A higher order coupled frequency characteristics study of smartmagneto-electro-elastic composite plates with cut-outs using finite element methods

This article deals with investigating the effect of cut-outs on the natural frequencies of magneto-electro-elastic (MEE) plates incorporating finite element methods based on higher order shear deformation theory (HSDT). In order to consider the influence of cut-out, the energy of the cut-out domain is sub-tracted from the total energy of the entire plate. The governing equations of motions are derived through incorporating Hamilton's principle and the solution is obtained using condensation technique. The proposed numerical formulation is verified with the results of previously published literature as well as the numerical software. In addition, this research focuses on evaluating the effect of geometrical skewness and boundary conditions on the frequency response. The influence of cut-outs on the degree of coupling between magnetic, electric and elasticfields is also investigated.     

Improvement of VIS and IR camouflage properties by impregnating cotton fabric with PVB/IF-WS2

In order to examine the possibility to improve its camouflage properties standard cotton fabric with camouflage print was impregnated with poly(vinyl butyral), PVB and fullerene-like nanoparticles of tungsten disulfide, PVB/IF-WS₂. FTIR analysis excluded any possible chemical interaction of IF-WS₂ with PVB and the fabric. The camouflage behavior of the impregnated fabric has been examined firstly in the VIS part of the spectrum. Diffuse reflection, specular gloss and color coordinates were measured for three different shades (black, brown and dark green). Thermal imaging was applied to examine the camouflage abilities of this impregnation in IR part of the spectrum. The obtained results show that PVB/IF-WS₂ impregnation system induced enhacement of the materials camouflage properties, i.e. that IF-WS₂ have a positive effect on spectrophotometric characteristics of the fabric.     

NEGOTIATING NONPROLIFERATION: Scholarship,Pedagogy, and Nuclear Weapons Policy

In nuclear nonproliferation negotiations, many governments pursue multiple objectives, and changes in policy can occur rapidly—and often unexpectedly. For these reasons, understanding nonproliferation requires empathy and imagination rather than just historical fact. This article considers one teaching tool to encourage such insight—simulations—and demonstrates how teaching and scholarship can interact to improve our understanding of the complex decisions and negotiations involved in nuclear nonproliferation. The article consists of five parts: first, it explains the benefits of simulations as both a policy development tool in Washington and as a teaching tool in universities; second, it describes the pedagogical strategy of the Stanford University simulation program; third, it shows how the simulations have identified and highlighted theoretical and substantive insights that are often neglected in scholarly studies of nonproliferation; and fourth, it describes how students are tested to enhance the learning experience from the simulation. Fifth and finally, the article provides concluding observations about how using simulations in the classroom can help scholars develop insights that improve their understanding of real-world nuclear negotiation dynamics and outcomes.     

US technological collaboration for nonproliferation: key evidence from the Cold War

ABSTRACT

Although the existing international-relations scholarship argues that technological assistance in the nuclear domain increases the probability of nuclear proliferation, the historical account indicates otherwise. Congressional legislation for nonproliferation, economic sanctions, and poor state capacity—specifically, inept managerial capabilities of the recipient state—explain merely part of the puzzle, but overlook the role of positive inducements offered to impede nuclear proliferation. Historical evidence shows that the United States often provided technological assistance with the deliberate intent to inhibit proliferation. In other words, Washington employed its technological leverage to attain nonproliferation goals. American technological preponderance since the end of World War II made such an approach feasible. This study examines key Cold War cases—Israel/Egypt, India, and West Germany—where the United States offered technological assistance with the deliberate intent to stall nuclear proliferation, thereby underscoring the role of assistance for inhibitive ends.     

Limiting cyberwarfare: applying arms-control models to an emerging technology

ABSTRACT

An arms race in cyberspace is underway. US and Western government efforts to control this process have largely been limited to deterrence and norm development. This article examines an alternative policy option: arms control. To gauge whether arms-control models offer useful lessons for addressing cyber capabilities, this article compiles a new dataset of predominantly twentieth-century arms-control agreements. It also evaluates two case studies of negotiated agreements that regulate dual-use technologies, the 1928 Geneva Protocol prohibiting chemical- and biological-weapon use and the 1944 Chicago Convention on International Civil Aviation. The analysis underscores the limits of norm development for emerging technologies with both civilian and military applications. It finds lessons for developing verifiable, international cooperation mechanisms for cyberwarfare in the regulatory model of international aviation. Conventionally, arms-control agreements take advantage of transparent tests or estimates of arms. To restrict cyberwarfare activities, experts and policy makers must adapt arms-control models to a difficult-to-measure technology at an advanced stage of development and use. Further investigation of international regulatory schemes for dual-use technology of similar diffusion and development to the internet, such as international civil aviation, is needed.     

The military recruiting productivity slowdown: The roles of resources,opportunity cost and the tastes of youth*

After a decade of successful recruiting, the US military began experiencing recruiting difficulties in the 1990s. Cyclical factors as well as trend factors may have played a role. This paper uses monthly data by state over the period 1989-1997 to estimate models of enlistment and evaluate the various explanations for the recruiting slowdown. Estimates of the impact of economic variables - relative military pay and unemployment - and recruiting resource variables - recruiters and advertising - are similar to those in previous studies. Two trend factors, rising college attendance and declining adult veteran population (influencers), are found to be important factors explaining the decline in enlistment.     

The right place at the right time,or the right person in the right place?

South Africa's military has, since the First World War, been an oft-used and effective tool in the conduct of South African foreign policy, but this role has not always translated into power for Defence Department principals in its formulation. South African Defence Ministers for most of the country's history have played a minor role in the making of foreign policy; despite a change in this dynamic between approximately 1975–1990, the post-apartheid era has once again seen a diminishment of Defence's power in this arena. This article examines why Defence Ministers have generally been such weak players, with an eye toward disaggregating whether this was a product of interpersonal relationships with Cabinet and – most importantly – the Head of State, or whether this influence (or lack thereof) was more a function of South Africa's international standing. While determining who has influence on this process is difficult given the primacy of the national leader in making foreign policy and a lack of insider accounts by participants in the process, this article relies upon several interviews with participants and knowledgeable observers that help illuminate the process and Defence's role in it.     

Defence closure and job loss: The case of swan hunter on tyneside

Recently in this journal Hooper and Butler (1996) drew attention to the scale of job loss associated with restructuring in the defence sector in the aftermath of the Cold War. They noted that there is comparatively little knowledge of the experiences of workers following the closure of defence plants. This research communication attempts to shed further light on this issue by reporting the results of a survey of the experiences of former Swan Hunter shipyard workers who were made redundant after the firm went into receivership. The results confirm the complex but generally negative effect of redundancy on the workers involved.     

The inherent propensity toward peace or war embodied in weaponry

Thomas Schelling argues that armed adversaries face an inherent propensity toward peace or war embodied in their weaponry, geography and military organizations. Inherent propensity is the idea that there are characteristics embodied in the weapons that push adversaries toward peace or war, independent of the goals of the decision‐makers, the political disagreement between adversaries, and misperceptions about mutual resolve and hostility. We theoretically illustrate inherent propensity in conventional and nuclear arms settings using Lanchester and Intriligator war models. Our work extends the Intriligator‐Brito model, identifies when the competing Richardson and Intriligator‐Brito views of the relationship between arms races and war are correct, illustrates the stabilizing/destabilizing effects of alliances, and highlights the importance of arms quality control in the US‐USSR relationship.