bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectrally selective filter design for passive radiative cooling
Authors: Kecebas Muhammed Ali , Menguc M. Pinar , Kosar Ali , Sendur Kursat
Published: February 2020

Radiative cooling is potentially one of the most innovative approaches
to reducing energy density in buildings and industry, as well as
achieving higher levels of energy efficiency. Several studies have
reported the design of spectrally selective layered structures for
daytime passive radiative cooling. However, a comprehensive design of
such systems requires the spectral behavior of different materials and
radiative heat transfer mechanisms to be addressed together. Here, we
introduce a design methodology for daytime passive radiative cooling
with thin film filters which accounts for the spectral tailoring at
the visible and infrared spectrum. The major difference of this method
is that it does not require a predefined target ideal emittance. The
results show that higher cooling powers are possible compared to the
previously reported thin-film structures, which were designed from a
purely spectral perspective. The underlying mechanisms of the
resulting spectral profiles, which give rise to improved performance,
are investigated by wave impedance analysis. Cooling powers up to

100

W

/

m

2

are obtained with seven layers on Ag.
The findings of this study indicate that structures with better
performance in terms of cooling powers and temperature reduction rates
can be obtained following the procedure discussed.
Polarization manipulated femtosecond localized surface plasmon dephasing time in an individual bowtie structure
Authors: Xu Yang , Qin Yulu , Ji Boyu , Song Xiaowei , Lin Jingquan
Published: February 2020

The performance of plasmon in applications is strongly related to plasmon damping, i.e., a dephasing of the optical polarization associated with the electron oscillation. Accurate measurement, manipulation, and, ultimately, prolongation of the dephasing time are prerequisites to the future development of the application of plasmonics. Here, we studied the dephasing time of different plasmonic hotspots in an individual bowtie structure by time-resolved photoemission electron microscopy and proposed an easy-to-operate method for actively and flexibly controlling the mode-dependent plasmon dephasing time by varying the polarization direction of a femtosecond laser. Experimentally, we achieved a large adjustment of the dephasing time ranging from 7 to 17 fs. In addition, a structural defect was found to drastically extend the plasmon dephasing time. Assisted with the finite-difference time-domain simulation, the underlying physics of the dephasing time extension by the structural defect was given.
Pulse dynamics in SESAM-free electrically pumped VECSEL
Authors: Chichkov Nikolai B. , Yadav Amit , Kovalev Anton V. , Smirnov Semyon V. , Herper Markus , Fedorova Ksenia A. , Viktorov Evgeny A. , Rafailov Edik U.
Published: February 2020

Self-starting pulsed operation in an electrically pumped (EP) vertical-external-cavity surface-emitting-laser (VECSEL) without intracavity saturable absorber is demonstrated. A linear hemispherical cavity design, consisting of the EP-VECSEL chip and a 10% output-coupler, is used to obtain picosecond output pulses with energies of 2.8 pJ and pulse widths of 130 ps at a repetition rate of 1.97 GHz. A complete experimental analysis of the generated output pulse train and of the transition from continuous-wave to pulsed operation is presented. Numerical simulations based on a delay-differential-equation (DDE) model of mode-locked semiconductor lasers are used to reproduce the pulse dynamics and identify different laser operation regimes. From this, the measured single pulse operation is attributed to FM-type mode-locking. The pulse formation is explained by strong amplitude-phase coupling and spectral filtering inside the EP-VECSEL.
Dual-band infrared optical coherence tomography using a single supercontinuum source
Authors: Zorin Ivan , Gattinger Paul , Brandstetter Markus , Heise Bettina
Published: February 2020

Recent developments and commercial availability of low-noise and bright infrared (IR) supercontinuum sources initiated intensive applied research in the last few years. Covering a significant part of near- and mid-infrared spectral ranges, supercontinuum radiation opened up unique possibilities and alternatives for the well-established imaging technique of optical coherence tomography (OCT). In this contribution, we demonstrate the development, performance, and maturity of a cost-efficient dual-band Fourier-domain IR OCT system (2 µm and 4 µm central wavelengths). The proposed OCT setup is elegantly employing a single supercontinuum source and a pyroelectric linear array. We discuss adapted application-oriented approaches to signal acquisition and post-processing when thermal detectors are applied in interferometers. In the experimental part, the efficiency of the dual-band detection is evaluated. Practical results and direct comparisons of the OCT system operating within the employed sub-bands are exhibited and discussed. Furthermore, we introduce the 2 µm OCT sub-system as an affordable alternative for art diagnosis; therefore, high resolution and sensitive measurements of the painting mock-ups are presented. Finally, potentials of the dual-band detection are demonstrated for lithography-based manufactured industrial ceramics.
'Like a Dance': Working creatively with healthcare practitioners to explore mobility and osteoporosis
Authors: Smith Margaret A. Coulter , Schrag Anthony , Kelly Fiona , Pearson Claire
Published: February 2020

Collaborations between health sciences and creative arts can generate insights into complex health phenomena. This article describes a creative workshop derived from an action research project that aimed to raise awareness of fracture risk in health practitioners supporting people with osteoporosis. The creative workshop aimed to provide opportunities for practitioners within the action research community to create new knowledge and share their practice insights. The article considers the notion of creative arts as a physical, embodied process that can facilitate learning by enabling tacit knowledge to be made explicit. Rather than applying an instrumental approach to arts within healthcare, the workshop became a mechanism for the convergence of ideas, disciplines and support structures and provided a learning environment where old beliefs could be challenged, practice insights shared and new knowledge constructed. We discuss the workshop development and outputs and suggest the utility of this approach for collaborative learning.
Hero or villain? Moral ambiguity and narrative structure under the Comics Code in 1950s Superman stories
Authors: Traver John C.
Published: February 2020

This article explores the decades-long influence of the Comics Code on American comic books’ storytelling form by identifying the interpretive processes underlying the Code’s application and adapting the Code as a theoretical model for approaching the narrative structure and implied ethical stance within 1950s Superman comics. Instead of treating the Comics Code as a series of regulations seemingly interpreted arbitrarily, this article explores how interpretive issues were framed by figures such as Charles Murphy, Leonard Darvin and John Goldwater to identify ‘the spirit and intent of the Code’ and resolve challenges such as distinguishing between the ‘spirit’ and ‘letter’ of the Code, identifying interpretive authority outside the Code, weighing past interpretive precedent and locating authorial ‘intent’. Ambiguities and aporia within the Code’s language demanded that administrators reconstruct the Code’s possible meanings and conceptualize ‘justice’ by distinguishing between the Code’s general preferences and actual prohibitions, resolving terminological nuance and prioritizing conflicting stipulations. Administrators’ efforts to balance competing stipulations regarding characters’ physical unattractiveness, criminality, justice and institutional authority shaped comics’ storytelling form and perpetuated ambiguities that comic creators could – intentionally or unintentionally – exploit. Where Silver Age DC Comics have often been viewed as sacrificing psychological complexity to plotting and social conformity, this article argues that the plotting intricacy in several 1950s Comics-Code era Superman comics in fact enabled writers to present a more complex rendering of moral issues. Where the Comics Code explicitly forbade that ‘crimes’ be ‘presented in such a way as to create sympathy for the criminal’, the Comics Code’s own textually unstable meaning – coupled with the narrative complexity of the stories’ plotting, shifting points of view and situational and dramatic irony – enabled 1950s Superman writers to create sympathy for a supposed ‘criminal’, depict the frequent inaccuracy of assumed knowledge and introduce moral ambiguity, all while arguably ‘following’ the Code.
Adsorption Behaviours of Anionic Azo Dye (Congo Red) from Aqueous
Solution on Magnetic Expanded Graphite Material (EG@CoFe2O4) Composites
Authors: Tan Lam Van , Hong Tham Nguyen Thi , Tran Van Thuan , To Uyen Dao Thi , Vu Pham Gia , Sy Do Trung , Danh Vo Thanh , Tien Nguyen Anh , N. Vo Dai Viet , Nguyen Trinh Duy
Published: February 2020

In this paper, a potentiality of magnetic expanded graphite material (EG@CoFe2O4) for the adsorptive removal of Congo red, an anionic azo dye, from aqueous solution was studied. The experiments were carried out in batch mode in which various experimental conditions including contact time, initial dye concentration, adsorbent dosage and pH were varied and their influences on the adsorption yield were investigated. The surface of the adsorbent before and after the removal of the dye was characterized by using FT-IR analysis. Maximum adsorption of dye was achieved at pH 6. The adsorption capacity of
Congo red onto EG@CoFe2O4 was found to be as high as 101.2 (mg/g), which is higher than the adsorption capacity of the CoFe2O4 (45.7 (mg/g)). These results suggested the use of expanded graphite materials as an efficient adsorbent for decontamination of Congo red dye from factory effluents.
Essential Oil from Lemon (Citrus aurantifolia) Grown in Ben Tre Province, Vietnam:
Condition Extraction, Chemical Composition and Antibacterial Properties
Authors: To Quyen Ngo Thi , Ngoc Quyen Nguyen Thi , Kieu Linh Huynh Thi , Le Ngoc Thuy Trang , Tuan Anh Hoang Le , Khoi Nguyen Nguyen Hong , Tran Thien Hien , Thanh Tam Huynh Ngoc , Cang Mai Huynh
Published: February 2020

In present study, a steam distillation method has been adopted for extraction of the essential oil from Vietnamese lemon (Citrus aurantifolia) peel harvested from Tien Giang Province, Vietnam. Various extraction conditions influencing the oil yield were investigated. The resulting essential oil was evaluated for physico-chemical characteristics and antibacterial activities. The chemic al composition of oil was investigated by GC-MS. The results showed that with grinded lemon peel, a ratio of water and lemon peels of 3:1 (mL/g), extraction time of 90 min at 120 ºC, the highest essential oil yield was attained at 2.1 %. Bioactive components found at high content included limonene (64.90 %), γ-terpinene (13.70 %), β-pinene (11.89 %), α-pinene (2.11 %), β-cymene (1.80 %) and sabinen (1.52 %). The lemon essential oil in this study was found to inhibit five bacteria strains including Staphylococcus aureus, Bacillus cereus, Escherichia coli, Salmonella enterica and Pseudomonas aeruginosa.
Fabrication of Graphene Oxide/Zinc Oxide Hybrid Nanocomposite and
Assessment on Structural, Thermal and Optical Characterizations
Authors: Padinhattayil Sanoop , Rai K. Sheshappa
Published: February 2020

The present work provides a selective review of research activities that focus on the graphene oxide (GO) and zinc oxide (ZnO) hybrid nanomaterials and their physical characterizations. The graphene oxide nanoparticle was prepared by modified Hummer’s method and the nanohybrids of GO/ZnO prepared by chemical method. Nanohybrids were characterized by thermogravimetric analyzer to find the thermal stability of the hybrid material, the structural nature and crystal size by P-XRD, functional group identification and surface morphology by using FTIR & SEM technique. This method provides a facile method to synthesize the nanohybrid and will be freely extended to do the research on other class of hybrids based of graphene oxide.
Structural Determination of Cephalexin/β-Cyclodextrin Inclusion
Complex and its Validation using Molecular Simulation Methods
Authors: Sharma Dinesh , Saraswat Harish , Banoo Syqa , Islam Maidul
Published: February 2020

In this work, molecular simulation methods combining molecular docking and the structure elucidation of inclusion complex of cephalexin/β-cyclodextrin (β-CD) was determined using 1H NMR. Molecular docking studies showed that the complex formation process between β-CD and cephalexin was favourable and spontaneous because of negative values of binding energies. Molecular docking studies also confirmed the entry of aromatic ring into the cavity. Molecular mechanics studies were performed for aromatic ring of cephalexin, in different orientations and from both cavity ends, to measure the
parameters of inclusion depth and mode of entry. The resultant structure was studied for HOMO-LUMO gap to validiate the method. The final structure was established using 1H NMR, molecular mechanics, HOMO-LUMO gap and molecular docking.
Synthesis, Characterization and Photo-Physical Properties of
Europium(III) and Terbium(III) Complexes with Thiosemicarbazones
Authors: Vishwakarma Ananya , Sengupta S.K. , Pandey O.P.
Published: February 2020

Europium(III) and Terbium(III) complexes of type [Eu(L)Cl(H2O)2] and [Tb(L)OAc(H2O)2] (H2L =
thiosemicarbazone ligands derived from substituted thiosemicarbazide and benzil/diacetyl) were synthesized. The ligands and synthesized complexes were characterized on the basis of elemental analysis, FT-IR and 1H NMR and X-ray diffraction studies. Photo-physical properties such as excitation spectra, emission spectra and luminescence curves of complexes were investigated. The most intense peak of Eu3+ ion found at 618 nm attributed to 5D0 → 7F2 transition and peak of Tb3+ ion at 549 nm
attributed to 5D4 →7F5 transition.
Modelo área-volume para a Represa Guarapiranga empregando o índice NDWI
Authors: Da Cunha Caroline Favoreto , Cardoso Sabrina Brandão , Teramoto Elias Hideo , Chang Hung Kiang
Published: February 2020

As represas representam uma importante fonte de água para fins de abastecimento urbano. A variação do volume de água armazenada nesses reservatórios pode ser estimada a partir da relação empírica área-volume, na qual a área do reservatório ocupada por água pode ser calculada a partir de técnicas de sensoriamento remoto, destacando-se aquelas estimadas a partir do emprego do cálculo Índice de Diferença Normalizada da Água (NDWI). Para a construção do modelo área-volume da Represa Guarapiranga, uma das principais fontes de abastecimento de água na Região Metropolitana de São Paulo, 21 imagens com o índice NDWI foram produzidas com base em imagens de satélite Landsat-8 OLI entre janeiro de 2013 e janeiro de 2020. A análise de regressão da área coberta por água e o volume efetivamente mensurado na Represa de Guarapiranga, permitiram a elaboração de um modelo empírico área-volume com o coeficiente de determinação (R2) de 0,79, o que demonstra a viabilidade do emprego desta abordagem para estimativas realistas do volume de água armazenada.
The Effect of Aqueous Extract of Ocimum gratissium (Linn) on 1, 2 - Dimethyl Hydrazine induced Colon Cancer in Male Wistar Rats
Authors: Umeaku Ugochukwu , Ofusori David A. , Umeaku Obioma P. , Edward Tolulope A.
Published: February 2020

Background
Colon cancer is one of the leading causes of cancer death world-wide. There is a steady increase in incidence over the past four decades in developing countries. This has been partly attributed to increasingly low intake of vegetables among other causes.

Aims
Therefore this study aims to evaluate the protective effect of aqueous extract of Ocimumgratissimum (OG) leaves (a staple vegetable) on experimental model of colon carcinogenesis induced with 1, 2 Dimethylhydrazine (DMH). This is compared with celecoxib (a cyclooxygenase-2 inhibitor) which is used in the chemoprevention of colon cancer.

Methods
Sixty adult male Wistar rats were randomly divided into six groups: A to F, n=10. Group A was the normal control, Group B was given only DMH weekly for 16 weeks,Groups C, D and E were given graded doses of OG for two weeks prior to cancer induction by DMH. After which both OG and DMH were given for 16weeks. Group F received celecoxib daily for two weeks prior to cancer induction. Colonic wall was analysed grossly, histologically and biochemically. The induced lesions were staged investigated and staged using Duke’s Staging method.

Results
The result showed tumour incidence in groups B and C while no evidence of primary colonic tumour was observed in groups A, D, E and F. There was a dose dependent increase in the goblet cell count in the groups treated with OG with group E being statistically higher than group F. There was a significant reduction in collagen staining intensity (F = 129.74, p < 0.0001) for the colonic wall in group B when compared to other groups. There was a decreased nucleo-cytoplasmic ratio in groups C, D, E and F when compared to group B. There was a significant increase in the concentration of nitric oxide and prostaglandin E2in group B when compared to other groups D, E and F.

Conclusion
In conclusion, this research showed a protective effect of Ocimumgratissimum leaves on 1, 2-dimethylhydrazine-induced colon cancer which further corroborated its ethno-medicinal use.
Islamic Education in Indonesia and Malaysia: Comparison of Islamic Education Learning Management Implementation
Authors: Munastiwi Erni , Marfuah Marfuah
Published: February 2020

This study aims to reveal the comparative management of Islamic Education (Islamic Education) learning in Indonesia and Malaysia. The research method was a case study. The aspect of the study includes planning, implementation, and evaluation. Data collecting techniques were documents, archive records, interviews, and observations. The informant selection technique was a purposive sampling procedure from Madrasah Ibtidaiyah (MI) Bego, Sembego, Maguwoharjo, Depok, Sleman, Yogyakarta, Indonesia and Sekolah Rendah Malaysia (Malaysian Primary School) or Sekolah Kebangsaan (Malay-medium National Schools) Jelotong, Paritraja, Batu Pahat, Johor, Malaysia. The results of the study show that both Indonesia and Malaysia produce similarities in terms of the stages of the planning, implementation, and evaluation processes. The uniqueness of other similarities can be found in choosing the topic of Islamic religious subjects in the learning process. In addition to the similarities, there are differences in the underlying philosophy of making an Islamic Education curriculum.
The Islamic Moderation Values on the Islamic Education Curriculum in Indonesia: A Content Analysis
Authors: Siswanto
Published: February 2020

The discourse of Islamic moderation in Indonesia is re-emerging as the phenomenon of radical religious understanding emerges. This study aims to analyze the values ​​of Islamic moderation in the curriculum of Education in Indonesia through the textbooks of Pendidikan Agama Islam and Budi Pekerti taught at the Senior High School level (SMA). The method used is content analysis. The results showed that the concept of Islamic moderation was not explicitly mentioned, but reflected in a material whose substance contained the values ​​of Islamic moderation, namely the values ​​of tolerance, democracy, simplicity, justice, and harmony. The mainstreaming of Islamic moderation values ​​in the education curriculum in Indonesia has become very important because of the emergence of concerns about strengthening extremist, intolerant and radicalism-terrorism movements in several educational institutions.
Sheikh Mahfudz at-Tarmasi’s Thought on Islamic Education
Authors: Ratnasari Dwi
Published: February 2020

Indonesia is a country with the largest Muslim population in the world. The role of scholars in developing and maintaining Islamic values ​​is vital. Among the scholars who play an essential role in the process is Shaykh Mahfudz at Tarmasi. This article aims to explore the traditions and intellectual networks of Shaykh Mahfudz, one of the archipelago scholars of the late nineteenth century who had a profound influence on the development of Islamic intellectual traditions in the archipelago. Despite spending his age in Mecca, he succeeded in educating Javanese clerics who were members of the Jawi community to become leaders of large pesantren in the archipelago. This research concludes that Shaykh Mahfudz is a productive ulama. The intellectual traditions and networks that he built spread to various Islamic worlds through several works he produced, and through his students who acted as transmitters of Islamic sciences from Mecca to the archipelago
MORE THAN JUST A GREEN FACADE: VERTICAL GARDENS FOR SOUND ABSORPTION AND ARCHITECTURAL ACOUSTICS
Authors: Davis M. J. M. , Pérez M. E. , Tenpierik M. J. , Ramírez F. R.
Published: February 2020

Noise can become uncomfortable for us in many situations both indoors and outdoors. External noise consists of activities (airplanes flying overhead, traffic on the road, etc.) that are either loud enough to be considered uncomfortable when outdoors, or are of an elevated volume to the extent that they infiltrate buildings at levels considered uncomfortable. In the case of internal uncomfortable noise, this can either stem from noisy activities that occur inside the building (people speaking loudly, printers, etc.), or when an unexpected sound suddenly permeates an area that has a very low level of background noise. The most common manner by which to mitigate excess noise is through the use of certain materials, which either insulate against noise passing through the material, or absorb the noise wavelengths. In the case of the latter, vertical gardens present themselves as not only an aesthetic element in architecture, but also as a potential acoustic control tool in building design. For this work 10 m2 of vertical garden substrate modules was tested in a full size reverberation chamber. The objective was to open the doors for vertical gardens to be used in architectural acoustic design.
MULTI CRITERIA MANAGEMENT OF SEWERAGE SYSTEM: ANALYSIS OF THE FAILURES AND THE CRITICALITY OF STRUCTURES
Authors: Cherrared Marzouk
Published: February 2020

The FMEA (Failure Modes and Effects Analysis) was used for management of failure risks of the sewerage system of Algiers. It’s based on a multi criteria analysis of failures risks of principal structures, their effects and their criticality. The implementation of criteria is based on the knowledge gained in previous phases of investigations. A criticality index "Ic" has been estimated to highlight the most sensitive structures to previously identified risks. This index is calculated based on three parameters: a "risk", a "severity", and a "detectability period" of the failure. Multi criteria analysis was performed to select and rank the criteria on the basis of scores assigned to each of them (from 0 to 7 according to the defined performance states). Four performance classes were defined according to the values of Ic. Classification scale and graphs representing criticality indices were established. A case study is presented. The results highlight the "black points" of the sewerage system. The most sensitive structures have been identified and the targeted interventions in the medium and long terms have been proposed. The weak points of FMEA were also highlighted.
DURABILITY STUDIES OF PQC MIX INCORPORATING RECYCLED CONCRETE AGGREGATE AND MINERAL ADMIXTURES
Authors: R. N. G. D. Ransinchung , Jindal Abhishek
Published: February 2020

Concrete as known globally is the most widely used construction material in all type of construction works. Recycled concrete aggregates have been eyed as a viable option for part replacement of natural coarse aggregates for concrete production by researchers for quite some time. However, their tendency to bring down the property parameters of new concrete makes it very important to investigate the extent of variation in durability properties of fresh concrete incorporating recycled concrete aggregates. Mineral admixtures are believed to improve the durability and mechanical aspects of concretes. This study makes an effort to understand the effects of incorporating recycled concrete aggregates and different mineral admixtures on durability aspects of pavement quality concrete mixes. In order to investigate the same, recycled concrete aggregates were used along with mineral admixtures in different proportions to study the variation in properties. Concrete mixes prepared with natural aggregates, recycled concrete aggregates and mixes containing recycled concrete aggregates and mineral admixtures were prepared and tested for variations in their durability properties. Laboratory investigations revealed that incorporating mineral admixtures does improves the durability aspects of pavement quality concrete having recycled concrete aggregates. Reduction in values for water absorption, sorptivity coefficients and chloride ion concentrations supported better durability aspects for mixes prepared with recycled concrete aggregates incorporating mineral admixtures.
TASK-TECHNOLOGY FIT IN THE ADOPTION OF LINEAR SCHEDULING METHOD
Authors: Yang Juneseok , Arditi David
Published: February 2020

Although the general consensus is that linear scheduling methods (LSMs) are quite powerful, their use in construction has been very limited. The linkage between the characteristics of scheduling methods and the requirements of the tasks performed by schedulers has been an on-going concern in the construction industry. This study proposes a “task-technology fit” model to understand why LSMs are not being used as extensively as expected. The model aims to determine whether the characteristics of LSM (technology) satisfy the duties and obligations of construction schedulers (tasks). By scrutinizing the task-technology fit in LSM applications, deficiencies can be detected which hinder the wider use of these methods in the industry. A questionnaire survey was administered to measure task-technology fit in LSM applications. The target population included schedulers, project managers, construction managers, and other professionals listed in the directory of the Construction Management Association of America (CMAA). The findings indicate that LSM is effective in repetitive projects and is able to provide a smooth and efficient flow of resources by adjusting activities’ rate of production. In addition, research findings point out that LSM effectively shows activity sequences as well as progress. However, the findings also reveal that LSM is not applicable when reliable resource data are not available. It should also be noted that very few software packages that perform LSM scheduling are commercially available on the market.
THE TECHNICAL AND ECONOMIC FEASIBILITY STUDY OF USING SMART PHONES IN CONSTRUCTION SITE MANAGEMENT
Authors: Safa Hamid Reza , Ravanshadnia Mehdi
Published: February 2020

Construction project management is the application of knowledge, skills, tools and techniques related to project activities achieving the project requirements. Accurate and timely acquisition of the site data and information could improve the project management decision processes. However, obtaining the data and information in minimum possible time is the complex process due to nature of the construction site condition. There are several limitations with regards to the site data acquisition including, monitoring construction site, and sharing a daily status report. This study investigates the potential of using smartphone as a new technology in construction sites: (1) to improve monitoring and controlling the site activities; (2) to accelerate decisions making process by improving the speed and accuracy of information exchange process. This study provides an overview of the feasibility of using smartphones in three areas of project management knowledge, discussed in a Guide to the Project Management Body of Knowledge (PMBOK), including time management, quality management and human resources management. Validation was conducted through the real case study based on the proposed scenarios. Return of investment and sensitivity analysis of the two scenarios were also compared to find the efficient scenario. The results of this study can be applied to improve the monitoring and understanding of the site status and can potentially facilitate the decision making process.
BIM DESIGN FLOW FOR CONSTRUCTION SITE
Authors: Trani Marco L. , Cassano Manuele , Todaro Davide
Published: February 2020

Construction site planning is an important task in a design team whereas a proper design of construction activities has a great influence in time and cost saving as well as in workers’ safety. Designers need to focus on site planning since the preliminary phase of building design in order to point out construction criticalities of the project that can affect execution phase. On the contrary, a scarce attention to operational issues during design phase is detectable in industry. Despite of the rapid diffusion of Building Information Modeling (BIM), a lack of BIM tools specifically studied for site design is detectable. Then the purpose of this paper is to describe a workflow developed with the aim to integrate site planning in a BIM design process, gaining thus operational advantages. The development of the workflow follows designers’ needs collected through the active participation of the authors in several design teams. A strong coordination and information sharing with other disciplines is the main task of the workflow, so that design choices can take into consideration operational issues as well. In order to simplify and accelerate the tasks of the site designer, the system is based on the use of some tools (such as databases of construction site elements and automatic checking tools), specifically developed for the purpose. The satisfaction of the designers involved demonstrates the efficiency of the system, in particular concerning the decrease of design time and the assistance of design choices thanks to operational information management.
WIND TUNNEL TEST OF SCAFFOLDS SET WITH WALL CONNECTERS WITH BASEBOARD HEIGHT AS A PARAMETER
Authors: Takahashi Hiroki , Ohdo Katsutoshi
Published: February 2020

The Japanese Industrial Safety and Health Law were revised in March 2009 to introduce new measures by which to prevent accidental falls in the construction industry. As part of this revision, authorities established regulations on the provision of guard rails, toe boards, mesh sheets, and other components in appropriate positions on scaffolds. When scaffolds are set in construction sites, their strength against wind force needs to be calculated. Japanese design guidelines regulate the strength of scaffolds against wind force; however, the design guidelines were written with old-style scaffolds in mind. It is not known whether the design guidelines are appropriate for new-style scaffolds. At the construction sites, the scaffolds connect to structures through the use of wall connecter, to keep scaffolds from falling down. The wind load that acts on the scaffolds was supported by the wall connecter at the construction sites. On the other hand, in conventional designs, a baseboard is used on construction sites. In this study, to set scaffolds at construction sites while using baseboard height as a parameter, we performed a wind tunnel test to examine the wind load that acts on scaffolds that have been set with wall connecters. The wind tunnel device has a total length 74,900 mm, while the device interior is 2,300 mm wide and 2,000 mm high. The load sell to set the wall connecter was used to measure wind load. The models, each of which was 1/10 in size, were used on scaffolds at general construction sites. The scaffolds were three stories high and one span wide. A baseboard was situated on one side of the long face of the scaffolds. The wind speed was set at a uniform flow of 10 m/s, because the wind force coefficient of a cylinder is stable at this speed. The characteristic length was positioned 5 mm along the diameter of a leg member. The Reynolds number was approximately 3.5 × 103. From our results, the wind force coefficient was found to increase as the baseboard height increased. With regard to efficient scaffold design, calculations of the wind force coefficient should therefore consider baseboard height.
PREVENTING UNETHICAL AND ILLEGAL PRACTICES IN CONSTRUCTION
Authors: Arditi David
Published: February 2020

Despite the fact that all professional associations, including ASCE, CMAA, PMI, AACE, and NSPE have codes of ethical conduct, the majority of the stakeholders in the construction process have encountered unethical behavior at one time or another. This is a contentious issue because there is always disagreement about what is and is not ethical. This paper looks into two practices that are most common in construction contracting, namely unbalanced bidding, and pre-award bid shopping. Both practices are considered to be totally acceptable by some, and totally unethical by others. Both practices can be stopped if preventive measures are put in place. The nature of these behaviors is examined, their impact is assessed, and preventive measures are formulated. In addition, in rare instances, illegal practices come to light. Collusive behavior is one such practice that is difficult but not impossible to detect. The nature of bid rigging is examined, its impact is assessed, and recommendations are made to detect parties that are involved in collusive practices. In addition to professional associations’ efforts to publish standards for ethical conduct, the construction industry needs to be proactive in creating awareness about ethics issues, clear the confusion about what is ethical and what is not, and in promote ethical values throughout the entire spectrum of professions involved in construction.
COLLAPSE TEST ON RECTANGULAR STEEL BEAM WITH DIFFERENT SUPPORT CONDITION
Authors: Park Sung-Hyun , Shin Kyung Jae , Lee Swoo-Heon , Lee Hee-Du , Kim Woo Bum
Published: February 2020

The behavior of beams with different support condition was investigated through three-point bending test for the purpose of studying difference of maximum load and catenary action of a beam. Beams are made of SPSR400 which has 245MPa of nominal yield strength and 400MPa of nominal tensile strength. The parameters of the supports condition are simple support and rotationally semi-rigid connection with different horizontal reaction strength applied by anchors. The support boundary conditions of beams were classified into three types; (A) simply supported with no anchors, (B) embedded anchors with 50mm depth of φ10mm, and (C) embedded anchors with 80mm depth of φ10mm. Both ends of the beams were connected by fillet welded angles and supported on a rigid concrete wall through anchors. The test result shows how much the load carrying capacity is increased by catenary action after large deflection at the center of the beam. First peak loads from each types are the loads when first plastic hinge occurs at the mid-span. There were no significant differences among the first peak loads measured from three types. After that, tensile force at anchors due to catenary action increased the load carrying capacity by approximately 55%, which is called as the second peak load. However, second peak load happens when the anchors at a support fully resist a tensile force, therefore it doesn’t happen with type (A) and (B). In conclusion, support boundary conditions of a beam don’t have an effect on the first collapse load, but the second collapse load is increased as embedded length of an anchor becomes deeper.
DESIGN CONSIDERATIONS FOR MAINTENANCE: FACILITY MANAGERS’ PERSPECTIVE
Authors: Sohi Armin Jalali , Arditi David , Sohi Afshin Jalali
Published: February 2020

Maintainability is one of the considerations designers take into account in the design stage of building construction projects. In other words, maintainability is a design consideration that may improve ease of maintenance during operation. The designer is expected to include maintenance knowledge and experience into the design, including planning for specific tools to facilitate implementation. Maintainability issues appear during the occupancy stage and have a direct impact on the cost of owning and operating a facility. Annual operation and maintenance expenses during the life cycle of a building could amount to many times the initial construction cost. Design deficiencies constitute one of the main reasons for high annual maintenance cost. Facility management involves activities to maintain and operate a constructed facility. It is essential to evaluate facility managers’ perspective on how maintainability characteristics should be considered at design phase of facilities. A survey of 168 facility managers in the mid-west region of the US is uncovered that (1) maintainability should be top priority in design, especially for mechanical systems, (2) deferred maintenance should be avoided because it increases costs over the life-cycle of buildings, and (3) constructed facilities should be handed over with a maintenance schedule provided by the designer. Paying special attention to maintainability in the design phase is expected to help reducing the cost of operation.
A CASE STUDY ON SOIL IMPROVEMENT WITH DEEP SOIL MIXING APPLICATION
Authors: Onur M. Inanc , Kilic H. Orkun , Tuncan Mustafa , Tuncan Ahmet
Published: February 2020

Soil improvement is defined as the improvement of the some soil parameters by using different methods when the soil properties are insufficient to prevent static and dynamic loads. The Deep Soil Mixing (DSM) is an in situ soil treatment technology whereby the soil is blended with cementitious and/or other materials. The method has gained its popularity after 1990’s in the world and last ten years in Turkey. In this study, a case study on soil improvement with deep soil mixing application in Eskisehir, Turkey is presented. The application procedure was created according to steps of usual geotechnical projects. Firstly, soil investigation was done and soil parameters were defined. And then, bearing capacity of deep soil mixing columns was calculated and modelled by “All Pile” software. After the site application, core samples were taken and the load test was applied to the core samples. Finally, deep soil mixing is becoming a popular as a soil improvement method and gives succeeding results.
REFUGEE CAMPS AND GATED COMMUNITIES AS A SOLUTION FOR HOUSING
Authors: Çat Büşra Özaydin
Published: February 2020

Today the World has a biggest crisis of refugee since The World War II. Refugee is a person who is depressed due to his/her religion, race and ideas or who defect to another country with fear of being oppressed. The refugee camps are high intensity places which provide refugees housing and other social and physical needs. On the other hand today in the capitalist and global cities the most important places for housing are gated communities. The scope of this study is to examine the social and physical similarities of refugee camps and gated communities. Within this framework when we look at some definitions of the concept of gated community, we can see the imitation of refugee camp. In this study, firstly the concept of housing/dwelling and the concept of security which is the most important reason of emerging of gated communities and refugee camps will be analyzed. Then physical and social resemblances of gated communities and refugee camps will be examined. For identifying physical similarities being surrounded by wall or fence, location of the gated communities and refugee camps in the city, their outbuildings like market, pharmacy and their intensity will be analyzed. For social similarities the sense of belonging of refugees and residents and their relations with city will be examined. The results of these will be summarized and evaluated.
OPPORTUNITIES FOR ATTEMPTING AMICABLE SETTLEMENT ALONG THE CLAIM/DISPUTE TIMELINE
Authors: Abdul-Malak Mohamed-Asem U. , Jaber Siba J.
Published: February 2020

Claims and disputes are considered an inevitable consequence of the construction process, and project participants are becoming more aware of their costly and lengthy resolution process. The conditions of contract normally include procedures for the submittal, administration and resolution of claims, while it is widely recognized that attempting to resolve claims/disputes through amicable settlement as opposed to arbitration or litigation can save on a lot of time and money. This paper presents a critical analysis of the windows of opportunities offered under both the 1987 and 1999 FIDIC conditions of contract for attempting to resolve claims/disputes amicably. It first focuses on the 56-day period specifically dedicated for attempting an amicable resolution of disputes and highlights the possibilities of effectively stretching this period in more than one way. It further explores the opportunities available at the earlier stages of the claim/dispute timeline, before a claim is escalated to the level of a dispute.
MACRO DEFECT FREE CEMENTS: A REVIEW
Authors: Ekincioglu Ozgur , Ozkul M. Hulusi , Patachia Silvia
Published: February 2020

The usage of polymers in different sectors has been increasing in recent decades, and even our current age may have been defined as polymer age. When concrete is considered polymers are also widely used to modify the properties of both mortar and concrete and the usage of polymers in concrete dates back to 1920’s. On the other hand, Macro-defect free (MDF) cements are one particular type of cement-polymer composites and developed and patented by scientists at Imperial College at the beginnings of 1980’s. MDF cements are produced by mixing cement (commonly calcium aluminate cement) with small amounts of polymer (usually polyvinyl alcohol acetate) and water. High shear, relatively low pressure (about 5 MPa) and moderate temperature (about 80-100 °C) are applied during the production of this material. MDF cements, although consist of more than 80% by weight of cement, show 20-30 times higher flexural strength comparing to ordinary Portland cements. However, MDF cements show a considerable reduction in strength when they are exposed to water even for a short time. Many studies have been conducted to solve the water sensitivity of MDF cements for over 30 years. In this study, production, basic properties and the current state of the art of MDF cements are explained, and the future research works are suggested.
IN SEARCH OF ALTERNATIVE AWARDING CRITERIA
Authors: Bauer Bernhard , Wall Johannes , Heck Detlef
Published: February 2020

In Austria, the public procurement of construction works is mainly based on two different types-the lowest acquisition costs and the most economically advantageous tender. The first one only considers the price, which means, that the contract is awarded to the bidder with the cheapest price. The other principle refers to the most economically advantageous tender, which has to be chosen for projects that exceed a certain overall tender value or are related to projects with higher complexity. This principle focuses on considering other awarding factors besides the price, but it often fails its purpose due to the lower weighting of these issues. Over the last years the market has not expanded very much, therefore there is a lot of competition related to the lowest price, which results in inadequate quality and opens up the field for further claims. In order to end the tense price competition among the competitors and to increase the quality of the projects, new criteria with serious weighting will be needed and to fulfill the most economically advantageous tender and supporting the focus on construction quality. Even though there are acknowledged guidelines dealing with environmental aspects of construction sites, like the RUMBA guideline (Richtlinien für umweltfreundliche Baustellenabwicklung-Guidelines for Sustainable Construction Site Management). However aspects of sustainability are no common standard within construction processes. To capture the common standards of sustainable measures on construction sites, and the industries’ understanding for environmental topics, research on experts in the field was done. Based on the authors’ acknowledgements, the paper targets the aspects of an environmental friendly construction site and introduces new criteria for the awarding process, and mentions some of the findings such as the “technical equipment expertise” or “sustainable construction site management”.
VIBRATION CONTROL OF STRUCTURES USING MAGNETO-RHEOLOGICAL DAMPERS WITH H∞ METHOD
Authors: Aggumus Huseyin , Cetin Saban
Published: February 2020

In this study, the vibration mitigation of the structures under the earthquake excitation using magneto-rheological (MR) damper is researched. For this purpose, one MR damper is installed to an eight story structure and the system performance is investigated. MR damper is installed between the second floor and the ground. The MR damper is a semi-active control device that can be controlled by only the voltage transmitted to the electromagnetic coils. Since the MR damper is a semi active device, damping force can be changed by applied voltage. Therefore, determination of the applied voltage is important for vibration reduction. A robust controller is designed for determination of the MR damper voltage. H∞ method and model reduction approach are used for robust control design and application. The performance of the proposed method is tested by numerical simulation on the semi active structural system with MR damper. The performance of the control algorithm and the effect of the MR damper arrangement is evaluated using earthquake (El-centro earthquake) data. The results are compared with situations in which MR damper is not connected and when the MR damper is situation of semi-active controlled. The evaluations are based on the displacement and acceleration responses. The simulation results showed that the arrangement of the MR damper connected between the second floor and the ground is effective in reducing the vibration amplitudes.
BEHAVIOR OF PLAIN AND STEEL FIBER HIGH STRENGTH REINFORCED CONCRETE COLUMNS CONFINED WITH CFRP
Authors: Erturkmen Duygu , Dundar Cengiz , Tokgoz Serkan
Published: February 2020

High strength reinforced concrete columns have been increasingly used in structural applications. It is known that high strength reinforced concrete columns exhibit brittle behavior under applied loads. Therefore, steel fibers can be added into the core concrete to improve the ductility and deformability of high strength reinforced concrete columns. In addition, reinforced concrete columns can be wrapped with carbon fiber reinforced polymer (CFRP) materials for strengthening the columns. In this work, experimental and analytical studies on plain and steel fiber reinforced concrete columns and CFRP confined columns have been presented. The experimental strength capacities, load-deflection relations and failure modes of the column specimens have been observed. The effects of the parameters of concrete compressive strength, load eccentricity, steel fibers, and carbon fiber polymer material on the structural behavior of high strength reinforced concrete columns have been examined. It is concluded that the inclusion of steel fibers has considerable effect on column ductility and deformability, but has insignificant effect on column strength capacity. The experimental study exposed that wrapping CFRP material on plain and steel fiber high strength reinforced concrete columns has provided significant improvement on the column strength capacity and confinement. The tested columns have been analyzed with a theoretical method considering the experimental stress-strain relations of CFRP confined concrete; and the analysis shows good agreement with the experimental results.