On Maximum Signless Laplacian Estrada Indices of Graphs with Given Parameters

Signless Laplacian Estrada index of a graph $G$, defined as $SLEE(G)=\sum^{n}_{i=1}e^{q_i}$, where $q_1, q_2, \cdots, q_n$ are the eigenvalues of the matrix $\mathbf{Q}(G)=\mathbf{D}(G)+\mathbf{A}(G)$. We determine the unique graphs with maximum signless Laplacian Estrada indices among the set of graphs with given number of cut edges, pendent vertices, (vertex) connectivity and edge connectivity.Comment: 14 pages, 3 figure

Graphene zigzag ribbons, square lattice models and quantum spin chains

We present an extended study of finite-width zigzag graphene ribbons (ZGRs) based on a tight-binding model with hard-wall boundary conditions. We provide an exact analytic solution that clarifies the origin of the predicted width dependence on the conductance through junctions of ribbons with different widths. An analysis of the obtained solutions suggests a new description of ZGRs in terms of coupled chains. We pursue these ideas further by introducing a mapping between the ZGR model and the Hamiltonian for N-coupled quantum chains as described in terms of 2N Majorana fermions. The proposed mapping preserves the dependence of ribbon properties on its width thus rendering metallic ribbons for N odd and zero-gap semiconductor ribbons for N even. Furthermore, it reveals a close connection between the low-energy properties of the ZGR model and a continuous family of square lattice model Hamiltonians with similar width-dependent properties that includes the $\pi-$flux and the trivial square lattice models. As a further extension, we show that this new description makes it possible to identify various aspects of the physics of graphene ribbons with those predicted by models of quantum spin chains (QSCs)

Perancangan Sistem Informasi Akademik pada TK Dalilussa'adah Berbasis Web

Utilization of informatics technology in business especially in education field can reduce the potential mistake of data processing compared to manual data processing. This study aims to build information system of academic at kindergarden Dalilussa'adah Karawang. The advantage is to provide convenience in processing the value of report cards and teaching scheduling. This application is implemented with, PHP programming language, MySQL database as data storage media. Test method using black box testing with structured approach. Approach to the development of systems equipped with flow map tools, context diagrams, DFD, data dictionary, ERD, table relationships and waterfall methods that create the initial form of the system to be created and continuously tested and developed. Information system of academic at kindergarden Dalilussa'adah Karawang are still done manually, so these can cause data errors caused by human error factor. This web-based application is designed online so teachers and homers can see the teaching schedule and input student grades. The results of scheduling teaching and processing of student report cards can be viewed and processed as reports in the form of useful information for homeroom teachers and students. The results of this study are expected to answer the difficulties that are often faced by the teaching, curriculum, teachers and homeroom so that it can be much more efficient and effective. This application is also expected to be a reference for other researchers and then can develop it for further research

Interactive effects of joint angle, contraction state and method on estimates of Achilles tendon moment arms

The muscle-tendon moment arm is an important input parameter for musculoskeletal models. Moment arms change as a function of joint angle and contraction state and depend on the method being employed. The overall purpose was to gain insights into the interactive effects of joint angle, contraction state and method on the Achilles tendon moment arm using the center of rotation (COR) and the tendon excursion method (TE). Moment arms were obtained at rest (TErest, CORrest) and during a maximum voluntary contraction (CORMVC) at four angles. We found strong correlations between TErest and CORMVC for all angles (0.72 ≤ r ≤ 0.93) with Achilles tendon moment arms using CORMVC being 33 - 36% greater than those obtained from TErest. The relationship between Achilles tendon moment arms and angle was similar across both methods and both levels of muscular contraction. Finally, Achilles tendon moment arms for CORrest were 1 – 8% greater than for CORMVC. [NB rendition of scientific symbols is approximate in this display; please check full text for precise rendition]

Modelling of a novel Stand-Alone, Solar Driven Agriculture Greenhouse Integrated With Photo Voltaic /Thermal (PV/T) Panels

This is the author accepted manuscriptThis paper presents an analytical study of a new stand-alone agriculture greenhouse (GH) system. This system utilizes the excess solar radiation (more than that required by the plants for photosynthetic process) to generate electricity via a set of Photo Voltaic/Thermal (PV/T) units which are placed on the GH roof and south side. In addition to electricity generation, PV/Ts reduce the cooling load of the GH and help the system to be naturally ventilated. The system recovers the GH air humidity, including the plants transpiration, and uses it as irrigating water. Two coupled mathematical models are developed using MATLAB. The first model calculates the absorbed and transmitted solar radiation by/through each GH surface for a Clear Sky Day. The results of the first model are used as inputs to the second one that predicts the GH performance (GH surfaces and air temperatures, air relative humidity, air velocity, water production, electricity production and power consumption). These models are applied on climate conditions of Zagazig city, Sharqia, Egypt. The results show that the system presents a good solution for water shortage in Egypt as it has the ability to provide suitable climate conditions for plant growth (high quality and quantity) and produce enough water for irrigation purposes.British CouncilScience & Technology Development Fund (STDF), Egyp

A stand-alone Zero-Liquid-Discharge greenhouse model with rainwater harvesting capability

This is the author accepted manuscriptGlobal warming is a prevalent topic throughout the world. The IPCC predicts that the maximum potential global temperature increase will be 4.8 oC by 2100. It has been concluded that a temperature rise of 1.4 oC or higher will have statistically significant impacts on global precipitation levels. Therefore, there is a need to investigate the future trends of precipitation and subsequent irrigation methods. This study will discuss a new multi-functional zero liquid discharge (ZLD) system for a greenhouse, incorporating a humidification dehumidification (HDH) mechanism, solar still desalination and rainwater harvesting. The focus of this paper is on analysing the water production of the system. Although previous literature discusses the inefficiency of solar still (SS) desalination, the fresh water produced during similar experiments has shown otherwise, desalinating 0.95 L/m²/hr of saline water. Using multiple panels could therefore give a substantial output of distilled water for certain usage such as agriculture. Implementing solar stills of large surface area would also allow the collection of rainwater thus increasing the total water productivity of the system. The ZLD system aims to produce no waste product and use the output brine water for aquaculture and salt cultivation.British CouncilScience & Technology Development Fund (STDF), Egyp

Availability and Feasibility of Water Desalination as Non-conventional Resource for Agricultural Irrigation in the MENA Region: A review

This is the final version. Available on open access from MDPI via the DOI in this recordMany countries in the MENA region (Middle East and North Africa) are facing water scarcity, which poses a great challenge to agricultural production. Furthermore, water scarcity is projected to increase due to climate change, particularly in arid and semi-arid regions. The integration of solar power and water desalination systems in greenhouses to overcome water shortages is one of the preferred technologies in crop-growing areas. Crop growth control is done through sufficient management of environmental climatic variables as well as the quantity and quality of water and applied fertilisers with irrigation. Numerous crops such as cucumbers, tomatoes, peppers, lettuces, strawberries, flowers, and herbs can be grown under greenhouse conditions using desalinated water. This paper displays the state of the art in (i) solar-driven saltwater desalination to irrigate crops, (ii) the feasibility of water desalination for agriculture in the MENA region, (iii) the economics and environmental impacts of the desalination process, (iv) the quality of desalinated water compared with other non-conventional water resources and (v) recommendations for the future in the MENA region.Science, Technology, and Innovation Funding Authority (STIFA) of EgyptBritish Counci

Analysing greenhouse ventilation using Computational Fluid Dynamics (CFD)

This is the author accepted manuscript. The final version is available from UKACM via the link in this recordGreenhouses (GH) are used to shield the crops from excessive cold or heat. They are used for growing certain types of cultivations during the year round. The aim of this study is to design a greenhouse using solar-powered technology to produce a Zero-Liquid-Discharge (ZLD) by using Solar Stills and adding condensers to dehumidify the excess vapoured water. This allows to have small-scale plants to reduce the cost of water treatment while increasing its sustainability. Computational fluid dynamics was used to find the best locations for the dehumidifiers in the GH and design the necessary ventilation. This can help to plan ahead and evaluate the optimal amount of produced water for different sizes of greenhouse before they are constructed physically.British Council - EgyptScience & Technology Development Fund (STDF), Egyp

Pulmonary bullet embolism – a safe treatment strategy of a potentially fatal injury: a case report

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens