587 research outputs found
Research on the Application of E-commerce to Small and Medium Enterprises (SMEs): the Case of India
SMEs account for a large proportion and play an important role in the development of each country in the world, including India. The globalization will bring many advantages for enterprises however SMEs will face fierce competition at the local, national and International level. In order to maintain and promote the important role of SMEs in the context of increased competition, SMEs have to change and adopt new technologies. E-commerce and digital technologies are bringing opportunities to help SMEs improve their competitiveness, narrow the gap with big enterprises thanks to their fairness and flexibility of the digital business environment. According to UNIDO (2017), India is one of the countries successfully applying e-commerce to SMEs. Contributing to this success is the important role of the Indian government. Therefore, this paper focuses on researching the application of e-commerce to SMEs in terms of the role of government in promoting and creating an ecosystem for SMEs and e-commerce development
Experimental Evaluation of Geopolymer Concrete Strength Using Sea Sand and Sea Water in Mixture
This paper presents the experimental strength evaluation of geopolymer concrete and ordinary concrete using sea sand and seawater in the mixture. A series of 30 cubic samples with a 150 mm side length and 12 rectangular specimens with a dimension of 100 × 100 × 400 mm (width × thickness × length) were cast and tested in this study. Specimens were divided equally into two groups. The first group of specimens was cast using geopolymer as the main binder (GPC), while the second group of samples was made using ordinary Portland Cement (OPC). While the compression tests were performed for specimens in two groups at the ages of 3, 7, 28, 60, and 120 days, the tensile tests were only performed for specimens at 7 and 28 days. The testing results revealed that the compression strength of GPC specimens using sea sand and seawater was significantly higher than that of OPC samples using the same type of salted sand and water. Besides, the use of sea sand and seawater for replacing river sand and fresh water in the production of GPC is feasible in terms of compressive strength since GPC produces a higher compressive strength than that of conventional concrete. Doi: 10.28991/CEJ-2022-08-08-03 Full Text: PD
Rateless codes-based secure communication employing transmit antenna selection and harvest-to-jam under joint effect of interference and hardware impairments
In this paper, we propose a rateless codes-based communication protocol to provide security for wireless systems. In the proposed protocol, a source uses the transmit antenna selection (TAS) technique to transmit Fountain-encoded packets to a destination in presence of an eavesdropper. Moreover, a cooperative jammer node harvests energy from radio frequency (RF) signals of the source and the interference sources to generate jamming noises on the eavesdropper. The data transmission terminates as soon as the destination can receive a sufficient number of the encoded packets for decoding the original data of the source. To obtain secure communication, the destination must receive sufficient encoded packets before the eavesdropper. The combination of the TAS and harvest-to-jam techniques obtains the security and efficient energy via reducing the number of the data transmission, increasing the quality of the data channel, decreasing the quality of the eavesdropping channel, and supporting the energy for the jammer. The main contribution of this paper is to derive exact closed-form expressions of outage probability (OP), probability of successful and secure communication (SS), intercept probability (IP) and average number of time slots used by the source over Rayleigh fading channel under the joint impact of co-channel interference and hardware impairments. Then, Monte Carlo simulations are presented to verify the theoretical results.Web of Science217art. no. 70
Roles of Matrix Metalloproteinases in Cutaneous Wound Healing
Wound healing is a complex process that consists of hemostasis and inflammation, angiogenesis, re-epithelialization, and tissue remodeling. Matrix metalloproteinases (MMPs) play important roles in wound healing, and their dysregulation leads to prolonged inflammation and delayed wound healing. There are 24 MMPs in humans, and each MMP exists in three forms, of which only the active MMPs play a role in the pathology or repair of wounds. The current methodology does not distinguish between the three forms of MMPs, making it challenging to investigate the roles of MMPs in pathology and wound repair. We used a novel MMP-inhibitor-tethered affinity resin that binds only the active form of MMPs, from which we identified and quantified active MMP-8 and active MMP-9 in a murine diabetic model with delayed wound healing. We showed that up-regulation of active MMP-9 plays a detrimental role whereas active MMP-8 is involved in repairing the wound in diabetic mice. These studies identified MMP-9 as a novel target for therapeutic intervention in the treatment of chronic wounds. A selective inhibitor of MMP-9 that leaves MMP-8 unaffected would provide the most effective therapy and represents a promising strategy for therapeutic intervention in the treatment of diabetic foot ulcers
On the Electrostatic Forces acting on Point Charges in the Presence of a Dielectric Slab
How will the electrostatic interaction between two point charges change if we
introduce a dielectric slab in the middle of them? While the physical setting
of this problem is relatively simple, it is easy to be wronged and the solution
is surprisingly complicated. Here we will show the correct answer by using the
method of images, which should be approachable for undergraduate students and
advance high school students. We also obtain analytical and algebraic results
in some special cases
Protein hydrolysates produced from rock lobster (Jasus edwardsii) Head: emulsifying capacity and food safety
his is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Lobster protein hydrolysates (LPH) were produced by an enzymatic process using a proteinase Alcalase, and a chemical process at strong alkaline condition (pH of 14), from rock lobster head (RLH), respectively. The chemical process recovered about 30% more protein than the enzymatic process (84.9% recovery of total protein in RLH by the chemical process and 54.5% recovery of total protein in RLH by the enzymatic process). The emulsifying capacity of LPH produced by the chemical process (69.7 m2/g) was significantly higher than the emulsifying capacity of the LPH produced by the enzymatic process (20.7 m2/g), and also exceeds the emulsifying capacity of cow gelatine (50.3 m2/g), a commercial emulsifier in the food industry. LPH produced by the chemical process possess 30.3% essential amino acids. This content is comparable with the essential amino acid content of fish protein, a commonly recognized food resource for essential amino acid supplement for human. The content of heavy metals, including inorganic arsenic, of LPH is lower than the standard levels regulated by Food Standard Australia and New Zealand (FSANZ). These results demonstrated the potential value of LPH used as a safe emulsifier with significant nutritional value for the food industry
Effects of foundation mass on dynamic responses of beams subjected to moving oscillators
This paper aims at the effects of foundation mass on the dynamic responses of beams subjected to moving oscillators. To achieve this aim, experiments were performed for a beam resting on the foundation considering effects of the foundation model including linear elastic spring, shear layer, viscous damping. In addition, special effects of mass density of foundation during vibration were established to obtain the characteristic parameter of the influence of foundation mass based on natural circular frequency of the structure system determined from FFT plots of the time history of acceleration data. Furthermore, the experimental parameters were used to analyze the influence of the foundation mass on the dynamic response of the beam subjected to moving oscillator. Comparisons between experimental and simulated results showed that the foundation mass showed significant effects on the dynamic characteristic response of the beam system. It increased the general vibrating mass of the structure system. Hence, it decreased of the natural frequency of the structural system and caused a significant increase on the dynamic response of the beam when compared with the case without considering the foundation mass. Finally, the relationships between the foundation properties and the parameters of foundation mass were derived and discussed
The influence of foundation mass on dynamic response of track-vehicle interaction
The influence of foundation mass on the dynamic response of track-vehicle interaction is studied in this paper. The moving vehicle is modeled as a two-axle mass-spring-damper four-degrees-of-freedom system. A new dynamic foundation model, called "Dynamic foundation model" including linear elastic spring, shear layer, viscous damping and foundation mass parameter, is used to analyze the dynamic response of the track-vehicle interaction. The railway track on the new dynamic foundation model subjected to a moving vehicle is regarded as an integrated system. By means of the finite element method and dynamic balance principle, the governing equation of motion for railway track-vehicle-foundation interaction is derived and solved by the step-by-step integration method. The accuracy of the algorithm is verified by comparing the numerical results with the other numerical results in the literature. The influence of foundation mass parameter on the dynamic response of railway track-vehicle interaction is investigated. The numerical results show that with the new dynamic foundation model the foundation mass effects more significantly on the dynamic response of track-vehicle interaction. The study shows that the new dynamic foundation model describes the true behavior of soil in the analysis of dynamic response of structures on the foundation
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