Search results for: sensitive characteristic

Authors: Enes Yasa, Guven Fidan

Abstract:

Building Simulation tools need to better evaluate convective heat exchanges between external air and wall surfaces. Previous analysis demonstrated the significant effects of convective heat transfer coefficient values on the room energy balance. Some authors have pointed out that large discrepancies observed between widely used building thermal models can be attributed to the different correlations used to calculate or impose the value of the convective heat transfer coefficients. Moreover, numerous researchers have made sensitivity calculations and proved that the choice of Convective Heat Transfer Coefficient values can lead to differences from 20% to 40% of energy demands. The thermal losses to the ambient from a building surface or a roof mounted solar collector represent an important portion of the overall energy balance and depend heavily on the wind induced convection. In an effort to help designers make better use of the available correlations in the literature for the external convection coefficients due to the wind, a critical discussion and a suitable tabulation is presented, on the basis of algebraic form of the coefficients and their dependence upon characteristic length and wind direction, in addition to wind speed. Many research works have been conducted since early eighties focused on the convection heat transfer problems inside buildings. In this context, a Computational Fluid Dynamics (CFD) program has been used to predict external convective heat transfer coefficients at external building surfaces. For the building facades model, effects of wind speed and temperature differences between the surfaces and the external air have been analyzed, showing different heat transfer conditions and coefficients. In order to provide further information on external convective heat transfer coefficients, a numerical work is presented in this paper, using a Computational Fluid Dynamics (CFD) commercial package (CFX) to predict convective heat transfer coefficients at external building surface.

Keywords: CFD in buildings, external convective heat transfer coefficients, building facades, thermal modelling

Procedia PDF Downloads 398

Authors: Duy Nguyen Do, Bart Julien Dewancker

Abstract:

Many Soviet-style collective housing complexes (also known as KTT) were built since the 1960s in Hanoi to support the post-war population growth. Those low-rise buildings have created well-knitted, robust communities, so much to the point that in most complexes, all families in one housing block would know each other, occasionally interact and provide supports in need. To understand how the community of collective housing complexes have developed and maintained in order to adapt their advantages into modern housing designs, the study is executed on the site of Nguyen Cong Tru KTT. This is one of the oldest KTT in Hanoi, completed in 1954. The complex also has an unique characteristic that is closely related to its community: the symbiotic relationship with Hom – a flea market that has been co-developing with Nguyen Cong Tru KTT since its beginning. The research consists of three phases: the first phase is a sociological investigation with Nguyen Cong Tru KTT’s current residents and a site survey on the complex’s economic and architectural characteristics. In the second phase, the collected data is analyzed to find out people’s opinions with the KTT’s concerning their satisfaction with the current housing status, floor plan organization, community, the relationship between the KTT’s dedicated public spaces with the flea market and their usage. Simultaneously, the master plan and gathered information regarding current architectural characteristics of the complex are also inspected. On the third phase, the analyses’ results will provide information regarding the issues, positive trends and significant historical features of the complex’s architecture in order to generate suitable proposals for the redesigning project of Nguyen Cong Tru KTT, a design focused on vitalizing modern apartments’ communities.

Keywords: collective house community, collective house public space, community-focused, redesigning Nguyen Cong Tru KTT, sociological investigation

Procedia PDF Downloads 337

Authors: Gerardo Sanjuan Sanjuan, Ángel Enrique Chavéz Castellanos

Abstract:

The knowledge of the rheological behavior of partially solidified metal alloy is an important issue when modeling and simulation of die filling in semisolid processes. Many experiments for like steady state, the step change in shear rate tests, shear stress ramps have been carried out leading that semi-solid alloys exhibit shear thinning, thixotropic behavior and yield stress. More advanced investigation gives evidence some viscoelastic features can be observed. The viscoelastic properties of materials are determinate by transient or dynamic methods; unfortunately, sparse information exists about oscillation experiments. The aim of this present work is to use small amplitude oscillatory tests for knowledge properties such as G´ and G´´. These properties allow providing information about materials structure. For this purpose, we investigated tin-lead alloy (Sn-15%Pb) which exhibits a similar microstructure to aluminum alloys and is the classic alloy for semisolid thixotropic studies. The experiments were performed with parallel plates rheometer AR-G2. Initially, the liquid alloy is cooled down to the semisolid range, a specific temperature to guarantee a constant fraction solid. Oscillation was performed within the linear viscoelastic regime with a strain sweep. So, the loss modulus G´´, the storage modulus G´ and the loss angle (δ) was monitored. In addition a frequency sweep at a strain below the critical strain for characterized its structure. This provides more information about the interactions among solid particles on a liquid matrix. After testing, the sample was removed then cooled, sectioned and examined metallographically. These experiments demonstrate that the viscoelasticity is sensitive to the solid fraction, and is strongly influenced by the shape and size of particles solid.

Keywords: rheology, semisolid alloys, thixotropic, viscoelasticity

Procedia PDF Downloads 350

Authors: Fernández-Brito David, Lopez-Medina Javier Alonso, Murillo-Bracamontes Eduardo Antonio, Palomino-Ovando Martha Alicia, Gervacio-Arciniega José Juan

Abstract:

Magnetic Force Microscopy (MFM) is an Atomic Force Microscopy (AFM) technique that characterizes, at a nanometric scale, the magnetic properties of ferromagnetic materials. Conventional MFM works by scanning in two different AFM modes. The first one is tapping mode, in which the cantilever has short-range force interactions with the sample, with the purpose to obtain the topography. Then, the lift AFM mode starts, raising the cantilever to maintain a fixed distance between the tip and the surface of the sample, only interacting with the magnetic field forces of the sample, which are long-ranged. In recent years, there have been attempts to improve the MFM technique. Bimodal MFM was first theoretically developed and later experimentally proven. In bimodal MFM, the AFM internal piezoelectric is used to cause the cantilever oscillations in two resonance modes simultaneously, the first mode detects the topography, while the second is more sensitive to the magnetic forces between the tip and the sample. However, it has been proven that the cantilever vibrations induced by the internal AFM piezoelectric ceramic are not optimal, affecting the bimodal MFM characterizations. Moreover, the Secondary Resonance Magnetic Force Microscopy (SR-MFM) was developed. In this technique, a coil located below the sample generates an external magnetic field. This alternating magnetic field excites the cantilever at a second frequency to apply the Bimodal MFM mode. Nonetheless, for ferromagnetic materials with a low coercive field, the external field used in SR-MFM technique can modify the magnetic domains of the sample. In this work, a Hybrid Bimodal MFM (HB-MFM) technique is proposed. In HB-MFM, the bimodal MFM is used, but the first resonance frequency of the cantilever is induced by the magnetic field of the ferromagnetic sample due to its vibrations caused by a piezoelectric element placed under the sample. The advantages of this new technique are demonstrated through the preliminary results obtained by HB-MFM on a hard disk sample. Additionally, traditional two pass MFM and HB-MFM measurements were compared.

Keywords: magnetic force microscopy, atomic force microscopy, magnetism, bimodal MFM

Procedia PDF Downloads 52

Authors: Laith K. Abbas, Xiaoting Rui, Pier Marzocca

Abstract:

Aerospace systems, generally speaking, are inherently nonlinear. These nonlinearities may modify the behavior of the system. However, nonlinearities in an aeroelastic system can be divided into structural and aerodynamic. Structural nonlinearities can be subdivided into distributed and concentrated ones. Distributed nonlinearities are spread over the whole structure representing the characteristic of materials and large motions. Concentrated nonlinearities act locally, representing loose of attachments, worn hinges of control surfaces, and the presence of external stores. The concentrated nonlinearities can be approximated by one of the classical structural nonlinearities, namely, cubic, free-play and hysteresis, or by a combination of these, for example, a free-play and a cubic one. Compressibility, aerodynamic heating, separated flows and turbulence effects are important aspects that result in nonlinear aerodynamic behavior. An issue related to the low-speed flutter and its catastrophic/benign character represented by Limit Cycle Oscillation (LCO) of all-movable fin, as well to their control is addressed in the present work. To the approach of this issue: (1) Quasi-Steady (QS) Theory and Computational Fluid Dynamics (CFD) of subsonic flow are implemented, (2) Flutter motion equations of a two-dimensional typical section with cubic nonlinear stiffness in the pitching direction and free play gap are established, (3) Uncoupled bending/torsion frequencies of the selected fin are computed using recently developed Transfer Matrix Method of Multibody System Dynamics (MSTMM), and (4) Time simulations are carried out to study the bifurcation behavior of the aeroelastic system. The main objective of this study is to investigate how the LCO and chaotic behavior are influenced by the coupled aeroelastic nonlinearities and intend to implement a control capability enabling one to control both the flutter boundary and its character. By this way, it may expand the operational envelop of the aerospace vehicle without failure.

Keywords: aeroelasticity, CFD, MSTMM, flutter, freeplay, fin

Procedia PDF Downloads 352

Authors: Yanhua Zhao, Yu Gou, Shu Feng, Dongdong Li, Chuanmin Tao

Abstract:

The natural history of HBV infection could experience immune tolerant (IT), immune clearance (IC), HBeAg-negative inactive/quienscent carrier (ENQ), and HBeAg-negative hepatitis (ENH). As current biomarkers for discriminating these four phases have some weaknesses, additional serological indicators are needed. Hepatits B core-related antigen (HBcrAg) encoded with precore/core gene contains denatured HBeAg, HBV core antigen (HBcAg) and a 22KDa precore protein (p22cr), which was demonstrated to have a close association with natural history of hepatitis B infection, but no specific cutoff values and diagnostic parameters to evaluate the diagnostic efficacy. This study aimed to clarify the distribution of HBcrAg levels and evaluate its diagnostic performance during the natural history of infection from a Western Chinese perspective. 294 samples collected from treatment-naïve chronic hepatitis B (CHB) patients in different phases (IT=64; IC=72; ENQ=100, and ENH=58). We detected the HBcrAg values and analyzed the relationship between HBcrAg and HBV DNA. HBsAg and other clinical parameters were quantitatively tested. HBcrAg levels of four phases were 9.30 log U/mL, 8.80 log U/mL, 3.00 log U/mL, and 5.10 logU/mL, respectively (p < 0.0001). Receiver operating characteristic curve analysis demonstrated that the area under curves (AUCs) of HBcrAg and quantitative HBsAg at cutoff values of 9.25 log U/mL and 4.355 log IU/mL for distinguishing IT from IC phases were 0.704 and 0.694, with sensitivity 76.39% and 59.72%, specificity 53.13% and 79.69%, respectively. AUCs of HBcrAg and quantitative HBsAg at cutoff values of 4.15 log U/mlmL and 2.395 log IU/mlmL for discriminating between ENQ and ENH phases were 0.931 and 0.653, with sensitivity 87.93% and 84%, specificity 91.38% and 39%, respectively. Therefore, HBcrAg levels varied significantly among four natural phases of HBV infection. It had higher predictive performance than quantitative HBsAg for distinguishing between ENQ-patients and ENH-patients and similar performance with HBsAg for the discrimination between IT and IC phases, which indicated that HBcrAg could be a potential serological marker for CHB.

Keywords: chronic hepatitis B, hepatitis B core-related antigen, hepatitis B surface antigens, hepatitis B virus

Procedia PDF Downloads 388

Authors: Soleen Karim, Meira Yasin, Rezhin Qader

Abstract:

Children’s books present a colorful life for kids around the world, their current environment or what they could potentially have- a home, two loving parents, a playground, and a safe school within a short walk or bus ride. These images are only pages in a donated book for children displaced by war. The environment they live in is significantly different. Displaced children are faced with a temporary life style filled with fear and uncertainty. Children of war associate various structural institutions with a trauma and cannot enter the space, even if it is for their own future development, such as a school. This paper is a collaborative effort with students of the Kennesaw State University architecture department, architectural designers and a mental health professional to address and link the design challenges and the psychological trauma for children of war. The research process consists of a) interviews with former refugees, b) interviews with current refugee children, c) personal understanding of space through one’s own childhood, d) literature review of tested design methods to address various traumas. Conclusion: In addressing the built environment for children of war, it is necessary to address mental health and well being through the creation of space that is sensitive to the needs of children. This is achieved by understanding critical design cues to evoke normalcy and safe space through program organization, color, and symbiosis of synthetic and natural environments. By involving the children suffering from trauma in the design process, aspects of the design are directly enhanced to serve the occupant. Neglecting to involve the participants creates a nonlinear design outcome and does not serve the needs of the occupant to afford them equal opportunity learning and growth experience as other children around the world.

Keywords: activist architecture, childhood education, childhood psychology, adverse childhood experiences

Procedia PDF Downloads 120

Authors: Nadia Allouache, Mohamed Belmedani

Abstract:

Energy source is a sustainable, totally inexhaustible and environmentally friendly alternative to the fossil fuels available. It is a renewable and economical energy that can be harnessed sustainably over the long term and thus stabilizes energy costs. Solar cooling technologies have been developed to decrease the augmentation electricity consumption for air conditioning and to displace the peak load during hot summer days. A numerical analysis of thermal and solar performances of an annular finned adsorber, which is the most important component of the adsorption solar refrigerating system, is considered in this work. Different adsorbent/adsorbate pairs, such as activated carbon AC35/methanol, activated carbon AC35/ethanol, and activated carbon BPL/Ammoniac, are undertaken in this study. The modeling of the adsorption cooling machine requires the resolution of the equation describing the energy and mass transfer in the tubular finned adsorber. The Wilson and Dubinin- Astakhov models of the solid-adsorbate equilibrium are used to calculate the adsorbed quantity. The porous medium and the fins are contained in the annular space, and the adsorber is heated by solar energy. Effects of key parameters on the adsorbed quantity and on the thermal and solar performances are analysed and discussed. The AC35/methanol pair is the best pair compared to BPL/Ammoniac and AC35/ethanol pairs in terms of system performance. The system performances are sensitive to the fin geometry. For the considered data measured for clear type days of July 2023 in Algeria and Morocco, the performances of the cooling system are very significant in Algeria.

Keywords: activated carbon AC35-methanol pair, activated carbon AC35-ethanol pair, activated carbon BPL-ammoniac pair, annular finned adsorber, performance coefficients, numerical analysis, solar cooling system

Procedia PDF Downloads 38

Authors: Frank Jaksoni Mweta, Nozomu Adachi, Yoshikazu Todaka, Hirokazu Sato, Yuta Sato, Hiromi Miura, Masakazu Kobayashi, Chihiro Watanabe, Yoshiteru Aoyagi

Abstract:

Advances in the consumption of hydrogen fuel increase demands of high strength steel pipes and storage tanks. However, high strength steels are highly sensitive to hydrogen embrittlement. Because the introduction of hydrogen into steel during the fabrication process or from the environment is unavoidable, it is essential to improve hydrogen embrittlement resistance of high strength steels through microstructural control. In the present study, the heterogeneous nanostructure with a tensile strength of about 1.8 GPa and the homogeneous nanostructure with a tensile strength of about 2.0 GPa of 316LN steels were generated after 92% heavy cold rolling and high-pressure torsion straining, respectively. The heterogeneous nanostructure is composed of twin domains, shear bands, and lamellar grains. The homogeneous nanostructure is composed of uniformly distributed ultrafine nanograins. The influence of heterogeneous and homogenous nanostructures on the hydrogen embrittlement resistance was investigated. The specimen for each nanostructure was electrochemically charged with hydrogen for 3, 6, 12, and 24 hours, respectively. Under the same hydrogen charging time, both nanostructures show almost the same concentration of the diffusible hydrogen based on the thermal desorption analysis. The tensile properties of the homogenous nanostructure were severely affected by the diffusible hydrogen. However, the diffusible hydrogen shows less impact on the tensile properties of the heterogeneous nanostructure. The difference in embrittlement behavior between the heterogeneous and homogeneous nanostructures was elucidated based on the mechanism of the cracks' growth observed in the tensile fractography. The hydrogen embrittlement was suppressed in the heterogeneous nanostructure because the twin domain became an obstacle for crack growth. The homogeneous nanostructure was not consisting an obstacle such as a twin domain; thus, the crack growth resistance was low in this nanostructure.

Keywords: diffusible hydrogen, heterogeneous nanostructure, homogeneous nanostructure, hydrogen embrittlement

Procedia PDF Downloads 103

Authors: Jhe-Hao Huang, Kun-Da Wu, Wei-Cheng Shih, Jui-Pin Hung

Abstract:

This study presented the investigation on the dynamic characteristics of a spindle tool system by experimental and finite element modeling approaches. As well known facts, the machining stability is greatly determined by the dynamic characteristics of the spindle tool system. Therefore, understanding the factors affecting dynamic behavior of a spindle tooling system is a prerequisite in dominating the final machining performance of machine tool system. To this purpose, a physical spindle unit was employed to assess the dynamic characteristics by vibration tests. Then, a three-dimensional finite element model of a high-speed spindle system integrated with tool holder was created to simulate the dynamic behaviors. For modeling the angular contact bearings, a series of spring elements were introduced between the inner and outer rings. The spring constant can be represented by the contact stiffness of the rolling bearing based on Hertz theory. The interface characteristic between spindle nose and tool holder taper can be quantified from the comparison of the measurements and predictions. According to the results obtained from experiments and finite element predictions, the vibration behavior of the spindle is dominated by the bending deformation of the spindle shaft in different modes, which is further determined by the stiffness of the bearings in spindle housing. Also, the spindle unit with tool holder shows a different dynamic behavior from that of spindle without tool holder. This indicates the interface property between tool holder and spindle nose plays an dominance on the dynamic characteristics the spindle tool system. Overall, the dynamic behaviors the spindle with and without tool holder can be successfully investigated through the finite element model proposed in this study. The prediction accuracy is determined by the modeling of the rolling interface of ball bearings in spindles and the interface characteristics between tool holder and spindle nose. Besides, identifications of the interface characteristics of a ball bearing and spindle tool holder are important for the refinement of the spindle tooling system to achieve the optimum machining performance.

Keywords: contact stiffness, dynamic characteristics, spindle, tool holder interface

Procedia PDF Downloads 273

Authors: Svetlana Guryeva, Inna Kornienko, Elena Petersen

Abstract:

At present, translational medicine is a rapidly developing branch of biomedicine. The main idea of translational medicine is a practical application of fundamental research. One of the possible applications for translational medicine is researching therapies that improve human age-related organism condition. To fill the gap between experiments and clinical practice, it is necessary to create the standardized system for the investigation of different effects on cellular aging models. In this study, primary human fibroblasts derived from patients of different ages were used as a cellular aging model. The senescence-associated β-galactosidase activity, lipofuscin, γ-H2AX, the reactive oxygen species level, and cell death markers (annexin V/propidium iodide) were used as biomarkers of the cell functional state. The effects of damaging exposures (oxidative stress and heat shock), potential positive factors (metformin and acetaminophen), and their combinations were investigated using the described biomarkers. Oxidative stress and heat shock caused the increase in the levels of all biomarkers, and only the cells from young patients partly coped with stress 3 days after the exposures. Metformin improved the state of pretreatment cells from young and old patients. The acetaminophen did not show significant changes in the biomarker levels compare to the action of metformin. This study proved the opportunity to develop a standardized screening system based on biomarkers of the cell functional state to identify potential positive or negative effects of some physical and chemical exposures. Moreover, such a system can be useful for the aims of regenerative medicine to determine the effect of cell pretreatment before transplantation.

Keywords: biomarkers, primary fibroblasts, regenerative medicine, senescence, test system, translational medicine

Procedia PDF Downloads 380

Authors: Hong Li, Haiyang Yu, Shiqing Cheng, Nai Cao, Zhiliang Shi

Abstract:

Unconventional resources have gradually become the main direction for oil and gas exploration and development. However, the productivity of gas wells, the level of water production, and the seepage law in tight fractured gas reservoirs are very different. These are the reasons why production prediction is so difficult. Firstly, a three-dimensional multi-scale fracture and multiphase mathematical model based on an embedded discrete fracture model (EDFM) is established. And the material balance method is used to calculate the water body multiple according to the production performance characteristics of water-producing gas well. This will help construct a 'virtual water body'. Based on these, this paper presents a numerical simulation process that can adapt to different production modes of gas wells. The research results show that fractures have a double-sided effect. The positive side is that it can increase the initial production capacity, but the negative side is that it can connect to the water body, which will lead to the gas production drop and the water production rise both rapidly, showing a 'scissor-like' characteristic. It is worth noting that fractures with different angles have different abilities to connect with the water body. The higher the angle of gas well development, the earlier the water maybe break through. When the reservoir is a single layer, there may be a stable production period without water before the fractures connect with the water body. Once connected, a 'scissors shape' will appear. If the reservoir has multiple layers, the gas and water will produce at the same time. The above gas-water relationship can be matched with the gas well production date of the Xujiahe gas reservoir in the Sichuan Basin. This method is used to predict the productivity of a well with hydraulic fractures in this gas reservoir, and the prediction results are in agreement with on-site production data by more than 90%. It shows that this research idea has great potential in the productivity prediction of water-producing gas wells. Early prediction results are of great significance to guide the design of development plans.

Keywords: EDFM, multiphase, multilayer, water body

Procedia PDF Downloads 177

Authors: Bushra Alghamdi, Alla Alsharif, Hamzah Aljohani, Saba Kassim

Abstract:

Introduction: Collaborative work has always been acknowledged as a fundamental concept in delivering oral health care. Aim: This study aimed to assess the perception and attitude of pharmacists in oral health promotion and to determine the confident levels of pharmacists in delivering advice on oral health problems. Methods: An observational cross-sectional survey, using self-administered anonymous questionnaires, was conducted between March and April 2017. The study recruited a convenience sample of registered community pharmacists who were working in local private pharmaceutical stores in the urban area of Madinah, Kingdom of Saudi Arabia (KSA). A preliminary descriptive analysis was performed. Results: Thirty-five pharmacists have completed the surveys. All participants were males, with a mean age of 35.5 ( ± 6.92) years. Eighty-six percent of the participants reported that pharmacists should have a role in oral health promotion. Eighty percent have reported adequate level of confident when giving advice on most of the common oral health problems that include; oral health related risk behaviors such as tobacco cessation (46%), bleeding gums (63%) and sensitive teeth (60%). However, higher percentages of pharmacists have reported low confident levels when giving advice in relation to specific domain of dentistry, such as lost dental fillings (57%), loose crowns (60%), trauma to teeth (40%), denture-related problems (51%) and oral cancer (6.9%). Conclusion: Community pharmacists recognized their potential role in promoting oral health in KSA. Community pharmacists had varying levels of ability and confidence to offer support for oral health. The study highlighted that inner professional collaboration between pharmacists and dental care healthcare should be enhanced.

Keywords: community, oral health, promotion, pharmacist

Procedia PDF Downloads 175

Authors: Courtney Manthey-Pierce, Anna Warrener

Abstract:

Polycystic ovarian syndrome (PCOS) is the most common endocrine disruptive disorder in females. PCOS is primarily characterized by polycystic ovaries, anovulation, hirsutism, insulin resistance, and hyperandrogenism. Despite negative reproductive consequences for females from anovulation and endocrine dysfunction, genes associated with the pathogenesis of PCOS are highly hereditable (h2 = 0.72). An evolutionary mismatch occurs when a trait that evolved in one environment has become maladaptive in another environment. The idea that PCOS is an evolutionary mismatch disease has been promoted by several researchers. Each trait of the resulting PCOS phenotype should be investigated individually in order to demonstrate an evolutionary mismatch. Hyperandrogenism is often regarded as the main characteristic of PCOS Hyperandrogenism may have aided with conception in older females, increased bone mineral density, and supported prolonged breastfeeding in nutritionally distressed populations. Because of the high prevalence of PCOS in the modern world, approximately 6%, it is often argued that PCOS emerged in an ancestral population prior to the migration out of Africa approximately 200,000 years ago. This environment would be characterized by sporadic periods of nutrition deficit and resource hardships as the climate began changing. Presently, modern society is characterized by obesity and sedentary lifestyles. The prevalence of obesity renders hyperandrogenism PCOS useless as there are no periods of nutritional distress requiring androgens for increased reproductive rates. In an ancestral environment, hyperandrogenism would likely lead to sporadic anovulation and mild secondary symptoms, however high levels of androgens in a modern environment led to prolonged if not permanent infertility and excessive secondary problems. Thus, hyperandrogenism related to PCOS appears to meet evolutionary mismatch criteria. Seen in this light, PCOS may be effectively treated as a probably evolutionary mismatch.

Keywords: evolutionary mismatch, heritability, hyperandrogenism, mismatch disorder

Procedia PDF Downloads 225

Authors: Ping Ren, Mao Wen, Kan Zhang, Weitao Zheng

Abstract:

The improvement of comprehensive properties including hardness, toughness, wear, and corrosion resistance in the transition metal carbides/nitrides TMCN films, especially avoiding the trade-off between hardness and toughness, is strongly required to adapt to various applications. Although incorporating ductile metal DM phase into the TMCN via thermally-induced phase separation has been emerged as an effective approach to toughen TMCN-based films, the DM is just limited to some soft ductile metal (i.e. Cu, Ag, Au immiscibility with the TMCN. Moreover, hardness is highly sensitive to soft DM content and can be significantly worsened. Hence, a novel preparation method should be attempted to broaden the DM selection and assemble much more ordered nanocomposite structure for improving the comprehensive properties. Here, we provide a new strategy, by activating solid-state dewetting during layered deposition, to accomplish the self-assembly of ordered TaC@Ta core-shell-like nanocomposite film consisting of TaC nanocrystalline encapsulated with thin pseudocrystal Ta tissue. That results in the superhard (~45.1 GPa) dominated by Orowan strengthening mechanism and high toughness attributed to indenter-induced phase transformation from the pseudocrystal to body-centered cubic Ta, together with the drastically enhanced wear and corrosion resistance. Furthermore, very thin pseudocrystal Ta encapsulated layer (~1.5 nm) in the TaC@Ta core-shell-like structure helps for promoting the formation of lubricious TaOₓ Magnéli phase during sliding, thereby further dropping the coefficient of friction. Apparently, solid-state dewetting may provide a new route to construct ordered TMC(N)@TM core-shell-like nanocomposite capable of combining superhard, high toughness, low friction, superior wear with corrosion resistance.

Keywords: corrosion, nanocomposite film, solid-state dewetting, tribology

Procedia PDF Downloads 119

Authors: Armando Cartenì, Ilaria Henke

Abstract:

The perceived public transport quality is an important driver that influences both customer satisfaction and mobility choices. The competition among transport operators needs to improve the quality of the services and identify which attributes are perceived as relevant by passengers. Among the “traditional” public transport quality attributes there are, for example: travel and waiting time, regularity of the services, and ticket price. By contrast, there are some “non-conventional” attributes that could significantly influence customer satisfaction jointly with the “traditional” ones. Among these, the beauty/aesthetics of the transport terminals (e.g. rail station and bus terminal) is probably one of the most impacting on user perception. Starting from these considerations, the point stressed in this paper was if (and how munch) the travel experience of the overall travel (e.g. how long is the travel, how many transport modes must be used) influences the perception of the public transport quality. The aim of this paper was to investigate the weight of the terminal quality (e.g. aesthetic, comfort and service offered) within the overall travel experience. The case study was the extra-urban Italian bus network. The passengers of the major Italian terminal bus were interviewed and the analysis of the results shows that about the 75% of the travelers, are available to pay up to 30% more for the ticket price for having a high quality terminal. A travel experience effect was observed: the average perceived transport quality varies with the characteristic of the overall trip. The passengers that have a “long trip” (travel time greater than 2 hours) perceived as “low” the overall quality of the trip even if they pass through a high quality terminal. The opposite occurs for the “short trip” passengers. This means that if a traveler passes through a high quality station, the overall perception of that terminal could be significantly reduced if he is tired from a long trip. This result is important and if confirmed through other case studies, will allow to conclude that the “travel experience impact" must be considered as an explicit design variable for public transport services and planning.

Keywords: transportation planning, sustainable mobility, decision support system, discrete choice model, design problem

Procedia PDF Downloads 276

Authors: Mengdie Ruan

Abstract:

The authors investigate how subjective well-being (SWB) and social trust changed in China over the period 2010–2020 by relying on data from six rounds of the China Family Panel Studies (CFPS), then re-examine Easterlin’s hypothesis for China, with a more focus on the role of social trust and estimate income-compensating differentials for social trust. They find that the evolution of well-being is not sensitive to the measures of well-being one uses. Specifically, self-reported life satisfaction scores and hedonic happiness scores experienced a significant increase across all income groups from 2010 to 2020. Social trust seems to have increased based on CFPS in China for all socioeconomic classes in recent years, and male, urban resident individuals with higher income have a higher social trust at a given point in time and over time. However, when we use an alternative measure of social trust, out-group trust, which is a more valid measure of generalized trust and represents “most people”, social trust in China literally declines, and the level is extremely low. In addition, this paper also suggests that in the typical query on social trust, the term "most people" mostly denotes in-groups in China, which contrasts sharply with most Western countries where it predominantly connotes out-groups. Individual fixed effects analysis of well-being that controls for time-invariant variables reveals social trust and relative social status are important correlates of life satisfaction and happiness, whereas absolute income plays a limited role in boosting an individual’s well-being. The income-equivalent value for social capital is approximately tripling of income. It has been found that women, urban and coastal residents, and people with higher income, young people, those with high education care more about social trust in China, irrespective of measures on SWB. Policy aiming at preserving and enhancing SWB should focus on social capital besides economic growth.

Keywords: subjective well-being, life satisfaction, happiness, social trust, China

Procedia PDF Downloads 52

Authors: Seetanah Boopen, Padachi Kesseven, R. Juwaheer , R. V. Sannassee, M. L. Lamport

Abstract:

This study aims primarily at investigating the importance of soft infrastructure in tourism development for the case of an island economy namely Mauritius. The study in the first place assesses the level of perceived and actual satisfaction of the present state of the different types of soft tourism infrastructure and the allied services provided by tourism stakeholders in Mauritius and address the identified gaps. In order to address the study objectives, a rigorous survey analysis among 1741 international tourists at the departure lounge of the Sir Seewoosagur International Airport of Mauritius was carried out. The respondents placed significant emphasis on the different elements of the soft infrastructure dimension, where many of the elements falling under this dimension were rated with a high mean score. In particular the visitors rated communication, both internet and telephone services, and security to be most important. Significant gap has been found in the categories of ‘Health’ and ‘Security’. This indicates that the tourists ascribe high importance to the soft infrastructure dimension. The link between the respondent profile and the key variables which influence the tourist choice of the island as a destination are found to be equally important for most of the international tourists. However, these were deemed to be more critical for tourists travelling with family members. Although the survey instrument attempted to measure any gap between on the one hand, the importance of the infrastructure dimension and on the other hand, the level of satisfaction with the infrastructure dimension, overall the results do not show any statistically significant gap among the different elements of the infrastructural dimension. The study dwells into further analysis by engaging into an econometric framework related to a Probit Model, using the data collected, to gauge the effect of soft infrastructure on tourist intention to repeat or recommend the destination. The results confirm that soft infrastructure is found to be sensible to tourists, although relatively less sensitive as compared to tourism and transport and hotel infrastructure.

Keywords: tourism development, soft infrastructure, Mauritius, hotel infrastructure

Procedia PDF Downloads 467

Authors: Mohammad Faheem, M. Tabish Rehman, Mohd Danishuddin, Asad U. Khan

Abstract:

The worldwide dissemination of CTX-M type β-lactamases is a threat to human health. Previously, we have reported the spread of blaCTX-M-15 gene in different clinical strains of Enterobacteriaceae from the hospital settings of Aligarh in north India. In view of the varying resistance pattern against cephalosporins and other β-lactam antibiotics, we intended to understand the correlation between MICs and catalytic activity of CTX-M-15. In this study, steady-state kinetic parameters and MICs were determined on E. coli DH5α transformed with blaCTX-M-15 gene that was cloned from Enterobacter cloacae (EC-15) strain of clinical background. The effect of conventional β-lactamase inhibitors (clavulanic acid, sulbactam and tazobactam) on CTX-M-15 was also studied. We have found that tazobactam is the best among these inhibitors against CTX-M-15. The inhibition characteristic of tazobactam is defined by its very low IC50 value (6 nM), high affinity (Ki = 0.017 µM) and better acylation efficiency (k+2/K9 = 0.44 µM-1s-1). It forms an acyl-enzyme covalent complex, which is quite stable (k+3 = 0.0057 s-1). Since increasing resistance has been reported against conventional b-lactam antibiotic-inhibitor combinations, we aspire to design a non-b-lactam core containing b-lactamase inhibitor. For this, we screened ZINC database and performed molecular docking to identify a potential non-β-lactam based inhibitor (ZINC03787097). The MICs of cephalosporin antibiotics in combination with this inhibitor gave promising results. Steady-state kinetics and molecular docking studies showed that ZINC03787097 is a reversible inhibitor which binds non-covalently to the active site of the enzyme through hydrogen bonds and hydrophobic interactions. Though, it’s IC50 (180 nM) is much higher than tazobactam, it has good affinity for CTX-M-15 (Ki = 0.388 µM). This study concludes that ZINC03787097 compound can be used as seed molecule to design more efficient non-b-lactam containing b-lactamase inhibitor that could evade pre-existing bacterial resistance mechanisms.

Keywords: ESBL, non-b-lactam-b-lactamase inhibitor, bioinformatics, biomedicine

Procedia PDF Downloads 219

Authors: Titis Indah Adi Rahayu

Abstract:

Angiogenesis is the process of generating new capillary from pre-existing blood vessels. VEGFA is a major regulator in angiogenesis that binds and activates two tyrosine kinase receptors, VEGFR1 (Flt-1) and VEGFR2 (Flk-1/KDR) which regulate pathological and physiological angiogenesis. Disruption of VEGFA and VEGFR2 regulation lead to many diseases. The study of α-Mangostin (derivate of xanthone) as anti-oxidant and anti inflammation has been explored recently and both of them have relation to vasculature however the effect of α-Mangostin in blood vessel formation in healthy tissue in vivo has not been studied. Zebrafish is a powerful model in studying angiogenesis and shared many advantages that is a viable whole animal model for screening small molecules that affect blood vessel formation. Therefore the aim of this study is to evaluate angiogenic activity of α-Mangostin in healthy tissue in vivo in zebrafish embryo in relation of patterning blood vessel. Blood vessel patterning is highly characteristic in the developing of zebrafish embryo and the subintestinal vessel (SIV) can be stained and visualized microscopically as a primary screen for α-Mangostin that effect angiogenesis. The zebrafish embryos are divided into 2 groups. Group one consists of the zebrafish embryos at 1 dpf for 4 days which are tested to α-Mangostin in several concentration 2 µM, 4 µM, 6 µM, 8 µM and 10 µM whereas in group two the zebrafish larva at 4 dpf are exposed to α-Mangostin 1,75 µM, 2,3 µM, 2,9 µM, 3,8 µM dan 5 µM for 2 days. DMSO is served as a control for each group. The level expression of vegfa and vegfr2 are observed quantitatively using real time q-PCR and patterning of SIV are then analized via alkaline phospatase staining. Result shows that the level expression of vegfa and vegfr2 is repressed quantitatively as shown in real time q-PCR in the group of 1-4 days of α-Mangostin exposure where it is increased in the group of 4-6 days of α-Mangostin exposure. The result is then compared to alkaline phospatase staining of SIV using stereo microscope. It indicates that α-Mangostin does not disturb the patterning of SIV formation in zebrafish.

Keywords: angiogenesis, Danio rerio, α-Mangostin, SIV, vegfa, vegfr2

Procedia PDF Downloads 326

Authors: Jonahid Chakder, Mahfuzul Haque

Abstract:

Flash flood is among the foremost disastrous characteristic hazards which cause hampering within the environment and social orders due to climate change across the world. In Northeastern region of Bangladesh faces severe flash floods regularly, Such, the Khowai river is a flash flood-prone river. But until now, there are no previous studies about the flash flood of this river. Farmlands Building resilience, protection of crops & fish enclosures of wetland in Habiganj Haor areas, regional roads, and business establishments were submerged due to flash floods. The flash floods of the Khowai River are frequent events, which happened in 1988, 1998, 2000, 2007, 2017, and 2019. Therefore, this study tries to analyze Khowai river morphology, Precipitation, Water level, Satellite image, and Catchment characteristics: a catchment scale analysis that helps to comprehend Khowai river flash flood characteristics and factors of influence. From precipitation analysis, the finding outcome disclosed the data about flash flood accurate zones at the Khowai district watershed. The morphological analysis workout from satellite image and find out the consequence of sinuosity and gradient of this river. The sinuosity indicates that the Khowai river is an antecedent and a meandering river and a meandering river can’t influence the flash flood of any region, but other factors respond here. It is understood that the Khowai river catchment elevation analysis from DEM is directly influenced. The left Baramura and Right Atharamura anticline of the Khowai basin watershed reflects a major impact on the stratigraphy as an impermeable clay layer and this consequence the water passes downward with the drainage pattern and Tributary. This drainage system, the gradient of tributary and their runoff, and the confluence of water in the pre-monsoon season rise the Khowai river water level which influences flash floods (within six hours of Precipitation).

Keywords: geology, gradient, tributary, drainage, watershed, flash flood

Procedia PDF Downloads 106

Authors: Mohammad Karimi, Magnus Heurlin, Lars Samuelson, Magnus Borgstrom, Hakan Pettersson

Abstract:

Nanowire semiconductors are promising candidates for optoelectronic applications such as solar cells, photodetectors and lasers due to their quasi-1D geometry and large surface to volume ratio. The functional wavelength range of NW-based detectors is typically limited to the visible/near-infrared region. In this work, we present electrical and optical properties of IR photodetectors based on large square millimeter ensembles (>1million) of vertically processed semiconductor heterostructure nanowires (NWs) grown on InP substrates which operate in longer wavelengths. InP NWs comprising single or multiple (20) InAs/InAsP QDics axially embedded in an n-i-n geometry, have been grown on InP substrates using metal organic vapor phase epitaxy (MOVPE). The NWs are contacted in vertical direction by atomic layer deposition (ALD) deposition of 50 nm SiO2 as an insulating layer followed by sputtering of indium tin oxide (ITO) and evaporation of Ti and Au as top contact layer. In order to extend the sensitivity range to the mid-wavelength and long-wavelength regions, the intersubband transition within conduction band of InAsP QDisc is suggested. We present first experimental indications of intersubband photocurrent in NW geometry and discuss important design parameters for realization of intersubband detectors. Key advantages with the proposed design include large degree of freedom in choice of materials compositions, possible enhanced optical resonance effects due to periodically ordered NW arrays and the compatibility with silicon substrates. We believe that the proposed detector design offers the route towards monolithic integration of compact and sensitive III-V NW long wavelength detectors with Si technology.

Keywords: intersubband photodetector, infrared, nanowire, quantum disc

Procedia PDF Downloads 352

Authors: Amin Abbasi, Fariborz Shekari, Seyed Bahman Mousavi

Abstract:

Seed aging during storage is a complex biochemical and physiological processes that can lead to reduce seed germination. This phenomenon associated with increasing of total antioxidant activity during aging. To study the effects of hormones on seed aging, aged wheat seeds (control, 90 and 80% viabilities) were treated with GA3, Salicylic Acid, and paclobutrazol and antioxidant system were investigated as molecular biomarkers for seed vigor. The results showed that, seed priming treatment significantly affected germination percentage, normality seedling percentage, H2O2, MDA, CAT, APX, and GPX activates. Maximum germination percentage achieve in GA3 priming in control treatment. Germination percentage and normal seedling percentage increased in other GA3 priming treatment compared with other hormones. Also aging increased MDA, H2O2 content. MDA is considered sensitive marker commonly used for assessing membrane lipid peroxidation and H2O2result in toxicity to cellular membrane system and damages to plant cells. Amount of H2O2 and MDA declined in GA3 treatment. CAT, GPX and APX activities were reduced by increasing the aging time and at different levels of priming. The highest APX activity was observed in Salicylic Acid control treatment and the highest GPX and CAT activity was obtained in GA3 control treatment. The lowest MDA and H2O2 showed in GA3 control treatment, too. Hormone priming increased Antioxidant enzyme activity and decreased amount of reactive oxygen space and malondialdehyde (MDA) under aging treatment. Also, GA3 priming treatments have a significant effect on germination percentage and number of normal seedling. Generally aging seed, increase ROS and lipid peroxidation. Antioxidant enzymes activity of aged seeds increased after hormone priming.

Keywords: hormones priming, wheat, aging seed, antioxidant, lipid peroxidation

Procedia PDF Downloads 471

Authors: Brunno Vasques

Abstract:

Due to the non-toxic nature and high performance in terms of vacuum specific impulse and density specific impulse, the combination of liquid oxygen and liquid methane have been identified as a promising option for future space vehicle systems. Applications requiring throttling capability include specific missions such as rendezvous, planetary landing and de-orbit as well as weapon systems. One key challenge in throttling liquid rocket engines is maintaining an adequate pressure drop across the injection elements, which is necessary to provide good propellant atomization and mixing as well as system stability. The potential scalability of pintle injectors, their great suitability to throttling and inherent combustion stability characteristics led to investigations using a variety of propellant combinations, including liquid oxygen and hydrogen and fluorine-oxygen and methane. Presented here are the preliminary performance and heat transfer information obtained during hot-fire testing of a pintle injector running on liquid oxygen and liquid methane propellants. The specific injector design selected for this purpose is a multi-configuration building block version with replaceable injection elements, providing flexibility to accommodate hardware modifications with minimum difficulty. On the basis of single point runs and the use of a copper/nickel segmented calorimetric combustion chamber and associated transient temperature measurement, the characteristic velocity efficiency, injector footprint and heat fluxes could be established for the first proposed pintle configuration as a function of injection velocity- and momentum-ratios. A description of the test-bench is presented as well as a discussion of irregularities encountered during testing, such as excessive heat flux into the pintle tip resulting from certain operating conditions.

Keywords: green propellants, hot-fire performance, rocket engine throttling, pintle injector

Procedia PDF Downloads 311

Authors: ZhenlinJu, Christopher P. Vellano, RehanAkbani, Yiling Lu, Gordon B. Mills

Abstract:

The epithelial–mesenchymal transition (EMT) is a process by which epithelial cells acquire mesenchymal characteristics, such as profound disruption of cell-cell junctions, loss of apical-basolateral polarity, and extensive reorganization of the actin cytoskeleton to induce cell motility and invasion. A hallmark of EMT is its capacity to promote metastasis, which is due in part to activation of several transcription factors and subsequent downregulation of E-cadherin. Unfortunately, current approaches have yet to uncover robust protein marker sets that can classify tumors as possessing strong EMT signatures. In this study, we utilize reverse phase protein array (RPPA) data and consensus clustering methods to successfully classify a subset of cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) tumors into an EMT protein signaling group (EMT group). The overall survival (OS) of patients in the EMT group is significantly worse than those in the other Hormone and PI3K/AKT signaling groups. In addition to a shrinkage and selection method for linear regression (LASSO), we applied training/test set and Monte Carlo resampling approaches to identify a set of protein markers that predicts the EMT status of CESC tumors. We fit a logistic model to these protein markers and developed a classifier, which was fixed in the training set and validated in the testing set. The classifier robustly predicted the EMT status of the testing set with an area under the curve (AUC) of 0.975 by Receiver Operating Characteristic (ROC) analysis. This method not only identifies a core set of proteins underlying an EMT signature in cervical cancer patients, but also provides a tool to examine protein predictors that drive molecular subtypes in other diseases.

Keywords: consensus clustering, TCGA CESC, Silhouette, Monte Carlo LASSO

Procedia PDF Downloads 440

Authors: Emmanuel Kamal Aziz Saba, Gihan Abd El-Lateif Younis El-Tantawi, Mohammed Hamdy Zahran, Ibrahim Khalil Ibrahim, Mohammed Abd El-Salam Shehata, Hussein Al-Moghazy Sultan, Medhat

Abstract:

Pelvic floor electrophysiological tests are essential for assessment of patients with obstructed defecation. The present study was conducted to determine the different patterns of pelvic floor electrophysiology that are associated with obstructed defecation. The present cross sectional study included 25 patients with obstructed defecation. A control group of 20 apparently healthy subjects were included. All patients were subjected to history taking, clinical examination, proctosigmoidoscopy, lateral proctography (evacuation proctography), dynamic pelvic magnetic resonance imaging, anal manometry and electrophysiological studies. Electrophysiological studies were including pudendal nerve motor conduction study, pudendo-anal reflex, needle electromyography of external anal sphincter and puborectalis muscles, pudendal somatosensory evoked potential and tibial somatosensory evoked potential. The control group was subjected to electrophysiological studies which included pudendal nerve motor conduction study, pudendo-anal reflex, pudendal somatosensory evoked potential and tibial somatosensory evoked potential. The most common pelvic floor electrodiagnostic pattern characteristics of obstructed defecation was pudendal neuropathy, denervation and anismus of external anal sphincter and puborectalis with complete interference pattern of external anal sphincter and puborectalis at squeezing and cough and no localized defect in external anal sphincter. In conclusion, there were characteristic pelvic floor electrodiagnostic patterns associated with obstructed defecation.

Keywords: obstructed defecation, pudendal nerve terminal motor latency, pudendoanal reflex, sphincter electromyography

Procedia PDF Downloads 414

Authors: Meenakshi Chaubey

Abstract:

A principle proposed in the cross-cultural adaption of behavior among Indian and Tibetan societies in which there are not any great variations between their young adults on the mindset of day-to-day marriage, Marriage plays a dominant position in constructing the society, which in large part comprises underneath the domain of lifestyle. Way of life is a social behavior and norm located in human societies where an extensive range of phenomena can be transmitted thru social studying. It acts characteristic of the individual has been the diploma day-to-day which they have got cultivated a specific stage of class in arts, science, architecture. The existing studies preliminarily on young adults of each community, wherein we carried out a comparative observe of the mindset of daily marriage among Indian and Tibetan teens. Further, we studied statistics comprehensively on the mindset closer day by day the marriage between Indian adult males and Tibetan younger males. With the extension of a complete look, we considered the mindset of an everyday marriage of Indian girls and Tibetan young ladies. Studies 1 showed that there might be no sizable distinction within the attitude of the day-to-day marriage of Indian and Tibetan teenagers. It, in addition, showed that they followed each different marriage beliefs and customs. Studies 2 showed that there might be no important difference in the attitude toward the everyday marriage of Indian and Tibetan young males. It similarly showcased that day-to-day secular schooling gadget in Tibetan society complements their clinical approach and changes their point of view on distinct social issues along with marriage. Research three confirmed that there is no substantial difference in the mindset of the daily marriage of Indian and Tibetan younger females. It similarly spread out the strict authorities' recommendations that they may no longer be allowed day-to-day comply with their marriage practices, including polygamy and polyandry. Thus, the information showed that there's a shift of lifestyle from one network every day to some other community because of social every day, which affects the conduct and results of daily past cultural adaptation.

Keywords: culture, marriage, attitude, society, young adults, Indian, Tibetan

Procedia PDF Downloads 61

Authors: Kita R. Ashman, Anthony R. Rendall, Matthew R. E. Symonds, Desley A. Whisson

Abstract:

Forest cover is decreasing globally, chiefly due to the conversion of forest to agricultural landscapes. In contrast, the area under plantation forestry is increasing significantly. For wildlife occupying landscapes where native forest is the dominant land cover, plantations generally represent a lower value habitat; however, plantations established on land formerly used for pasture may benefit wildlife by providing temporary forest habitat and increasing connectivity. This study investigates the influence of landscape, site, and climatic factors on koala population density in far south-west Victoria where there has been extensive plantation establishment. We conducted koala surveys and habitat characteristic assessments at 72 sites across three habitat types: plantation, native vegetation blocks, and native vegetation strips. We employed a hierarchical modeling framework for estimating abundance and constructed candidate multinomial N-mixture models to identify factors influencing the abundance of koalas. We detected higher mean koala density in plantation sites (0.85 per ha) than in either native block (0.68 per ha) or native strip sites (0.66 per ha). We found five covariates of koala density and using these variables, we spatially modeled koala abundance and discuss factors that are key in determining large-scale distribution and density of koala populations. We provide a distribution map that can be used to identify high priority areas for population management as well as the habitat of high conservation significance for koalas. This information facilitates the linkage of ecological theory with the on-ground implementation of management actions and may guide conservation planning and resource management actions to consider overall landscape configuration as well as the spatial arrangement of plantations adjacent to the remnant forest.

Keywords: abundance modelling, arboreal mammals plantations, wildlife conservation

Procedia PDF Downloads 95

Authors: Abdul Basit Kiani

Abstract:

The software for the digital library system is a cutting-edge solution designed to revolutionize the way libraries manage and provide access to their vast collections of digital content. This advanced software leverages the power of technology to offer a seamless and user-friendly experience for both library staff and patrons. By implementing this software, libraries can efficiently organize, store, and retrieve digital resources, including e-books, audiobooks, journals, articles, and multimedia content. Its intuitive interface allows library staff to effortlessly manage cataloging, metadata extraction, and content enrichment, ensuring accurate and comprehensive access to digital materials. For patrons, the software offers a personalized and immersive digital library experience. They can easily browse the digital catalog, search for specific items, and explore related content through intelligent recommendation algorithms. The software also facilitates seamless borrowing, lending, and preservation of digital items, enabling users to access their favorite resources anytime, anywhere, on multiple devices. With robust security features, the software ensures the protection of intellectual property rights and enforces access controls to safeguard sensitive content. Integration with external authentication systems and user management tools streamlines the library's administration processes, while advanced analytics provide valuable insights into patron behavior and content usage. Overall, this software for the digital library system empowers libraries to embrace the digital era, offering enhanced access, convenience, and discoverability of their vast collections. It paves the way for a more inclusive and engaging library experience, catering to the evolving needs of tech-savvy patrons.

Keywords: software development, empowering digital libraries, digital cataloging and access, management system

Procedia PDF Downloads 51

Authors: Meimei Shi

Abstract:

Objectives: The identification of endangered species, especially simultaneous detection of multiple species in complex samples, plays a critical role in alleged wildlife crime incidents and prevents illegal trade. This study was to develop a multi-locus DNA metabarcoding method for endangered animal species identification. Methods: Several pairs of universal primers were designed according to the mitochondria conserved gene regions. Experimental mixtures were artificially prepared by mixing well-defined species, including endangered species, e.g., forest musk, bear, tiger, pangolin, and sika deer. The artificial samples were prepared with 1-16 well-characterized species at 1% to 100% DNA concentrations. After multiplex-PCR amplification and parameter modification, the amplified products were analyzed by capillary electrophoresis and used for NGS library preparation. The DNA metabarcoding was carried out based on Illumina MiSeq amplicon sequencing. The data was processed with quality trimming, reads filtering, and OTU clustering; representative sequences were blasted using BLASTn. Results: According to the parameter modification and multiplex-PCR amplification results, five primer sets targeting COI, Cytb, 12S, and 16S, respectively, were selected as the NGS library amplification primer panel. High-throughput sequencing data analysis showed that the established multi-locus DNA metabarcoding method was sensitive and could accurately identify all species in artificial mixtures, including endangered animal species Moschus berezovskii, Ursus thibetanus, Panthera tigris, Manis pentadactyla, Cervus nippon at 1% (DNA concentration). In conclusion, the established species identification method provides technical support for customs and forensic scientists to prevent the illegal trade of endangered animals and their products.

Keywords: DNA metabarcoding, endangered animal species, mitochondria nucleic acid, multi-locus

Procedia PDF Downloads 113