Search results for: expected annual loss

Authors: Edgar Ochoa, G. Torres-Villasenor

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Superplastic deformation is shown by materials with a fine grain size, usually less than 10 μm, when they are deformed within the strain rate range 10-5 10-1 s-1 at temperatures greater than 0.5Tm, where Tm is the melting point in Kelvin. According to the constitutive equation for superplastic flow, refinement of the grain size would be expected to increase the optimum strain rate and decrease the temperature required for superplastic flow. Ribbons of eutectic Ag-Cu and Bi-Cd alloys were manufactured by using a single roller melt-spinning technique to obtain a fine grain structure for later test in superplastic regime. The eutectics ribbons were examined by scanning electron microscopy and X-Ray diffraction, and the grain size was determined using the image analysis software ImageJ. The average grain size was less than 1 μm. Tensile tests were carried out from 10-4 to 10-1 s-1, at room temperature, to evaluate the superplastic behavior. The largest deformation was shown by the Bi-Cd eutectic ribbons, Ɛ=140 %, despite that these ribbons have a hexagonal unit cell. On the other hand, Ag-Cu eutectic ribbons have a minor grain size and cube unit cell, however they showed a lower deformation in tensile test under the same conditions than Bi-Cd ribbons. This is because the Ag-Cu grew in a strong cube-cube orientation relationship.

Keywords: eutectic ribbon, fine grain, superplastic deformation, cube-cube orientation

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Authors: Edwin Cartledge, Jack Clark, Mazaher Molaei-Chalchooghi

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The mixing in the crystallization step of active pharmaceutical ingredient manufacturers was studied via advanced modeling tools to enable a successful scale-up. A virtual representation of the vessel was created, and computational fluid dynamics were used to simulate multiphase flow and, thus, the mixing environment within this vessel. The study identified a significant dead zone in the vessel underneath the impeller and found that increasing the impeller speed and power did not improve the mixing. A series of sensitivity analyses found that to improve mixing, the vessel had to be redesigned, and found that optimal mixing could be obtained by adding two extra cylindrical baffles. The same two baffles from the simulated environment were then constructed and added to the process vessel. By identifying these potential issues before starting the manufacture and modifying the vessel to ensure good mixing, this study mitigated a failed crystallization and potential batch disposal, which could have resulted in a significant loss of high-value material.

Keywords: active pharmaceutical ingredient, baffles, computational fluid dynamics, mixing, modelling

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Authors: Howaidi M. Al-Otaibi, Abdulrahman S. Al-Suhaibani, Hamad A. Alsoliman

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Fibers are extensively used in civil engineering applications for many years. In this study, empty fruit bunch of date palm trees were used to produce cellulose fiber that were used as additives in the asphalt binder. Two sizes (coarse and fine) of cellulose fibers were pre-blended in PG64-22 binder with various contents of 1.5%, 3%, 4.5%, 6%, and 7.5% by weight of asphalt binder. The physical and rheological properties of fiber modified asphalt binders were tested by using conventional tests such as penetration, softening point and viscosity; and SHRP test such as dynamic shear rheometer. The results indicated that the fiber modified asphalt binders were higher in softening point, viscosity, and complex shear modulus, and lower in penetration compared to pure asphalt. The fiber modified binders showed an improvement in rheological properties since it was possible to raise the control binder (pure asphalt) PG from 64 to 70 by adding 6% (by weight) of either fine or coarse fibers. Such improvement in stiffness of fiber modified binder is expected to improve pavement resistance to rutting.

Keywords: cellulose date palm fiber, fiber modified asphalt, physical properties, rheological properties

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Authors: Ruqia Nazir, Robin Perutz

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Collision-induced dissociation (CID) can be used to study the intrinsic properties of ions in the gas phase.1 Decay pathways of transition metal difluoride complexes of titanium, zirconium, hafnium, and ruthenium were studied by CID in an ESI-Ion trap mass spectrometer. Furthermore, the decay pathways of multiply charged anions (MCAs) of titanium and zirconium were also studied. The CID results are illustrated by the behaviour of (Cp*)₂TiF₂, which initially forms the ions [M-F-]⁺, [M+Na]⁺, and [M+K]⁺. The [(Cp*₂)TiF⁺ ion decays on resonant excitation to lose HF forming [Cp*(C₅Me₄CH₂)Ti]⁺ (Figure). The other major ion, [(Cp*)₂TiF₂+Na]⁺, decays on resonant excitation with production of [(Cp*)₂TiF₂]⁺ and [C₅Me₄CH₂]⁺. We also report the behaviour of Cp₂MF₂ (M = Zr, Hf) and Ru(PMe₃)₄F₂. The decay pathway of the multiply charged anions (MCAs), notably TiF₆²⁻ and ZrF₆²⁻ was concluded to be ionic fragmentation with loss of F⁻ rather than electron detachment.

Keywords: collision induced dissociation, transition metal difluoride comolexes, multiply charged anions, mass spectrometry

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Authors: Byeal-I Han, Michael Lee

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Ageing is associated with an increased risk of diseases such as cancer, and neurodegenerative disorders. Increased autophagy delays ageing and extends longevity. In this study, we investigated the role of autophagy in longevity using human foreskin fibroblast HS68 cells, in which a senescence-like growth arrest can be induced. In particular, cellular senescence is manifested by the irreversible cell cycle arrest, and may contribute to the ageing of organisms. The senescence state was measured with staining for senescence-associated β-galactosidase (SA-β-gal) activity that represents a sensitive and reliable marker to quantify senescent cells. We detected a significantly increased percentage (%) of SA-β-gal positive cells in HS68 cultures at passage 40 (63%) when compared with younger ones at passage 15 (0.5%). As expected, HS68 cells at passage 40 exhibited much lower proliferation rate than cells at passage 15. The basal levels of LC3 were measured by immunoblotting showing a comparison of LC3-I and LC3-II levels at 3 age-points in serially passaged HS68 cells. LC3-II/LC3-I ratio at different passage levels relative to β-actin levels of each band confirmed that cells at passage 34 showed lower conversion of non-autophagic LC3-I to autophagic LC3-II than the cells at passage 16. Furthermore, Cyto-ID autophagy assay also revealed that late passage cells showed lower autophagy than the early passage cells. Together, our findings suggest that senescence induction might be associated with decreased autophagy.

Keywords: ageing, autophagy, senescence, HS68

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Authors: Lavanya Madhuri Bollipo, K. V. Kadambari

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Objective: To discuss key issues in the diagnosis of Parkinson disease (PD), To discuss features influencing PD progression, To discuss importance of brain SPECT data in PD diagnosis, and To discuss the essentiality of machine learning techniques in early diagnosis of PD. An accurate and early diagnosis of PD is nowadays a challenge as clinical symptoms in PD arise only when there is more than 60% loss of dopaminergic neurons. So far there are no laboratory tests for the diagnosis of PD, causing a high rate of misdiagnosis especially when the disease is in the early stages. Recent neuroimaging studies with brain SPECT using 123I-Ioflupane (DaTSCAN) as radiotracer shown to be widely used to assist the diagnosis of PD even in its early stages. Machine learning techniques can be used in combination with image analysis procedures to develop computer-aided diagnosis (CAD) systems for PD. This paper addressed recent studies involving diagnosis of PD in its early stages using brain SPECT data with Machine Learning Techniques.

Keywords: Parkinson disease (PD), dopamine transporter, single-photon emission computed tomography (SPECT), support vector machine (SVM)

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Authors: Vivian Guo, Yan Qu

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Online marketplaces are not only digital places where consumers buy and sell merchandise, and they are also destinations for brands to connect with real consumers at the moment when customers are in the shopping mindset. For many marketplaces, brands have been important partners through advertising. There can be, however, a risk of advertising impacting a consumer’s shopping journey if it hurts the use experience or takes the user away from the site. Both could lead to the loss of transaction revenue for the marketplace. In this paper, we present user-based methods for cannibalization control by selectively turning off ads to users who are likely to be cannibalized by ads subject to business objectives. We present ways of measuring cannibalization of advertising in the context of an online marketplace and propose novel ways of measuring cannibalization through purchase propensity and uplift modeling. A/B testing has shown that our methods can significantly improve user purchase and engagement metrics while operating within business objectives. To our knowledge, this is the first paper that addresses cannibalization mitigation at the user-level in the context of advertising.

Keywords: cannibalization, machine learning, online marketplace, revenue optimization, yield optimization

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Authors: Nasim Babazadeh

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Growing demand for a quieter dwelling environment has turned the attention of construction companies to reducing the propagated noise of their project. In inner-city constructions, close distance between the construction site and surrounding buildings lessens the efficiency of passive noise control methods. Dwellers of the nearby areas may file complaints and lawsuits against the construction companies due to the emitted construction noise, thereby leading to the interruption of processes, compensation costs, or even suspension of the project. Therefore, construction noise should be predicted along with the project schedule. The advantage of managing the noise in the pre-construction phase is two-fold. Firstly, changes in the time plan and construction methods can be applied more flexibly. Thus, the costs related to rescheduling can be avoided. Secondly, noise-related legal problems are expected to be reduced. To implement noise mapping methods for the mentioned prediction, the required detailed information (such as the location of the noisy process, duration of the noisy work) can be exported from the 4D BIM model. The results obtained from the noise maps would be used to help the planners to define different work scenarios. The proposed approach has been applied for the foundation and earthwork of a site located in a residential area, and the obtained results are discussed.

Keywords: building information modeling, construction noise management, noise mapping, 4D BIM

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Authors: Hamid Aslani, Ahmed Radwan

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In this paper, a single element microstrip antenna is presented for UWB applications by using techniques as partial ground plane and modified the shape of the patch. The antenna is properly designed to have a compact size and constant gain against frequency. The simulated results have done using two EM software and show good agreement with the measured results for the fabricated antenna. Then a designing of two elements patch antenna array for UWB in the frequency band of 3.1-10 GHz is presented in this paper. The array is constructed by means of feeding two omni-directional modified circular patch elements with a modified power divider. Experimental results show that the array has a stable radiation pattern and low return loss over a broad bandwidth of 64% (3.1–10 GHz). Due to its planar profile, physically compact size, wide impedance bandwidth, directive performance over a wide bandwidth proposed antenna is a good candidate for portable UWB applications and other UWB integrated circuits.

Keywords: ultra wide band, radiation performance, microstrip antenna, size miniaturized antenna

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Authors: Mazlynda Md Yusuf, Wafa' Mahadzir, Mohamad Yazis Ali Basah

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Nowadays, financing long-term care for elderly people is a crucial issue, either towards the family members or the care institution. Corresponding with the growing number of ageing population in Malaysia, there’s a need of concern on the uncertaintiness of future family care and the need for long-term care services. Moreover, with the increasing cost of living, children feels the urge of needing to work and receive a fixed monthly income that results to sending their elderly parents to care institutions. Currently, in Malaysia, the rates for private nursing homes can amount up to RM 4,000 per month excluding medical treatments and other recurring expenses. These costs are expected to be paid using their Employees Provident Fund (EPF) savings that they accumulate during their working years, especially for those working under private sectors. Hence, this study identifies the adequacy of EPF in funding the cost of long-term care service during old age. This study used a hypothetical simulation model to simulate different scenarios. The findings of this study could be used for individuals to prepare on the importance of planning for retirement, especially with the increasing cost of long-term care services.

Keywords: long-term care cost, employees provident fund Malaysia, ageing population, Malaysian elderly

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Authors: Manaf Bashir

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Corporate social responsibility (CSR) has become a tool for corporations to meet the expectations of different stakeholders about economic, social and environmental issues. It has become indispensable for an organization’s success, positive image and reputation. Equally important is how corporations communicate and report their CSR. Employing the stakeholder theory, the purpose of this research is to analyse CSR content of leading Kuwaiti corporations. No research analysis of CSR reporting has been conducted in Kuwait and this study is an attempt to redress in part this empirical deficit in the country and the region. It attempts to identify the issues and stakeholders of the CSR and if corporations are following CSR reporting standards. By analysing websites, annual and CSR reports of the top 100 Kuwaiti corporations, this study found low mentions of the CSR issues and even lower mentions of CSR stakeholders. Environmental issues were among the least mentioned despite an increasing global concern toward the environment. ‘Society’ was mentioned the most as a stakeholder and ‘The Environment’ was among the least mentioned. Cross-tabulations found few significant relationships between type of industry and the CSR issues and stakeholders. Independent sample t-tests found no significant difference between the issues and stakeholders that are mentioned on the websites and the reports. Only two companies from the sample followed reporting standards and both followed the Global Reporting Initiative. Successful corporations would be keen to identify the issues that meet the expectations of different stakeholders and address them through their corporate communication. Kuwaiti corporations did not show this keenness. As the stakeholder theory suggests, extending the spectrum of stakeholders beyond investors can open mutual dialogue and understanding between corporations and various stakeholders. However, Kuwaiti corporations focus on few CSR issues and even fewer CSR stakeholders. Kuwaiti corporations need to pay more attention to CSR and particularly toward environmental issues. They should adopt a strategic approach and allocate specialized personnel such as marketers and public relations practitioners to manage it. The government and non-profit organizations should encourage the private sector in Kuwait to do more CSR and meet the needs and expectations of different stakeholders and not only shareholders. This is in addition to reporting the CSR information professionally because of its benefits to corporate image, reputation, and transparency.

Keywords: corporate social responsibility, environmental responsibility, Kuwait, stakeholder theory

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Authors: Sylwia Wiewiorowska, Zbigniew Muskalski

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The article presents part of research on the development of nickel plated welding wire production technology, whose application will enable the elimination of the flaws of currently manufactured welding wires. The nickel plated welding wire will be distinguished by high quality, because the Ni layer which is deposited electrochemically onto it from acid baths is characterized by very good adhesion to the steel wire surface, while the ductile nickel well deforms plastically in the drawing process and the adhesion of the Ni layer increases in the drawing process due to the occurring process of diffusion between the Ni and the steel. The Ni layer obtained in the proposed technology, despite a smaller thickness than when the wire is coated with copper, is continuous and tight, thus ensuring high corrosion resistance, as well as unsusceptible to scaling, which should provide a product that meets requirements imposed by the market. The product will also reduce, to some extent, the amount of copper brought in to steel through recycling, while the wire coating nickel introduced to the weld in the welding process is expected, to a degree, to favorably influence its mechanical properties. The paper describes the tests of the process of nickel plating of f1.96 mm-diameter wires using various nickel plating baths with different process parameters.

Keywords: steel wire, properties, welding process, Ni layer

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Authors: Shaohua Li, Aihua Zhang, Kelly Zatopek, Saba Parvez, Andrew F. Gardner, Ivan R. Corrêa Jr., Christopher J. Noren, Ming-Qun Xu

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Covalent immobilization of enzymes on solid supports is an alternative approach to biocatalysis with the added benefits of simple enzyme removal, improved stability, and adaptability to automation and high-throughput applications. Nevertheless, immobilized enzymes generally suffer from reduced activities compared to their soluble counterparts. One major factor leading to activity loss is the intrinsic hydrophobic property of the supporting material surface, which could result in the conformational change/confinement of enzymes. We report a strategy of utilizing flexible poly (ethylene oxide) (PEO) moieties as to improve the surface hydrophilicity of solid supports used for enzyme immobilization. DNA modifying enzymes were covalently conjugated to PEO-coated magnetic-beads. Kinetics studies proved that the activities of the covalently-immobilized DNA modifying enzymes were greatly enhanced by the PEO modification on the bead surface.

Keywords: immobilized enzymes, biocatalysis, poly(ethylene oxide), surface modification

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Authors: Abdul-Nasser El-Kassar, Walid Elgammal, Hisham Jawhar

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This paper studies the determinants of the dividends payout ratio. The factors affecting the dividends payout ratio are to be identified. The study focuses only on the cement and construction industry within the MENA region in an attempt to isolate any incoherent behavior. The factors under consideration are: sales growth, ROE, ROA, ROS, debt to equity ratio, firm size, and free cash flow. Data were collected from official stock exchange markets in addition to annual reports. The study considered all firms that paid dividend in each of the three consecutive years starting from 2010 till 2012. Out of the 123 listed firms that work in cement and construction industry in MENA region, only 19 paid dividends in the three consecutive years 2010-12. Our sample consists of the 19 firms (57 observations) which are selected according to purposive sampling. Moreover, the study uses the homogeneous subcategory within the purposive sampling since only similar firms in the construction industry had been examined. The outcome of the study provides a vital insight into the determinants of dividends payout ratio of companies in MENA region. The results showed that the dividend payout ratio has a strong and positive relationship with return on assets and strong but negative relationship with return on equity. On the other hand, the results detected weak relationships between dividend payout ratio and sale growth, debt to equity ratio, firm size, and free cash flow. The study suggests that board of directors tend to compensate shareholders and minimize the agency cost by distributing a high portion of profits in form of dividends whenever return on equity decreases. Also, when the performance of the firm improves, and hence return on assets increases, boards of directors are more generous in distributing profits.

Keywords: dividends payout ratio, profitability firm size, free cashflow, debt to equity ratio

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Authors: Martin Cvek, Miroslav Mrlik, Michal Sedlacik, Tomas Plachy

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Magnetorheological elastomers (MREs) are multi-phase composite materials containing micron-sized ferromagnetic particles dispersed in an elastomeric matrix. Their properties such as modulus, damping, magneto-striction, and electrical conductivity can be controlled by an external magnetic field and/or pressure. These features of the MREs are used in the development of damping devices, shock attenuators, artificial muscles, sensors or active elements of electric circuits. However, imperfections on the particle/matrix interfaces result in the lower performance of the MREs when compared with theoretical values. Moreover, magnetic particles are susceptible to corrosion agents such as acid rains or sea humidity. Therefore, the modification of particles is an effective tool for the improvement of MRE performance due to enhanced compatibility between particles and matrix as well as improvements of their thermo-oxidation and chemical stability. In this study, the carbonyl iron (CI) particles were controllably modified with poly(trimethylsilyloxyethyl methacrylate) (PHEMATMS) nano-grafts to develop magnetic core–shell structures exhibiting proper wetting with various elastomeric matrices resulting in improved performance within a frame of rheological, magneto-piezoresistance, pressure-piezoresistance, or radio-absorbing properties. The desired molecular weight of PHEMATMS nano-grafts was precisely tailored using surface-initiated atom transfer radical polymerization (ATRP). The CI particles were firstly functionalized using a 3-aminopropyltriethoxysilane agent, followed by esterification reaction with α-bromoisobutyryl bromide. The ATRP was performed in the anisole medium using ethyl α-bromoisobutyrate as a macroinitiator, N, N´, N´´, N´´-pentamethyldiethylenetriamine as a ligand, and copper bromide as an initiator. To explore the effect PHEMATMS molecular weights on final properties, two variants of core-shell structures with different nano-graft lengths were synthesized, while the reaction kinetics were designed through proper reactant feed ratios and polymerization times. The PHEMATMS nano-grafts were characterized by nuclear magnetic resonance and gel permeation chromatography proving information to their monomer conversions, molecular chain lengths, and low polydispersity indexes (1.28 and 1.35) as the results of the executed ATRP. The successful modifications were confirmed via Fourier transform infrared- and energy-dispersive spectroscopies while expected wavenumber outputs and element presences, respectively, of constituted PHEMATMS nano-grafts, were occurring in the spectra. The surface morphology of bare CI and their PHEMATMS-grafted analogues was further studied by scanning electron microscopy, and the thicknesses of grafted polymeric layers were directly observed by transmission electron microscopy. The contact angles as a measure of particle/matrix compatibility were investigated employing the static sessile drop method. The PHEMATMS nano-grafts enhanced compatibility of hydrophilic CI with low-surface-energy hydrophobic polymer matrix in terms of their wettability and dispersibility in an elastomeric matrix. Thus, the presence of possible defects at the particle/matrix interface is reduced, and higher performance of modified MREs is expected.

Keywords: atom transfer radical polymerization, core-shell, particle modification, wettability

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Authors: Yuan-Ching Lin, Sin-Yu Chen, Pei-Yu Wu

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This study reports the improvement in the wear performance of A6061 aluminum alloy clad with mixed powders of titanium carbide (TiC), copper (Cu) and aluminum (Al) using the gas tungsten arc welding (GTAW) method. The wear performance of the A6061 clad layers was evaluated by performing pin-on-disc mode wear test. Experimental results clearly indicate an enhancement in the hardness of the clad layer by about two times that of the A6061 substrate without cladding. Wear test demonstrated a significant improvement in the wear performance of the clad layer when compared with the A6061 substrate without cladding. Moreover, the interface between the clad layer and the A6061 substrate exhibited superior metallurgical bonding. Due to this bonding, the clad layer did not spall during the wear test; as such, massive wear loss was prevented. Additionally, massive oxidized particulate debris was generated on the worn surface during the wear test; this resulted in three-body abrasive wear and reduced the wear behavior of the clad surface.

Keywords: GTAW、A6061 aluminum alloy, 、surface modification, tribological study, TiC powder cladding

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Authors: Shin Je Lee, Go Bong Choi, Jeong Cheol Seo, Jong Min Lee, Gibaek Lee

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Water pipe network is installed underground and once equipped; it is difficult to recognize the state of pipes when the leak or burst happens. Accordingly, post management is often delayed after the fault occurs. Therefore, the systematic fault management system of water pipe network is required to prevent the accident and minimize the loss. In this work, we develop online fault detection system of water pipe network using data of pipes such as flow rate or pressure. The transient model describing water flow in pipelines is presented and simulated using Matlab. The fault situations such as the leak or burst can be also simulated and flow rate or pressure data when the fault happens are collected. Faults are detected using statistical methods of fast Fourier transform and discrete wavelet transform, and they are compared to find which method shows the better fault detection performance.

Keywords: fault detection, water pipeline model, fast Fourier transform, discrete wavelet transform

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Authors: Huyuan Zhang, Yi Chen

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Compacted sewage sludge has been proved to be feasible as a barrier material for tailing impoundment because of its low permeability and retardation of heavy metals. The long-term penetration of acid mine drainage, however, would acidify the barrier system and result in remobilization of previously immobilized heavy metal pollutants. In this study, the effect of decreasing pH on the mobility of three typical heavy metals (Zn, Pb, and Cu) is investigated by acid titration test on sewage sludge under various conditions. The remobilization of heavy metals is discussed based on the acid buffering capacity of sewage sludge-leachate system. Test results indicate that heavy metals are dramatically released out when pH is decreased below 6.2, and their amounts take the order of Zn > Cu > Pb. The acid buffering capacity of sewage sludge decreases with the solid-liquid ratio but increases with the anaerobic incubation time, and it is mainly governed by dissolution of contained carbonate and organics. These results reveal that the sewage sludge possesses enough acid buffering capacity to consume protons within the acid mine drainage. Thus, this study suggests that an explosive remobilization of heavy metals is not expected in a long-term perspective.

Keywords: acid buffering capacity, barrier, heavy metals, remobilization, sewage sludge

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Authors: Murat Çolak, Elifnaz Tanyıldızı

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Today, human mobility with globalization has increased the interaction between countries significantly; although this contact has advanced societies in terms of civilization, it has also increased the likelihood of pandemics. The coronavirus (COVID-19) pandemic, which caused the most loss of life among them, turned into a global epidemic by covering the whole world in a short time. While there was an explosion in demand in some businesses around the world, some businesses temporarily stopped or had to stop their activities. The businesses affected by the crisis had to adapt to the new legal regulations but had to make changes in matters such as their working styles, human resources practices, and policies. One of the measures taken into account is the reduction of the workforce. The current COVID-19 crisis has posed serious challenges for many organizations and has generated an unprecedented wave of termination notices. This study examined examples of companies affected by the pandemic process and changed their working policies after the pandemic. This study aims to reveal the impact of the global COVID-19 pandemic on human resources policies and employees and how these situations will affect businesses in the future.

Keywords: human resource management, crisis management, COVID-19, business function

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Authors: Yori Gidron, Laura Caton, Irit Ben-Aharon

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Background: Many patients and even certain clinicians attribute cancer development to psychosocial factors. Yet, empirical data supports more the prognostic role, rather than the etiological role, of psychosocial factors in cancer. Part of the inconsistency may result from not considering possible moderating factors in the etiological role of psychosocial factors. One important candidate moderating factor is the vagal nerve, whose activity is indexed by heart-rate variability (HRV). The vagal nerve may prevent cancer since it reduces inflammation on the one hand, and since it increases anti-tumor immunity on the other hand. This study examined the moderating role of the vagus in the relation between life threatening events (LTE) and cancer development. Method: We re-analyzed data from the Lifelines Dutch longitudinal cohort study of over 150,000 people. The present study included 82,751 adults, who initially were cancer-free. We extracted information on background factors (e.g., age, gender, fat consumption), whether they ever experienced LTE, HRV and cancer diagnosis as reported by patients in annual clinic visits. HRV was derived from brief ECGs. Results: Of the full sample, 1011 people developed cancer during a follow-up. In the full sample, LTE significantly predicted cancer development (R.R = 1.063 p < .01) and HRV significantly predicted a reduced risk of cancer development (R.R = .506 p <.001). Importantly, LTE significantly predicted cancer only when HRV was low (R.R = 1.056, 95% CI: 1.007 - 1.108, p < .05) but not when HRV was high (R.R = 1.014; 95% CI: 0.916 - 1.122, p > 0.05), independent of confounders. Conclusions: To the best of our knowledge, this is the first study showing in a large sample that LTE predict cancer development, and that this occurs only when vagal nerve activity (HRV) is relatively low. These results could result from lack of vagal modulation of inflammation and also from lack of vagal modulation of stress responses. Results are in line with the cancer-protective role of the vagus. HRV needs to be routinely monitored in the population and future intervention trials need to examine whether vagal nerve activation can prevent cancer in people with LTE and with other cancer risk factors.

Keywords: cancer development, life-events, moderation, vagal nerve

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Authors: Amin H. Almasria, Rajai Z. Alrousanb, Al-Harith Manasrah

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The collapse of a light weight pedestrian bridges due to vehicle collision is investigated and studied in detail using a dynamic nonlinear finite element analysis. Typical bridge widely used in Jordan is studied and modeled under truck collision using one dimensional beam finite element in order to minimize analysis time due to the dynamic nature of the problem. Truck collision with the bridge is simulated at different speeds and locations of collisions using dynamic explicit finite element scheme with material nonlinearity taken into account. Energy absorption of bridge is investigated through principle of energy conservation, where truck kinetic energy is assumed to be stored in the bridge as strain energy. Weak failure points in the bridges were identified, and modifications are proposed in order to strengthen the bridge structure and prevent total collapse. The proposed design modifications on bridge structure were successful in allowing the bridge to fail locally rather than globally and expected to help in saving lives.

Keywords: finite element method, dynamic impact, pedestrian bridges, strain energy, collapse failure

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Authors: Lama Yaseen, Nourah Al-Hosain

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A Multi-modal system in urban mobility is an essential framework for an optimized urban transport network. Many cities are still heavily dependent on vehicle transportation, dominantly using conventional fuel-based cars for daily travel. With the reliance on motorized vehicles in large cities such as Riyadh, the capital city of Saudi Arabia, traffic congestion is eminent, which ultimately results in an increase in road emissions and loss of time. Saudi Arabia plans to undergo a massive transformation in mobility infrastructure and urban greening projects, including introducing public transport and other massive urban greening infrastructures that enable alternative mobility options. This paper uses a Geographic Information System (GIS) approach that analyzes the accessibility of current and planned public transport stations and how they intertwine with massive urban greening projects that may play a role as an enabler of micro-mobility and walk-ability options in the city.

Keywords: urban development, urban mobility, sustainable mobility, Middle East

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Authors: Ali Amiri, Arash Esfandiari, Elham Zarenezhad

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We report here an efficient and rapid method for the preparation of 3,4-dihydro-1H-quinoxalin-2-ones and 1H‑quinolin-2-ones that involves grinding of o-, m-, or p‑phenylenediamine and three dialkyl acetylenedicarboxylates using a pestle and mortar. This solvent-free approach requires only a few minutes of reaction time. This type of reaction is expected to be the most economical method since neither catalyst nor solvent is used. Finally, all synthesised compounds were screened for antimicrobial activity against two Gram-positive bacteria (Pseudomonas aeruginosa PTCC 1077, Escherichia coli PTCC1330) and two Gram-negative bacteria (Staphylococcus aureus PTCC 1133, Bacillus cereus PTCC 1015) and their activity. Compared with gentamycin and ampicillin as reference drugs for Gram-negative and Gram-positive bacteria, respectively. The minimum inhibitory concentration (MIC) of the synthesised compounds and reference drugs were determined by the microdilution method. Good antibacterial activity was observed for 3,4-dihydro-1H-quinoxalin-2-ones against all species of Gram-positive and Gram-negative bacteria, and1H‑quinolin-2-ones showed good antibacterial activity against two Gram-positive bacteria.

Keywords: quinolin, quinoxalin, anti-bacterial activity, minimum inhibitory concentration (MIC)

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Authors: Amira Potter

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Since three years, ESPRIT has adopted project-based learning across its curricula. The philosophy behind this reform is to prepare its future engineers to become more operational once they integrate the workplace. It allows them to learn all the required skills expected from them by their future employers. This learner-centered method helps the students take responsibility for their own learning, solve real-world problems and carry out muli-faceted projects. Therefore, the teacher who used to be considered as the detainer of the knowledge has become more of a facilitator and a coach, encouraging their students’ learning process. This innovative way to English teaching has enabled the students to learn the English language differently. The target language is learnt cooperatively through group work, presentations, debating and many other communicative activities. The speaking skill in English language remains by far the most challenging skill for Tunisian students with an educational background based on Arabic as a first language and French as a second language. The student’s initial resistance to speak English in front of their classmates and the way they end up performing their work, shows the real progress they managed to achieve through PBL approach. The article will focus on the positive impact PBL has had on oral fluency among Esprit engineering students and how it has been achieved. It will also describe how speaking skill is taught and assessed at ESPRIT.

Keywords: cooperative, engineer, innovative, project-based learning

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Authors: D. Kumar, S. Kumar, A. G. Memon, R. A. Memon, K. Harijan

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A considerable amount of energy is usually lost due to compression of insulation in Heating, ventilation, and air conditioning (HVAC) duct. In this paper, the economic impact of compression of insulation is estimated. Relevant mathematical models were used to estimate the optimal thickness at the points of compression. Furthermore, the payback period is calculated for the optimal thickness at the critical parts of supply air duct (SAD) and return air duct (RAD) considering natural gas (NG) and liquefied petroleum gas (LPG) as fuels for chillier operation. The mathematical model is developed using preliminary data obtained for an HVAC system of a pharmaceutical company. The higher heat gain and cooling loss, due to compression of thermal insulation, is estimated using relevant heat transfer equations. The results reveal that maximum energy savings (ES) in SAD is 34.5 and 40%, while in RAD is 22.9% and 29% for NG and LPG, respectively. Moreover, the minimum payback period (PP) for SAD is 2 and 1.6years, while in RAD is 4.3 and 2.7years for NG and LPG, respectively. The optimum insulation thickness (OIT) corresponding to maximum ES and minimum PP is estimated to be 35 and 42mm for SAD, while 30 and 38mm for RAD in case of NG and LPG, respectively.

Keywords: optimum insulation thickness, life cycle cost analysis, payback period, HVAC system

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Authors: Leveque Benjamin, Rabaud Suzanne, Anest Hugo, Catalan Caroline, Neveux Guillaume

Abstract:

Human products consumption is one of the main drivers of biodiversity loss. However, few pertinent ecological indicators regarding product life cycle impact on species and ecosystems have been built. Life cycle assessment (LCA) methodologies are well under way to conceive standardized methods to assess this impact, by taking already partially into account three of the Millennium Ecosystem Assessment pressures (land use, pollutions, climate change). Coupling LCA and ecological data and methods is an emerging challenge to develop a product biodiversity footprint. This approach was tested on three case studies from food processing, textile, and cosmetic industries. It allowed first to improve the environmental relevance of the Potential Disappeared Fraction of species, end-point indicator typically used in life cycle analysis methods, and second to introduce new indicators on overexploitation and invasive species. This type of footprint is a major step in helping companies to identify their impacts on biodiversity and to propose potential improvements.

Keywords: biodiversity, companies, footprint, life cycle assessment, products

Procedia PDF Downloads 327

Authors: Galila Aisyah Latif Amini, Husnul Khatimah, Citra Amelia

Abstract:

Smoking among women is of particular concern for the maternal and child health community due to the strong association between prenatal smoking and adverse birth outcomes. Pregnancy is perceived to be a unique reason for smoking cessation, as motivation to care for the unborn fetus. This study aimed to find out the determinants of smoking cessation among pregnant women. Method that we use in this study is systematic review. We identified relevant studies by searching on science database online through SAGE journals, Proquest, Scopus, Emerald, JSTOR, and Springerlink. Journals were screened by title and abstract according to the research topic then filtered using the criteria exclusion and inclusion. And then we did critical appraisal. The results of the four studies reviewed were found that the determinant of smoking cessation are parity, the level of education, socioeconomic status, household SHS exposure, smoking habits of both parents, partner smoking status, psychological factors, antenatal care, intervention for health care provider, age smoking duration. The factor most strongly associated with smoking cessation is parity (OR 2,55; Cl 2,34-2,77). The results of this study are expected to give advice for developing future smoking cessation and relapse prevention programs.

Keywords: pregnancy, smoking cessation, tobacco use cessation, smoking

Procedia PDF Downloads 243

Authors: Vitali Kremez

Abstract:

The researcher monitored an organized ransomware campaign in order to gain significant visibility into the tactics, techniques, and procedures employed by a campaign boss operating a ransomware scheme out of Russia. As the Russian hacking community lowered the access requirements for unsophisticated Russian cybercriminals to engage in ransomware campaigns, corporations and individuals face a commensurately greater challenge of effectively protecting their data and operations from being held ransom. This report discusses two notorious ransomware campaigns. Though the loss of data can be devastating, the findings demonstrate that sending ransom payments does not always help obtain data. Key learnings: 1. From the ransomware affiliate perspective, such campaigns have significantly lowered the barriers for entry for low-tier cybercriminals. 2. Ransomware revenue amounts are not as glamorous and fruitful as they are often publicly reported. Average ransomware crime bosses make only $90K per year on average. 3. Data gathered indicates that sending ransom payments does not always help obtain data. 4. The talk provides the complete payout structure and Bitcoin laundering operation related to the ransomware-as-a-service campaign.

Keywords: bitcoin, cybercrime, ransomware, Russia

Procedia PDF Downloads 195

Authors: Aude Pérard Lecomte, Georges Fokoua, Amine Mehel, Anne Tanière

Abstract:

Air quality in urban areas is deteriorated by pollution, mainly due to the constant increase of the traffic of different types of ground vehicles. In particular, particulate matter pollution with important concentrations in urban areas can cause serious health issues. Characterizing and understanding particle dynamics is therefore essential to establish recommendations to improve air quality in urban areas. To analyze the effects of turbulence on particulate pollutants dispersion, the first step is to focus on the single-phase flow structure and turbulence characteristics in the wake of a heavy truck model. To achieve this, Computational Fluid Dynamics (CFD) simulations were conducted with the aim of modeling the wake airflow of a full- and reduced-scale heavy truck. The Reynolds Average Navier-Stokes (RANS) approach with the Reynolds Stress Model (RSM)as the turbulence model closure was used. The simulations highlight the apparition of a large vortex coming from the under trailer. This vortex belongs to the recirculation region, located in the near-wake of the heavy truck. These vortical structures are expected to have a strong influence on particle dynamics that are emitted by the truck.

Keywords: CDF, heavy truck, recirculation region, reduced scale

Procedia PDF Downloads 219

Authors: Priya Arora, Jaspreet K. Rajput

Abstract:

Superparamagnetism has accelerated the research and use of more economical and ecological magnetically separable catalysts due to their more efficient isolation by response to an applied magnetic field. Magnetite nanomaterials coated by SiO2 shell have received a great deal of focus in the last decades as it provides high stability and also easy further surface functionalization depending upon the application. In this protocol, Fe3O4 magnetic nanoparticles have been synthesized by co-precipitation combined with sonication method. Further, Fe3O4 superparamagnetic nanoparticles have been functionalized by various moieties to serve as efficient catalysts for multicomponent reactions. The functionalized nanoparticles were characterized by techniques like Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) surface area analysis. The as prepared nanocatalysts can be reused for several times without any significant loss in its activity. The utilization of magnetic nanoparticles as catalysts for this reaction is one approach i.e. green, inexpensive, facile and widely applicable.

Keywords: functionalized, magnetite, multicomponent reactions, superparamagnetic

Procedia PDF Downloads 340