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The hydrodynamics and thermal characteristics of a laminar rivulet flow down a vertical surface are investigated. The velocity distribution within a rivulet is determined numerically by the use of a finite element method. In turn, a regression analysis is performed to fit the numerical data with an assumed closed form function. The breakup of a thin liquid film into rivulets is also considered. Heat transfer characteristics are determined. Nusselt numbers were obtained for the two cases of prescribed constant wall temperature and constant wall heat flux.

A numerical solution for ‘running wet’ aircraft anti‐icing systems is developed. The model includes breakup of the water film, which exists in regions of direct impingement, into individual rivulets. The wetness factor distribution resulting from the film breakup and rivulet configuration on the surface are predicted in the numerical solution procedure. The solid wall is modelled as a multi‐layer structure and the anti‐icing system used is of the thermal type utilizing hot air and/or electrical heating elements embedded within the layers. Details of the calculation procedure and the methods used are presented.

Rainfall is one of the main atmospheric conditions that significantly affect the aerodynamic performance of the low Reynolds number flights. In this paper, the adverse effects of rain on the aerodynamic performance of a two-dimensional (2D) airfoil with a chord-based low Reynolds number of 2 × 10⁵ and the mini-unmanned aerial vehicle (UAV) for various flight conditions, i.e. 0°–40° at Mach number 0.04 were studied numerically. The purpose of this study is to explore the aerodynamic penalties that affect the liquid water content (LWC = 5.33) of the airfoil and UAV performance in rain under different flying conditions.

The Eulerian–Lagrangian two-phase flow method is adopted to simulate the rain environment over an airfoil and mini-UAV aerodynamic performances. The Reynolds Averaged Navier–Stokes equations are considered to solve the time-averaged equations of motion for fluid flow.

The effect of rainfall on the airfoil and mini-UAV is studied numerically and validated experimentally. For 2D airfoil, the lift and drag coefficients for both numerical and experimental results show a very good correlation at Reynolds number 2 × 10⁵. For three-dimensional (3D) mini-UAV, the lift and drag coefficients for both numerical and experimental results show a very good correlation at Mach number 0.04. The raindrops distribution around the airfoil, premature trailing edge separation, boundary-layer velocity profiles at five different chord positions (i.e. LE, 0.25c, 0.5c, 0.75c and 0.98c) on the upper surface of the airfoil, water film height and the location of rivulet formation on the upper surface of the airfoil are also presented.

For 2D airfoil, the recorded maximum variation of the coefficient of lift and lift-to-drag (L/D) ratio is observed to be 5.33% at an 8° and 10.53% at a 4° angle of attack (AOA) between numerical and experimental results under the influence of rainfall effect for LWC = 5.33. The L/D ratio percentage degradation is seen to be 61.9% at an AOA of 0°–2° for the rain environment. For 3D mini-UAV, the recorded maximum variation of the coefficient of lift and L/D ratio are observed to be 2.84% and 4.60% at a 30° stall AOA under the influence of rainfall effect for LWC = 5.33. The numerical results are impressively in agreement with the experimental results. UAV designers will benefit from the findings presented in this paper. This will be also helpful for training the pilots to control the airplanes in a rain environment.

Chilika Lagoon is the largest brackishwater lagoon in the Indian subcontinent, situated at latitude 19°28′ and 19°54′ north and longitude 85°05′ and 85°38′ east (Fig. 2.1). The lagoon extends from the southwest corner of Puri and Khurdra districts to the adjoining Ganjam district of Orissa state. The pear-shaped lagoon is around 64.3km long and its width varies from 18to 5km. It is connected to the sea through irregular water channels with several small sandy and usually ephemeral islands (CDA, 2008). The average lagoon area is 1,055km² which increases to 1,165km² during the rainy season and shrinks to 906km² during the summer season. Chilika Lagoon becomes less saline during the rainy season due to flood waters from 52 rivers and rivulets. It becomes more saline during the dry season as the supply of flood water is cut off when the south wind begins to blow and saline waters enter from the Bay of Bengal at high (Patro, 2001). The lagoon has three hydrologic subsystems (Mahanadi delta, western catchments, and the Bay of Bengal) influencing the hydrological regimes as shown in Fig. 2.1. The total inflow of freshwater from the Mahanadi delta has been estimated to be 4,912 million cubic meter, accounting for 80 percent of the total water flow. The maximum discharge of 3,182 million cubic meter comes from Makara River, followed by Bhargavi River (1,108 million cubic meter) and Luna River (428 million cubic meter) (CDA, 2008). Meanwhile, the western catchments account for 20 percent of the total fresh water flow.

This article, to be published in two parts, is based on a lecture given by the author to the North‐Eastern Branch of the Institution of Corrosion Technology on 14 Feb. 1967 and to the London branch on 28 March 1967. Mr. Banfield is Corrosion and Materials officer in the Laporte Group of Companies.

This study aims to enrich the current theoretical debate on the growth of start-up firms by extensively investigating the ongoing empirical studies in this research stream. Moreover, this study identifies drivers whose support roles are confirmed in the literature and recommends further research opportunities.

In this study, we analysed the results of 316 empirical studies on start-up firms and growth and also identified and categorised 66 growth drivers. We presented these drivers in three-dimensional charts: 1) the frequency of using each driver in the 316 studies, 2) the consistency of each driver as measured by the number of studies supporting its statistical significance and 3) the net effect (positive or negative) of each driver on growth.

Our analysis compares extant studies on growth drivers and shows some under-explored growth factors of start-up firms.

Both start-up managers and policymakers can benefit from this study. This study provided managers with a fine-grained tool on the main growth drivers and can guide policymakers in supporting policies for start-up firms.

This study provides a rich, fine-grained and coherent picture of several potential growth drivers of start-up firms. Moreover, we extended our analysis to various potential drivers more than previous studies on this topic, thereby providing fruitful insights into the critical growth factors for start-up firms.

David Huffman, as a graduate student, earned his immortality by solving a problem that had stumped Claude Shannon, the creator of the field of information theory. How he saw the problem differently and the nature of his discovery have implications for how we get stuck, how we get unstuck, and how the internal models limit the ability to see patterns in the world. The paper aims to discuss these issues.

This paper describes how Huffman discovered his elegant algorithm, why it had not been discovered previously, how the algorithm may relate to the attempt to find meaning in decision making, and generalises implications for problem solving and daily lives.

Huffman was only able to see the problem anew in the cathartic moment of abandoning it. The algorithm he discovered suggests that the concept of “meaning” was an obstacle in his process.

Huffman coding is one of the underpinnings of computer science. While it should be widely understood for that alone, the process of its discovery and its fundamental methodology are deeply instructional.

Alexander Pope said “As the twig is bent, so grows the tree”, a classic statement about conscious purpose and man's controlling nature. Huffman's algorithm suggests the real world works the other way around: “As the leaves are lit, so grows the tree”.

Norberto Bobbio's Birth Centenary was celebrated in Turin in October 2009. This article acknowledges an important 20th century legal philosopher whose work is yet to be fully appreciated in the Anglo-American context. A short introduction is followed by an overview of his works in English, and intellectual profile. Relevant excerpts aim to convey some understanding of his legal scholarship. Three exemplars of his contribution to law: jurisprudence, legal sociology and the general theory of law are discussed. It is argued that a Bobbian lens can be usefully employed to consider some of the pressing 21st century legal-political and social issues.

The case has been developed as an illustrative case study using primary data. The data and images used for developing the case have been collected from the Alipurduar Division of Indian Railways with suitable permissions. The specific newspaper studies used in developing the case content have been referenced as footnotes on the relevant pages of the case study document.

Train operations in Alipurduar Division of Northeast Frontier Railway zone of Indian Railways are difficult. The division provides the vital rail link between the northeast states and the rest of India. Railway lines in the Alipurduar Division pass through several forests with a significant elephant population. As an outcome of train–elephant conflicts, train operations on one of the railway lines operate under severe speed restrictions. Moreover, the region is known for heavy rainfall and thunderstorms for almost six months every year. For the Divisional Railway Manager (DRM), the protagonist of the case, this implied repeated congestion, traffic disruptions, inadvertent delays and lack of time for critical maintenance of the tracks. A solution was planned several years ago for creating an alternative path to de-congest the traffic; however, it ran into a roadblock due to land acquisition issues.With all these limitations, could a solution be found and implemented? How could it be executed?The case illustrates how a simple yet innovative solution was proposed by the DRM in 2015 and implemented in 2016.With this case, students will be able to understand the innovation process that is embedded within long-term infrastructure projects. The case will help students understand how innovation can take place even in the later stages of project implementation, and how simple and creative solutions can have a long-term impact.

The case can be used in graduate and executive education courses in General Management and in Public Policy Management. It can also be used in Doctoral-Level Programmes such as those taught to scholars pursuing Fellow Programme in Management. Since the case brings out elements of problem framing and critical thinking, the case can be used for courses in strategic management. Many professionals, particularly those working in large organizations dealing with large infrastructure projects, will identify with the DRM and the challenges faced by him.