Armchair Case Research Articles

Diversity and inclusion: a local or a global issue?

Objective: This teaching case focuses on a multinational insurance firm from a developed country that decides to implement a global human resources program for diversity and inclusion (D&I) across all its branches, after realizing that some of them were already developing successful local initiatives on their own. This case is designed for graduate or undergraduate students in International Business or Human Resources disciplines, in Management and Business Administration courses. Method: This is an armchair case, based on both primary and secondary sources of information. Fictional company and character were created to illustrate the case, based on empirical evidence about many multinational insurance companies operating in Brazil. Relevance / Originality: This teaching case seeks to engage students in a discussion about how important it is to implement a D&I agenda in today’s companies, and how multinational enterprises (MNEs) should manage the duality of establishing a global program in such a sensitive matter, in which local diversity is so crucial. The case provide instructors with is a dynamic and active-learning way of teaching traditional global strategy concepts. The contemporaneity and importance of the D&I thematic allows for interesting discussions of traditional concepts. Theoretical contributions: Students are put in the protagonist’s shoes, thereby training their decision-making skills. Through dealing with issues of diversity and inclusion, students are expected to learn concepts of global strategy related to global integration (GI) versus local responsiveness (LR) strategies; subsidiaries and headquarters’ roles and contexts and traditional and reverse transfer of practices/knowledge.

Group role play case: Designing a multiple sting, digitally focussed, marketing communications campaign plan for Cirque du Soleil’s next London show.

Drawing on the magic of Cirque du Soleil, this armchair case study invites you to make an imaginary step into the world of digital advertising agencies. Flexing your communication skills and applying your marketing knowledge, this real world, hands-on activity challenges you to collaborate together to create a digitally focussed campaign that addresses the author-developed client brief. This case is designed for use in digital marketing and marketing communication (marcom) modules on both undergraduate and postgraduate programmes.

Improving the thermoelectric properties of carbon nanotubes through introducing graphene nanosprings

Carbon nanotube (CNT) is a typical one-dimensional nanomaterial containing sp2 hybridization states. In this paper, we investigate the ballistic thermoelectric performance of CNTs incorporating graphene nanosprings by using non-equilibrium Green's function. The calculations reveal that the thermoelectric figure of merit could be obviously improved by introducing graphene nanosprings, which is about ten times of that of pristine CNTs at 700 K. Such enhancement is mainly attributed to the remarkable suppression of phononic and electronic thermal conductance and improvement of Seebeck coefficient. In addition, compared to the zigzag graphene nanospring, introducing of the armchair case possesses better thermoelectric performance. The results presented in this paper indicate that embedding graphene nanospring is a viable method to optimize the thermoelectric performance of CNTs and could provide useful theoretical guidance for design and fabrication of CNTs-based thermoelectric devices.

Zeeman magnetic field effect on the thermodynamic properties of armchair and zigzag phosphorene

We evaluate analytically the effect of Zeeman magnetic field on the direction-dependent electronic heat capacity (EHC) and magnetic susceptibility (MS) of phosphorene within the continuum Hamiltonian model and the Green’s function approach. Our findings show the electronic phase transition from semiconductor to semimetal for the spin-up of electrons at strong magnetic fields. We found that the critical thermal energy of EHC along the armchair (AC) direction is larger than the zigzag (ZZ) one. Also, we report an oscillating and decreasing behavior for the heat capacity of the AC and ZZ case, respectively. Furthermore, we showed that a magnetic phase transition occurs from the antiferromagnetic to ferromagnetic in both AC and ZZ directions of unbiased magnetic field-induced phosphorene, provided by the temperature-dependent MS. Finally, we have shown that there is no electronic and magnetic phase transition in both directions when the bias voltage as an electronic perturbation is present. Our remarkable points are useful for future applications of phosphorene in nanoelectronics and optoelectronics.

Mechanical properties of defective double-walled boron nitride nanotubes for radiation shielding applications: A computational study

Radiation shielding is of great importance because of the wide-spread use of nuclear radiation in various applications, such as power generation, space industries, nuclear medicine, etc. Current research focuses on developing materials with high shielding efficiency and robust mechanical properties. Boron nitride nanotubes (BNNTs) make good candidate materials for space radiation shielding applications. They are usually mixed with polymer composites to boost their mechanical properties and increase their shielding capability. Shielding can be further enhanced by adding hydrogen to the BNNT lattice, where it binds to atomic sites, or resides in vacancies. These vacancy defects can degrade the mechanical properties of the shielding materials, making them unsuitable for industrial prolonged use. In this work, we study the effect of vacancies on the mechanical properties of double-walled BNNTs (DWBNNTs). Using density functional theory, we calculate Young’s modulus of defective DWBNNTs having up to 4 divacancies, in two configurations, armchair and zigzag. We find that defective armchair DWBNNTs suffer a decrease of 5–25% of their Young’s moduli, while zigzag DWBNNTs show a lesser decrease of 3–15%, relative to the defect-free DWBNNTs. In addition, the divacancies cause a length contraction in the armchair case, and an ellipsoidal deformation for the zigzag one. Our findings are important for predicting of the tolerance of DWBNNTs to space radiation environment.

Spectral Gaps of Dirac Operators Describing Graphene Quantum Dots

The two-dimensional Dirac operator describes low-energy excitations in graphene. Different choices for the boundary conditions give rise to qualitative differences in the spectrum of the resulting operator. For a family of boundary conditions, we find a lower bound to the spectral gap around zero, proportional to $|\Omega|^{-1/2}$, where $\Omega \subset \mathbb{R}^2$ is the bounded region where the Dirac operator acts. This family contains the so-called infinite mass and armchair cases used in the physics literature for the description of graphene quantum dots.

What Kind of Business Case Studies are We Writing?

What is the difference between a research paper and a business case study? Are all good business cases decision-focused? This note provides a brief description of field-based, research-based, and armchair cases. It also reviews the notion of a descriptive or evaluative case. Although the material was written to generate a discussion of what a business case study is for case writing workshops, it is useful for those who are new to case writing—students and faculty. Excerpt UVA-PHA-0064 Apr. 12, 2012 WHAT KIND OF BUSINESS CASE STUDIES ARE WE WRITING? From time to time, debate bubbles up in the literature and at conferences over what exactly constitutes a business case study. Questions are raised, such as: Are cases theory-building tools? Verbal representations of practitioners' experiences? Perhaps a bit of both? What's the difference between a research paper and a business school case study? Understanding what exactly a case study is in the business field can be complicated. To avoid any misunderstanding in terminology, using a full description, such as business case study, distinguishes the material from a qualitative empirical approach to research that investigates a single example or limited number of cases (for example, n = 1), often called a case study. The original business case studies presented an executive's experience with a practical business issue or problem. All data was gathered through field-based interviews and, with any luck, company provided documents. Yet as business school programs expanded, so did the range of business case studies. Practicing managers and their firms were sometimes reluctant to share proprietary information, so case writers had to use existing sources of data, and the research-based business case study was born. When executives didn't want to air their missteps publicly, field-based data would be disguised, a practice that evolved into the armchair business case study, which is completely fabricated. . . .

Effective Factors of Diversified HR and Relationship Management: A Qualitative Case Study on TokyaTech, NY

This qualitative case study is specially drafted for the purpose of enhancing students’ exposure on diversified HR and relationship Management. Modern age is the age of Human Resources and Relationship Management in order to have a corporate success in today’s stiff competition. This case adopts an armchair case approach to discuss the required concept of HR & Management and apply on an imaginary company mentioned in this case. The proposed frameworks in this Case study are the primary sources of authors and properly aligned to apply on the company mentioned in this case. This case holds 100 percent primary source for the purpose of clarity on HR & Management diversity for Business graduates especially for HR & Management subjects. The practical implication of this approach is beneficial for Business students & Faculty to help students in understanding basic case approach and enhance the exposure to apply on any organization. This study covers the cultural and diversity issues around four sampled locations. The case proposes the solution with the help of descriptive models that are proposed to address the case situations in this paper.

Velocity renormalization and Dirac cone multiplication in graphene superlattices with various barrier-edge geometries

The electronic properties of one-dimensional graphene superlattices strongly depend on the atomic size and orientation of the 1D external periodic potential. Using a tight-binding approach, we show that the armchair and zigzag directions in these superlattices have a different impact on the renormalization of the anisotropic velocity of the charge carriers. For symmetric potential barriers, the velocity perpendicular to the barrier is modified for the armchair direction while remaining unchanged in the zigzag case. For asymmetric barriers, the initial symmetry between the forward and backward momentum with respect to the Dirac cone symmetry is broken for the velocity perpendicular (armchair case) or parallel (zigzag case) to the barriers. At last, Dirac cone multiplication at the charge neutrality point occurs only for the zigzag geometry. In contrast, band gaps appear in the electronic structure of the graphene superlattice with barrier in the armchair direction.

Negative differential resistance behavior in molecular devices based on carbon nanotubes: Effects of chirality and electrode–electrode distance

Using first-principles density functional theory and real-space non-equilibrium Green′s function formalism for quantum transport calculation, we investigate all-carbon mechanically controlled molecular devices which consists of only two (5,5) armchair and two (6,0) zigzag single-walled carbon nanotubes (SWCNTs) opposing one another. Our results show that the chirality of SWCNTs and the electrode–electrode distance have crucial effects on the electronic transport properties of such systems. When the right SWCNT electrode is mechanically pushed forward along its axial direction, obvious negative differential resistance behaviors are observed in the zigzag system, but not in the armchair case.

WKB analysis of edge states in graphene in a strong magnetic field

We investigate the fine structure of the edge states energy spectrum for zigzag and armchair ribbons of graphene in a strong magnetic field. At low energy, the spectra can be described by an effective Schrodinger Hamiltonian with a double well potential, symmetric in the zigzag case and asymmetric in the armchair case. We develop a semiclassical formalism based on the WKB approximation to calculate analytically the energy spectrum for the two types of edges, including regions which were not studied earlier. Our results are in very good quantitative agreement with numerical calculations. This approach leads to a qualitative description of the spectra in terms of the quantization of unusual classical orbits in the real space.

Atomic-Scale Deformation in N-Doped Carbon Nanotubes

We present the N-doping induced atomic-scale structural deformation in N-doped carbon nanotubes by using density functional theory calculations. For substitutional N-doped nanotube clusters, the N dopant with an excess electron lone pair exhibits the high negative charge, and the homogeneously distributed dopants enlarge the tube diameter in both zigzag and armchair cases. On the other hand, in pyridine-like N-doped ones, the concentrated N atoms result in a positively curved graphene layer and, thus, can be responsible for tube wall roughness and the formation of interlinked structures.

Fermi level quantum numbers and secondary gap of conducting carbon nanotubes

For the single-wall carbon nanotubes conducting in the simplest tight-binding model, the complete set of line group symmetry based quantum numbers for the bands crossing at Fermi level are given. Besides linear ( k), helical ( k ̃ ) and angular momenta, emerging from roto-translational symmetries, the parities of U-axis and (in the zig-zag and armchair cases only) mirror planes appear in the assignation. The helical and angular momentum quantum numbers of the crossing bands never vanishes, which supports the proposed chirality of currents. Except for the armchair tubes, the crossing bands have the same quantum numbers and, according to the non-crossing rule, a secondary gap arises, as shown by the accurate tight-binding calculation. In the armchair case the different vertical mirror parity of the crossing bands provides substantial conductivity, though k F is slightly decreased.

Frustration Effects and Microscopic Growth Mechanisms for BN Nanotubes

Using ab initio molecular dynamics simulations, we have studied the growth mechanisms of boron-nitride (BN) nanotubes. In this experimental conditions of temperature, the behavior of single-wall BN nanotubes strongly depends on their helicity. Open-ended zigzag tubes close into an amorphouslike tip, preventing further growth. In the armchair case, the formation of squares traps the tip into a flat cap able to revert to a growing hexagonal network by incorporating incoming atoms. These findings are related to the greater stability of B-N bonds as compared to B-B or N-N bonds.

Case study development in the UK

A case study may be defined as a description of a situation that has arisen within an organisation. The case may concern one specific problem or cover a wide range of problems. Preferably the case should be based on a real life situation although there are some who advocate the use of armchair cases, ie cases written without being based on a specific company although they may be an amalgam of the case writer's own personal experiences.