Search results for: sodium sulphate attack resistance

Authors: Guneet Saini, Uthej Vattipalli

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In a world with increased demand for sustainable construction, waste product of one industry could be a boon to the other in reducing the carbon footprint. Usage of industrial waste such as fly ash and ground granulated blast furnace slag have become the epicenter of curbing the use of cement, one of the major contributors of greenhouse gases. In this paper, empirical studies have been done to develop alkali activated self-compacting geopolymer concrete (GPC) using ground granulated blast furnace slag (GGBS), incorporated with 2% nano-silica by weight, through evaluation of its fresh and hardening properties. Experimental investigation on 6 mix designs of varying molarity of 10M, 12M and 16M of the alkaline solution and a binder content of 450 kg/m³ and 500 kg/m³ has been done and juxtaposed with GPC mix design composed of 16M alkaline solution concentration and 500 kg/m³ binder content without nano-silica. The sodium silicate to sodium hydroxide ratio (SS/SH), alkaline activator liquid to binder ratio (AAL/B) and water to binder ratio (W/B), which significantly affect the performance and mechanical properties of GPC, were fixed at 2.5, 0.45 and 0.4 respectively. To catalyze the early stage geopolymerisation, oven curing is done maintaining the temperature at 60˚C. This paper also elucidates the test results for fresh self-compacting concrete (SCC) done as per EFNARC guidelines. The mechanical properties tests conducted were: compressive strength test after 7 days, 28 days, 56 days and 90 days; flexure test; split tensile strength test after 28 days, 56 days and 90 days; X-ray diffraction test to analyze the mechanical performance and sorptivity test for testing of permeability. The study revealed that the sample of 16M concentration of alkaline solution with 500 Kg/m³ binder content containing 2% nano silica produced the highest compressive, flexural and split tensile strength of 81.33 MPa, 7.875 MPa, and 6.398 MPa respectively, at the end of 90 days.

Keywords: alkaline activator liquid, geopolymer concrete, ground granulated blast furnace slag, nano silica, self compacting

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Authors: Dheeraj Sharma, Santosh Kumar Vishvakarma

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We present a detailed analysis of analog and radiofrequency (RF) performance with different gate lengths for nanowire cylindrical gate (CylG) gate-all-around (GAA) MOSFET. CylG GAA MOSFET not only suppresses the short channel effects (SCEs), it is also a good candidate for analog/RF device due to its high transconductance (gm) and high cutoff frequency (fT ). The presented work would be beneficial for a new generation of RF circuits and systems in a broad range of applications and operating frequency covering the RF spectrum. For this purpose, the analog/RF figures of merit for CylG GAA MOSFET is analyzed in terms of gate to source capacitance (Cgs), gate to drain capacitance (Cgd), transconductance generation factor gm = Id (where Id represents drain current), intrinsic gain, output resistance, fT, maximum frequency of oscillation (fmax) and gain bandwidth (GBW) product.

Keywords: Gate-All-Around MOSFET, GAA, output resistance, transconductance generation factor, intrinsic gain, cutoff frequency, fT

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Authors: T. A. Rosy, M. R. I. Talukdar, N. S. Juyena, F. Y. Bari, M. N. Islam

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The ovarian follicular dynamics, vaginal electrical resistance (VER) and progesterone (P4) and estrogen (E2) profiles were investigated during estrus cycle in four indigenous ewes. Daily VER values were recorded with heat detector. The follicles were observed and measured by trans-rectal ultrasonography. Blood was collected daily for hormonal profiles. Results showed a significant variation in VER values (P<0.05) at estrus in regards to ewes and cycles. The day difference between two successive lower values in VER waves ranged from 13-17 days which might indicate the estrus cycle in indigenous ewes. Trans-rectal ultrasonography of ovaries revealed the presence of two to four waves of follicular growth during the study period. Results also showed that follicular diameter was negatively correlated with VER values. Study of hormonal profiles by ELISA revealed a positive correlation between E2 concentration and development of follicle and negative correlation between P4 concentration and development of follicle. The concentrations of estradiol increased at the time of estrus and then fall down in a basal level. Development of follicular size was accompanied by an increase in the concentration of serum estradiol. Inversely, when follicles heed to ovulation concentration of progesterone starts to fall down and after ovulation it turns its way to the zenith and remains at this state until next ovulatory follicle comes to its maximum diameter. This study could help scientists to set up a manipulative reproductive technique for improving genetic values of sheep in Bangladesh.

Keywords: ovarian follicle, hormonal profile, sheep, ultrasonography, vaginal electrical resistance

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Authors: M. Simchi, M. Amiri, E. Rezvani, I. Mirzaei, M. Berahman, A. Simchi, M. Fardmanesh

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Graphene is a single-atomic two-dimensional crystal of carbon atoms that has considerable properties due to its unique structure and physics with applications in different fields. Graphene has sensitive electrical properties due to its atomic-thin structure. Along with the substrate materials and their influence on the transport properties in graphene, design and fabrication of graphene-based devices for biomedical and biosensor applications are challenging. In this work, large-area high-quality graphene nanosheets were prepared by low pressure chemical vapor deposition using methane gas as carbon source on copper foil and transferred on the biocompatible substrates. Through deposition of titanium and gold contacts, current-voltage response of the transferred graphene on four biocompatible substrates, including PDMS, SU-8, Nitrocellulose, and Kapton (Fig. 2) were experimentally determined. The considerable effect of the substrate type on the electrical properties of graphene is shown. The sheet resistance of graphene is changed from 0.34 to 14.5 kΩ/sq, depending on the substrate.

Keywords: biocompatible substrates, electrical properties, graphene, sheet resistance

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Authors: Lucian Mocan, Cristian Matea, Flaviu A. Tabaran, Teodora Mocan, Cornel Iancu

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Introduction: Due to antibiotic resistance, systemic infections caused by Meticilin resistant Staphyloccocous Aureus (MRSA) are the main cause of millions of deaths each year. Development of new active biomolecules that are highly effective and refractory to antibiotic resistance may open new avenues in the field of antimicrobial therapy. In this research, we have focused on the development of a novel nanobiosystem with high affinity for MRSA microorganism to mediate its selective laser thermal ablation. Materials and Methods: Gold nanoparticles (15nm in diameter) linked to a specific antibody against MRSA surface were selectively delivered (at various concentrations and incubation times) and internalized into MRSA microorganism following the treatment these multidrug-resistant bacteria were irradiated using a 2w, 808 nm LASER. Results and Discussions: The post-irradiation necrotic rate ranged from 51.2% (for 1 mg/L) to 87.3% (for 50 mg/L) at 60 seconds (p<0.001), while at 30 minute the necrotic rate increased from 64.3% (1 mg/L) to 92.1% (50 mg/L), p value<0.001. Significantly lower apoptotic rates were obtained in irradiated MRSA treated with GNPs only (control) treated for 60 seconds and 30 minutes at concentrations ranging from 1 mg/L to 50 mg/L. We show here that the optimal LASER mediated the necrotic effect of MRSA after incubation with anti-MRSA-Ab was obtained at a concentration of 50 mg/L. Conclusion: In the presented research, we obtained a very efficacious pulse laser mode treatment of individual MRSA agents with minimal effects on the surrounding medium, providing highly localized destruction only for MRSA microorganism.

Keywords: MRSA, photothermolysis, antibiotic resistance, gold nanoparticles

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Authors: Arash Sadeghi, Taimaz Larimian

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This study explores the intricate interplay between community-based social capital (CBSC) and neighbourhood dynamics in enhancing resilience of Iranian SMEs, particularly under the strain of international sanctions. Utilising fuzzy-set Qualitative Comparative Analysis (fsQCA), we examine how different dimensions of CBSC—structural, relational, and cognitive—interact with neighbourhood socio-economic and built-environment characteristics to influence SME resilience. Findings reveal four configurations that contribute to the presence of resistance and five configurations associated with the adaptation outcome. Each configuration demonstrates a distinct combination of social capital elements, which vary according to the specific socio-economic and built-environmental characteristics of the neighbourhoods. The first configuration highlights the importance of structural social capital in deprived areas for building resistance, while the second emphasises the role of relational social capital in low-density, minimally deprived areas. Overall, cognitive social capital seems to be less effective in driving economic resilience compared to structural and relational types. This research contributes to the literature by providing a nuanced understanding of the synergistic effects of CBSC dimensions and neighbourhood characteristics on SME resilience. By adopting a configurational approach, we move beyond traditional methodologies, offering a comprehensive view of the complex dynamics of CBSC and neighbourhood characteristics and their impact on SME resilience in varying neighbourhoods.

Keywords: community-based social capital, fuzzy-set qualitative comparative analysis (fsQCA), place-based resilience, resistance

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Authors: Çağla Aras, Kübra Bi̇nay, Aysberg Şamil önlü, Mine Baydan Aran, Dicle Aras

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The purpose of the present research was to investigate the acute effects of 30-min hatha yoga and 30-min resistance-based aerobic exercise (RBAE) on computerized dynamic posturography (CDP) and functional head impulse test (fHIT) scores in adult female yoga practitioners. To reach this aim, ten participants executed CDP and fHIT three times in total: at rest, after yoga, and after RBAE. The yoga practice lasted a total of 30 minutes, including 25 min of asanas and 5 minutes of savasana. RBAE lasted a total of 30 minutes with an intensity of 70-75% of the heart rate reserve method. When the results were examined, no change was observed in any parameters of the fHIT scores due to resting or exercise implementation. On the contrary, some changes were observed in CDP test results depending on the type of exercise. The post-RBAE somatosensory and visual systems values were higher than resting (p<0.05). The composite balance score derived after RBAE was found to be improved when compared to post-yoga and resting values (p<0.01). Lastly, the post-RBAE vestibular system score was found to be statistically significantly higher than the post-Yoga values. In addition, it was observed that body composition parameters, especially decreasing BW, LBM, PBF, MBF and TBW, were associated with improved postural stability values. According to the results, it can be stated that neither hatha yoga nor resistance-based aerobic exercise has an acute effect on functional vestibulo-ocular reflex. In addition, although there was no change in balance level after yoga, it was observed that RBAE performed at 70-75% of the heart rate reserve and for 30 minutes had positive acute effects on postural stability and balance.

Keywords: hatha yoga, resistance training, aerobic training, high intensity training, computerized dynamic posturography, functional head impulse test

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Authors: Zeynep Tanriverdi̇

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Sustainable architecture is a design approach that provides healthy, comfortable, safe, clean space production as well as utilizes minimum resources for efficient and economical use of natural resources and energy. Traditional houses located in rural areas are sustainable structures built at the design and implementation stage in accordance with the climatic environmental data of the region and also effectively using natural energy resources. The fact that these structures are located in an earthquake geography like Türkiye brings their earthquake resistance to the agenda. Since the construction of these structures, which contain the architectural and technological cultural knowledge of the past, is shaped according to the characteristics of the regions where they are located, their resistance to earthquakes also differs. Analyses in rural areas after the earthquake show that there are light-damaged structures that can survive, severely damaged structures, and completely destroyed structures. In this regard, experts can implement repair, consolidation, and reconstruction applications, respectively. While simple repair interventions are carried out in accordance with the original data in traditional houses that have shown great resistance to earthquakes, reinforcement work blended with new technologies can be applied in damaged structures. In reconstruction work, a wide variety of applications can be seen with the possibilities of modern technologies. In rural areas experiencing earthquakes around the world, there are experimental new housing applications that are renewable, environmentally friendly, and sustainable with modern construction techniques in the light of scientific data. With these new residences, it is aimed to create earthquake-resistant, economical, healthy, and pain-relieving therapy spaces for people whose daily lives have been interrupted by disasters. In this study, the preservation of high earthquake-prone rural areas will be discussed through the knowledge transfer of traditional architecture and also permanent housing practices using new sustainable technologies to improve the area. In this way, it will be possible to keep losses to a minimum with sustainable, reliable applications prepared for the worst aspects of the disaster situation and to establish a link between the knowledge of the past and the new technologies of the future.

Keywords: sustainability, conservation, traditional construction systems and materials, new technologies, earthquake resistance

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Authors: Mohammad Ali Badri, Pouya Molana, Amin Rezvanpour

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In this paper, planning catamaran and mono-hull vessels resistance and trim in calm waters were considered. Hydrodynamic analysis of fast mono-hull planning vessel was also investigated. In order to hull form geometry optimization, numerical methods of different parameters were used for this type of vessels. Hull material was selected in carbon fiber composite. Exact architectural aspects were specified and stability calculations were performed as well. Hydrodynamic calculations to extract the resistance force using semi-analytical methods and numerical modeling were carried out. Free surface numerical analysis of vessel in designed draft using finite volume method and double phase were evaluated and verified by experimental tests.

Keywords: fast vessel, hydrostatic and hydrodynamic optimization, free surface flow, computational fluid dynamics

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Authors: R. A. Ribeiro, P. D. Angelo Assunção, E. M. Braga

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The microhardness in weld beads is a function of the microstructure obtained in the welding process, and this by its time is dependent of the input variables established at the outset of the process. In this study the influence of angle between the plate and the cold wire, the position in which the cold wire is introduced and the rate in which this introduction is made are assessed as input parameters in CW-GMAW process. This paper looks to show that ordinary changes in the frame of CW-GMAW can improve microhardness, which is expected to vary as the input parameters change. To properly correlate the changes in the input parameters to consequent changes in microhardness of the weld bead, a full factorial design was employed. In fact, changes in the operational parameters improved the overall microhardness of the weld bead, which in turns can be an indication of improvement in the resistance to abrasive wear, constituting a cheap way to augment the abrasion wear resistance of welds used for cladding.

Keywords: abrasion, CW-GMAW, full factorial design, microhardness

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Authors: Mwafaq Ibdah, Mossab, Yahyaa, Dor Rachmany, Yoram Gerchman, Doron Holland, Liora Shaltiel-Harpaz

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Pear Psylla is the most important pest of pear in all pear-growing regions, in Asian, European, and the USA. Pear psylla damages pears in several ways: high-density populations of these insects can cause premature leaf and fruit drop, diminish plant growth, and reduce fruit size. In addition, their honeydew promotes sooty mold on leaves and russeting on fruit. Pear psyllas are also considered vectors of pear pathogens such as Candidatus Phytoplasma pyri causing pear decline that can lead to loss of crop and tree vigor, and sometimes loss of trees. Psylla control is a major obstacle to efficient integrated pest management. Recently we have identified two naturally resistance pear accessions (Py.760-261 and Py.701-202) in the Newe Ya’ar live collection. GC-MS volatile metabolic profiling identified several volatile compounds common in these accessions but lacking, or much less common, in a sensitive accession, the commercial Spadona variety. Among these volatiles were styrene and its derivatives. When the resistant accessions were used as inter-stock, the volatile compounds appear in commercial Spadona scion leaves, and it showed reduced susceptibility to pear psylla. Laboratory experiments and applications of some of these volatile compounds were very effective against psylla eggs, nymphs, and adults. The genes and enzymes involved in the specific reactions that lead to the biosynthesis of styrene in plant are unknown. We have identified a phenolic acid decarboxylase that catalyzes the formation of p-hydroxystyrene, which occurs as a styrene analog in resistant pear genotypes. The His-tagged and affinity chromatography purified E. coli-expressed pear PyPAD1 protein could decarboxylate p-coumaric acid and ferulic acid to p-hydroxystyrene and 3-methoxy-4-hydroxystyrene. In addition, PyPAD1 had the highest activity toward p-coumaric acid. Expression analysis of the PyPAD gene revealed that its expressed as expected, i.e., high when styrene levels and psylla resistance were high.

Keywords: pear Psylla, volatile, GC-MS, resistance

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Authors: Gusa Hall, Barrie Keeler, Achal Khanna

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Introduction: NICE guidelines have highlighted the consequences of IV fluid mismanagement. The main aim of this study was to audit fluid prescribing post laparotomies to identify if fluids were prescribed in accordance to NICE guidelines. Methodology: Retrospective database search of eight specific laparotomy procedures (colectomy right and left, Hartmann’s procedure, small bowel resection, perforated ulcer, abdominal perineal resection, anterior resection, pan proctocolectomy, subtotal colectomy) highlighted 29 laparotomies between April 2019 and May 2019. Two of 29 patients had secondary procedures during the same admission, n=27 (patients). Database case notes were reviewed for date of procedure, length of admission, fluid prescribed and amount, nasal gastric tube output, daily bloods results for electrolytes sodium and potassium and operational losses. Results: n=27 based on 27 identified patients between April 2019 – May 2019, 93% (25/27) received IV fluids, only 19% (5/27) received the correct IV fluids in accordance to NICE guidelines, 93% (25/27) who received IV fluids had the correct electrolytes levels (sodium & potassium), 100% (27/27) patients received blood tests (U&E’s) for correct electrolytes levels. 0% (0/27) no documentation on operational losses. IV fluids matched nasogastric tube output in 100% (3/3) of the number of patients that had a nasogastric tube in situ. Conclusion: A PubMed database literature review on barriers to safer IV prescribing highlighted educational interventions focused on prescriber knowledge rather than how to execute the prescribing task. This audit suggests IV fluids post laparotomies are not being prescribed consistently in accordance to NICE guidelines. Surgical management plans should be clearer on IV fluids and electrolytes requirements for the following 24 hours after the plan has been initiated. In addition, further teaching and training around IV prescribing is needed together with frequent surgical audits on IV fluid prescribing post-surgery to evaluate improvements.

Keywords: audit, IV Fluid prescribing, laparotomy, NICE guidelines

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Authors: D. W. Mohammed, J. Bowen, S. N. Kukureka

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Successful design and fabrication of flexible devices for electrode components requires a low sheet resistance, high optical transmittance, high mechanical reliability. Indium tin oxide (ITO) film is currently the predominant transparent conductive oxide (TCO) film in potential applications such as flexible organic light- emitting diodes, flat-panel displays, solar cells, and thin film transistors (TFTs). However ITO films are too brittle and their resistivity is rather high in some cases compared with ITO/Ag/ ITO, and they cannot completely meet flexible optoelectronic device requirements. Therefore, in this work the mechanical properties of ITO /Ag/ITO multilayer film that deposited on Polyethylene terephthalate (PET) compared with the single layered ITO sample were investigated using bending fatigue, twisting fatigue and thermal cycling experiments. The electrical resistance was monitored during the application of mechanical and thermal loads to see the pattern of relationship between the load and the electrical continuity as a consequent of failure. Scanning electron microscopy and atomic force microscopy were used to provide surface characterization of the mechanically-tested samples. The effective embedment of the Ag layer between upper and lower ITO films led to metallic conductivity and superior flexibility to the single ITO electrode, due to the high failure strain of the ductile Ag layer. These results indicate that flexible ITO/Ag/ITO multilayer electrodes are a promising candidate for use as transparent conductor in flexible displays. They provided significantly reduced sheet resistance compared to ITO, and improved bending and twisting properties both as a function of radius, angle and thermal cycling.

Keywords: ITO/Ag/ITO multilayer, failure strain, mechanical properties, PET

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Authors: C. Chhorn, S. H. Han, S. W. Lee

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Roller-compacted concrete (RCC) has been used for decades in many pavement applications due to its economic cost and high construction speed. However, due to the lack of deep researches and experiences, this material has not been widely employed. An RCC mixture with appropriate consistency can induce high compacted density, while high density can induce good aggregate interlock and high strength. Consistency of RCC is mainly known to define its constructability. However, it was not well specified how this property may affect other properties of a constructed RCC pavement (RCCP). This study suggested the possibility of an ideal range of consistency that may provide adequate quality of RCCP. In this research, five sections of RCCP consisted of both 13 mm and 19 mm aggregate sections were investigated. The effects of consistency on compacted depth, strength, international roughness index (IRI), skid resistance are examined. From this study, a new range of consistency is suggested for RCCP application.

Keywords: compacted depth, consistency, international roughness index (IRI), pavement, roller-compacted concrete (RCC), skid resistance, strength

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Authors: Rajeev Manhas, M. A. Bhat, A. K. Taku, Dalip Singh, Deep Shikha, Gulzar Bader

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The study was aimed to understand the distribution of various serogroups of Pasteurella multocida in bovines, small ruminants, pig, rabbit, and poultry from Jammu, Jammu and Kashmir and to characterize the isolates with respect to LPS synthesizing genes, dermonecrotic toxin gene (toxA) gene and antibiotic resistance. For isolation, the nasopharyngeal swab procedure appeared to be better than nasal swab procedure, particularly in ovine and swine. Out of 200 samples from different animals, isolation of P. multocida could be achieved from pig and sheep (5 each) and from poultry and buffalo (2 each) samples only, which accounted for 14 isolates. Upon molecular serogrouping, 3 isolates from sheep and 2 isolates from poultry were found as serogroup A, 2 isolates from buffalo were confirmed as serogroup B and 5 isolates from pig were found to belong to serogroup D. However, 2 isolates from sheep could not be typed, hence, untypable. All the 14 isolates were subjected to mPCR genotyping. A total of 10 isolates, 5 each from pig and sheep, generated an amplicon specific to genotype L6 and L6 indicates Heddleston serovars 10, 11, 12 and 15. Similarly, 2 isolates from bovines generated an amplicon of genotype L2 which indicates Heddleston serovar 2/5. However, 2 isolates from poultry generated specific amplicon with L1 signifying Heddleston serovar 1, but these isolates also produced multiple bands with primer L5. Only, one isolate of capsular type A from sheep possessed the structural gene, toxA for dermonecrotoxin. There was variability in the antimicrobial susceptibility pattern in sheep isolates, but overall the rate of tetracycline resistance was relatively high (64.28%) in our strains while all the isolates were sensitive to streptomycin. Except for the swine isolates and one toxigenic sheep isolate, the P. multocida isolates from this study were sensitive to quinolones. Although the level of resistance to commercial antibiotics was generally low, the use of tetracycline and erythromycin was not recommended.

Keywords: antibiogram, genotyping, Pasteurella multocida, serogrouping, toxA

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Authors: Mehmet Karahan, Nevin Karahan

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Water and air permeability and thermal resistance of fabrics are the important attributes which strongly influence the thermo-physiological comfort properties of sportswear fabrics in different environmental conditions. In this work, terry and fleece fabrics were developed by varying the fiber content and areal density of fabrics. Further, the thermo-physical properties, including air permeability, water vapor permeability, and thermal resistance, of the developed fabrics were analyzed before and after washing. The multi-response optimization of thermo-physiological comfort properties was done by using principal component analysis (PCA) and Taguchi signal to noise ratio (PCA-S/N ratio) for optimal properties. It was found that the selected parameters resulted in a significant effect on thermo-physiological comfort properties of knitted fabrics. The PCA analysis showed that before wash, 100% cotton fabric with an aerial weight of 220 g.m⁻² gave optimum values of thermo-physiological comfort.

Keywords: thermo-physiological comfort, fleece knitted fabric, air permeability, water vapor transmission, cotton/polyester

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Authors: Hsiang-Yu Yuan, Marc Baguelin, Kin O. Kwok, Nimalan Arinaminpathy, Edwin Leeuwen, Steven Riley

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Traditional syndromic surveillance for influenza has substantial public health value in characterizing epidemics. Because the relationship between syndromic incidence and the true infection events can vary from one population to another and from one year to another, recent studies rely on combining serological test results with syndromic data from traditional surveillance into epidemic models to make inference on epidemiological processes of influenza. However, despite the widespread availability of serological data, epidemic models have thus far not explicitly represented antibody titre levels and their correspondence with immunity. Most studies use dichotomized data with a threshold (Typically, a titre of 1:40 was used) to define individuals as likely recently infected and likely immune and further estimate the cumulative incidence. Underestimation of Influenza attack rate could be resulted from the dichotomized data. In order to improve the use of serosurveillance data, here, a refinement of the concept of the stratified immunity within an epidemic model for influenza transmission was proposed, such that all individual antibody titre levels were enumerated explicitly and mapped onto a variable scale of susceptibility in different age groups. Haemagglutination inhibition titres from 523 individuals and 465 individuals during pre- and post-pandemic phase of the 2009 pandemic in Hong Kong were collected. The model was fitted to serological data in age-structured population using Bayesian framework and was able to reproduce key features of the epidemics. The effects of age-specific antibody boosting and protection were explored in greater detail. RB was defined to be the effective reproductive number in the presence of stratified immunity and its temporal dynamics was compared to the traditional epidemic model using use dichotomized seropositivity data. Deviance Information Criterion (DIC) was used to measure the fitness of the model to serological data with different mechanisms of the serological response. The results demonstrated that the differential antibody response with age was present (ΔDIC = -7.0). The age-specific mixing patterns with children specific transmissibility, rather than pre-existing immunity, was most likely to explain the high serological attack rates in children and low serological attack rates in elderly (ΔDIC = -38.5). Our results suggested that the disease dynamics and herd immunity of a population could be described more accurately for influenza when the distribution of immunity was explicitly represented, rather than relying only on the dichotomous states 'susceptible' and 'immune' defined by the threshold titre (1:40) (ΔDIC = -11.5). During the outbreak, RB declined slowly from 1.22[1.16-1.28] in the first four months after 1st May. RB dropped rapidly below to 1 during September and October, which was consistent to the observed epidemic peak time in the late September. One of the most important challenges for infectious disease control is to monitor disease transmissibility in real time with statistics such as the effective reproduction number. Once early estimates of antibody boosting and protection are obtained, disease dynamics can be reconstructed, which are valuable for infectious disease prevention and control.

Keywords: effective reproductive number, epidemic model, influenza epidemic dynamics, stratified immunity

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Authors: Chien-Wan Hun, Shao-Fu Chang, Chien-Chon Chen, Ker-Jer Huang

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This study presents how to use a high-efficiency process for producing cesium iodide (CsI) crystal columns by rapid heating method. In the past, the heating rate of the resistance wire heating furnace was relatively slow and excessive iodine and CsI vapors were therefore generated during heating. Because much iodine and CsI vapors are produced during heating process, the composition of CsI crystal columns is not correct. In order to enhance the heating rate, making CsI material in the heating process can quickly reach the melting point temperature. This study replaced the traditional type of external resistance heating furnace with halogen-type quartz heater, and then, CsI material can quickly reach the melting point. Eventually, CsI melt can solidify in the anodic aluminum template forming CsI crystal columns.

Keywords: cesium iodide, high efficiency, vapor, rapid heating, crystal column

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Authors: Elżbieta Cygan, Bączek, Piotr Wyżga

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This paper presents the results of research on the physical, mechanical, and tribological properties of materials constituting the matrix in sintered metallic-diamond tools. The ground powders based on the Fe-Mn-Cu-Sn-C system were modified with micro-sized particles of the ceramic phase: SiC, Al₂O₃ and consolidated using the SPS (spark plasma sintering) method to a relative density of over 98% at 850-950°C, at a pressure of 35 MPa and time 10 min. After sintering, an analysis of the microstructure was conducted using scanning electron microscopy. The resulting materials were tested for the apparent density determined by Archimedes’ method, Rockwell hardness (scale B), Young’s modulus, as well as for technological properties. The performance results of obtained diamond composites were compared with the base material (Fe–Mn–Cu–Sn–C) and the commercial alloy Co-20% WC. The hardness of composites has achieved the maximum at a temperature of 900°C; therefore, it should be considered that at this temperature it was obtained optimal physical and mechanical properties of the subjects' composites were. Research on tribological properties showed that the composites modified with micro-sized particles of the ceramic phase are characterized by more than twice higher wear resistance in comparison with base materials and the commercial alloy Co-20% WC. Composites containing Al₂O₃ phase particles in the matrix material were composites containing Al₂O₃ phase particles in the matrix material were characterized by the lowest abrasion wear resistance. The manufacturing technology presented in the paper is economically justified and can be successfully used in the production process of the matrix in sintered diamond-impregnated tools used for the machining of an industrial floor system. Acknowledgment: The study was performed under LIDER IX Research Project No. LIDER/22/0085/L-9/17/NCBR/2018 entitled “Innovative metal-diamond tools without the addition of critical raw materials for applications in the process of grinding industrial floor systems” funded by the National Centre for Research and Development of Poland, Warsaw.

Keywords: abrasive wear resistance, metal matrix composites, sintered diamond tools, Spark Plasma Sintering

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Authors: Jaswinder Kumar, Kulbir Singh Sandhu

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Friction stir processing (FSP) is a solid-state surface processing technique. A single-pass FSP was performed on Aluminum alloy at combinations of different tool rotational speeds with cylindrical threaded pin profiled tool. The effect of these parameters on tribological properties was studied. The wear resistance is found to be increased from base metal to a single pass FSP sample. The results revealed that with an increase in tool rotational speed, the wear rate increases. The high heat generation causes matrix softening, which results in an increased wear rate; on the other hand, high heat generation leads to coarse grains, which also affected tribological properties. Furthermore, Microstructure results showed that FSPed alloy has a more refined grain structure as compare to the base material, which may be resulted in enhancement of hardness and resistance to wear in FSP.

Keywords: friction stir processing, aluminium alloy, microhardness, microstructure

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Authors: Jinjun Jiang, Lianzhong Chen, Rui Xu

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The accurate of model attitude angel plays an important role on the aerodynamic test results in the wind tunnel test. The original method applies the spherical coordinate system transformation to obtain attitude angel calculation.The model attitude angel is obtained by coordinate transformation and spherical surface mapping applying the nominal attitude angel (the balance attitude angel in the wind tunnel coordinate system) indicated by the mechanism. First, the coordinate transformation of this method is not only complex but also difficult to establish the transformed relationship between the space coordinate systems especially after many steps of coordinate transformation, moreover it cannot realize the iterative calculation of the interference relationship between attitude angels; Second, during the calculate process to solve the problem the arc is approximately used to replace the straight line, the angel for the tangent value, and the inverse trigonometric function is applied. Therefore, in the calculation of attitude angel, the process is complex and inaccurate, which can be solved approximately when calculating small attack angel. However, with the advancing development of modern aerodynamic unsteady research, the aircraft tends to develop high or super large attack angel and unsteadyresearch field.According to engineering practice and vector theory, the concept of vector angel coordinate systemis proposed for the first time, and the vector angel coordinate system of attitude angel is established.With the iterative correction calculation and avoiding the problem of approximate and inverse trigonometric function solution, the model attitude calculation process is carried out in detail, which validates that the calculation accuracy and accuracy of model attitude angels are improved.Based on engineering and theoretical methods, a vector angel coordinate systemis established for the first time, which gives the transformation and angel definition relations between different flight attitude coordinate systems, that can accurately calculate the attitude angel of the corresponding coordinate systemand determine its direction, especially in the channel coupling calculation, the calculation of the attitude angel between the coordinate systems is only related to the angel, and has nothing to do with the change order s of the coordinate system, whichsimplifies the calculation process.

Keywords: attitude angel, angel vector coordinate system, iterative calculation, spherical coordinate system, wind tunnel test

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Authors: Monalisa Pal, Kalyan Mandal

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Herein we report the molecular functionalization of promising transition metal oxide nanostructures, such as Co3O4 nanocubes, using nontoxic and biocompati-ble organic ligand sodium tartrate. The electronic structural modification of the nanocubes imparted through functionalization and subsequent water solubilization reveals multiple absorption bands in the UV-vis region. Further surface modification of the solubilized nanocubes, leads to the emergence of intrinsic multi-color fluorescence (from blue, cyan, green to red region of the spectrum), upon excitation at proper wavelengths, where the respective excitation wavelengths have a direct correlation with the observed UV-vis absorption bands. Using a multitude of spectroscopic tools we have investigated the mechanistic insight behind the origin of different UV-vis absorption bands and emergence of multicolor photoluminescence from the functionalized nanocubes. Our detailed study shows that ligand to metal charge transfer (LMCT) from tartrate ligand to Co2+/Co3+ ions and d-d transitions involving Co2+/Co3+ ions are responsible for generation of this novel optical properties. Magnetic study reveals that, antiferromagnetic nature of Co3O4 nanocubes changes to ferromagnetic behavior upon functionalization, however, the overall magnetic response was very weak. To combine strong magnetism with this novel optical property, we followed the same surface modification strategy in case of CoFe2O4 nanoparticles, which reveals that irrespective of size and shape, all Co-based oxides can develop intrinsic multi-color fluorescence upon facile functionalization with sodium tartrate ligands and the magnetic response was significantly higher. Surface modified Co-based oxide nanostructures also show excellent catalytic activity in degradation of biologically and environmentally harmful dyes. We hope that, our developed facile functionalization strategy of Co-based oxides will open up new opportunities in the field of biomedical applications such as bio-imaging and targeted drug delivery.

Keywords: co-based oxide nanostructures, functionalization, multi-color fluorescence, catalysis

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Authors: Yue-Tzu Yang, Shu-Ching Liao

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This study presents the numerical simulation of three-dimensional incompressible steady and laminar fluid flow and conjugate heat transfer of a trapezoidal microchannel heat sink using water as a cooling fluid in a silicon substrate. Navier-Stokes equations with conjugate energy equation are discretized by finite-volume method. We perform numerical computations for a range of 50 ≦ Re ≦ 600, 0.05W ≦ P ≦ 0.8W, 20W/cm2 ≦ ≦ 40W/cm2. The present study demonstrates the numerical optimization of a trapezoidal microchannel heat sink design using the response surface methodology (RSM) and the genetic algorithm method (GA). The results show that the average Nusselt number increases with an increase in the Reynolds number or pumping power, and the thermal resistance decreases as the pumping power increases. The thermal resistance of a trapezoidal microchannel is minimized for a constant heat flux and constant pumping power.

Keywords: microchannel heat sinks, conjugate heat transfer, optimization, genetic algorithm method

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Authors: Markus Bredel, Sindhu Nair, Hoa Q. Trummell, Rajani Rajbhandari, Christopher D. Willey, Lewis Z. Shi, Zhuo Zhang, William J. Placzek, James A. Bonner

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Purpose: EGFR-targeted monoclonal antibodies (mAbs) provide clinical benefit in some patients with H&N squamous cell carcinoma (HNSCC), but others progress with minimal response. Missense mutations in the EGFR ectodomain (ECD) can be acquired under mAb therapy by mimicking the effect of large deletions on receptor untethering and activation. Little is known about the contribution of EGFR ECD mutations to EGFR activation and anti-EGFR response in HNSCC. Methods: We selected patient-derived HNSCC cells (UM-SCC-1) for resistance to mAb Cetuximab (CTX) by repeated, stepwise exposure to mimic what may occur clinically and identified two concurrent EGFR ECD mutations (UM-SCC-1R). We examined the competence of the mutants to bind EGF ligand or CTX. We assessed the potential impact of the mutations through visual analysis of space-filling models of the native sidechains in the original structures vs. their respective side-chain mutations. We performed CRISPR in combination with site-directed mutagenesis to test for the effect of the mutants on ligand-independent EGFR activation and sorting. We determined the effects on receptor internalization, endocytosis, downstream signaling, and radiation sensitivity. Results: UM-SCC-1R cells carried two non-synonymous missense mutations (G33S and N56K) mapping to domain I in or near the EGF binding pocket of the EGFR ECD. Structural modeling predicted that these mutants restrict the adoption of a tethered, inactive EGFR conformation while not permitting association of EGFR with the EGF ligand or CTX. Binding studies confirmed that the mutant, untethered receptor displayed a reduced affinity for both EGF and CTX but demonstrated sustained activation and presence at the cell surface with diminished internalization and sorting for endosomal degradation. Single and double-mutant models demonstrated that the G33S mutant is dominant over the N56K mutant in its effect on EGFR activation and EGF binding. CTX-resistant UM-SCC-1R cells demonstrated cross-resistance to mAb Panitumuab but, paradoxically, remained sensitive to the reversible receptor tyrosine kinase inhibitor Erlotinib. Conclusions: HNSCC cells can select for EGFR ECD mutations under EGFR mAb exposure that converge to trap the receptor in an open, constitutively activated state. These mutants impede the receptor’s competence to bind mAbs and EGF ligand and alter its endosomal trafficking, possibly explaining certain cases of clinical mAb and radiation resistance.

Keywords: head and neck cancer, EGFR mutation, resistance, cetuximab

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Authors: Saifurahman Fayiz

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overall, India had friendly relation with different governments in Afghanistan except for the Taliban regime amongst the years 1996 to 2001. The terrorist attack in the United States provided India a chance to follow its strategy in Afghanistan. India support Afghanistan since 9\11. The objectives of this study to study India’s strategy towards Afghanistan and its implication to neighbor countries. The research method conducted based on qualitative research method with descriptive. The research findings propose that; India has chosen a soft power policy to implement its strategy in Afghanistan.

Keywords: strategy, policy, soft power, Afghanistan

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Authors: Dativa Maria Aliddeki, Fred Monje, Godfrey Nsereko, Benon Kwesiga, Daniel Kadobera, Alex Riolexus Ario

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Background: Cholera is a severe gastrointestinal disease caused by Vibrio cholera. It has caused several pandemics. On 26 February 2018, a suspected cholera outbreak, with one death, occurred in School X in Hoima Municipality, western Uganda. We investigated to identify the scope and mode of transmission of the outbreak, and recommend evidence-based control measures. Methods: We defined a suspected case as onset of diarrhea, vomiting, or abdominal pain in a student or staff of School X or their family members during 14 February–10 March. A confirmed case was a suspected case with V. cholerae cultured from stool. We reviewed medical records at Hoima Hospital and searched for cases at School X. We conducted descriptive epidemiologic analysis and hypothesis-generating interviews of 15 case-patients. In a retrospective cohort study, we compared attack rates between exposed and unexposed persons. Results: We identified 15 cases among 75 students and staff of School X and their family members (attack rate=20%), with onset from 25-28 February. One patient died (case-fatality rate=6.6%). The epidemic curve indicated a point-source exposure. On 24 February, a student brought fried fish from her home in a fishing village, where a cholera outbreak was ongoing. Of the 21 persons who ate the fish, 57% developed cholera, compared with 5.6% of 54 persons who did not eat (RR=10; 95% CI=3.2-33). None of 4 persons who recooked the fish before eating, compared with 71% of 17 who did not recook it, developed cholera (RR=0.0, 95%CIFisher exact=0.0-0.95). Of 12 stool specimens cultured, 6 yielded V. cholerae. Conclusion: This cholera outbreak was caused by eating fried fish, which might have been contaminated with V. cholerae in a village with an ongoing outbreak. Lack of thorough cooking of the fish might have facilitated the outbreak. We recommended thoroughly cooking fish before consumption.

Keywords: cholera, disease outbreak, foodborne, global health security, Uganda

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Authors: Masoumeh Ghorbania, Falk Liebnerb, Hendrikus W.G. van Herwijnenc, Johannes Konnertha

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Phenol formaldehyde (PF) resins are widely used as wood adhesives for variety of industrial products such as plywood, laminated veneer lumber and others. Lignin as a main constituent of wood has become well-known as a potential substitute for phenol in PF adhesives because of their structural similarity. During the last decades numerous research approaches have been carried out to substitute phenol with pulping-derived lignin, whereby the lower reactivity of resins synthesized with shares of lignin seem to be one of the major challenges. This work reports about a systematic screening of different types of lignin (plant origin and pulping process) for their suitability to replace phenol in phenolic resins. Lignin from different plant sources (softwood, hardwood and grass) were used, as these should differ significantly in their reactivity towards formaldehyde of their reactive phenolic core units. Additionally a possible influence of the pulping process was addressed by using the different types of lignin from soda, kraft, and organosolv process and various lignosulfonates (sodium, ammonium, calcium, magnesium). To determine the influence of lignin on the adhesive performance beside others the rate of viscosity development, bond strength development of varying hot pressing time and other thermal properties were investigated. To evaluate the performance of the cured end product, a few selected properties were studied at the example of solid wood-adhesive bond joints, compact panels and plywood. As main results it was found that lignin significantly accelerates the viscosity development in adhesive synthesis. Bonding strength development during curing of adhesives decelerated for all lignin types, while this trend was least for pine kraft lignin and spruce sodium lignosulfonate. However, the overall performance of the products prepared with the latter adhesives was able to fulfill main standard requirements, even after exposing the products to harsh environmental conditions. Thus, a potential application can be considered for processes where reactivity is less critical but adhesive cost and product performance is essential.

Keywords: phenol formaldehyde resin, lignin phenol formaldehyde resin, ABES, DSC

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Authors: Mohammed Abed, Rita Nemes, Salem Nehme

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The present study experimentally investigated the impact of incorporating unprocessed waste fly ash (UWFA) on the residual mechanical properties of self-compacting concrete (SCC) after exposure to elevated temperature. Three mixtures of SCC have been produced by replacing the cement mass by 0%, 15% and 30% of UWFA. Generally, the fire resistance of SCC has been enhanced by replacing the cement up to 15% of UWFA, especially in case of residual modulus of elasticity which considers more sensitive than other mechanical properties at elevated temperature. However, a strong linear relationship has been observed between the residual flexural strength and modulus of elasticity, where both of them affected significantly by the cracks appearance and propagation as a result of elevated temperature. Sustainable products could be produced by incorporating unprocessed waste powder materials in the production of concrete, where the waste materials, CO₂ emissions, and the energy needed for processing are reduced.

Keywords: self-compacting high-performance concrete, unprocessed waste fly ash, fire resistance, residual modulus of elasticity

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Authors: Irit Rutman Halili, Tehila Zvulun, Natali Elgabsi, Revaya Cohen, Shlomo Sarig

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Active sand dunes (ASD) may cause significant damage to field crops and livelihood, and therefore, it is necessary to find a treatment that would enhance ADS soil stability. Biological soil crusts (biocrusts) contain microorganisms on the soil surface. Metabolic polysaccharides secreted by biocrust cyanobacteria glue the soil particles into aggregates, thereby stabilizing the soil surface. Filter cake powder (FCP) is a waste by-product in the final stages of the production of sugar from sugarcane, and its disposal causes significant environmental pollution. FCP contains high concentrations of polysaccharides and has recently been shown to be soil stability enhancing agent in ASD. It has been reported that adding FCP to the ASD soil surface by dispersal significantly increases the level of penetration resistance of soil biocrust (PRSB) nine weeks after a single treatment. However, it was not known whether a similar effect could be obtained by administering the FCP in liquid form by means of spraying. It has now been found that spraying a water solution of FCP onto the ASD soil surface significantly increased the level of penetration resistance of soil biocrust (PRSB) three weeks after a single treatment. These results suggest that FCP spraying can be used as a short-term soil stability-enhancing agent for ASD, while administration by dispersal might be more efficient over the long term. Finally, an additional benefit of using FCP as a soil stabilizer, either by dispersal or by spraying, is the reduction in environmental pollution that would otherwise result from the disposal of FCP solid waste.

Keywords: active sand dunes, filter cake powder, biological soil crusts, penetration resistance of soil biocrust

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Authors: Lawrence Williams

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As the mechanism which converts domains to internet protocol (IP) addresses, Domain Name System (DNS) is an essential part of internet usage. It was not designed securely and can be subject to attacks. DNS attacks have become more frequent and sophisticated and the need for detecting and preventing them becomes more important for the modern network. DNS tunnelling attacks are one type of attack that are primarily used for distributed denial-of-service (DDoS) attacks and data exfiltration. Discussion of different techniques to detect and prevent DNS tunneling attacks is done. The methods, models, experiments, and data for each technique are discussed. A proposal about feasibility is made. Future research on these topics is proposed.

Keywords: DNS, tunneling, exfiltration, botnet

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