Tate Model Research Articles

Feasibility of kinetic orbital bombardment

Abstract In this paper, the possible impact effects of orbital bombardment systems and their feasibility are studied. These effects are the projectile penetration into concrete and steel targets and seismic effects. The equations of motion for the re-entry of a projectile and the penetration were solved numerically. The projectile penetration is modelled using the Alekseevskii–Tate model. By varying the altitude (h), projectile length (L), manoeuvre velocity (ΔV) and the target properties, the flight time (t), earthquake magnitude (M) and penetration depth (P) are calculated. The calculations show that the impact of a tungsten alloy rod with a length of 8 m and a 0.4 m diameter results in an earthquake with a seismic magnitude of only 2.5 on the Richter scale. For concrete, the optimal result is obtained for a projectile with a length of 0.56 m. It penetrates 1.79 m with a minimal ΔV trajectory. These results show that a kinetic orbital bombardment system is not feasible without major technological developments, the impact angle being a bottleneck of the concept. Moreover, one has to accept very high costs. Without any means to change the attitude of the projectile, using ICBMs or bombers shows a better penetration performance than re-entry. Highlights Weapons in orbit may provide a strategic advantage. However, they are restricted by international space laws. Impact angle of the projectile is a bottleneck for kinetic orbital bombardment. Larger impact angles can be achieved, but at the expense of a larger mass-to-orbit. A hypersonic drag device may be used to optimise the impact angle and thus improve the system. Alternative projectile delivery methods (Bomber, Intercontinental Ballistic Missile (ICBM)) show better performance for both steel and concrete targets. Essentially, only penetration phenomena matter because the seismic effects are not significant. Therefore, orbital bombardment systems don’t even resemble weapons of mass destruction (WMD). Given their limited effect, destroying a particular target requires a guidance and flight control system, which, given the high velocities, may not be feasible.

Practice-led Research in the Art Museum

As art museum education practices get more ambitious in form and content, and to a higher degree inform the overall audience strategies, the need for a research framing is required. The art museum is facing new and high expectation from society and policy makers in terms of being a relevant social and democratic platform inclusive for everyone. To manifest the changes, the institution must draw on all the different museal knowledges, not least the one about the audience. There has been a history of professional hierarchy and knowledge hegemony inside the art museum, where the object-based knowledge has trumped the practice-based. An important reason for this imbalance has been the lack of adequate practice related research methods and a theoretical framing within art museum education. Research in art museum has to a large extent operated within the classical art historical field, but more and more museums are looking to and are drawing on other models outside the museum disciplines to develop new adequate research standards. One of the museums that have undergone a profound change much due to a change in how they think about practice and research, is Tate with research leader Emily Pringle in the lead. Inspired by models within the arts and school system, they have developed a practice-led research method. In this article I will reflect on how and why it is important for art museum educators to do research on their own practice, drawing on both the Tate model and my own experience from working at the National Museum for over ten years.

Impact of globalization on human rights: evidence from Sub-Saharan Africa

PurposeThe purpose of this study is to examine the impact of globalization and its multiple dimensions on human rights in Sub-Saharan Africa.Design/methodology/approachThe study extends the Poe and Tate (1994) model, which enumerates the various determinants of human rights. Ordered probit estimation is used to estimate the impact of globalization and its dimensions. For the purpose of empirical analysis, the period has been divided into three phases: short, medium and long term. This helps in understanding how the impact of the different dimensions of globalization has evolved over a period of time. Furthermore, analysis has been carried out to detect causality between human rights and globalization.FindingsAs per the results, overall globalization and social dimension of globalization do have a positive impact on human rights in long and medium term and, also, Granger-cause human rights. The political dimension of globalization has a positive relation with human rights, though there exists no causality between the two. On the other hand, the economic dimension of globalization fails to have a statistically significant impact on human rights. Impact of the social dimension of globalization dominates that of other dimensions of globalization.Originality/valueThis is one of the few studies that examine, in an empirical fashion, the impact of globalization on human rights in Sub-Saharan Africa.

Experimental investigation of impact of long rod eroding projectiles against rolled homogeneous armour

Long rod eroding penetrators exhibit hydrodynamic behaviour upon impact against the target plates. An experimental study was carried out to investigate the factors affecting the penetration of tungsten alloy rods against rolled homogenous armour at ordnance velocities. Experiments were carried out for range of projectile length to diameter ratios to determine the penetration efficiency of the projectile, where the projectile penetration efficiency is the penetration depth per unit projectile length. Analytical Alekseevski–Tate model was implemented to predict the penetration depth across the length to diameter range and the results were compared with the experimental data. The tungsten percentage of the projectile material was also varied to change its mechanical properties and thus observe the effect of the same on the penetration depth. The experimental results showed a linear relationship between the penetration efficiency and the length to diameter ratio across the considered range of length to diameter ratios. The Alekseevski–Tate model predictions were not consistent across as the model does not consider the effect of length to diameter ratio. The projectiles with high impact energy were able to perforate the target plate.

The TATE model: a curriculum design framework for language teaching

The TATE model: a curriculum design framework for language teaching

The Forgiver and the Forgiven: A Discussion of “An Analyst Has a Birthday – Can Forgiveness Heal?”

The following discussion of Diane Barclay’s paper (this issue) focuses on the meaning of forgiveness when viewed through the lens of a multiple self tate model of the mind. The discussion also emphasizes the psychoanalytic centrality of self-forgiveness as a counterpoint to the question of whether one can forgive the other.

Analysis of the velocity relationship and deceleration of long-rod penetration

The relationship between the average penetration velocity, $$ \bar{U} $$ , and the initial impact velocity, $$ V_{ 0} $$ , in long-rod penetration has been studied recently. Experimental and simulation results all show a linear relationship between $$ \bar{U} $$ and $$ V_{ 0} $$ over a wide range of $$ V_{ 0} $$ for different combinations of rod and target materials. However, the physical essence has not been fully revealed. In this paper, the $$ \bar{U} - V_{ 0} $$ relationship is comprehensively analyzed using the hydrodynamic model and the Alekseevskii–Tate model. In particular, the explicit $$ \bar{U} - V_{ 0} $$ relationships are derived from approximate solutions of the Alekseevskii–Tate model. In addition, the deceleration in long-rod penetration is discussed. The deceleration degree is quantified by a deceleration index, $$ \alpha = {{2\bar{\mu }} \mathord{\left/ {\vphantom {{2\bar{\mu }} {(K\varPhi_{Jp} )}}} \right. \kern-0pt} {(K\varPhi_{Jp} )}} \approx Y_{p} \rho_{p}^{{{{ - 1} \mathord{\left/ {\vphantom {{ - 1} 2}} \right. \kern-0pt} 2}}} \left( {\rho_{p}^{{{{ - 1} \mathord{\left/ {\vphantom {{ - 1} 2}} \right. \kern-0pt} 2}}} + \rho_{t}^{{{{ - 1} \mathord{\left/ {\vphantom {{ - 1} 2}} \right. \kern-0pt} 2}}} } \right)V_{0}^{ - 2} , $$ which is mainly related to the impact velocity, rod strength, and rod/target densities. Thus, the state of the penetration process can be identified and designed in experiments.

Correction to: Approximate solutions of the Alekseevskii–Tate model of long-rod penetration

In the original publication of this article, Eq. (20b) is incorrectly published due to the negligence of the author’s proofreading.

How can I make this work? Genre affordances, agency and identity in a doctoral research journey

Abstract This article considers my engagement with two contrasting writing practices as part of my doctoral journey. I analyse and reflect upon extracts taken from progression reports and autoethnographic writing informed by work on genre affordances, writer identity and essayist literacy. My analysis indicates that the progression report genre offers limited possibilities for the construction of researcher identity and typically embeds a normative notion of research chronology and temporality. Furthermore, it permits limited opportunity for doctoral researchers to address affective and embodied aspects of their experience. I argue that this generic form of progress monitoring may inhibit forms of exploratory research, particularly those involving creative practice which can be inherently disorderly. In contrast, I explore how writing self-initiated autoethnographic vignettes permitted the construction of a more ambiguous discoursal identity within which I was able to explore aspects of embodiment, hesitancy and ‘not knowing’ as productive motifs. The affordances to explore personal experience, informality, evocation and open-endedness meant that I was able to experiment with the form of the writing (e.g. intertextuality) and narrative genres (e.g. the quest or journey) to approach research issues and dilemmas in an oblique way. I draw on Melissa Trimingham’s ‘hermeneutic-interpretative’ model, Theresa Lillis’s advocacy of juxtaposition and Guy Claxton’s TATE model to suggest that the progression process could be reconsidered, at the level of genre resources, to be better attuned to the rhythms and temporality of a more diverse range of approaches to research.

Approximate solutions of the Alekseevskii–Tate model of long-rod penetration

The Alekseevskii–Tate model is the most successful semi-hydrodynamic model applied to long-rod penetration into semi-infinite targets. However, due to the nonlinear nature of the equations, the rod (tail) velocity, penetration velocity, rod length, and penetration depth were obtained implicitly as a function of time and solved numerically. By employing a linear approximation to the logarithmic relative rod length, we obtain two sets of explicit approximate algebraic solutions based on the implicit theoretical solution deduced from primitive equations. It is very convenient in the theoretical prediction of the Alekseevskii–Tate model to apply these simple algebraic solutions. In particular, approximate solution 1 shows good agreement with the theoretical (exact) solution, and the first-order perturbation solution obtained by Walters et al. (Int. J. Impact Eng. 33:837–846, 2006) can be deemed as a special form of approximate solution 1 in high-speed penetration. Meanwhile, with constant tail velocity and penetration velocity, approximate solution 2 has very simple expressions, which is applicable for the qualitative analysis of long-rod penetration. Differences among these two approximate solutions and the theoretical (exact) solution and their respective scopes of application have been discussed, and the inferences with clear physical basis have been drawn. In addition, these two solutions and the first-order perturbation solution are applied to two cases with different initial impact velocity and different penetrator/target combinations to compare with the theoretical (exact) solution. Approximate solution 1 is much closer to the theoretical solution of the Alekseevskii–Tate model than the first-order perturbation solution in both cases, whilst approximate solution 2 brings us a more intuitive understanding of quasi-steady-state penetration.

Three-index symmetric matter representations of SU(2) in F-theory from non-Tate form Weierstrass models

We give an explicit construction of a class of F-theory models with matter in the three-index symmetric (4) representation of SU(2). This matter is realized at codimension two loci in the F-theory base where the divisor carrying the gauge group is singular; the associated Weierstrass model does not have the form associated with a generic SU(2) Tate model. For 6D theories, the matter is localized at a triple point singularity of arithmetic genus g=3 in the curve supporting the SU(2) group. This is the first explicit realization of matter in F-theory in a representation corresponding to a genus contribution greater than one. The construction is realized by "unHiggsing" a model with a U(1) gauge factor under which there is matter with charge q=3. The resulting SU(2) models can be further unHiggsed to realize non-Abelian G_2xSU(2) models with more conventional matter content or SU(2)^3 models with trifundamental matter. The U(1) models used as the basis for this construction do not seem to have a Weierstrass realization in the general form found by Morrison-Park, suggesting that a generalization of that form may be needed to incorporate models with arbitrary matter representations and gauge groups localized on singular divisors.

Box graphs and resolutions I

Box graphs succinctly and comprehensively characterize singular fibers of elliptic fibrations in codimension two and three, as well as flop transitions connecting these, in terms of representation theoretic data. We develop a framework that provides a systematic map between a box graph and a crepant algebraic resolution of the singular elliptic fibration, thus allowing an explicit construction of the fibers from a singular Weierstrass or Tate model. The key tool is what we call a fiber face diagram, which shows the relevant information of a (partial) toric triangulation and allows the inclusion of more general algebraic blowups. We shown that each such diagram defines a sequence of weighted algebraic blowups, thus providing a realization of the fiber defined by the box graph in terms of an explicit resolution. We show this correspondence explicitly for the case of SU(5) by providing a map between box graphs and fiber faces, and thereby a sequence of algebraic resolutions of the Tate model, which realizes each of the box graphs.

Toward an inclusive model of lesbian identity development: Outlining a common and nuanced model for cis and trans women

ABSTRACTThis article proposes an integrative model of lesbian identity development that places cis and trans women together as equal contributors. Two of the most influential current models of female sexuality are reviewed, and we use their commonalities to build the foundation of our integrative model. We also use Tate's model of lesbian identity as a scaffolding to integrate trans women's experiences alongside cis women's. Finally, we provide the outline of the Inclusive Model of Female Sexuality and discuss the convergences and divergences that exist between cis women and trans women in the formation of lesbian identity.

Respect for Physical-Integrity Rights in the Twenty-First Century: Evaluating Poe and Tate's Model 20 Years Later

Poe and Tate's 1994 study is likely the most influential in the quantitative study of human rights, serving as a foundation for a great deal of scholarship. In this article, we briefly consider the impact this article had on academic research on state repression, particularly in relation to democracy. We then empirically revisit Poe and Tate's model using a longer timeframe, updated method of estimation, improved measure of state repression, improved measures of some independent variables, and a spatial indicator. We stratify our results by specific physical-integrity right, world region, and time, finding variation in the associates of state repression across types of rights and world regions but stability over time. Finally, like Davenport and Armstrong (2004), we find a threshold where democracy's protective effects appear to begin, but this threshold differs across specific types of rights and that democracy may have rights-protective effects at lower levels than expected.

An Examination of DOP Test of Ceramic Tile Subjected to Long Rod Penetration

Depth of penetration (DOP) test of ceramic tile subjected to long rod impact was analyzed by applying the Tate model. This paper investigated the influence of impact velocity and tile thickness on the ballistic performance measurement of the tested ceramic tiles. DOP test was simplified as an eroding rod penetrating a target composed of multilayered materials. Through applying the Tate model, the method of obtaining the numerical solution was proposed. For a constant impact velocity, it was found that the measured differential tile efficiency (DEF) was independent of the thickness of the ceramics tiles. But the measured DEF decreased as the impact velocity increased. These analytical conclusions were verified by the using of the results of DOP tests of SiC and Al2O3 tiles subjected to impact of long tungsten alloy rods at a nominal impact velocity of 1.3 km/s.

Formula omitted]-flux, chiral matter and singularity resolution in F-theory compactifications

We construct a set of chirality inducing G 4 -fluxes in global F-theory compactifications on Calabi–Yau four-folds. Special emphasis is put on models with gauge group SU ( 5 ) × U ( 1 ) X relevant in the context of F-theory GUT model building, which are described in terms of a U ( 1 ) -restricted Tate model. A G 4 -flux arises in a manner completely analogous to the U ( 1 ) X gauge potential. We describe in detail the resolution by blow-up of the various singularities responsible for the U ( 1 ) X factor and the standard SU ( 5 ) gauge group and match the result with techniques applied in the context of toric geometry. This provides an explicit identification of the structure of the resolved fibre over the matter curves and over the enhancement points relevant for Yukawa couplings. We compute the flux-induced chiral index both of SU ( 5 ) charged matter and of SU ( 5 ) singlets charged only under U ( 1 ) X localised on curves which are not contained in the SU ( 5 ) locus. We furthermore discuss global consistency conditions such as D3-tadpole cancellation, D-term supersymmetry and Freed–Witten quantisation. The U ( 1 ) X gauge flux is a global extension of a class of split spectral cover bundles. It constitutes an essential ingredient in the construction of globally defined F-theory compactifications with chiral matter. We exemplify this in a three-generation SU ( 5 ) × U ( 1 ) X model whose flux satisfies all of the above global consistency conditions. We also extend our results to chiral fluxes in models without U ( 1 ) restriction.

Abelian gauge symmetries and proton decay in globalF-theory GUTs

The existence of abelian gauge symmetries in four-dimensional F-theory compactifications depends on the global geometry of the internal Calabi-Yau fourfold and has important phenomenological consequences. We study conceptual and phenomenological aspects of such U(1) symmetries along the Coulomb and the Higgs branch. As one application we examine abelian gauge factors arising after a certain global restriction of the Tate model that goes beyond a local spectral cover analysis. In SU(5) GUT models this mechanism enforces a global U(1)_X symmetry that prevents dimension-4 proton decay and allows for an identification of candidate right-handed neutrinos. We invoke a detailed account of the singularities of Calabi-Yau fourfolds and their mirror duals starting from an underlying E_8 and E_7 x U(1) enhanced Tate model. The global resolutions and deformations of these singularities can be used as the appropriate framework to analyse F-theory GUT models.

A comparison of three approaches to spatial generalization of rainfall–runoff models

The generalization of the parameters of rainfall-runoff models, to enable application at ungauged sites, is an important and ongoing area of research. This paper compares the performance of three alternative methods of generalization, for two parameter-sparse conceptual models (PDM and TATE), specifically for use in flood frequency estimation using continuous simulation. Two of the methods are based on fitting regression relationships between catchment properties and calibrated parameter values, using weighted or sequential regression (with weights based on estimates of calibration uncertainty), and the third is based on the use of pooling groups, defined through measures of site-similarity based on catchment properties. The study uses a relatively large sample of catchments in Britain. For the PDM, the site-similarity method performs best, but not greatly better than either regression method, so there may be cases where the use of regression would be preferable. For the TATE model, weighted regression performs best (with a very similar level of performance to that of the PDM with site-similarity), whereas site-similarity performs worst (due to poor performance for catchments with higher baseflow), indicating that the choice of model and generalization method should not be separated. The use of sequential regression, which was developed to try to allow for parameter interdependence, shows no clear advantage for either model. Other than the poor performance of the TATE model with site-similarity for catchments with a higher baseflow index, there are no clear relationships between performance of any model/method and catchment type.

Shock-induced structural transitions and dynamic strength of solids

Shock tests of series of materials under uniaxial strain conditions including constructional and armor steels, aluminum alloy, copper and beryllium, show that spall-strength sensitively depends on the structural instability of material under compression at the front of compressive pulse. This instability is shown to be a shock-induced structural transition which results in irreversible mesostructure formation in solid. It is also shown that value of structural instability threshold under dynamic compression measured in uniaxial strain tests determines a strength-component of resistance of material to high-velocity penetration in Alekseevskii–Tate model.

Effect of Processes at the Compression Pulse Front on Spalling Strength of a Material and Resistance to High-Velocity Penetration

Tests on backward spalling of 38KhN3MFA structural steel, D-16 aluminum alloy, M-2 copper, 02Kh18K9M5-VI maraging steel, KhN75VMYu alloy, beryllium, and other materials show that spalling strength correlates with the threshold of structural instability of a material to compression at the leading edge of the compression pulse. It is shown that the threshold of structural instability to compression obtained in experiments on uniaxial deformation of flat targets determines the strength of resistance to high-velocity penetration in the Alekseevskii–Tate model.