bluuebunny/crossref_metadata_2025 huggingface dataset:
Crosstalk estimation of 21.12 Tb/S Nyquist superchannels with hybrid modulation using trench‐assisted multicore fibre
Authors: Goyal Shivani , Kaler Rajinder Singh , Singh Hardeep
Published: February 2019

The transmission of 5 × 4.224 Tb/s Nyquist superchannels over 2688 km distance has been demonstrated using trench‐assisted multicore fibre (TA‐MCF) at different spans for the first time at reduced channel spacing. The channel spacing has been efficiently reduced from 32 GHz (before modulation) to 25 GHz (after modulation) using Nyquist superchannels with hybrid modulation to transmit 15 subcarriers in one superchannel without any distortion. Five Nyquist superchannels, each using 15 × 35.2 Gbaud PM‐16QAM subcarriers (4.224 Tb/s), are transmitted over seven cores of TA‐MCF with low crosstalk over the same distance. Further, by utilising the core‐to‐core rotation scheme, the inter‐core crosstalk from the neighbouring cores has been reduced after WDM/SDM transmission.
Enhanced high‐gain SLC‐ZSI at low‐duty region
Authors: Bussa Vinod Kumar , Singh Rajeev Kumar , Mahanty Ranjit
Published: February 2019

An enhanced high‐gain switched inductor capacitor (LC) Z‐source inverter (eSLC‐ZSI) is proposed in this study. It has a lesser number of elements to achieve high‐gain inversion at low‐duty region as compared with the conventional non‐isolated high‐gain ZSIs. It gives continuous input current at reduced high‐frequency ripple, which is essential for the sources such as solar photovoltaic cells, fuel cells and batteries to enhance their lifetime. Owing to its operation at low‐duty region (i.e. increased modulation index), it gives high‐gain inversion at low harmonic distortion. A detailed mathematical modelling of the proposed enhanced SLC‐ZSI is carried out using the developed switching logic. In addition, a comparative analysis is given among the reported ZSIs and the proposed ZSI in terms of number of elements, boosting capability, voltage gain, the volume of the passive elements, voltage and current stresses on the elements. The steady‐state behaviour of the proposed ZSI is verified through PSIM‐based simulation studies and scaled down 250 W laboratory prototype. Using the experimental results, power losses in different elements of the proposed ZSI are calculated at rated power and its efficiency is measured at different loading conditions.
Review and re‐evaluation of modulation techniques for neutral‐point‐clamped inverters with high‐order filters
Authors: Tang Fen , Liang Jiazhi , Jiang Jiuchun , Xin Zhen , Huang Songwei , Loh Poh Chiang
Published: February 2019

The centred space vector modulation scheme is considered to be the best since it produces the least switching harmonics among the modulation techniques developed for neutral‐point‐clamped (NPC) inverters. However, this common belief was concluded in the condition when inverters interfaced to the grid with a simple inductor filter. Nevertheless, to achieve an excellent harmonic attenuation performance, higher‐order filter is much preferred for NPC inverter. Consequently, the aforementioned common belief may lose its correctness due to the distinctive resonance characteristics accompanied by high‐order filters. The objective is to review and re‐evaluate the performances of the commonly used modulation techniques for NPC inverters when different high‐order filters are applied. Furthermore, this study provides a guide to choose an appropriate modulation scheme when high‐order filters are used. The sinusoidal pulse‐width modulation with alternative phase opposition disposition shows the best performance since it always ensures high‐quality current waveforms when high‐order filters are used in NPC inverters. Apparently, this conclusion is against the common belief. Moreover, different conclusions in terms of the performances have also been found for other modulation techniques considered in this review. Finally, to validate the correctness of the analysis and the findings, simulated and experimental results are provided and discussed.
Systematic approach to construct and assess power electronic conversion architectures using graph theory and its application in a fuel cell system
Authors: Zhang Wenping
Published: February 2019

With the proliferation of renewable energy generations, power conversion systems (PCSs) are becoming much more complex; it is becoming challenging to search all possible power conversion architectures (PCAs) and find the best optimisation in terms of different objectives. Therefore, this study investigates a systematic approach to construct and evaluate PCAs using graph theory. First, the components in PCSs are graphically modelled as either nodes or edges. Then, a generalised PCA deduction methodology is proposed, and all possible PCAs can be mathematically deduced by modifying elements in adjacency matrices. For a fuel cell (FC) generation system, 45 possible PCAs are found with the proposed method. Furthermore, an evaluation methodology based on graph theory is proposed. The performance indices of the deduced PCAs, including costs, efficiency, and reliability, are calculated. Then, an optimisation approach is applied to finding the best architecture compromise, where the one with the shortest distance to the ideal architecture is considered the best architecture compromise. For the FC demo system, with the proposed assessment methodology, the best architecture compromise (dc‐bus structure) is found among 45 possible architectures. Finally, the experimental platform, which adopts the dc‐bus optimised architecture, is built and experimental results validate the architecture selection.
Multiloop current control for an inductive–capacitive–inductive‐filtered grid‐connected inverter with frequency‐adaptive capability under distorted grid environment
Authors: Yoon Seung‐Jin , Kim Kyeong‐Hwa
Published: February 2019

To eliminate the adverse effects of grid voltages such as the harmonic distortion and frequency variation, this study presents a multiloop current control scheme for an inductive–capacitive–inductive‐filtered grid‐connected inverter. The proposed scheme is achieved by multiloop control structure which is composed of the grid‐side current control loop, capacitor voltage control loop, and inverter‐side current control loop. This structure has an advantage of seamless mode transfer between the grid‐connected mode and islanding mode. In addition, the proposed scheme offers a frequency adaptation capability even under distorted grid environment, providing a high quality of injected current in grid‐connected mode. Whereas the conventional schemes require lots of state measurements, the proposed scheme eliminates the need of additional sensing devices by employing a discrete‐time state observer. The resonant controllers are implemented in outer grid‐side current controller to deal with harmonically distorted grid voltage at the 5th, 7th, 11th, and 13th orders. The proposed scheme ensures the quality of grid currents even in the presence of both the harmonic distortion and frequency change in grid voltages by using only the measurement of the grid‐side currents and grid voltages. Simulation and experimental results are given to validate the usefulness of the proposed scheme.
Alpha particle thermodynamics in the inner heliosphere fast solar wind
Authors: Stansby D. , Perrone D. , Matteini L. , Horbury T. S. , Salem C. S.
Published: February 2019

Context.Plasma processes occurring in the corona and solar wind can be probed by studying the thermodynamic properties of different ion species. However, most in situ observations of positive ions in the solar wind are taken at 1 AU, where information on their solar source properties may have been irreversibly erased.

Aims.In this study we aim to use the properties of alpha particles at heliocentric distances between 0.3 AU and 1 AU to study plasma processes occurring at the points of observation, and to infer processes occurring inside 0.3 AU by comparing our results to previous remote sensing observations of the plasma closer to the Sun.

Methods.We reprocessed the original Helios positive ion distribution functions, isolated the alpha particle population, and computed the alpha particle number density, velocity, and magnetic field perpendicular and parallel temperatures. We then investigated the radial variation of alpha particle temperatures in fast solar wind observed between 0.3 AU and 1 AU.

Results.Between 0.3 AU and 1 AU alpha particles are heated in the magnetic field perpendicular direction and cooled in the magnetic field parallel direction. Alpha particle evolution is bounded by the alpha firehose instability threshold, which provides one possible mechanism to explain the observed parallel cooling and perpendicular heating. Closer to the Sun our observations suggest that the alpha particles undergo heating in the perpendicular direction, whilst the large magnetic field parallel temperatures observed at 0.3 AU may be due to the combined effect of double adiabatic expansion and alpha particle deceleration inside 0.3 AU.
Green envelope as an architectural strategy for energy efficiency in a library building
Authors: Ariff Azlan Ariff Ali , Ahmad Sabarinah Sheikh , Hussin Mohd Aljefri
Published: February 2019

In the context of Malaysian tropical climate, green envelope functions to provide satisfying indoor environment and achieve the best performance with minimal energy consumption. Buildings that rely on air-conditioning to improve thermal comfort could benefit from green envelope potentials. Hence, the objective of this paper is to explore the impacts of various types of green envelope towards reducing the energy consumption of a two-storey library building. The methodology approach is quantitative and data are collected through building simulation using Revit Building Information Modelling (BIM). Parameters studied are building orientation, wall insulation, envelope materials, and façade treatment. Results showed that different types of green envelope posed different impact on energy consumption of the library and double glazed windows contribute the most significant reduction of energy consumption. The study establishes the contribution of green envelope and advocates the use of building simulation as research methodology, as it helps to improve envelope design, and to predict the possible outcomes of design alternatives.
Malaysian as the Component of Labour Force for Construction Industry in Malaysia
Authors: Mohd Najib Iskandar Zulkarnain , Mohd Nordin Rumaizah , Mohd Ahnuar Ezlina , Mohd Sukor Khalida
Published: February 2019

The construction sector plays a significant role in the economy in order to achieve the inspiration to be a developed nation in 2020. In the effort to increase the efficiency of the sector, Construction Industry Development Board (CIDB) had pledged to continue investing in human capital development in the construction industry as one of its initiatives under Productivity Thrust in Construction Industry Transformation Programme (CITP). However, currently, the construction industry of Malaysia is depressed by the low-wage and low productivity trap due to substantial reliance on low-skilled foreign workers. The number of local workers are not only low but are decreasing drastically due to out-migration towards better job opportunities in other sectors. Therefore, this research aims to establish a conceptual framework for Malaysians as the component of the labour force in the construction industry in Malaysia through identifying the landscape of participation of local labour, investigating factors hindering participation of local labour and propose initiatives to increase the numbers of participation of local labour. This paper presents a review of literature from journals, conference proceedings, and books. Based on the review, a framework consisting of four (4) components (i.e., Government Agenda, Local Labour in Malaysian Construction Industry, strategies to improve participation, and expected key outcomes of CITP for Productivity) is proposed. These findings will assist the extended investigation in the identification of ways to improve the participation of local labour for the Construction Industry in Malaysia.
A Review on Green BIM Potentials in Enhancing the Construction Industry Practice
Authors: Ismail Noor Akmal Adillah , Ramli Hazwani , Ismail Elma Dewiyana , Rooshdi Raja Rafidah Raja Muhammad , Sahamir Shaza Rina , Idris Nur Hidayah
Published: February 2019

The construction industry environment nowadays is becoming more complex with more issues to be resolved with the agreeable approaches amongst the team. Nevertheless, the Building Information Modelling (BIM) innovation is acknowledged to disentangle those prevalent issues towards delivering a better project performance. With the emergence of BIM technology, various concerns such as constant errors and reworks, team-miscommunication, construction waste, energy inefficiencies, and many more in the industry practices, could be refined. Specifically, BIM capabilities mainly facilitate the design and construction operations. Albeit the processes involved demand an early planning and profound decision-making, the BIM mechanism helps the project team to execute the proposed construction projects effectively. With regards to maintaining the sustainability in the industry, “Green BIM” term is introduced to describe the manipulation of BIM technology to be incorporated along with the sustainable design and construction techniques. Therefore, this paper reviews the potentials of “Green BIM” in improving the traditional practices of project stakeholders throughout the project life cycle, particularly focusing on the design and construction phases. It discusses the previous studies on “Green BIM”, “Green BIM” concepts, and “Green BIM” approaches concerning its benefits and challenges in enhancing the construction industry practices. Significantly, through the appropriate “Green BIM” resolution, the procedures initiated with the green settings and completed with the green requirements, could empower more sustainable construction industry
Thermal Environment Analysis of a Scientific Laboratory using Computational Fluid Dynamics
Authors: Kwong Qi Jie , Yang Jim Yexin , Ling Oliver Hoon Leh , Abdullah Jamalunlaili
Published: February 2019

University staff and students typically spend most of their time indoors. This paper evaluates the thermal environment of an air-conditioned scientific laboratory in a tertiary educational institution in Malaysia using Computational Fluid Dynamics (CFD). This computational technique has been used in analysing the indoor environments and has been found to be useful in aiding facilities management. A pilot survey was conducted to collect the required information such as indoor parameters and boundary conditions for the setting up of a CFD model of the laboratory. The model was then simulated based on the data obtained from field observations. Results indicate that the laboratory users sitting at different rows and work desks would experience different thermal sensations. The mean air temperature was below the recommended comfort zone specified in the local energy standard, but the air velocities were generally within the acceptable range. Based on the calculated predicted mean vote (PMV) and predicted percentage dissatisfied (PPD) indices, most of the users would be thermally uncomfortable, and a warmer environment was preferred. Recommendations were made to regulate the inlet air temperature of the laboratory to improve thermal comfort of laboratory users and for energy saving purposes.
Indoor Air Quality (IAQ) Performance in Refurbished Projects: A Case Study of Two Private Schools in Selangor
Authors: Zawawi E.M.A , Azaiz A.Z , Kamaruzzaman S.N , Ishak N.M. , Yussof F.N.M
Published: February 2019

This study discusses the Indoor Air Quality (IAQ) in two refurbished private schools in Shah Alam, Selangor. The level of IAQ may affect the comfort, health and well-being of the occupants of the building. Lack of monitoring IAQ in a school may affect the academic performance of the children. The objectives of the research are to observe the ventilation system used in the selected school and the comfort of the occupants; to measure the IAQ; and finally to provide an improvement plan for better air quality. The result shows that the IAQ level of both schools was average, so both were classified as safe for occupation. It is anticipated that this study will benefit the school owners in making sure that their school buildings are conducive to teaching and learning.
BOURDIEU CAPITALS AND LEADERSHIP: THE CASE OF DESIGN CONSULTANT FIRMS’ MANAGERS IN THE MALAYSIAN CONSTRUCTION INDUSTRY
Authors: Ariffin Mohd Hisham , Rahim Abdul Rahman Abdul , Arshad Ruslan Affendy , Zahari Ruzaini
Published: February 2019

The creative products of Malaysian design firms are critical for sustained competitiveness in the increasing globalised and local construction market. These products are derived from the collaborative efforts of the design leaders and their subordinates. Owner-managers of design firms are aware of the role of their leadership in increasing the productivity of their creativity workers. Knowledge of effective leadership traits has initially guided leadership development and sustainability. Later theories such as charismatic theories and leader-member exchange theories have a common theoretical paradigm of leader-follower relations. A novel approach to this leadership theoretical paradigm is replacing relevant leaders’ traits with Bourdieu capitals that effectively influence their followers. This paper reports the findings of interviews with subordinates in Malaysian architecture, civil engineering and landscape architecture consultant firms regarding the influence of the superior’s Bourdieu capitals upon their creativity. Qualitative thematic coding analysis of the interview transcripts generated the relevant Bourdieu capital categories and theme. The leader’s human, emotional, leadership, cultural and social capitals were found to influence the subordinate’s creativity motivation. The data indicate a common theme of followers’ creativity motivation through learning from leader’s superior human capital. The learning is aided by the leader’s emotional capital. Thus, Bourdieu capitals offer an innovative perspective in studying and possibly quantifying leaders’ influence upon their followers.
Significant Ways to Improve the Performance of Medium and Large Local Contractors in the Jigawa State, Nigeria
Authors: Zainal Rozlin , Hamza Garba , Manap Norpadzlihatun , Shahifah Syahrom Noor
Published: February 2019

Contractors’ performance is an important criterion for the success of any construction project, as it is the contractor that converts designs into practical reality. While evidence suggests that there is much need for further improvement particularly in cost, time and quality, in Nigeria contractors’ performance is the subject that requires much research. This paper is to identify the significant ways to improve the performance of medium and large local contractors in the Jigawa state, Nigeria. Literature about contractors and their performance was reviewed to identify the ways believed to improve their performance in executing construction projects. Questionnaires distributed to 45 clients, 45 consultants, and 45 medium and large local contractors. The findings show that the respondents agree that the most significant ways to improve medium and large local contractor’s performance are transparent bidding process mechanism, proper selection of construction procurement system, quality control and standard assurance, local contractor patronage by the government and adopting information and communication technology (ICT) in design and construction. This paper offers better performance and expands the pool of knowledge to the Nigerian contractor regarding essential element that is needed to be observed in order to improve their performance.
South African Construction Craftsmen’s Perceptions of Effective Personnel Management Practices
Authors: Aghimien Douglas , Aigbavboa Clinton , Oke Ayodeji , Makhwathana Mbavhalelo
Published: February 2019

The recent skill shortage within South Africa has raised the need for proper management of the available craftsmen in the construction industry, as a large portion of work executed within the industry is done by this set of workers. It is based on this knowledge that this study assessed South African construction craftsmen’s perception on how effective personnel management can be achieved. A survey approach was adopted and a structured questionnaire was used in harnessing information form craftspeople within the construction industry in Johannesburg metropolitan area. Data analyses were done using percentage, mean item score and standard deviation. The reliability of the questionnaire was also tested using Cronbach alpha test. The study revealed that provision of competitive pay, effective leadership, recruiting the multi-skilled workers, the reward for dedicated workers, and paying attention to employee’s needs were the key measures for improving the management of personnel. The study further recommends that managers of construction organisations should give attention to the identified measures of improving management of employees and implement them to recruit and retain employees within their organisations. The study adds to existing knowledge on the theme of measures for effective personnel management in the construction industry.
Settlement Behaviour of Peat Reinforced With Recycled Waste Tyre Granules
Authors: Md Zain Nor Hazwani , Mustapha Mazlizawati , Abdul Rahman Abdul Samad
Published: February 2019

Peat is a problematic soil for having high organic content and high water content in nature. This soil is normally avoided for construction as it shows significant primary and secondary settlement even under moderate load. Ground improvement is conducted to improve peat properties by using cement column, soil replacement, chemical and biological stabilisation and others. However, some of these methods have their drawbacks for being non-sustainable to the environment, very costly, ineffectiveness and slow result performance. Alternative method using recycled waste tyre granules is seen as an innovative approach to reduce the settlement behaviour of peat in a more sustainable way. This paper investigates the effect of waste tyre granules on the settlement behaviour of peat. One-Dimensional consolidation test is carried out on natural sample and samples added with 5 % waste tyre granules with and without addition of sand as filler. The settlement curves for all samples do not show distinct separation between primary and secondary compression stages when using Casagrande’s method. Sample which is reinforced with 5 % waste tyre granules and sand has lower compression index and swelling index compared to other samples. The coefficient of volume of compressibility for all samples is reduced with increasing stress levels.
Automatic Materials Tracking Practices Through RFID Implementation in Construction Projects
Authors: Kasim Narimah , Sarpin Norliana , Mohd Noh Hamidun , Zainal Rozlin , Mohamed Sulzakimin , Manap Norpadzlihatun , Yahya Mohd Yamani
Published: February 2019

Materials tracking for materials management play a vital role and contributed a major portion of the total cost in a construction project. In addition, the improper handling and storage of materials at the construction site has made it difficult to track and locate at the time are needed to carry out construction works. These problems subsequently contribute to the project delays and increase in the total project costs. Thus, this paper seeks to identify problems regarding current material tracking practices in materials management processes. In this paper, ICT and potential implementation of Radio Frequency Identification (RFID) for automatic materials tracking is also scrutinised. Data for this paper was obtained from the literature review and the case studies conducted in several construction projects. Semi-structured interviews with construction practitioners were carried out in order to gain insights into current problems, information and communication technologies (ICT) implementation, and RFID capability in assisting materials tracking practices. This paper reveals that construction projects in Malaysia are still using manual materials tracking practices, basic ICT implementation, and totally none RFID existence. Thus, there is a need for the application of RFID in order to facilitate materials tracking automatically for enhancing construction industry processes through IR 4.0.
Measuring Bourdieu Capitals of Landscape Architects In Malaysian Landscape Architecture Firms
Authors: Zahari Ruzaini , Ariffin Mohd Hisham , Othman Noriah
Published: February 2019

Pierre Bourdieu (1986) introduced the concept of capitals as forms of intangible resources that individual use to advance their socio-economic status. Past relevant researches have not focused on all Bourdieu capitals. This study conceptualises the Bourdieu capitals to empirically determine the intangible resources of Malaysian leader landscape architects. The aim of this study is to determine the type of capitals of leader landscape architects in Malaysian landscape architecture firms. All landscape architecture firms (73 nos.) in the database of the Institute of Landscape Architects Malaysia were chosen for the survey. The firms were given the letter of invitation and questionnaires through the post. Thirty-nine firms responded to the invitation which resulted in 90 subordinates landscape architects and assistant landscape architects as respondents. The subordinates were asked to rate their leaders’ (landscape architects) capitals. The data were analysed using descriptive statistics and factor analysis. Factor analysis findings generated 5 factors (capitals). The capitals are social, human, emotional, cultural and design authority. The study findings provide evidence of the validity of scales to measure the intangible resources of the leading landscape architects in Malaysian landscape architecture firms. It also suggests a new research perspective for the Trait Theory of Leadership by replacing the traits with Bourdieu’s forms of capitals.
An Investigation On The Liveability Of Urban Settlement. Case Study: Mandy Villa, Segambut, Kuala Lumpur City, Malaysia
Authors: Hoon Leh Oliver Ling , Abdul Aziz Muhammad Hanif , Azyyati Marzukhi Marlyana , Abdul Rasam Abdul Rauf
Published: February 2019

Urban areas are the main centres of growth in every country. However, urban areas face challenges such as environmental destruction, social deprivation, insecurity, health problem, and accessibility issue. These problems affect liveability level of the urban settlements. Liveability is influenced by the aspects of physical environment and social. A study had been carried out in Kuala Lumpur city with the Mandy Villa at Segambut as the study area. The purpose of the study is to investigate the liveability level of the study area and the relationship with the urban planning aspects of physical, and social. A questionnaire survey had been carried out. The respondents with different socio-economic background were mostly felt that the study area was liveable. From the relationship analysis by using correlation tests, the study found that some of the physical planning aspects and most of the social aspects were positively and significantly correlated to the liveability level. With the research findings, town planners, developers and government agencies are able to have a better understanding of the physical and social determinants of liveability. However, more future studies should be carried out for different cities and towns to further improve the understanding on the topic of urban liveability.
The Malaysian Cycling-Friendly Neighbourhood: A Signal For The Enhancement Of The Convenience Infrastructure.
Authors: Mohd Salleh Mohd Zahid , Abdul Malek Nurhayati , Othman Noriah , Syed Othman Thani Sharifah Khalizah
Published: February 2019

In Malaysia, a carbon neutral country aspiration relatively by 2050 through sustainable approaches should have heeded further. The concept of Green Mobility in the residential neighbourhood is an essential mechanism towards improving the lifestyle and sustaining the environmental quality by providing the cycling-friendly environment. The study aims to identify the cycling-oriented design factors specifically on the cycling infrastructure in Malaysian Residential Neighbourhood through the relationship between the perceived physical environments and cycling participation. The content analysis through the review of the literature applies in this study. By modifying the Ecological approach in the Cycling-Friendly Neighbourhood enhancement for the cycling infrastructure in Malaysia, the awareness and experience of the people are required to evaluate. Henceforth, the relationship between perceived environment, cycling participation level and cycling-oriented design factor will take part later to validate the significant relationship for each construct through empirical study. The convenience infrastructure design factors have been highlighted in the study comprises four elements such as safety and security, accessibility and connectivity, attractiveness and aesthetic and convenience and comfort. Thus, it will give interest and facilitate the stakeholders in creating the cycling-friendly environment in the residential neighbourhood through supportive infrastructure for the communities.
Assessment Of Morphological Analysis Of Iraqi Traditional Courtyards Houses
Authors: Jawad Shakir Haraty Hayder , Yazah Mat Raschid Mohammad , Yazid Mohd Yunos Mohd
Published: February 2019

The traditional Iraqi courtyards house demonstrates fundamentals principles in term of construction, its spatial organization and design can be compared with the modern home. The research claims the current housing design in Iraq does not fulfill the cultural and the social need of their residence; the traditional courtyard houses have manifested that in the uniqueness form in the plan. This research attempts to analyze the historical and traditional courtyard house as the arisen construction of houses in Iraq. The research objective is to document the architectural forms of the courtyards houses in Iraq. The form of the house is one of the aspects to be studied and understood as it measures and establishes the architecture design concept of these dwellings. Morphological study on the form of eight case studies of the Iraqi Traditional Courtyards Houses has been utilized. The aim is to discuss and inspect the uniqueness of these units that served their residences for decades. Additionally, the author used computer software (AutoCAD and 3d Max) to redraw the cases to be more representative. The study’s significance is to add a distinct understanding among designers, planners and decision-makers to put into consideration the future architecture of houses design and to preserve the traditional houses from vanishing. The findings revealed that privacy has a great influence on the design layout of the traditional house which presented in the simplicity of design and the separation between zones.
A Concept of WSD as an Implemented Approach to the Successful Design of a High-Rise Residential
Authors: Listyaningsih Diah , Utomo Christiono
Published: February 2019

Construction project success depends on success of design. It is very rare previous research about the success of design as a determinant to the success of construction projects. The Whole System Design (WSD) approach in a planning of a high-rise residential property consider the success interrelatedness of both problems and solutions. It can help to create more sustainable designs. Nevertheless, designers often face several factors that exclusively reduce the rate of successful design i.e. design model and methods. One way to manage this issue is to reduce ambiguousness by using a whole system design approach. This study purposes to explore framework of Whole System Design approach for successful design. Application of literature review method is used to understanding the problem by analysing 20 articles about high-rise building, residential and whole system design. The result presents a mapping of several methods that used in previous research. It is to help more widespread the successful design in a high-rise residential property.
Numerical simulation of particle dispersion in a pre-processing of a static culture
Authors: Kanemaru Yoshiki , Sekimoto Atsushi , Okano Yasunori , Kanie Kei , Kato Ryuji , Kino-oka Masahiro
Published: February 2019

For producing high-quality induced pluripotent stem (iPS) cells in a static culture, initial placement of cells is one of the most important factors. Dense distribution of cells increases the risk of cell death. Thus, the cells need to be uniformly distributed during the preprocess of a static culture. This process depends on the operator’s experiences and has not been standardized. In this study, the authors have performed numerical simulations to investigate the efficient of cell dispersion by using OpenFOAM. The numerical domain is a square-shaped dish. Two shaking methods, one-direction and multi-direction reciprocal shaking, were considered and calculations were conducted under five oscillation frequencies. The cell colony was assumed as a solid spherical particle. The initial particles were densely positioned at the center. The numerical result showed that the multi-direction reciprocal shaking was more effective to disperse the particles than the one-direction reciprocal shaking. In addition, almost all particles at low frequency sank to the bottom and hardly dispersed. These results indicate that strong fluctuations can lift particles from the bottom, and frequent change of flow direction makes distribution area wide.
Connected flow-through chromatography processes as continuous downstream processing of proteins
Authors: Yoshimoto Noriko , Ichihara Takamitsu , Yamamoto Shuichi
Published: February 2019

Continuous manufacturing is expected to increase the productivity of protein drug production. However, it is not easy to build the continuous process especially for downstream processing as many unit operations (chromatography and membrane filtration) are involved. An operation method known as flow-through chromatography (FTC) is considered to be an efficient method for separating two components as the flow is continuous. In FTC, a target protein is eluted from the chromatography column without adsorption whereas contaminants are strongly bound. Since at least two different modes of chromatography are needed in order to remove contaminants, two FTC columns have to be connected in order to build the continuous process. This is not an easy task since the mobile phase properties (pH, salt, buffer ions) are different for the two columns. In this paper, we investigated how connected FTC columns can remove impurities efficiently from the cell culture broth containing monoclonal antibody. It was found that the sequence (activated carbon - anion exchange chromatography - cation exchange chromatography) is most efficient when the mobile phase pH and conductivity were properly chosen.
Development and characterization of perlite from Lamba, Albay, Bicol as packing material and the design of a packed column for the absorption of ammonia gas
Authors: San Mateo Beatriz , Valorozo Jervin , Yturralde Ma. Niña Jasmer , Pestaño Lola Domnina
Published: February 2019

Gas absorption is a unit operation and separation process wherein soluble components of a gas mixture are dissolved in liquid solvent. This unit operation utilizes packing materials which play a vital role in providing surface area for gas and liquid contact. In this study, perlite from Lamba, Albay, Bicol was used in the production of packing material. The objectives of the study are to develop and characterize a packing material using a geopolymer derived from perlite and to design a packed column for the absorption of ammonia gas. The study determines the ideal perlite-Na2SiO3 concentration, packing factor, and L/D ratio. Three perlite-Na2SiO3 concentrations (45%, 60%, 75% wt. Na2SiO3) were subjected to various tests such as: thermal stability, chemical resistance, and compressive strength. The 45% wt. Na2SiO3 exhibited the least weight loss and the highest compressive strength making this geopolymerized perlite a potential packing material for gas absorption with a packing factor of 0.00175 ft-1. Based on the results, a packed column was designed for the absorption of ammonia gas with an L/D ratio of 2.5.
Acetylation of Nata de coco (bacterial cellulose) and membrane formation
Authors: Alberto Erika Louise , de Ocampo Ailey Nicole , Depasupil Christopere Ghil , Ligaray Mayzonee , Eusebio Ramon Christian , Orbecido Aileen , Beltran Arnel , Patacsil Liza
Published: February 2019

Nata de coco (NDC), a bacterial cellulose formed by Acetobacter xylinum, was utilized to fabricate a membrane via acetylation and phase inversion methods. The NDC was activated and dissolved in N,N-Dimethylacetamide (DMAc) with lithium chloride (LiCl) at varying amounts of NDC, LiCl/DMAc ratio, activation temperature, and dissolution temperature. Acetylation was done by adding acetic anhydride (in a mass ratio of 1:12 NDC-anhydride) to NDC-DMAc/LiCl solution at a dissolution temperature of 110 °C for 3 hours. The modified-NDC was recovered via precipitation in methanol. The modified-NDC was washed with deionized water then freeze-dried. Modification was verified by determining the degree of substitution (DS) using titration and FTIR analysis. It was observed that the modification could be carried out at an NDC/DMAc (w/v) ratio of 1:75 at 120 °C for 1 hour, and addition of 8% (w/v) LiCl catalyst at 110 °C for 20 minutes. The DS of the modified-NDC was observed in the range of 2.84 – 3.69, which indicates a successful modification. This was further verified by the FTIR results. Membrane fabrication was carried out using the modified-NDC via immersion-precipitation and solvent evaporation methods. A successful membrane formation was observed using solvent evaporation.
Synthesis of geopolymer spheres with photocatalytic activity
Authors: Bravo Patricia Isabel , Malenab Roy Alvin , Shimizu Eiza , Yu Derrick Ethelbhert , Promentilla Michael Angelo
Published: February 2019

Geopolymer is an emerging “green” cementitious material which has a potential to valorize waste such as rice hull ash (RHA). Geopolymer is a kind of alkali-activated material which forms from the reaction of alumino-silicates in an alkaline solution. This study uses RHA as the raw material for alkaline activator while metakaolin (MK) serves as a geopolymer precursor to synthesize the so-called geopolymer sphere. Then its capacity as a porous matrix was explored upon incorporation of TiO2 nanomaterial using horizontal vapor phase growth (HVPG) technique to enhance its photocatalytic property. Indication suggests that the synthesized MK-geopolymer spheres activated with RHA-based water glass solution (WGS) were comparable to that of commercial WGS. Furthermore, the geopolymer spheres were successfully coated with TiO2 in the form of nanocrystals. Its photocatalytic activity was evaluated in terms of methylene blue degradation. This material’s potential environmental application for water purification and wastewater treatment will be investigated for future works.
Process Optimization Potassium Nanofertilizer Production via Ionotropic Pre-gelation using Alginate-Chitosan Carrier
Authors: Nido Princess Jenine , Migo Veronica , Maguyon-Detras Monet Concepcion , Alfafara Catalino
Published: February 2019

Potassium nanofertilizer synthesis by incorporating potassium in alginate-chitosan carrier via ionotropic pre-gelation was optimized to maximize potassium content and develop controlled release fertilizer. Utilizing two-level factorial design, potassium to alginate ratio, calcium chloride to alginate ratio, and pre-gelation time were determined significant. Central Composite Design for optimization was utilized to generate a Response Surface model relating the factors to the response for numerical optimization. Optimum process conditions for maximum potassium content were (1) 1.5:1 (w/w) potassium to alginate ratio, (2) 6.5:117.5 (v/v) calcium chloride to alginate ratio, and (3) 40 minutes pre-gelation time. The potassium content of the fertilizer formulated at optimum condition was successfully verified to contain 29.75 %K(w/w). Characterization showed that potassium was successfully incorporated in the alginatechitosan carrier as shown by the SEM surface images. DLS result showed two peaks at particle sizes near 594.1 nm and 102.8 nm indicating that potassium nanofertilizer was successfully synthesized. Potassium nanofertilizer may be a controlled release fertilizer since only 14.6 %K was released after 24 hours in Britton-Robinson buffer solution. Preliminary costing shows higher cost of production based on raw materials, but it may be offset in the long run by longer availability of nutrient and low fertilizer application rate.
Performance evaluation and upgrade options for existing sequencing batch reactor for nutrient removal
Authors: Lantin Jahziel , Abenoja Jeremy Ynnos , Ly Jason , Castillones Cheenee Marie , Beltran Arnel , Orbecido Aileen
Published: February 2019

Assessment and upgrade of existing sewage treatment plants (STPs) are necessary due to the revision of the existing effluent regulations which now monitors nutrients including ammonia, nitrate and phosphates. The aim of this study is the performance evaluation of four sequencing batch reactor (SBR) type of STP based on the following parameters: biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), nitrates, ammonia, phosphates and pH; and their potential upgrade based on the revised regulations stated in DAO 2016-08. Four sequencing batch reactor (SBR) type of STP were assessed for 12 weeks for this study. Results showed noncompliance with nutrient levels, thus upgrade is necessary. Analytical Hierarchy Process (AHP), a Multi-Criteria-Analysis (MCA) tool, was used to select the best option for upgrade among options that include (1) additional SBR tank, (2) diverting wastewater to another treatment facility, and (3) converting the SBR into membrane bioreactor (MBR). Considering the criterion for upgrade, option 2 was the most preferred decision followed by option 1 then option 3.
Enhancing the photoactivity of TiO2/SiO2 monolithic catalyst and its reusability for wastewater treatment
Authors: Huynh Ngoc Diem Trinh , Vo Kieu Duyen , Nguyen Thao Vy , Le Minh Vien
Published: February 2019

A series of TiO2/SiO2 photocatalysts were successfully synthesized by the sol-gel method. The TiO2/SiO2 monolith was also synthesized by dip-coating process. The crystalline structure of TiO2/SiO2 powders was identified as pure anatase. The photocatalytic activity of the TiO2/SiO2 powders was evaluated by photodegradation of 20 ppm methylene blue (MB) using a 26W lamp which has the wavelength in the visible light region under different Ti: Si molar ratios and calcination temperatures. The TiO2/SiO2 powders which have Ti: Si molar ratio of 85:15 (TS15) and calcined at 550tC showed the highest photodegradation yield of 84 % after 3h irradiation. Furthermore, the 550˚C calcined TS15 monolith performed the MB degradation yield of 88.9 % after 3h irradiation and its photoactivity still remained after 4 recycle times. The results of this study demonstrated that the TS15 monolith photocatalyst has a reasonable efficiency in the degradation of methylene blue, it could be a promising photocatalyst for removal and degradation of organic pollutants.
Les futures missions spatiales dédiées aux planètes extrasolaires
Authors: Baudoz Pierre
Published: February 2019

Avec 4000 planètes découvertes en 20 ans dont plus de la moitié dans les trois dernières années, l’étude des planètes extrasolaires est devenue un thème majeur de l’astronomie moderne. La découverte de planètes différentes de celles observées dans notre système solaire interroge les modèles de formation et d’évolution des systèmes planétaires. Pour bien comprendre la nature de ces nouveaux objets, les données actuelles sont trop limitées et des grands projets notamment spatiaux seront nécessaires dans les années qui viennent.
Sagittales Profil der Wirbelsäule: Was ist sinnvoll, was gefährdet den Patienten, was ist Hype ? Pro: Korrektur ist oberste Maxime
Authors: Koller Heiko
Published: February 2019

Die Notwendigkeit der Rekonstruktion eines physiologischen sagittalen Wirbelsäulenprofils bei Wirbelsäulenoperationen wird regelhaft in Fachdiskussionen kritisch hinterfragt. Die Gründe dafür liegen in der Natur sog. Deformitäteneingriffe, welche eine gesteigerte Komplexizität, operativen Schweregrad und auch Komplikationspotenzial mit sich führen. Der vorliegende Artikel erarbeitet ausführlich die Bedeutung der Rekonstruktion eines spinalen Alignments und einer sagittalen spinalen Balance. Vorteile und potenzielle Schwierigkeiten sowie Herausforderungen werden ausgewogen dargestellt. Die klinische Erfahrung, gestützt von wachsender publizierter Evidenz, bestärkt den Wirbelsäulenchirurgen in seinem Auftrag, auch die spinale sagittale Balance bei Wirbelsäuleneingriffen zu wahren und bei Bedarf auch zu rekonstruieren.
Pars-plana-Vitrektomie
Authors: Bopp Silvia , Kellner Ulrich
Published: February 2019

Die Pars-plana-Vitrektomie (PPV) ermöglicht die Therapie von zahlreichen Erkrankungen der Netzhaut und des Glaskörpers und wird bei der Diagnostik z. B. retinaler Tumoren eingesetzt. Verschiedene OP-Techniken sind möglich, abhängig von der Ausgangssituation und der Präferenz des Chirurgen. Die Erfolgsaussichten einer PPV sind im Wesentlichen abhängig von der Grunderkrankung, der Ausgangssituation und insbesondere der Veränderungen in der Makula.
„Unexplained physiological events“ in Hochleistungsflugzeugen
Authors: Ledderhos Carla
Published: February 2019

Seit 2008 klagten F-22-Raptor-Piloten wiederholt über hypoxieähnliche Symptome im Flugbetrieb, die unter dem Begriff „hypoxia-like events“ in die Literatur eingegangen sind. Nach Verlusten von Piloten und Maschinen hatte im Mai 2011 die gesamte F-22-Flotte der USA Startverbot. Gleichzeitig sind intensive Untersuchungen zu möglichen Ursachen der Zwischenfälle eingeleitet worden, die bis heute andauern. Indessen häuften sich diese Ereignisse auch bei weiteren Hochleistungsflugzeugen. Alle Versuche der US Air Force, US Navy und NASA, die Ursachen der nunmehr als „unexplained physiological events“ (UPEs) oder „physiological events“ (PEs) bezeichneten Vorfälle aufzuklären, schlugen ungeachtet intensiver Bemühungen fehl. Momentan stellen PEs eine der größten Herausforderungen für die Flugmedizin überhaupt dar, die es in Zusammenarbeit mit Piloten, Ingenieuren sowie anderen Fachleuten auf diesem Gebiet zu lösen gilt. Ohne Fortschritte beim physiologischen Inflight-Monitoring und Anpassung des Trainings der Piloten wird dies jedoch unmöglich.