bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement of Acoustic Properties of the Safety Anti-Skid Modification - ROCBINDATM
Authors: Kozak Petr , Matuszkova Radka , Radimsky Michal
Published: March 2018

The noise pollution is an important factor for people living near roads. The road traffic noise is endangering the health of these residents and the quality of their lives. The tyre / road noise became the most significant source of the road traffic noise due reduced noise emissions from the vehicle propulsion system by the automotive industry. An important recent trend is increasing the traffic safety by improving anti-skid properties of roads in critical locations. Experts have concluded that some anti-skid modifications may increase the noise pollution. Because the usage of such pavements is predominantly in urban areas, problems may occur. This paper deals with the noise level of the safety anti-skid modification of the road surface used in the urban areas. Based on the presented measurement values it can be said that the RocbindaTM safety anti-skid modification does not achieve any increased acoustic performance compared to the asphalt pavement.
Effect of GGBFS on Compressive Strength and Durability of Concrete
Authors: Chi Mao Chieh , Chi Jen Hao , Wu Chung Hao
Published: March 2018

Facing the cement and concrete development process, reducing greenhouse gases and the consumption of natural resources has become an important issue. To reduce the cement content in concrete, the increased use of concrete combining large amounts of industrial by-products is expected. Ground granulated blast furnace slag (GGBFS) has been used as a supplementary cementitious material in ordinary Portland cement (OPC) concrete. In this study, GGBFS at different cement replacement ratios of 0%, 20%, 40%, and 60% by weight were used to produce concrete. Compressive strength test, water absorption, electrical resistivity, and rapid chloride penetration test (RCPT) were performed to investigate the effect of GGBFS on compressive strength and durability of concrete. Test results show that GGBFS concrete with 40% cement replacement (G40) has the highest compressive strength. The water absorption and chloride permeability reduced with the increasing cement replacement percentage by GGBFS. Meanwhile, the electrical resistivity increased with an increasing GGBFS replacement percentage. Based on the results, GGBFS concrete with 40% cement replacement seems to be the optimum replacement in this study.
Laponite Nanoparticle as a High Performance Rheological Modifier in Water-Based Drilling Fluids
Authors: Liu Fan , Jiang Guang Cheng , Wang Kai , Wang Jin Xi
Published: March 2018

In this paper, we demonstrated an artificial nanoparticles, Laponite, as a high performance rheological modifier in water-based drilling fluids. We made a comparison between Laponite nanoparticle and bentonite as rheological modifier in polyanionic cellulose (PAC) solution and weitghted water-based drilling fluids. In viscosity-shear rate test, both Laponite and bentonite could translate 0.5 wt.% PAC solution from Newton fluids to yield-pseudoplastic fluid. However, 1 wt.% Laponite was better in improving the shear-thinning behavior compared with 4 wt.% bentonite. In the stress-shear rate test, the results were fit with Bingham model with a high R2, and 1 wt.% Laponite/0.5 wt.% PAC suspension had a yield point of 5.19 Pa, which was higher than that of 4 wt.% bentonite/0.5 wt.% PAC suspension (3.13 Pa). Similarly, 1 wt.% Laponite/0.5 wt.% PAC suspension maintained a G’ of 12 Pa in the oscillation frequency sweep test, whereas G’ of 4%bentonite/0.5%PAC suspension was nearly 5 Pa. Particularly, 0.5 wt.% PAC /Laponite suspensions could maintain higher gel structure, yield point and better shear-thinning behaviors after 120°C hot rolling. The TEM image revealed that nanoscaled Laponite could form a “star network” with PAC in water, which explained the good rheological properties of PAC/LAP mixed suspensions. Besides, in the weighted drilling fluids, 1 wt.% Laponite could maintained a much higher gel strength compared with 4 wt.% bentonite.As the unique rheological properties, Laponite nanoparticles can greatly enhance abilities of water-based drilling fluids in circulating cuttings and making the borehole clean.
The Synthesis of Super-Hydrophobic Nano-Silica and its Effect to the Surface Wettability of Sandstone
Authors: Ni Xiao Xiao , Jiang Guang Cheng , Yang Li Li
Published: March 2018

In this paper, the researcher synthesis a super-hydrophobic nanosilica to alter the wettability of the sandstone surface from hydrophilic to super-hydrophobic. Fourier transform infrared (FTIR), Thermogravimetric analysis (TGA), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) were used to test the characterization of the products, and the wettability were examined by contact angle measurement, glass capillary tube rise measurement and spontaneous imbibition tests. The results shows that the water contact angle is over 150°,the liquid level is down to-42mm and the spontaneous volume is only 0.025mL after the surface modified with super-hydrophobic nanosilica which means the surface wettability is altered to be super-hydrophobic.
Synthesis and Characterization of Nanocrystalline M-Mg-O and Carbon-Coated MgO Systems
Authors: Karnaukhov Timofey , Vedyagin Aleksey , Mishakov Ilya , Bedilo Alexander , Volodin Alexander
Published: March 2018

Two different approaches to modify the structure and reaction ability of nanocrystalline MgO have been discussed. In the first case, a series of two-component x%MOx–MgO systems (M = Fe, Co and Ni, x = 1–45 wt.%) was synthesized via sol–gel technique. Aqueous solution of inorganic salt precursor was used as a hydrolyzing agent. Samples obtained were characterized by number of physicochemical methods (differential thermal analysis, X-ray diffraction analysis, low-temperature adsorption, etc.). It was shown that presence of inorganic salt in magnesium hydroxide matrix shifts the temperature of decomposition of latter towards lower values. Structural and textural characteristics of MgO-based oxide systems were found to be strongly affected by the presence of additive and their concentration. Formation of joint phase was observed in the case of cobalt oxide only. Second way of MgO modification was represented by creating a controlled carbon coating over its surface via decomposition of C4H10 at 400 °C. The obtained x%C/MgO (x = 1–10 wt.%) samples were shown to possess the improved reaction ability in destruction sorption of CF2Cl2 as well as in catalytic dehydrochlorination of 1-chlorobutane in presence of water vapors.
Selective Grain Growth and Grain Boundary Character Distribution Relationships in Magnetostrictive Fe-Ga Thin Sheets
Authors: Na Suok Min , Jones Nicholas J. , Flatau Alison B.
Published: March 2018

Grain growth and grain boundary character distribution relationships in Fe-Ga rolled sheet is investigated to study the influence of H2S gas content in argon on the development of selective grain growth through secondary recrystallization. Abnormal growth of (011) grains was predominant at the low content of H2S gas, while (113) grain growth was well developed at contents higher than 1.33% H2S. On the other hand, the development of (001) grains was challenging to produce because it is very sensitive to the anneal environment and has a relatively low fraction of high energy grain boundaries associated with misorientation angles that determine the mobility of boundaries.
Effect of Cold Rolling on the Microstructure and Hardness of Al5Cr12Fe35Mn28Ni20 High Entropy Alloy
Authors: Elkatatny Sally , Gepreel Mohamed Abdel Hady , Hamada Atef
Published: March 2018

The microstructure and hardness changes of a non-equiatomic Al5Cr12Fe35Mn28Ni20high-entropy-alloys (HEA) with cold rolling are presented here. Using a variety of characterization methods, it is shown that the alloy is single FCC phase structure which doesn't change with cold rolling up to90%CR. With increasing the cold rolling reduction ratio, the hardness increased and the dendritic structures are broken and refined.
Servo Forging Technology and Mold Development of the Pulley of AISI-1010 Low Carbon Steel
Authors: Yang Tung Sheng , Wang Chun , Liu Li Xiu , Yao Shuen Huei
Published: March 2018

Aimed at AISI-1010 low carbon steel pulley components, a finite element method-based metal forming simulation software of DEFORM 3D was used to simulate and analyze the near net forging process for the low carbon steel pulley, and to design forging molds. This technology was used in the pulley tooth forging in conjunction with the servo press-based servo motion curve technology. First, the cold forging process of the pulley preform forging and the near net forging were simulated. Also, the applications of the pulse wave servo motion curve in the pulley tooth forging was simulated, which was compared with the traditional motion curve-based forging forming, where the comparisons focused on the maximum forming force and maximum equivalent stress. The results indicated that the maximum forming force and the maximum equivalent stress of the punch caused by the pulse wave servo motion curve was smaller than caused by the traditional motion curve.
Effects of Formulation and Temperature on the Rheological Behavior of Nitroguanidine-Based Propellants
Authors: Shen Wan Wu , Nan Feng Qiang , Zhu Chun Jiu , Lu Jun Hui
Published: March 2018

The rheological properties of propellant are several key factors in the process design, which affect the quality of propellant processing that determines the weapon's performance. The main technological parameters influencing the quality of nitroguanidine-based propellant are nitroguanidine (NGu) content, solvent ratio and temperature. Rheological test of the propellant dough was carried out by using capillary rheometer. The effects of these main process parameters on the shear stress and shear viscosity of the propellant during the rheological process were discussed. Power law model, modified Bingham model and Cross model were used to fit the rheological data. The results show that Power law model is better than the other two models, explaining Power law model can be used as the constitutive equation to describe the actual rheological behavior of the propellant extrusion moulding more accurately.
Dynamic Mechanical Thermal Analysis of High Density Polyethylene Reinforced with Nanodiamond, Carbon Nanotube and Graphite Nanoplatelet
Authors: Kumar Sahu Santosh , Dhar Badgayan Nitesh , Samanta Sutanu , Rama Sreekanth Pattela Srinivasa
Published: March 2018

Present work reports on Dynamic Mechanical Thermal Analysis (DMTA) of HDPE reinforced with surface modified 0D (Nanodiamonds-NDs), 1D (Multi Walled Carbon Nanotubes-MWCNTs) and 2D (Graphite nanoplatelets-GNPs) nanofillers. Composite samples were prepared using twin screw injection moulding machine. Dynamic properties like storage, loss modulus and tan delta were investigated as a function of temperature and at constant oscillation of 1 Hz. Optimum properties were exhibited by 0.1 CNT/HDPE during a temperature swept from 30 to 110 oC. The storage modulus and loss modulus of 0.1 CNT/HDPE increased by 57 and 28% on comparison with pure HDPE. 0.1 CNT/HDPE exhibited highest ascent during tan delta evaluation confirming good damping property. TEM analysis was carried out to investigate the morphology of ND, MWCNT and GNP.
Multi-Objective Optimization of Bi-Layer Metallic Sheet Using Pareto-Based Genetic Algorithm
Authors: Darabi Roya , Azodi Hamed Deilami , Jung Dong Won
Published: March 2018

The bi-layer materials have been used widely during past decades due to their specific characteristics like lighter weight, more corrosion resistance, and insulation features in comparison with mono-layers which consisting them. In this research the aim is achieving to best combination of bi-layer material (Al3105-St14) to satisfy two objectives of weight and formability while it has a constant total thickness. The represent the formability objective and is derived from M-K model associated with Barlat-Lian yield criteria. Another objective is weight of per unit area. The data of experiments are designed based on full factorial method and the surfaces are best polynomial which can fit the variables and objectives. The MATLAB software and the genetic algorithm (GA) are used to generate feasible combination of thickness to provide to minimize the weight and maximize the formability. The Pareto frontier is utilized to satisfy two objective functions simultaneously. The best answer is selected with norm approaching and minimum distance method.
Effect of Heat Treatment Condition on the Characteristics of MnO2 Added-Fe2TiO5 Ceramics for NTC Thermistors Using Local Iron Oxide
Authors: Wiendartun  , Kamal Jaenudin , Rusdiana Dadi , Setiawan Andhy , Syarief Dani Gustaman
Published: March 2018

A study on the effect of heat treatment condition on the characteristics of MnO2 added-Fe2TiO5 ceramics for NTC thermistor has been carried out. The ceramics were produced by pressing an homogenous mixture of Fe2O3 (local/ yarosite), TiO2 and MnO2 (2.0 mole %) powders in appropriate proportions to produce Fe2TiO5 based ceramics and sintering the pressed powder at 1050 °C for 3 hours in oxygen gas. Some sintered pellets were heat treated by heating them at 300 °C for 5, 15 and 25 minutes in Ar + 7% H2 gas. The XRD analyses showed that the Fe2TiO5 ceramics with and without heat treatment time had orthorhombic structure. No peak from second phase was observed from the XRD profiles. From the electrical characteristics data, it was known that the heat treatment could change the electrical characteristics of the Fe2TiO5 based-thermistor. The thermistor constant (B) and room temperature resistivity (ρRT) decreased with the increasing of heat treatment time. All ceramics made had thermistor characteristics namely B = 3459-7596 K and ρRT = 1.056-6936.062 MΩcm. Thermistor constant of the ceramics was relatively big, indicated that ceramics made from local iron oxide in this work fit the market requirement for NTC thermistor.
Preparation of Nano-Structured Cathode for Proton-Conducting Fuel Cell by Dispersing Agent-Assisted Sol-Gel Method
Authors: Ismail Ismariza , Md Jani Abdul Mutalib , Osman Nafisah
Published: March 2018

The development of high-performance cathodes is essential towards the operation of proton-conducting fuel cells (PCFCs) at intermediate temperatures. To that end, the performance of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) cathodes is very attractive. In the present works, LSCF cathode powders were synthesized by a sol-gel method with the aid of ethylene glycol which served as the dispersing agent. The pristine and modified samples were each denoted as LSCF64 and LSCF-EG5. The phase formation and morphology of the cathode powders were examined by X-Ray diffractometer (XRD) and field emission scanning electron microscopy (FESEM), respectively. In order to evaluate the cathode performance, a symmetrical cell of electrolyte supported PCFCs were examined using an electrochemical impedance spectroscopy (EIS) at a 700 oC in atmosphere containing humidified air. The formation of LSCF single phase was attained at 700 °C for both prepared samples. The FESEM images confirms an improvement in the microstructure of the modified cathode. The impedance spectra obtained from the electrochemical impedance measurement were resolved by a fitting procedure using an equivalent circuit that consists of a combination of two parallel pairs of resistor-constant phase element (R-Q) in series. The area specific resistance (ASR) determined for LSCF64 and LSCF-EG5 is 1.55 and 0.23 Ωcm2 , respectively. The better performance exhibited by LSCF-EG5 is attributed to its higher cathode reaction site due the improved microstucture. This study reveals that the application of ethylene glycol as dispersing agent is effective in producing a high quality cathode material for better PCFCs performance.
Experimental Investigations of Bulge Formation for Burnishing on Plain Surfaces
Authors: Putz Matthias , Dix Martin , Stöckmann Rico
Published: March 2018

Burnishing as a forming finishing process enables the production of precise and mechanical compressed surfaces. The forming operation can be easily integrated into cutting processes due to its kinematic similarities. Through this integration it was possible to create highly efficient process chains for the machining of rotational symmetrical parts. The formed surface qualities are also interesting for prismatic geometries, but the adaptation of this force controlled process is challenging, because of its multiaxial characteristics. A main limiting factor for burnishing on plain surfaces is the formation of a burnishing bulge on the edges of the burnished area. Several investigations of the process on plain surfaces where done to analyse the bulge formation characteristics of the aluminium EN AW-2007 material. Experiments of different single burnished paths and burnished areas with the subsequent 3D capturing of the created surfaces were done. The investigations show, that the deformation is highly dependent on the applied burnishing force and the burnishing feed. The length and width of the burnished area does not have an influence on the bulge formation.
Optimization of Tooling Design for Hot Mandrel Bending of Pipe Elbows
Authors: Diekmann Uwe , Homberg Werner , Prehm Jens , Rostek Tim , Schönhoff Nils , Tabakajew Dmitri , Trasca Andreea , Uysal Haris
Published: March 2018

This paper presents the finite element model developed for the simulation of pipe elbow production by the so-called ‘Hamburg process’ in order to improve productivity and resource efficiency. To optimize the tooling design, a sensitivity analysis of the tool parameters that influence the quality of pipe elbows, such as mandrel height and length, is conducted. Different materials data sets including damage models were considered. Using numerical simulations, it is possible to determine an optimized tool geometry for the production of specific pipe elbow dimensions. Furthermore, as a result of the experiments and numerical simulations conducted, it is possible to increase the production velocity of the serial plant. Along with deformation, damage models are included in simulations in order to identify the right process boundaries. Finally, an experimentally validated model is developed for increasing resource efficiency in pipe elbow fabrication.
Preparation of Novel Al-Er Master Alloys in Chloride-Fluoride Melt
Authors: Kosov Yaroslav Igorevich , Bazhin Vladimir Yuryevich
Published: March 2018

A novel Al-Er master alloy has been prepared through in situ metallothermic reactions of NaErF4 and aluminium melts. The compound NaErF4 is formed as a result of the interaction of NaF and ErF3 in the melt medium KCl. The metallothermic reactions produce erbium, which through low solubility in molten aluminium and forms intermetallic compound Al3Er. The microstructures of the Al-Er master alloy with different contents of the alloying metal has been investigated. The results showed that the Al-Er master alloy mainly consisted of phases of α-Al and Al3Er, that confirmed by the results of X-ray diffraction. Backscattered electron imaging of the Al-Er master alloy under a scanning electron microscope (SEM) revealed the presence of phase Al3Er, which crystallized in the eutectic composition [Al+Al3Er]. The observed microstructure is explained according to the eutectic reaction in an Al-Er phase diagram. The preparation of Al-Er master alloy by the metallothermic reduction method will allow to reduce energy consumption for master alloy production and to reduce the cost of aluminium alloys alloyed with Er through the novel master alloy.
Development of an Innovative and Quality-Focused Production Technology for Magnesium Wire
Authors: Moses Marie , Kawalla Claudia , Kawalla Rudolf , Höck Michael
Published: March 2018

In order to meet customer requirements, technology developments need to stay focused at process rationalization and quality improvements. Combining the twin-roll casting technology and caliber rolling technology for magnesium wire, customer demands concerning cost-efficiency and high quality can be satisfied. The resulting long products can be applied in the automotive industry and aircraft sector as joining and welding elements or in biomedicine as screws. For this purpose, the paper analyzes potential application fields and their induced quality properties. Special requirements of illustrative magnesium long products are shown by adapting existing requirements of aluminum wire. Finally, the innovative magnesium wire production technology will be explained and the advantages, in particular the resource efficiency, of the developed technology will be discussed.
Asymmetric Twin-Roll Casting of an Al-Mg-Si-Alloy
Authors: Grydin Olexandr , Stolbchenko Mykhailo , Bauer Maria , Schaper Mirko
Published: March 2018

The industrial application of high-alloyed Al-Mg-Si alloys for the production of thin strips by means of twin-roll casting is limited due to the structural inhomogeneity and segregation formation. To reach the highest mechanical properties of the finished product, a direct influence on the strip formation conditions during the twin-roll casting can be applied. Analogous to the asymmetric rolling process, additional shear stresses were created in the strip forming zone by using different circumferential velocities and torques of the caster rolls. To provide the asymmetric process conditions, only one caster roll was left driven and the second one was left idling during the casting process. The microstructure and the mechanical properties of the strips in the as-cast state as well as after the homogenization and subsequent age-hardening were analyzed. A comparison of the test results showed a positive influence of the asymmetry conditions on the strips’ properties.
Repeatability of macular thickness measurements with the iVue-100 optical coherence tomographer
Authors: Rampersad Nishanee , Hansraj Rekha
Published: March 2018

Background: The reliability of an instrument is dependent on its accuracy and repeatability. The iVue-100 optical coherence tomographer (OCT) is a spectral domain device that has the advantage of being able to measure both the anterior and posterior segments of the eye. But its repeatability for macular thickness measurements has not been assessed and this was the primary purpose of this study.Aim: To determine the repeatability of the iVue-100 OCT for macular thickness measurements.Settings: This study was conducted at the University of KwaZulu-Natal.Methods: Repeatability (intra-observer, inter-observer and inter-session) of the iVue-100 OCT was assessed on 50 participants selected using convenience sampling. Data were statistically analysed using Bland–Altman analysis, the intra-class correlation coefficient (ICC), coefficient of variation and the paired t-test.Results: The mean age and standard deviation for the 50 participants were 23.88 ± 6.93 years (range 18–51 years). The ICCs for intra-observer repeatability ranged between 0.940 and 0.989, whereas the coefficients of variation ranged between 0.040 and 0.084. For both inter-observer and inter-session repeatability, the t-test showed no statistically significant differences (p > 0.05), and Bland–Altman analysis found the majority of the measurements to be within the 95% limits of agreement.Conclusion: Irrespective of whether repeated measurements are being taken consecutively by the same examiner, by a different observer or at a different time, the iVue-100 OCT is highly reliable in terms of repeatability which is of paramount importance in any clinical or research setting.
The role of the church in the #FeesMustFall movement in South Africa: Practical Theological reflection
Authors: Kgatle Mookgo S.
Published: March 2018

In 2015 and 2016, South Africa experienced one of the unique student-led protests since the dawn of democracy that touched the world, the #FeesMustFall movement. Out of the many demands that the students made in the movement, one is outstanding, fee-free higher education. A large number of publications have been written on the movement from an economical and educational point of view. Most of these publications argue that a fee-free higher education for all students is not an affordable or sustainable option for South Africa at the moment. What is new in this article is a practical theological reflection on the movement in general and the demand for a fee-free higher education by students in particular. The article looks at the possibilities of fee-free higher education for the poor students in South Africa by exploring the roles of the church in the #FeesMustFall movement.
Jesus and Mehr recognition according to oriental sources
Authors: Rokhzadi Amir A. , Shafei Kaivan
Published: March 2018

Early oriental historians have used two series of sources about ancient history of Iran, including Iranian and non-Iranian sources. As these sources are independent of each other, two different chronologies about these ancient periods have arisen. Naturally, this duality has led to different and contradictory results about dating important events of this period. One of them is the contradictory reports about two separate religious personalities – Messiah Mehr and Jesus of Nazareth. Despite the fact that these historians have taken the identity and time of appearance of Messiah Mehr and Jesus from the abovementioned two sources, they unknowingly considered the two characters as one and the same person. Al-Mas’udi is one of the earlier oriental historians who made remarkable reports and points regarding the alterations of political and religious history of the Ashkanian dynasty by the earlier Sasanians. These alterations caused the reality of Messiah Mehr to be concealed. This article tries to explain briefly the reasons for this topic through the viewpoints of oriental historians with emphasis on Al-Mas’udi’s reports.
The political ecology of stakeholder-driven climate change adaptation: Case study from Ntalale ward, Gwanda district, in Zimbabwe
Authors: Mbereko Alexio , Chimbari Moses J. , Mukaratirwa Samson
Published: March 2018

Vulnerable rural communities face climate change-related shifts in rainfall patterns, particularly droughts and floods. The study investigated how Ntalale ward households in Gwanda district of Zimbabwe interpret climate change and adapt to its stressors in the context of the Zimbabwean political economy. Focus group discussions and interviews collected qualitative data. The community has experienced the following climate change-related risks: droughts, floods, heatwave and intra-seasonal rainfall variability. Droughts were reported to be occurring more frequent in the past 25 years as compared to the period before 1991. Ntalale area experienced floods in the 2002–2003 rainy season only. Respondents generally perceived that the rainy season had changed in the past 5 years, with the season now beginning in December and ending in March. The households have resorted to shifting cultivation practices, replanting, use of wetlands in preference to upland fields, changing of seed varieties or crops, selling of livestock and informal trading as coping strategies. Although non-governmental organisations have assisted the community to set up irrigation schemes, a few selected community members have benefited from the initiative. The Ntalale community has experienced four climate change-related risks and institutions have assisted the community. It is recommended that cooperation between households and institutions is key in developing stakeholder-driven adaptation strategies.
Statistical analysis of annual maximum daily rainfall for Nelspruit and its environs
Authors: Masereka Eric M. , Ochieng George M. , Snyman Jacques
Published: March 2018

Nelspruit and its environs frequently experience extreme high annual maximum daily rainfall (AMDR) events resulting in flood hazards. These flood hazards have caused flood disasters that have resulted in loss of property and lives. The main objective of this study was to carry out statistical analysis of extreme high AMDR events that have caused flood hazards, which in turn have caused flood disasters in Nelspruit and its environs. Empirical continuous probability distribution functions (ECPDF) and theoretical continuous probability distribution functions (TCPDF) were applied to carry out the statistical analysis of the extreme high AMDR events. Annual maximum daily rainfall event of magnitude 100 mm was identified as a threshold. Events > 100 mm were considered as extreme high events resulting in flood disasters. The results of empirical frequency analysis showed that the return period of flood disasters was 10 years. The occurrence probability of flood disaster event at least once in 1, 2, 3, 4 and 5 years was 0.10, 0.19, 0.27, 0.34 and 0.41, respectively. Generalised logistic PDF was identified as the best-fit theoretical PDF for statistical analysis of the extreme high AMDR events in Nelspruit and its environs. The results of this study contributed to the understanding of frequency and magnitude of extreme high AMDR events that could lead to flood disasters. The results could be applied in developing flood disaster management strategies in Nelspruit and its environs.
The relationship between readiness to change and work engagement: A case study in an accounting firm undergoing change
Authors: Matthysen Megan , Harris Chantel
Published: March 2018

Orientation: Readiness to change is a critical element for the successful implementation of organisational change. Work engagement ensures that employees are committed to the organisations’ goals and is an important driver for organisational success. It is important that organisations sustain work engagement during organisational changes.Research purpose: To investigate the relationship between readiness to change and work engagement within an accounting firm.Motivation for the study: A change process can only be implemented successfully if there is a level of readiness to change. When readiness exists, resistance to change is reduced. Engaged employees remain enthusiastic about their organisation and choose to remain with the organisation. Change agents need to consider work engagement as an integral part of the change process, that is, before, during and after change has taken place. Work engagement and readiness to change are important elements for successful organisational change.Research design, approach and method: A cross-sectional survey design was utilised to collect the data. A convenience sample of employees and top management from the accounting firm (n = 340) were included. Cronbach’s alpha coefficients, Pearson’s product-moment correlations, analysis of variance (ANOVA), Scheffé tests, confirmatory factor analysis and structural equation modelling were used to analyse the data.Main findings: Results indicated a practical and statistically significant relationship between readiness to change and work engagement. High levels of work engagement will generate high levels of readiness to change. Further to this, readiness to change is influenced by employees’ work engagement and an organisation’s change processes.Practical or managerial implications: An employee’s work engagement and an organisation’s processes of change influence an employee’s readiness to change. Therefore, organisations need to sustain work engagement and improve change processes.Contribution: The contribution of this study is that it has provided new insights into the relationships between readiness to change and work engagement in a South African context.
Type I Kounis syndrome variant: A case report and literature review
Authors: Haddad Abdullah , Smith Triston , Bole Aneel , Shah Moneal , Chakravarthy Mithun
Published: March 2018

Kounis syndrome defined as the occurrence of acute coronary syndrome in the setting of allergic reaction due to mast cells activation and inflammatory mediators release that induces coronary vasospasm, plaque erosion, or even stent thrombosis. A 25-year-old postpartum female with asthma and recurrent episodes of chest pain was admitted with ST-segment elevation myocardial infarction in the setting of coronary artery spasms. The patient was started on calcium channel blockers and nitrite-based medication with no improvement. She was noted to have eosinophilia and initiation of corticosteroid-based regimen lead to resolution of chest pain episodes and normalization of eosinophilia. Kounis syndrome should be considered in young patients with chest pain. Coronary vasodilators are considered as the first-line of treatment. The use of corticosteroids has been described in the literature in severe or refractory cases.
The Islamic tradition and health inequities: A preliminary conceptual model based on a systematic literature review of Muslim health-care disparities
Authors: Padela Aasim I. , Zaidi Danish
Published: March 2018

Objective: The objective of this study was to identify mechanisms by which Islamic beliefs, values, and Muslim identity might contribute to health inequities among Muslim populations. Methods: A systematic literature review of empirical studies in Medline from 1980 to 2009 was conducted. The search strategy used three terms covering health-care disparities, ethnicity, and location to uncover relevant papers. Results A total of 171 articles were relevant based on titles and abstracts. Upon subsequent full-text review, most studies did not include religious identity or religiosity as explanatory variables for observed health disparities. Of 29 studies mentioning Islam within the text, 19 implicated Muslim identity or practices as potential explanations for health differences between Muslim and non-Muslim groups. These 19 studies generated six mechanisms that related the Islamic tradition, Muslim practices, and health inequities: (1) Interpretations of health and/or lack of health based on Islamic theology; (2) Ethical and/or cultural challenges within the clinical realm stemming from Islamic values or practices; (3) Perceived discrimination due to, or a lack of cultural accommodation of, religious values or practices in the clinical realm; (4) Health practices rooted within the Islamic tradition; (5) Patterns of health-care seeking based on Islamic values; and (6) Adverse health exposures due to having a Muslim identity. Conclusion: While there is scant empirical research on Muslim health-care disparities, a preliminary conceptual model relating Islam to health inequities can be built from the extant literature. This model can serve to organize research on Muslim health and distinguish different ways in which a Muslim identity might contribute to the patterning of health disparities.
Malignant Peripheral Nerve Sheath Tumor of the Pelvic Retroperitoneum Misdiagnosed as Carcinoma Ovary
Authors: Subbaiah Murali , Badhe Bhawna A , Dorairajan Gowri , Dehuri Priyadarshini
Published: March 2018

A 52-year-old postmenopausal female was found to have a large solid cystic adnexal mass, compressing the right ureter, and was suspected to have carcinoma ovary. However, it turned out to be a retroperitoneal neurogenic tumor. Malignant peripheral nerve sheath tumors (MPNST) may have cystic areas and may be misdiagnosed as ovarian tumors. Treatment of MPNST involves complete surgical excision of the tumor with a wide margin.
Nonsteroidal Anti-inflammatory Drugs and Clinical Outcomes among Men with Prostate Cancer: A Systematic Review and Meta-analysis
Authors: Thakker Divyesh , Raval Amit D , Raval Nilixa , Vyas Ami
Published: March 2018

Background: Nonsteroidal anti-inflammatory drugs (NSAIDs) have shown properties of inhibiting the progression of prostate cancer (PCa) in preclinical studies. However, epidemiological studies yield mixed results on the effectiveness of NSAIDs in PCa. Objective: The objective of this study was to determine the effect of NSAID use on clinical outcomes in PCa using systematic review and meta-analysis. Methods: Original articles published until the 1st week of October, 2016, were searched in electronic databases (Medline-Ovid, PubMed, Scopus, The Cochrane Library, and Web of Science) for studies on NSAID use in PCa. The main clinical outcomes for the review were: PCa-specific (PCM) and all-cause mortality (ACM), biochemical recurrence (BCR), and metastases. Meta-analysis was performed to calculate the pooled hazard ratio (pHR) and their 95% confidence interval (95% CI). Heterogeneity between the studies was examined using I2 statistics. Appropriate subgroup analyses were conducted to explore the reasons for heterogeneity. Results: Out of 4216 retrieved citations, 24 observational studies and two randomized controlled studies with a total of 89,436 men with PCa met the inclusion criteria. Overall, any NSAID use was not associated with PCM, ACM, and BCR, with significant heterogeneity. Neither precancer treatment aspirin use (pHR: 1.00, 95% CI: 0.83, 1.19, P = 0.97, 5 studies, I2: 51%) nor postcancer treatment aspirin use (pHR: 0.94, 95% CI: 0.72, 1.23, P = 0.67, 8 studies, I2: 86%) was associated with PCM. Similar findings, that is, no significant association was observed for NSAID use and ACM or BCR overall, and in subgroup by types of NSAID use, and NSAID use following radiation or surgery. Conclusion: Although NSAID use was not associated with ACM, PCM, or BCR among men with PCa, significant heterogeneity remained in the included studies even after subgroup analyses.
CT-guided Lung Fine Needle Aspiration Biopsy: Analysis of Efficacy, Yield and Intricacies
Authors: Nair Anirudh V , Anirudh Soumya , Moorthy Srikanth , Cyril P , Rajamma Bindhu Mangalath , Ramachandran PV
Published: March 2018

Aim: This study aims to evaluate various factors that affect the cytological yield while performing computed tomography (CT) guided lung fine needle aspiration biopsy and to determine the complication rate of this procedure. Materials and Methods: In this cross sectional study, we analyzed 70 patients undergoing CT-guided transthoracic lung fine-needle aspiration biopsy (FNAB). 22-gauge spinal needle was used in sixty patients and 20-gauge in ten patients. The presence and absence of an onsite cytopathologist affecting the adequacy of yield for a conclusive cytodiagnosis was compared in groups of 35 patients each. The incidence of complications such as pneumothorax, pulmonary hemorrhage was recorded. Results: Cytological yield was adequate for a conclusive cytodiagnosis in 59 cases (84.2%). Thirty-seven cases (52.8%) were malignant with adenocarcinoma (70.2%) being the most common, 22 cases (31.4%) had benign etiology. Cytological yield was adequate for a conclusive diagnosis in the group (n = 35) with an onsite cytopathologist (100%) compared with those cases without an onsite cytopathologist (68.6%) (P = 0.005). Pneumothorax was observed in 16 cases (22.8%), the incidence of pneumothorax was higher when there was an intervening parenchyma (P = 0.005). Conclusion: CT-guided transthoracic FNAB is an accurate method to rule out malignancy with a reasonable rate of complications. The presence of an onsite-cytopathologist significantly improves the adequacy of yield for a conclusive cytodiagnosis, and should be routinely employed. Pneumothorax and pulmonary hemorrhage are the most common complications as a result of FNAB. The incidence of pneumothorax is higher when there is intervening lung parenchyma.
Cancer of Unknown Primary: Opportunities and Challenges
Authors: Rajeev L K , Asati Vikas , Lokesh K N , Rudresh A H , Babu Suresh , Jacob Linu Abraham , Lokanatha D , Babu Govind , Lakshmaiah K C
Published: March 2018

Cancer of unknown primary (CUP) is defined as histologically proven metastatic tumors whose primary site cannot be identified during pretreatment evaluation. Among all malignancies, 3%–5% remained as CUP even after the extensive radiological and pathological workup. Immunohistochemistry and molecular gene expression tumor profiling are being utilized to predict the tissue of origin. Unfortunately, the survival of these patients remains poor (6–9 months) except in 20% of patients who belong to a favorable subset (12–36 months). There is a need to understand the basic biology and to identify the molecular pathways which can be targeted with small molecules. This article reviews our current approach as well as treatment evolution occurred in the past three decades.
Neoadjuvant Chemotherapy for Larynx Preservation: Has it Lost Importance?
Authors: Benson Rony , Mallick Supriya , Rath G K
Published: March 2018

Over the time, the aim of treatment for locally advanced laryngeal and hypopharyngeal carcinoma has changed from cure to cure with the functional larynx. Chemoradiation has emerged as the most important therapeutic modality for patients with locally advanced disease. However, systemic failure remains an important area of concern. Induction chemotherapy has emerged as promising organ preservation approach as it gives an window to select responders and continuing treatment with nonsurgical approach as well as reduces systemic recurrence and improve survival with a functional larynx. However, there are questions about the efficacy of this approach. In this context, we aim to evaluate the trials for locally advanced laryngeal and hypopharyngeal cancer attempting to optimize therapeutic outcome with addition of induction chemotherapy. This present review intends to look into the therapeutic ratio of induction chemotherapy for disease control, organ preservation.
Sources of PM2.5 carbonaceous aerosol in Riyadh, Saudi Arabia
Authors: Bian Qijing , Alharbi Badr , Shareef Mohammed M. , Husain Tahir , Pasha Mohammad J. , Atwood Samuel A. , Kreidenweis Sonia M.
Published: March 2018

Abstract. Knowledge of the sources of carbonaceous aerosol affecting air quality in
Riyadh, Saudi Arabia, is limited but needed for the development of pollution
control strategies. We conducted sampling of PM2.5 from April to
September 2012 at various sites in the city and used a thermo-optical
semi-continuous method to quantify the organic carbon (OC) and elemental
carbon (EC) concentrations. The average OC and EC concentrations were
4.7 ± 4.4 and 2.1 ± 2.5 µg m−3, respectively, during this
period. Both OC and EC concentrations had strong diurnal variations, with
peaks at 06:00–08:00 LT and 20:00–22:00 LT, attributed to the combined effect of increased
vehicle emissions during rush hour and the shallow boundary layer in the
early morning and at night. This finding suggested a significant influence of
local vehicular emissions on OC and EC. The OC ∕ EC ratio in primary emissions
was estimated to be 1.01, close to documented values for diesel emissions.
Estimated primary organic carbon (POC) and secondary organic carbon (SOC) concentrations
were comparable, with average concentrations of 2.0 ± 2.4 and 2.8 ± 3.4 µg m−3, respectively. We also collected 24 h samples of PM10 onto quartz microfiber
filters and analyzed these for an array of metals by inductively
coupled plasma atomic emission spectroscopy (ICP-AES). Total OC was
correlated with Ca (R2 of 0.63), suggesting that OC precursors and Ca
may have similar sources, and the possibility that they underwent similar
atmospheric processing. In addition to a ubiquitous dust source, Ca is
emitted during desalting processes in the numerous refineries in the region
and from cement kilns, suggesting these sources may also contribute to
observed OC concentrations in Riyadh. Concentration weighted trajectory
(CWT) analysis showed that high OC and EC concentrations were associated
with air masses arriving from the Persian Gulf and the region around
Baghdad, locations with high densities of oil fields and refineries as well
as a large Saudi Arabian cement plant. We further applied positive matrix
factorization to the aligned dataset of EC, OC, and metal concentrations
(Al, Ca, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, and V). Three factors were derived
and were proposed to be associated with oil combustion, industrial emissions
(Pb based), and a combined source from oil fields, cement production, and
local vehicular emissions. The dominant OC and EC source was the combined
source, contributing 3.9 µg m−3 (80 %) to observed OC and 1.9 µg m−3 (92 %) to observed EC.
Link between the Surface Mass Balance of the Greenland Ice Sheet
and the North Atlantic Oscillation under preindustrial and last
interglacial climates:
a study
with a
Coupled Global Circulation
Model
Authors: Ramos Buarque Silvana , Salas y Melia David
Published: March 2018

Abstract. The relationship between the Surface Mass Balance (SMB) of the Greenland Ice Sheet (GrIS) and the North Atlantic Oscillation (NAO) is examined from numerical simulations performed with a new atmospheric stretched grid configuration of the Centre National de Recherches Météorologiques – Coupled Model (CNRM-CM) version 5.2 under three periods : preindustrial climate, a warm phase (early Eemian, 130 ka BP) and a cool phase (glacial inception, 115 ka BP) of the last interglacial. The horizontal grid of the atmospheric component of CNRM-CM5.2 is stretched from the tilted pole on the Baffin Bay (72° N, 65° W) in order to obtain a higher spatial resolution on Greenland. The correlation between simulated SMB anomalies averaged over Greenland and the NAO index is weak in winter and significant in summer (about 0.6 for the three periods). In summer, spatial correlations between the NAO index and SMB display different patterns from one period to another. These differences are analysed in terms of the respective influence of the positive and negative phases of the NAO on accumulation and melting. Accumulation in South Greenland is significantly correlated with the positive (negative) phase of the NAO in a warm (cold) climate. Under preindustrial and 115 ka climates, melting along the margins is more correlated with the positive phase of the NAO than with its negative phase, whereas at 130 ka it is more correlated with the negative phase of the NAO in North and North-East Greenland.
Heinrich events show two-stage climate response in transient glacial simulations
Authors: Ziemen Florian Andreas , Kapsch Marie-Luise , Klockmann Marlene , Mikolajewicz Uwe
Published: March 2018

Abstract. Heinrich events are among the dominant modes of glacial climate variability. During these events, massive iceberg armadas were released by the Laurentide Ice Sheet, sailed across the Atlantic, and caused large-scale climate changes. We study these events in a fully coupled complex ice sheet–climate model with synchronous coupling between ice sheets and oceans. The ice discharges occur as internal variability of the model with a recurrence period of 5 kyr, an event duration of 1–1.5 kyr, and a peak discharge rate of about 50 mSv, roughly consistent with reconstructions. The climate response shows a two-stage behavior, with freshwater release effects dominating the surge phase and ice-sheet elevation effects dominating in the post-surge phase. As a direct response to the freshwater discharge during the surge phase, the deepwater formation in the North Atlantic decreases and the North Atlantic deepwater cell weakens by 3.5 Sv. With the reduced oceanic heat transport, the surface temperatures across the North Atlantic decrease, and the associated reduction in evaporation causes a drying in Europe. The ice discharge lowers the surface elevation in the Hudson Bay area and thus leads to increased precipitation and accelerated ice sheet regrowth in the post-surge phase. Furthermore, the jet stream widens to the north and becomes more zonal. This contributes to a weakening of the subpolar gyre, and a continued cooling over Europe even after the ice discharge. This two-stage behavior can explain previously contradicting model results and understandings of Heinrich Events.