An experimental investigation of turbulent forced convection heat transfer by a multi-walled carbon-nanotube nanofluid

Abstract In this work, a nanofluid based on multi-walled carbon nanotubes was formulated, and its heat transfer characteristics experimentally examined for turbulent flow in a straight tube. The experiments found that using the nanofluid resulted in an increase in pumping power and also a decrease in the observed convective heat transfer characteristics. This suggests that multi-walled carbon nanotube nanofluids in turbulent flows will actually impair heat transfer rather than improve it, and so may not be an appropriate heat transfer media in forced turbulent flows

Natural convection heat transfer in façade integrated solar concentrators

The use of facade (wall) integrated concentrating solar collectors is an area of developing interest within the field of energy-efficient building technology. One way of achieving such a device could be through the use of a static flat or parabolic reflector used in conjunction with a photovoltaic/thermal absorber and a vertical glazed aperture. However, to precisely predict the performance of such facade integrated collectors, it is essential to understand the heat losses from them. In general the thermal losses from these collectors can be calculated using existing relationships for flat plate solar collectors and fundamental heat transfer concepts. However there is no relationship in the literature to describe the natural convection heat transfer in the asymmetric enclosed air gap formed by a façade integrated concentrator as described. Hence, in this study, a relationship to describe the natural convection heat transfer in such enclosures was developed using an experimentally validated computational fluid dynamics analysis. The relationship shows that the heat transfer, expressed in terms on the Nusselt number, is strongly dependent on the Rayleigh number and the aspect ratio (A/H), and can be expressed in the form Nu = a Rab (A/H)c

Microscopic and morphometric study on the epididymis of Sri Lankan cattle

Epididymides were collected from five mature healthy indigenous bulls and brought to the laboratory in ice. Tissue sections were taken from six different areas; two (proximal and distal) from each head, body and tail regions of the epididymis, processed and stained with Haematoxylin& Eosin (H&E) or Van-Gieson to study the microscopic anatomy and morphometry. The volume densities of the epididymal duct, ductular lumen, epithelium, and the intestitium were measured. The tubular and lumen diameters and heights of the epithelium and stereo cilia were also measured. The commonest cell type found was principal cells with steriocilia. The basal cells, the second abundant cell type, found closer to the basement membrane of the tubules and rich in the body region. The apical cells were located closer to luminal surface of the duct. The halo cells were the least common cell type observed. The smooth muscle layers that encircle epididymal duct increase its thickness from head to tail direction. The volume density of epididymal duct was high in head and tail region compare with that of body region. The epithelial volume density decreased from head to tail direction and the opposite was observed for the luminal volume density. The tubular diameter found to be similar in all six regions except proximal tail which had the highest diameter (5.9 mm). The decrease of the epithelial height from head to tail direction contributed for the increase of the luminal diameter in the same direction. The height of stereocilia was found low in the distal head (1.2 mm) and distal tail (1.4 mm) region compare to the rest of the regions. Four types of cells namely principal cells, halo cells, basal cell and epical cells, are present in the epididymal duct. The sperm storage area in the tail of the epididymis is increased due to an increase in the luminal diameter caused by a decreased in epithelial height and length of stereocilia

Effect of feeding strategies on economy of milk production in small scale dairy production systems in the Thirunelvery area of the Jaffna district

The objectives of the study were to identify the local feeding strategies adopted by the small-scale dairy farms in selected areas of the Thirunelvely area of the Jaffna district and to determine its effect on economy of milk production. Using a structured questionnaire, information on milk yield, expenses incurred and income generated were gathered from S3 dairy farmers in the study area. Based on the information collected a cost benefit analysis was performed using the statistical package SAS. Samples of feeds used on the farm also were taken and chemical composition of feed samples were analysed. Eleven feedstuffs identified were grouped into: High fiber low protein (HFLP); High fiber high protein (HFHP) and Low fiber high protein (LFHP) feeds. Three feeding strategies were identified: strategy 1 used HFLP and LFHP; strategy 2 used HFLP and HFHP and strategy 3 HFLP, HFHP and LFHP feeds. Out of the 53 farms, 28.31 % followed strategy 1, 16.98 % followed strategy 2 and 54.71 % followed strategy 3. All feeding strategies produced positive economic returns but, the feeding strategy 2 was the most effective system than the other two systems

Towards a Digital Lean Hospital: Concept for a Digital Patient Board and Its Integration with a Hospital Information System.

Lean management applied to healthcare aims at creating maximum value for patients by reducing waste and waits. It puts the patient's needs center stage, emphasizes employee involvement and continuous improvement. To realize this, visual tools such as the huddle board or the patient board are implemented in hospital wards. The boards are currently realized by whiteboards or flipcharts, which leads to duplicated data entries and loss of information. The objective of this work is to introduce a concept for digitalizing the patient board and integrate with a hospital information system (HIS) for improved data availability. Data on appointments, personnel planning and master patient data can be directly accessed from the HIS database. A digital patient board has several benefits: data can be collected from information systems, making it obsolete to record information several times. Even more functionalities, in particular, those supporting the communication between a patient and a healthcare team can be included by means of a digital board which improves patient involvement

Dynamic Pocket Card for Implementing ISBAR in Shift Handover Communication.

A risk factor for patient safety are communication failures among health professionals. Communication standards such as SBAR or ISBAR (situation, background, assessment, recommendation) aim at improving the exchange of information between health professionals by specifying a certain structure and content of information. However, those tools are not well established in daily clinical practice and IT support is missing which results in unstructured, inefficient and error prone information exchange. In this paper, we address this issue by presenting a mobile application that implements the ISBAR communication standard for the intensive care unit (ICU). The system can serve as digital pocket card supporting nurses in preparation for reporting and in a structured information provision during shift handover and in daily reporting. We collected requirements in collaboration with a hospital and developed a prototype. Within the application, nurses can take notes on the five information categories of ISBAR, which allows to reproduce the information in reporting situations in a structured manner. In future, it will be assessed in a pilot phase whether the digital pocket card is suitable for everyday clinical use

SR 232 Pilot Project-Development of a Balanced Mix Design for Cold In-Place Recycling: Nevada Department of Transportation (NDOT)

Nevada currently has various low-volume roads that can no longer be surface treated, requiring a complete rebuild or another cost-effective solution. Studies have shown that CIR can mitigate expensive costs by deferring full reconstruction. Recently a collaborative effort among NDOT, industry, and the University of Nevada, Reno (UNR) using a risk-informed decision-making process and incorporating research findings transformed the NDOT CIR design process. This study serves as a pilot project to evaluate this new Balanced Mix Design (BMD) approach for CIR of an existing non-traditional pavement

Building-Integrated Photovoltaic/Thermal (BIPVT): LCA of a façade-integrated prototype and issues about human health, ecosystems, resources

Building-Integrated Photovoltaic/Thermal (BIPVT) technology offers multiple advantages; however, these types of installations include materials such as Photovoltaic (PV) cells and metals which considerably influence BIPVT environmental impact. Therefore, there is a need to evaluate BIPVT environmental profile, for instance by means of Life Cycle Assessment (LCA). In light of the issues mentioned above, the present article is an LCA study that assesses the environmental performance of a BIPVT prototype that has been developed and patented at the Ulster University (Belfast, UK). The investigation places emphasis on material manufacturing, based on Cumulative Energy Demand (CED), Global Warming Potential (GWP), ReCiPe, Ecological footprint and USEtox. The results show that according to all the adopted methods/environmental indicators and based on primary materials, the PV cells and the two vessels (steel) are the components with the three highest impacts. Scenarios which include recycling of steel, plastics and brass (landfill for the other materials has been assumed), based on CED, GWP 100a and ReCiPe endpoint, have been examined. It was found that steel recycling offers a considerable impact reduction, ranging from 47% to 85%. Furthermore, the impact of the proposed BIPVT module per m2 of thermal absorber has been calculated. The results, based on primary materials, show 4.92 GJprim/m2 and 0.34 t CO2.eq/m2 (GWP 100a). In addition, according to USEtox/ecotoxicity, USEtox/human toxicity-non-cancer (scenario based on primary materials), the PV cells present the highest contributions to the total impact of the module: 55% in terms of ecotoxicity and 86% concerning human toxicity/non-cancer. A comparison with literature is provided. Moreover, a separate section of the article is about factors which influence BIPVT environmental profile, discussing parameters such as the storage materials and the end-of-life management.The authors would like to thank “Ministerio de Economía y Competitividad” of Spain for the funding (grant reference ENE2016-81040-R)

Designing Cold Mix Asphalt (CMA) and Cold-In-Place Recycling (CIR) using SUPERPAVE Gyratory Compactor

The purpose of this research was to develop a performance related mix design procedure for both cold mix asphalt (CMA) and cold-in-place Recycling (CIR) using the Superpave Gyratory compactor (SGC) and evaluate the performances of the mixes using the proposed mix design method.Two types of aggregate gradations (coarse and fines) according to Superpave specifications and two types of emulsions (CSS-1 and engineered emulsion) were used for the mix design of CMA. The mix designs were conducted following two different methods: a modified Proctor method and a mix design method using the Superpave gyratory compactor. The modified Proctor method was useful in identifying the total fluid content required to achieve maximum dry density of the CMA, but it did not help to obtain the required amounts of water and emulsion separately. The mix design method using the Superpave gyratory compactor was successful in identifying both optimum emulsion content and water content of CMA mixes. The designed CMA mixes using the Superpave gyratory compactor were evaluated for their moisture susceptibility and raveling performance. The mixes did not perform well in both tests. As a mitigation measure for moisture susceptibility problem, hydrated lime was added to the CMA mixes and the mix designs were conducted again. The identified mix design method for designing CMA mixes was not successful in achieving the target air void of 10.0±1.0% suggesting that the mix design needs to be studied further.For the mix design of CIR, two types of RAP gradations were evaluated; a graded RAP according to Pacific Coast Conference on Asphalt Specifications (PCCAS), and a non-graded RAP passing 1 inch sieve and two types of emulsions (CMS-2s and engineered emulsion) were used. The mix designs for CIR were conducted following two different methods: a modified Proctor method and a mix design method using the Superpave gyratory compactor. The modified Proctor test method resulted in higher water content to achieve the maximum dry density of the CIR mixes, but it is not practical in the field. Therefore, the modified Proctor method was not evaluated further. The mix design method using the Superpave gyratory compactor was successful in identifying both optimum emulsion content and water content of CIR mixes. The designed CIR mixes using the Superpave gyratory compactor were evaluated for their moisture susceptibility and raveling performance. The mixes did not perform well in both tests. As a mitigation measure for moisture susceptibility problem, hydrated lime was added to the CIR mixes and the mix designs were conducted again. The CIR mixes with lime were evaluated for their performances and they showed significant improvement. The CIR mixes were evaluated further for their rutting resistance using the repeated load triaxial (RLT) test and they performed well. The dynamic modulus of the CIR mixes were measured and the master curves were developed using a modified equation given in AASHTO PP61 and they were found to be equivalent to that of hot mix asphalt