters of a first-order theory, that is automatically moment conserving. From this result, other expressions for $R$ that are equivalent to it at low temperatures, including that of Callen's decoupling scheme, are derived. The differences and difficulties that arise in the special case $S=\frac{1}{2}$ are brought out clearly and discussed. The appropriate modulation that the $R$ factor of the randomphase must undergo in this case in order to lead to the correct low-temperature series for $\ensuremath{\sigma}$ is deduced. It is also proved that it is impossible for a linearized Green's-function theory for the $S=\frac{1}{2}$ ferromagnet to yield correct results at low $T$ for both $\ensuremath{\sigma}$ and the specific heat if the theory is of the pure pole type (the Green's function is given by a magnon pole term alone) with a wave-vector-independent renormalization of the spin wave spectrum: it is necessary to have at least a $k$-dependent $R$, or a dispersive part in addition to the pole term. Writing the spectral relation for the Hamiltonian in terms of the spin-spin correlation functions, is is shown that theories of the above kind (pole type, with $k$-independent $R$) also suffer from a serious defect near ${T}_{C}$, for all $S$. The central role of the longitudinal correlation is emphasized and the conditions necessary for its proper determination to ensure a consistent linearized theory are discussed. The detailed derivation of a theory with the requisite characteristics will be presented in another paper.

In-line Gas Analyzer for UF6and F2through Differential Thermal Conductivity Measurements

For the purpose of analyzing UF6 and F2 continuously in the fluorination of U, a system of differential thermal conductivity cells (TCC), equipped with shock absorber, and also NaF and KCl traps, has been trially constructed. Mixed flow-through/diffusion type katharometers are used, provided with four and two Ni filaments (∼30Ω) on the UF6 and F2 cells, respectively. Based on data obtained from preliminary operating tests, the standard conditions for operating the system were established i.e., 500 mmHg abs. Cell pressure, 200 ml/min flow rate and 80 mA bridge current. Under these operating conditions and for UF6 and F2 concentrations of 2 and 20 v/o respectively, the overall out-put variations are below 1%. The total response time of the system including the transport lag is below 1 and 2.5 min for UF6 and F2 cells, respectively. The dead time due to blow-back noise is observed to have about the same period as the above response time. The sensitivities for UF6 and F2 are found respectively to be 11.5 and 0.37 mV/v/o, for which the limits of analytical determination are 0.01 and 0.05 v/o;, respectively. By practical application to uranium fluorination, the TCC system thus devised, has proven to possess the requisite characteristics for measurements of reaction rate, fluorine utilization and end of reaction in fluid-bed fluorination of uranium oxides. The system has possibilities of application to the study of reaction steps.

In-line Gas Analyzer for UF6 and F2 through Differential Thermal Conductivity Measurements

For the purpose of analyzing UF6 and F2 continuously in the fluorination of U, a system of differential thermal conductivity cells (TCC), equipped with shock absorber, and also NaF and KCl traps, has been trially constructed. Mixed flow-through/diffusion type katharometers are used, provided with four and two Ni filaments (∼30Ω) on the UF6 and F2 cells, respectively. Based on data obtained from preliminary operating tests, the standard conditions for operating the system were established i.e., 500 mmHg abs. Cell pressure, 200 ml/min flow rate and 80 mA bridge current. Under these operating conditions and for UF6 and F2 concentrations of 2 and 20 v/o respectively, the overall out-put variations are below 1%. The total response time of the system including the transport lag is below 1 and 2.5 min for UF6 and F2 cells, respectively. The dead time due to blow-back noise is observed to have about the same period as the above response time. The sensitivities for UF6 and F2 are found respectively to be 11.5 and 0.37 mV/v/o, for which the limits of analytical determination are 0.01 and 0.05 v/o;, respectively. By practical application to uranium fluorination, the TCC system thus devised, has proven to possess the requisite characteristics for measurements of reaction rate, fluorine utilization and end of reaction in fluid-bed fluorination of uranium oxides. The system has possibilities of application to the study of reaction steps.

A Transistorized Communication Receiver for Use in the Police Radio Organization

The paper describes the design, development and construction of a good transistorized communication receiver to suit the requirements of the Police Radio Organizations in the country. The details of the various stages of the receiver employing latest techniques in solid state design using transistors in direct coupled configurations with a view to achieving a high degree of quality and other requisite characteristics of a high grade communication receiver are described in the paper. The specifications of the solid state communication receiver are in fact better than a similar commercial receiver (valve version). No such solid state communication receiver appears to have been developed in the country so far. The communication receiver meets the requirements of the Police Radio Organizations admirably well. It is meant for A1 operation.

Creativity in Rubber Industry Research. Charles Goodyear Medal Address—1971

Abstract Over the span of 36 years in rubber research and development, I was involved in a wide range of problems, some of which ended in frustration, others fortunately in success. Overall, during this entire period, I've had a whale of a good time. During these years nothing has provided me more satisfaction than working with creative people. And since this phenomenon of creativity is so important and yet so little understood, I thought I'd see whether from my own experience I could throw a little light on it today. My main qualification is that I have for years been interested in creativity, what it is, how it manifests itself, the type of people who exhibit it, and how they may be encouraged toward greater efficiency. Successful creativity, in general, involves conceiving new ideas and following them through to where they become potentially useful. It does not only mean the synthesis of a new chemical, but more broadly, the achieving of any new, not previously recognized, result. This might involve merely bringing together two well-known mechanical devices never before associated. For example, the electric blanket invented by Kearsley of General Electric: blankets and electric heating wire were well known, separately, but it took Kearsley's imagination to bring them together into a brand-new useful product. Many instances of creativity sart with Observation, the creative person being alert for new combinations and phenomena, being led on by his scientific Curiosity, aroused by his Imagination and Enthusiasm, and drawing upon his Memory, since creative thinking is frequenly no more than bringing together factors not hitherto associated. Among the requisite personal characteristics for creativity arc a prepared mind, a large range of skills and technical know-how, a certain mechanical ingenuity, and a favorable environment. The creative mind must, of course, have imagination, as well as enthusiam. Its results may range from discovering a whole new world of knowledge to merely inventing an easier way of doing an old job. To enhance the creativity of research personnel, management cannot impose a rigid application of job specialization and supervisory control, but must create a climate with such necessary freedom and flexibiliy as to be conducive to invention. Technological innovations can result from following various creativity routes which, for convenience here, I have divided into seven categories. For a clearer picture of how creativity manifests itself, let us examine some appropriate examples, based on projects with which I had direct personal contact. Of these examples, some are important, others relatively minor, the basis of selection being primarily suitability for illustrating various facets of creativity. These might be considered case histories, as it were, of creativity.

Race and American Expansion in Cuba and Puerto Rico, 1895-1905

The United States, as a result of the Spanish-American War, acquired supervision over a number of purportedly inferior native peoples in the Caribbean and the Pacific. American expansionists justified the new role of the United States by emphasizing the responsibility the country had undertaken in elevating less-fortunate peoples to govern themselves. The expansionists were convinced of the superior capacity for self-government on the part of the white, Anglo-Saxon people of the United States. They held dark-skinned people in low regard, for the latter had not yet acquired the requisite characteristics of self-control and political maturity upon which the capacity for self-government was based. The burden of carrying forward the world's work, as Theodore Roosevelt put it, consisted in large measure of supervising the native peoples in these insular areas eventually to direct their own affairs through limited participation in government, and through a program of organized instruction in the schools. The inhabitants, after an unspecified period of tutelage, would unlearn archaic or decadent Latin ways and substitute in their stead the way of life of their American mentors.

First Paper: Plant Aspects of Turbine Generator Foundations

The paper begins with a description of the various types of turbine generator foundations that have been installed and those that are intended for use in the near future. Then follows a section detailing the requisite characteristics of machine foundations and the factors that must be considered in order to obtain satisfactory operation. As the foundations support rotating machinery, the subject of vibration is discussed, including fundamental equations and their practical applications to the problem of calculating frequencies in the structures. Among the many factors that have to be considered when selecting the type of foundation are the size of machine and the station arrangement. The various factors are presented with comments. Important characteristics relating to the material properties and to the erection and behaviour of steel and concrete foundations are described. The topic of alignment is considered, including methods of maintaining machine alignment relative to the foundation structure. The causes of foundation distortion and the resulting effect on the alignment of the machine are summarized and some reference is made to precompensation in anticipation of misalignment developing.

Three port tuned microwave reflectometer

The three-port tuned microwave reflectometer is both conceptually and practically simpler than the familiar two-auxiliary-arm, four-port reflectometer which usually needs an electronic ratio instrument. The theory of the ideal reflectometer is sketched, and a set of conditions delineating the requisite characteristics of the three-port reflectometer developed in a rigorous fashion. Considerable attention is given to an error analysis which results in a single simple set of error curves presented in terms of readily measurable parameters. An anomalous practical source of error is discussed. An operating WG-12 waveguide reflectometer is described. The errors for this reflectometer are presented and evaluated in terms of the instrument's use as an impedance standard; at a frequency of 4.7 Gc/s the maximum error in measuring a reflection coefficient magnitude of 0.1 is less than ¼%.