bluuebunny/crossref_metadata_2025 huggingface dataset:
Prospective games for defence strategic decisions in Brazil
Authors: Correa C. R. , Cagnin C. H.
Published: March 2016

Purpose

– This paper aims to propose a model, based on strategic simulation and scenario planning, to improve the decision-making process in the Brazilian defence area.

Design/methodology/approach

– Participants are disposed in three levels: decision-makers team – which goes beyond the Ministry of Defence (and military services) alone and includes other representatives of the executive and legislative branches; political and strategic advisory team – civilian representatives with a broad understanding of the national and international contexts that can contribute to developing insights and shaping the forces that may contribute to the nation’s future; and experts database— experts in fields of interest to national defence, comprising representatives of several sectors and broad areas of knowledge, including scholars, scientists, politicians, military, industry, among others.

Findings

– The planning and preparation of national defence strategies require a long-term approach, which is multidisciplinary, participatory and contextualized to the geopolitical and institutional frames of the country.

Research limitations/implications

– However, despite many policy papers intentions, defence issues have always been considered a matter for the military arena due to the country’s cultural background.

Practical/implications

– Because decisions about defence have long-range impacts and political implications, policy-makers should shape them bearing in mind a complex and politically shared foresight process.

Social/implications

– This proposed planning process enables a participatory engagement with some civil organizations and individuals as well as amplifies their commitment in national defence issues.

Originality/value

– The proposal is innovative in South America, considering that it encompasses integrated simulations on participatory foresight processes as well as broadened the civilian–military dynamic relationship and the diverse viewpoints in defence implications analysis to include a wider share of the Brazilian society.
The impact of strategic organizational orientations on green supply chain management and firm performance
Authors: Kirchoff Jon F , Tate Wendy L , Mollenkopf Diane A
Published: March 2016

Purpose

– Empirical research provides evidence that green supply chain management (SCM) practices positively impact firm performance. Yet, questions remain regarding how firms configure their organizations and design green practices to achieve improved performance, especially in light of a constantly changing business environment. This research uses the resource-based and strategic choice theories to better understand the antecedent roles of two strategic orientations, supply chain orientation (SCO) and environmental orientation (EO), on both the implementation and outcomes of green SCM practices. The paper aims to discuss these issues.

Design/methodology/approach

– Survey responses from 367 supply chain managers are tested through structural equation modeling.

Findings

– Findings suggest that a combination of SCO and EO capabilities positively influence the implementation of green SCM practices, and positively impact firm performance. Results also suggest that the capability bundle of SCO, EO, and green SCM should be adaptable to the changing business environment.

Originality/value

– This research contributes through the combination of the resource-based theory, supported by strategic choice theory, to better understand how managers configure and re-configure valuable green-related capabilities to adapt to the constantly changing business environment.
The benefits of logistics clustering
Authors: Rivera Liliana , Gligor David , Sheffi Yossi
Published: March 2016

Purpose

– The purpose of this paper is to analyze the benefits of logistics clustering, with the intent to explain their growth and popularity among private agents and policy makers during the last decade.

Design/methodology/approach

– Because of limited knowledge about the benefits of logistics clustering a main objective of this paper is theory building. The authors employed a grounded theory approach and conducted 135 open and semi structured interviews with logistics executives, government officials, academics, and chambers of commerce representatives.

Findings

– Study results revealed that, the agglomeration of logistics firms provides several key benefits to companies. Specifically, it was found that logistics clustering facilitates collaboration-related benefits, offering of value added services, career mobility for the logistics workforce within the cluster, and promotes job growth at multiple levels within the cluster. The authors offer a rich description of these benefits and the mechanisms that facilitate these outcomes.

Research limitations/implications

– This paper uses a qualitative approach. Further research using a quantitative approach to measure the magnitude of the impacts and benefits of logistics clusters would be desirable.

Originality/value

– This paper identifies the benefits associated with logistics clustering and thus provides justification for public authorities and private agents to invest in this phenomenon.
An empirical study on applicability of lean and green practices in the foundry industry
Authors: Prasad Suresh , Khanduja Dinesh , Sharma Surrender K.
Published: March 2016

Purpose

– The purpose of this paper is to investigate the applicability of lean and green practices to foundry industry in India for improving productivity and eliminating waste, incorporating the sustainability into business performance measures.

Design/methodology/approach

– The study used survey questionnaire method to collect data against 16 lean and green practices from 71 middle- to senior-level professionals belonging to Indian foundry industry. The survey instrument of lean and green practices was developed based on a number of sources from the literature and formal discussions with academicians and foundry industry professionals. The responses were received on a five-point Likert scale ranging from least applicable to most applicable. Exploratory factor and reliability analyses are conducted to obtain and validate constructs and measure each constructs Cronbach’s α (i.e. a consistency coefficient). The lean and green practices are categorized into the four constructs, namely, workplace organization practices, management practices, inventory control practices, and industrial manufacturing and quality improvement practices. Further, descriptive statistics is employed to find out the relative significance of lean and green practices.

Findings

– Factor and reliability analyses show that all four constructs are adequate and reliable to illustrate lean and green practices. Descriptive statistics indicates that lean and green practices are applicable for implementation to a certain extent in the foundry industry. Correlation analysis shows that lean practices are positively and moderately interrelated with green practices. Thus, the results present a strong evidence that lean and green practices are moderately applicable for implementation in the foundry industry.

Originality/value

– The paper provides insights into the applicability of lean and green practices implementation in the context of a developing country and presents evidence that lean and green practices are moderately applicable in the foundry industry. In addition, this paper is one of the few efforts to promote sustainable development within the industry.
Just-in-time: organizing the Lakota Sun Dance
Authors: Modaff Daniel Paul
Published: March 2016

Purpose

– The purpose of this paper is to investigate the organizing practices of a Lakota Sun Dance, and to contribute to the literature on rituals and ceremonies in organizational culture.

Design/methodology/approach

– The researcher acted as participant-as-observer during this extended ceremony. Fieldnotes capturing observations and informal interviews with Lakota elders were the source of data as recording devices were not permitted on the Sun Dance grounds. Observations were conducted for approximately 45 hours over the course of five days.

Findings

– The Lakota Sun Dance can be understood through organizational theory, particularly through a unique integration of the concepts of agency, loosely coupled systems, and just-in-time organizing. The current research highlights the role of agency in organizational ceremonies.

Originality/value

– This research offers a thick description of the organizing practices of an extended Lakota ceremony. The integration of traditional Lakota organizing principles with modern organizational theory is absent from the literature, and offers a unique perspective on organizing from a non-Western perspective.
Planning an accessible expo 2020 within Dubai’s 5 star hotel industry from legal and ethical perspectives
Authors: Morris Stephanie , Kazi Scolah
Published: March 2016

Purpose

The purpose of this paper is to provide an understanding of the accessibility laws currently in effect in the United Arab Emirates and, specifically, Dubai. Further, it recommends methods of integrating accessible hospitality and tourism in Dubai with core legal and ethical direction in preparation for EXPO 2020.

Design/methodology/approach

Review of current legislation and analysis of interpretation by industry providers was used to illustrate the impact on the current accessibility environment in Dubai and to recommend a revised regulatory scheme.

Findings

The paper explains how legal and ethical issues have influenced the planning and building of 5 star hotels in Dubai, and offers recommendations for amendments and additions to the region’s current laws that address needs of people with disabilities (PwD).

Originality/value

Little research has been conducted in the region concerning the rights and needs of PwD. The paper significantly contributes by demonstrating how an ethical and legal framework will address the needs of PwD thereby aiding in Dubai’s successful hosting of EXPO 2020. This contribution is notably opportune in view of the anticipated changes in applicable legislation.
Past, present and future of tourist tracking
Authors: Thimm Tatjana , Seepold Ralf
Published: March 2016

Purpose

The purpose of this paper is to find out tourism movement patterns via the tracking of tourists with the help of positioning systems like GPS in the rural area of the Lake Constance destination in Germany. In doing so past, present and future of tourist tracking is illustrated.

Design/methodology/approach

The tracking is realized via common smartphones extended by an app, with dedicated sensors like position loggers and a survey. The three different approaches are applied in order to compare and cross-check results (triangulation of data and methods).

Findings

Movement patterns turned out to be diverse and individualistic within the rural destination of Lake Constance and following an ants trail in sub-destinations like the city of Constance. Repeat visitors and first-time visitors alike always visit the bigger cities and main day-trip destinations of the Lake. A possible prediction tool enables new avenues of governing tourism movement patterns.

Research limitations/implications

The tracking techniques can be developed further into the direction of “quantified self” using gamification in order to make the tracking app even more attractive.

Practical implications

An algorithm-based prediction tool would offer new perspectives to the management of tourism movements.

Social implications

Further research is needed to overcome the feeling of invasiveness of the app to allow tracking with that approach.

Originality/value

This study is original and innovative because of the first-time use of a smartphone app in tourist tracking, the application on a rural destination and the conceptual description of a prediction tool.
A framework for planning academic library spaces
Authors: Choy Fatt Cheong , Goh Su Nee
Published: March 2016

Purpose

– The focus on designing spaces for users in the last decade or so signifies the gradual change in the mission of libraries from provision of resources to that of a pro-active partner in learning. Planning for user space in support of learning is far more complex as it needs to take into account the variety of users’ needs and behaviour. Before specifying the actual layout and design of users’ spaces it is important to consider all the major factors that affect the use of the intended library space. The purpose of this paper is to provide a guide to library planning base on the experience of the authors at Nanyang Technological University (NTU) Libraries.

Design/methodology/approach

– The framework for planning library spaces developed at NTU Libraries consists of four components – collaborative space, sanctuary space, interaction space and community space. Discussion on the rationale of these spaces and suggestions for their implementation will assist others in asking appropriate questions on their own library space planning exercise.

Findings

– The paper reinforced the view that a good library building has to provide a wide variety of spaces, some of which are contradictory as the needs of a student is different from another. A student also has different needs at different times. Providing and balancing these needs is essential.

Originality/value

– This paper provides a tried and tested conceptual framework for use by library space designers.
Intangible organizational resources in Polish libraries
Authors: Wojciechowska Maja Dorota
Published: March 2016

Purpose

– The purpose of this paper is to present the main assumptions of the resource-based theory according to which the success of an organization is mainly dependent on the ability of capitalizing its inner capacity. The author draws attention to the measurement of intangible resources of libraries and their evaluation, crucial from the point of view of library effectiveness and the quality of its services. The author also emphasizes the specific character of intangible resources, including lack of their mobility, specialization and difficulty in their replacing, which may result in hindering management processes.

Design/methodology/approach

– The second part of the paper illustrates the author’s research in the field of intangible resources in Polish libraries, including human resources (knowledge, competencies, employee skills), competencies of library management staff, business strategies, organizational culture, communication skills and relations between employees, the ability to communicate and relations with the library community, in particular with its users, library reputation, brand, library innovativeness and the ability to adapt to changes and expectations of the community, the ability of the library to cooperate with other institutions, including networks and consortia, the ability to use and support new technological solutions, the ability to introduce new technologies in the library, the ability to create and acquire intellectual property (copyright, licensing, trademark protection, etc.).

Findings

– Research has shown that libraries pay growing attention to the relation with the community. Concentrating on library resources means concentrating on readers and providing services that would satisfy readers. However, it seems that the knowledge of library management in the field of managing of intangible resources is still insufficient.

Originality/value

– The paper presents the first study of this kind conducted in Poland.
Job analysis of academic librarians in Greece
Authors: Mouza Anna Maria , Grigoriadou Sofia P.
Published: March 2016

Purpose

– The purpose of this paper is to identify the obligations and responsibilities of librarians, working in Greek academic libraries and to investigate whether there are significant differences among various institutions.

Design/methodology/approach

– The survey was based on a questionnaire containing 161 duties performed by academic librarians, classified into five main categories which are: general management, collection management, materials organization, user service and system management. The respondents were 31 managers at Greek academic libraries, who were asked to assess their duties according to importance, difficulty and frequency, and whether such tasks were deemed professional, para-professional or non-professional. A two-way ANOVA was applied to determine whether performed duties significantly differed according to institution size and/or type.

Findings

– The results revealed no significant differences regarding importance of duties while many differences were detected across all main categories regarding difficulty. Differences were also recorded concerning the frequency of duties for some of the subcategories under general and collection management, materials organization and the subcategory cultural events and programs. Finally, professional duties represented 86 percent of total duties, indicating the necessity of professional librarians for the effective management of their responsibilities.

Originality/value

– These findings, which are first recorded in Greece and refer to academic librarians’ duties, will be particularly useful for decision makers to reach the right decisions regarding the implementation of human resource practices, taking into account the individuality of the institutions under consideration. Also these outcomes can be viewed as a valuable guide for adapting the indicated decisions under the rapidly introduced technological changes and properly tackling problems stemming from the economic recession.
CEO power and CEO hubris: a prelude to financial misreporting?
Authors: Cormier Denis , Lapointe-Antunes Pascale , Magnan Michel
Published: March 2016

Purpose

– The purpose of this paper is to explore how the tension between a firm’s CEO power features and externally observable hubris attributes may determine the likelihood of financial misreporting.

Design/methodology/approach

– The analyses are based on a sample of 16 Canadian firms for which there were formal accusations of financial reporting fraud filed by securities regulators, assorted with regulatory sanctions; as well as 16 firms matched on industry and size with no evidence of financial misreporting.

Findings

– The findings suggest that firms accused of financial misreporting exhibit features of strong CEO power and hubris as reflected in their relations with the self, others and the world. Governance mechanisms do not seem to be effective in detecting or preventing financial misreporting, with independent boards of directors proving especially ineffectual.

Social implications

– The findings suggest that formal governance processes may get coopted by a CEO with hubristic tendencies.

Originality/value

– While the tentative model is more explanatory than predictive, it opens up a new research area as it brings the concept of hubris into accounting research.
How abusive supervision and abusive supervisory climate influence salesperson creativity and sales team effectiveness in China
Authors: Jiang Wan , Gu Qinxuan
Published: March 2016

Purpose

– Adopting the social information processing theory and social comparison theory, the purpose of this paper is to examine how abusive supervision and abusive supervisory climate jointly influence salesperson creativity, sales team creativity, and team performance.

Design/methodology/approach

– The study conducted hierarchical linear modeling and hierarchical regression to analyze the paired data from 102 sales teams comprising 319 salespeople and 102 managers.

Findings

– At the individual level, abusive supervision had negative effect on salesperson creativity via psychological safety. Abusive supervisory climate played a cross-level moderating role in the relationship between abusive supervision and psychological safety. At the team level, abusive supervisory climate was negatively related to sales team creativity via averaged salesperson creativity and negatively associated with sales team performance through sales team creativity.

Originality/value

– This study adds to knowledge of how abusive supervision and abusive supervisory climate jointly affect salesperson psychological safety and creativity. It also contributes to abusive supervision and creativity literature by linking abusive supervisory climate and sales team creativity by integrating social information processing theory and social comparison theory.
A Biologically Inspired Knee Actuator for a KAFO
Authors: Tian Feng , Hefzy Mohamed Samir , Elahinia Mohammad
Published: March 2016

Knee–ankle–foot orthoses (KAFOs) are prescribed to improve abnormal ambulation caused by quadriceps weakness. There are three major types of KAFOs: passive KAFOs, semidynamic KAFOs, and dynamic KAFOs. Dynamic KAFOs are the only type that enables to control knee motions throughout the entire walking gait cycle. However, those available in the market are heavy, bulky, and have limited functionality. The UT dynamic KAFO is developed to allow knee flexion and assist knee extension over the gait cycle by using a superelastic nitinol actuator, which has the potential to reduce volume and weight and reproduce normal knee behavior. In order to match the normal knee stiffness profile, the dynamic actuator consists of two actuating parts that work in the stance and swing phases, respectively. Each actuating part combines a superelastic torsional rod and a torsional spring in parallel. Geometries of the two superelastic rods were determined by matlab-based numerical simulations. The simulation response of the dynamic actuator was compared with the normal knee stiffness, verifying that the proposed design is able to mimic the normal knee performance. The surrounding parts of the dynamic knee joint have then been designed and modeled to house the two actuating parts. The dynamic knee joint was fabricated and mounted on a conventional passive KAFO, replacing its original knee joint on the lateral side. Motion analysis tests were conducted on a healthy subject to evaluate the feasibility of the UT dynamic KAFO. The results indicate that the UT dynamic KAFO allows knee flexion during the swing phase of gait and provides knee motion close to normal.
The Cross-Plane Thermal Conductance of Multi-Layer Graphene Bundles
Authors: Liu Chenhan , Wei Zhiyong , Chen Weiyu , Chen Hui , Yang Juekuan , Bi Kedong , Chen Yunfei
Published: March 2016

In this paper, the cross-plane thermal conductance σ of multi-layer graphene nanobundles (MLGNBs) is investigated using the non-equilibrium Green’s function method. For the normal MLGNBs, the σ has a positive dependence on the lateral area S due to more atoms involved in the heat transport in the larger S. However, the thermal conductance per unit area Λ is negative dependent on the S since high-frequency phonons contribute less to Λ with low transmission function and small number while the increased phonon branches are mainly located in the high-frequency range. Interestingly, as the S is larger than several square nanometers, the Λ converges to the macroscopic value, independently on the S. Then the staggered MLGNBs is investigated, the results show that increasing both staggering distance between neighboring graphene layers with each other and the graphene layer number in the central device can modulate the σ in a large scope due to the boundary scattering. Finally, in the MLGNBs junction, we found the variation of heat flux direction has an important effect on the σ while the layer number in the central device has weak effect on the cross-plane thermal transport. Our results help understand the cross-plane thermal transport of MLGNBs and provide a model to investigate the thermal property of layered material nanobundles.
Heat Transfer During Constrained Melting of Graphite-Based Nanofluids in a Spherical Capsule
Authors: Zhu Zi-Qin , Fan Li-Wu , Liu Min-Jie , Zeng Yi
Published: March 2016

Transient heat transfer during constrained melting of graphite-based solid-liquid phase change nanofluids in a spherical capsule was investigated experimentally. Nanofluids filled with self-prepared graphite nanosheets (GNSs) were prepared at various loadings up to 1% by weight, using a straight-chain saturated fatty alcohol, i.e., 1-dodecanol (C12H26O), with a nominal melting point of 22 °C as the base fluid. In-house measured thermal properties were adopted for data reduction, including thermal conductivity, dynamic viscosity, latent heat of fusion, specific heat capacity and density. A proper experimental approach depended on volume expansion was figured out to monitor the melting process of nano-enhanced phase change fluid in a spherical capsule indirectly and qualitatively characterize the process. A variety of boundary temperatures were also adopted to vary the intensity of natural convection. It was shown that under low boundary temperatures, a monotonous melting acceleration came into being while increasing the loading due to the monotonously increased thermal conductivity of the nanofluids. While increasing the boundary temperature leads to more intensive natural convection that in turn slowed down melting under the influence of nanoparticles because the contribution by natural convection is significantly suppressed by the dramatically grown dynamic viscosity, e.g., more than 60-fold increase at the loading of 1 wt.%. The melting rate is determined by the competition between the enhanced heat conduction and deteriorated natural convection.
An Ultra Fast Cooling Method for Cell Vitrification Cryopreservation Utilizing Thin Film Evaporation
Authors: Su Fengmin , Zhao Nannan , Deng Yangbo , Tian Bohan , Mu Chunfeng , Ma Hongbin
Published: March 2016

Ultra-fast cooling is the key to successful cell vitrification cryopreservation of lower concentration cryoprotective solution. This research develops a cell cryopreservation methodology which utilizes thin film evaporation and achieves vitrification of relatively low concentration cryoprotectant with an ultra-fast cooling rate. Experimental results show that the average cooling rate of dimenthylsulphoxide cryoprotective solution reaches 150,000°C/min in a temperature range from 10°C to −180°C. The ultra-fast cooling rate can remarkably improve the vitrification tendencies of the cryoprotective solution. This methodology opens the possibility for more successful cell vitrification cryopreservation.
Fluorine-Induced Superhydrophilic TiO2 Nanotube Arrays
Authors: Luo Zhi-Yong , Mo Dong-Chuan , Lyu Shu-Shen
Published: March 2016

Continuous water film formed on a hydrophilic or superhydrophilic surface can delay the formation of a vapor film in boiling and thus improve critical heat flux (CHF), therefore, the fabrication of hydrophilic or superhydrophilic surface is an efficient approach to enhance boiling heat transfer. In the present work, superhydrophilic TiO2 nanotube arrays (TiNAs) interfaces are fabricated by anodization in fluoride contained electrolyte, and the fluorine is found out to be the key factor affecting the wettability of TiNAs interfaces. After anodization, a stable oxy-fluoride layer was formed at the interface as form of -O-Ti-F, the fluorine atoms are linked to the interface as terminal groups. Due to the strong polarity of titanium oxy-fluorides, superhrophilic TiO2 nanotube arrays interface is obtained. Furthermore, we characterize the stability of titanium oxy-fluorides by storing. After store for 2 months, the inner titanium fluorides (TiF4) are lost due to its strong volatility. Fortunately, the content of titanium oxy-fluorides remains the same, and retain its remarkable superhydrophilic properties. It is potential to design energy-efficient devices ranging from boiling heat transfer to self-cleaning.
Near-Field Radiative Thermal Control of a Metal Structure With Graphene
Authors: Wang Ao , Xuan Yimin
Published: March 2016

Based on the structure of metal parallel plates, this paper points out that thermal radiation in near field is greatly enhanced due to near-field effect, exceeding Planck’s blackbody radiation law. To study the effect of graphene on thermal radiation in near field, we add graphene layer into the structure. The result indicates that the graphene layer effectively suppresses the near-field thermal radiation between metal plates, having good ability of thermal insulation. In consideration of the thickness of 0.34nm of single-layer graphene, we can say graphene plays a very important role in controlling the near-field thermal radiation.
Optimum Structural Design of Thermal Protection Using Photonic Crystal Material Considering Thermophysical Properties in Micro/Nanoscale
Authors: Wei Y.-Q. , Zhang H.-C. , Zhao Y. , Wang J.-L. , Li Y. , Xie G.-N.
Published: March 2016

With the rapid development of the supersonic aircraft technology, tremendously, the aircraft Mach numbers get higher and higher, but on the other hand, the working condition become worse and worse. The photonic crystal material which is formed by the periodic micro/nanoscale structures can generate the photonic band gaps, and the photonic band gaps could reflect the energy of the electromagnetic wave effectively. Consequently, the photonic crystal material turns into the newly-developing hotspot on the field of thermal protection for the supersonic aircraft. In this paper, the aircraft states of Mach 6 are set as the target operating condition, and 5 optimum proposals are presented for the structures of typical photonic crystal material. The energy which gets into the body material is calculated; Based on the theory of the electromagnetic field, using the method of transmission matrix and Plane Wave Expansion (PWE), the characteristics of the photonic band gaps for one-and-three dimensional photonic crystals are calculated. Finally, the characteristics of the photonic band gaps are discussed, and optimal design for the performance of the photonic crystal material thermal protection are proposed.
Characteristics of Jumping Droplet-Enhanced Condensation on Nanostructured Micromesh Surface
Authors: Aili Abulimiti , Li Hongxia , Alhosani Mohamed H. , Zhang TieJun
Published: March 2016

Jumping-droplet enhanced condensation has recently attracted huge interest due to its remarkable potential of heat transfer performance enhancement, and studies have been done to design superhydrophobic surfaces with various surface morphologies. We fabricated a superhydrophobic micromesh-covered surface using a facile and scalable method. ESEM condensation experiment results show that droplets in pores formed by the mesh wires had faster growth rate in the upward direction than droplets on wires. This is mainly because of the confining role of the wires and higher heat transfer rate due to larger solid-liquid contact area. Also, these droplets always jumped at the size of pores (∼35 μm) when they coalesced with other droplets on wires. Moreover, droplets in pores were distorted by mesh wires, resulting in larger surface area. Theoretical predictions show, for a specific droplet radius, coalescence jumping of distorted droplets on the mesh-covered surface releases more excess surface free energy, and has larger jumping velocity than that of spherical droplets on the plate surface without mesh. This better performance was further validated by constant exposure of those two surfaces to electron beam during which work of adhesion was gradually increased. As expected, droplets on the mesh-covered surface coalesced and jumped while coalescing droplets on the plate surface could not as the exposure time increased. Our results offer new insights for designing hierarchical structured superhydrophobic surfaces to further enhance the performance of condensation heat transfer processes.
Experimental Investigation on the Heat Transferring of Nanofluid in Self-Exciting Mode Oscillating-Flow Heat
Authors: Shang Fu-Min , Dong Yi-Fang , Liu Jian-Hong , Liu Deng-Ying
Published: March 2016

In this article, the heat transferring property of the copper-water nanofluids in self-exciting mode oscillating flow heat pipe under different laser heating power is experimented, as well as is compared with that of the distilled water medium in self-exciting mode oscillating flow heat pipe under same heating condition. The objective of this article is to provide the heat transfer characteristics of Cu-H2O nanofluids in self-exciting mode oscillating-flow heat pipe under different laser heating input, and to compare with the heat transfer characteristics of the same heat pipe with distilled water as working fluids.

The SEMOS HP used in this experiment is made of brass tube with 2mm interior diameter, which is consisted of 8 straight tubes with 4 turns’ evaporation section and 12 turns’ condensation section. The heat resource for the evaporation zone is eight channel quantum pitfall diode array semi-conductor laser heater with 940nm radiation wave length, while the radiation power of each channel is changeable within 0–50W and the facular size is 1×30mm2. The condensation section is set in a cooling water tank in which water is from another higher tank. The actual transferring rate could be calculated by the flow rate of the cooling water and the change of the temperature. The change of the temperature of the heat pipe wall is measured by those thermo-couple fixed in different section in the heat pipe and data is collected by a data acquisition. In the heat pipe the fluid filling rate is 43%, the pressure is 2.5×10−3Pa, and the heat pipe inclination angle is 55° while the size of the brass particle in the nanofluids is less than 60nm and volume proportion is 0.5%.

In this paper, the particularity of heat transfer rate of the SEMOS heat pipe with Cu-H2O fluid has been experimentally confirmed by changing the proportion of working fluid and Cu nonsocial particles in the heat pipe. By comparing the experimental result of these two different medium in the SEMOS HP, it is shown that the heat transferring rate with brass-water nanofluids as medium is much better than that with distilled water as medium under same volume proportion.
Suppression of Frost Propagation With Micropillar Structure Engineered Surface
Authors: Zhao Yugang , Yang Chun
Published: March 2016

Despite that using surface-roughness-induced superhydrophobic surface as a solution for ice/snow accretion issues has achieved extensive progresses, its icephobicity breaks down in case of condensation frosting, while the high aspect ratio structure brings more concerns on its durability and sustainability. In this work we investigated condensate frosting on substrates fabricated with patterned micropillars having a small aspect ratio, and studied the freezing propagation with different pattern sizes. The results show that a coarse patterned substrate can effectively suppress the freeing propagation while a fine patterned one can drastically promote the freezing propagation. Frost coverage can also be reduced with proper pattern design. A theoretical model was developed to explain the mechanism of surface ice propagation, and agrees well in tendency with experiment measurements. The aim of this study is to provide some new insights on the influence of surface morphology on ice growth.
Ceramic Tile With Air Purification Capability
Authors: Yang Ting , Zhang Yufei , Ma Lijuan , Liu Yanhua
Published: March 2016

In recent years, with the social progress and the rising of living standard, people have realized the importance of clean air. Microscale or nanometer photocatalyst has a certain application advantages in the purification of pollutants. Nano-TiO2 is one of novel promising environmental-friendly catalytic materials. However, the, only can absorb ultraviolet irradiation which accounts little in sunlight. Co-doping is beneficial in modifying TiO2. The synergistic action of dopants not only increased the activity of photocatalytic degradation, but also expanded the response range of light to the visible light region.

Ceramic tile is a kind of common building material, and has broad application to the outside and inside wall of buildings for decoration. If we carry nanometer TiO2on ceramic tiles, they can clear pollutants in indoor and outdoor air.

In this study, we prepared a TiO2 photocatalytic gel in advance by doping amount of N, F and/or Fe. Then we coated the gel on a kind of ceramic tile. After calcination we prepared a special ceramic tile with TiO2. The TiO2 was co-doped with N, F and Fe elements. The photo-catalytic activities of the ceramic tile samples under visible light irradiation were evaluated by the degradation of methylene blue solution. The result showed that the photocatalytic activity of the ceramic tile co-doped with TiO2 doped with 4wt % N, 0.06 wt% Fe, 0 wt% F, calcinated at 500°C, was the highest. The influence order of the factors was calcination temperature >Fe >F> N.
The Impingement of Droplet Train Onto a Flat Hot Surface With High Wall Superheat
Authors: Qiu Lu , Dubey Swapnil , Choo Fook Hoong , Duan Fei
Published: March 2016

Single droplet based investigations have been performed for hundreds of years. However, in many industrial applications, such as printing, spray cooling and coating etc, numerous droplets will be produced. Droplet train, therefore, is a physical model to approach the complex situation. When the wall temperature is higher than the boiling point, the problem becomes even complex. The subcooling of the droplet, the superheat of the wall also influence the hydrodynamic pattern of the droplet impingement. The hydrodynamic behavior of the water droplet train impinging onto a hot surface (up to 220 °C) is investigated. A droplet train generator is employed to produce stable high velocity (around 6.35 to 19.13 m/s) droplet train (with a diameter around 0.1 mm) at the droplet frequency ranges from 27990 Hz to 55560 Hz. The hot surface is made by copper and heated with cartridge heaters. The effect of wall superheat on flow pattern is experimentally examined and reported. The results show that the wall temperature plays an significant role to the impingement. It influences the spreading speed, stable spreading diameter and splashing angle apparently.
Investigation of Sessile Droplet Wetting, Dynamics and Evaporation on Micro-Structured Substrates
Authors: Zhu Gui-Ping , Ong Kian-Soo , Chong Karen Siew-Ling , Huang Hu-Lin , Duan Fei
Published: March 2016

The wetting, spreading and drying of pure liquid and nanofluid sessile droplets on a patterned solid surface were investigated systematically in terms of liquid and surface property. The patterned nickel surface was characterized with diamond, circular, hexagon and rectangular pillars. The size ratio between interval and pillars varies from 1.0 to 5.0. The study was firstly carried out for the effect of pure water droplet size on liquid spreading and droplet evaporation process on diamond-shape micro structured substrate with LInterval/LPillar=1.0. Larger amount of liquid leads to a larger wetting area. With fixed substrate (diamond, LInterval/LPillar=1.0) and droplet size (1 μm), mixture of DI water and Ethanol (volume ratio varies from 0.5 to 2.0) was used for generating droplets with different surface tension and evaporation coefficient. Fingering shape would generate on the contact line. With higher concentration of ethanol, the fingering effect is stronger and appeared in a shorter time. The contact area shrinks when increase the size ratio of interval and pillar. This would reduce the length of the contact line, and thus slow down the liquid evaporation. The role of pillar shape was examined based on time for complete evaporation. The effect of surface material on evaporation process was conducted on nickel and PMMA substrate fabricated with the same design. Additionally, investigations were conducted with solutions consisted with nanoparticles and DI water. The mixture were made at different weight ration to achieve concentration of nanoparticles varies from 0.02% to 0.18% with an interval at 0.04%.
Pore-Scaled Analytical Modelling of Permeability and Inertial Coefficient for Pressure Drop Prediction of Open-Cell Metallic Foams
Authors: Yang X. H. , Song S. Y. , Zhang L. Y. , Lu T. J.
Published: March 2016

Amongst various porous media, open-cell metallic foams exhibit distinctive properties: relatively low manufacturing cost, ultra-low density, moderate stiffness and strength, and high surface area-to-volume ratio. They have been, therefore, utilized in a variety of applications such as microelectronics cooling, fuel cells, and compact heat exchangers. For such applications, the knowledge of pressure drop of fluid flowing across the foam is often a key issue, enabling control of fluid flow, heat transfer enhancement, planning and designing chemical engineering processes, optimal flow analysis as well as practical designs. We present in this paper an analytical model capable of predicting the pressure drop of a Newtonian incompressible fluid flowing unidirectionally across isotropic and fully-saturated micro open-cell cellular foams within the Darcy and Forchheimer flow regimes. Analytical exploitations are conducted to determine the foam permeability and inertial coefficient. The analytical model is based on the basis of volume-averaging approach and the assumption of piece-wise plane Poiseuille flow with the modified cubic lattice with spherical node at the junction of struts. To better mimic the foam struts shape, a concave-triangular-shaped strut consisting of two nose-to-nose cones is considered and particular attentions have been paid to both analytically and numerically examine the node shape as well as struts shape effect. Built upon a generalized tortuosity model derived from the modified cubic unit cell, an analytical model of permeability on the basis of a cubic unit cell is developed, valid within a typical engineering range of porosity (ε = 0.86 ∼ 0.98) and pore size (0.254 mm ∼ 5.08 mm). With the effect of Reynolds number considered, the pore-scaled Reynolds number dependent drag coefficient expression is introduced and through this the inertial coefficient is analytically modeled on the basis of flow over bluff bodies, which is found to agree well with experimental data from various sources. The modeling procedure for pressure drop (permeability and inertial coefficient) is based on physical principles and geometrical considerations, and the model predictions agree satisfactorily with existing experimental data. Results show that by building the analytical model on the basis of a cubic unit cell to represent the topology of metallic foams, pressure drops as well as hydrodynamic conditions within both the Darcy and Forchheimer regimes in a Newtonian fluid can be analytically predicted.
Thermal and Flow Characteristics of Water-Nitrogen Taylor Flow Inside Vertical Circular Tubes
Authors: Zhang Jingzhi , Li Wei
Published: March 2016

Heat transfer and flow characteristics of Taylor flow in vertical capillaries with tube diameters ranging from 0.5 mm to 2 mm have been investigated numerically with the Volume of Fluid (VOF) method. Streamlines, bubble shapes, pressure drops, and heat transfer characteristics of Taylor flow were investigated in detail. The results indicate that the dimensionless bubble length increases with increasing Re, while the variation of diameters have slight influence on it. A flat tail and sharper nose bubble with longer bubble length and thicker film thickness are obtained at higher Re for the increasing inertia force. Pressure drops in liquid slug region are higher than single phase flow because of the Laplace pressure drop. The flow pattern dependent model and modified separate model in this work can predict the simulation data well with a MAE of 2.416% and 2.289%, respectively. Bo and Re are adopted in the modified separate model to taking surface tension, gravity, inertia, and viscous force into account. The wall temperature Tw increases along X axis in liquid region, and gets its peak at the tail of Taylor bubble region. Nutp, which is about 1.2∼3 times of fully developed single phase flow with constant wall heat flux, is negatively proportional to the dimensionless liquid slug length (Ls*). Taylor flow can enhance the heat transfer efficiently.
Thermal Wave Model for Analysis of Multilayer Tissue Medium in Presence of Inhomogeneity in Laser Tissue Treatment
Authors: Verma A. K. , Mahapatra S. K.
Published: March 2016

In this current investigation a modified model of Pennes Bioheat equation i.e. the thermal wave model of bioheat transfer (TWMBT) is applied for the heat transfer processes underlying the laser tissue interaction to investigate the thermal damage of biological tissues.

For analysing the thermal effect, a two dimensional domain is taken with three layers (simulating human skin) of different thermal properties with inhomogeneity in the middle layer. The inhomogeneity considered in this problem simulates the presence of tumor inside tissue medium. The finite volume method (FVM) is used for discretization. The central difference scheme is adapted for discretizing the spatial term. The incident collimated beam on the top layer is provided to destroy the unwanted tumor cell represented by inhomogeneity in the middle layer. Subsequent to the discretization of governing equation of hyperbolic nature, implicit scheme has been employed to obtain the solution and its stability has been assessed. As per the findings, the hyperbolic thermal wave model is more appropriate than the Pennes model of bioheat transfer for laser-tissue treatment.
Numerical Study of Cyclic Melting and Solidification of Nano Enhanced Phase Change Material Based Heat Sink in Thermal Management of Electronic Components
Authors: Sahoo S. K. , Das M. K. , Rath P.
Published: March 2016

The Present investigation has been carried out to study the performance of nano enhanced phase change material (NEPCM) based heat sink for thermal management of electronic components. Enthalpy based finite volume method is used for the analysis of phase change process in NEPCM. To enhance the thermal conductivity of phase change material (PCM), copper oxide nano particles of volume fractions 1%, 2.5% and 5% are added to PCM. A heat flux of 2500 W/m2 is taken as input to the heat sink. The thermal performance of the heat sink with PCM is compared with NEPCM for each volume fraction of nano particle for both finned and unfinned configurations. It is observed that the nano particle volume concentration plays a major role in removing the heat from the chip in case of unfinned heat sink configuration. However, for finned heat sink configuration, the volume concentration effect is not appreciable. In addition, the performance of NEPCM based finned heat sink is studied under cyclic loading in both natural and forced convection boundary conditions. It is observed that under forced convection the solidification time is reduced.
Numerical Simulation of Nonlinear Flow and Heat Transfer in a Sudden Expansion and Contraction Channel
Authors: Yang M. , Yang L. Q. , Lu W. , Li L. , Liu Q. X. , Zhang Y. W.
Published: March 2016

Numerical simulation of forced flow in sudden-expansion followed by sudden-contraction rectangular channel was presented for the whole flow region. The nonlinear flow and heat transfer characteristics were investigated by various Reynolds number and geometrical dimension and the critical Reynolds numbers under different conditions have been calculated. The results show flow and heat transfer from symmetric state to asymmetric state with the increase of Re. When Re<Rec (critical Reynolds number for flow transformation), the symmetric state is stable. On the other hand, when Re ≥Rec, the flow loses stability and from symmetric to asymmetric via a symmetry-breaking bifurcation. And the heat transfer performance have relevant characteristics as fluid flow.