Evaluation of luminous efficacy models against Japanese data: Technical note

This note presents the evaluation of Perez and other simpler luminous efficacy models for Japan using the data now emerging from the CIE International Daylight Measurement Proaramme. The results indicate that the perez model, although exhibiting a low scatter, has a tendency to consistently underpredict global and diffuse illuminance while it heavily overpredicts zenith luminance. The average-values for global and diffuse luminous efficacies for Fukuoka data have been found to be significantly different from the ones reported for other geographical locations.     

Solar operated absorption air-conditioner for a Kufra house

The use of solar energy for domestic water heating and space heating has proved to be viable. Space cooling is another promising avenue for utilization of solar energy. Solar operated absorption air-conditioning systems, in different situations, have been found to be feasible. Such systems can make use of the expensive collectors which are, in any case, installed for water and space heating.

In this paper the cooling of a prototype house, in Kufra, is reported. Starting with measured radiation and ambient data, calculations are performed on an hourly basis to determine the cooling load, radiation in the collector plane, heat delivered by the collectors and the heat stored in or discharged from the storage tank. Three different types of collectors with varying efficiencies are considered. These collectors are of the evacuated tube, selective coated and black painted types. The study confirms that the water-lithium bromide absorption system can provide summer air conditioning in arid zones of Jamahiriya where there are diffuclties with the supply of electricity and fossil fuels.     

Location-Aware Personalized Traveler Recommender System (LAPTA) Using Collaborative Filtering KNN

Many tourists who travel to explore different cultures and cities worldwide aim to find the best tourist sites, accommodation, and food according to their interests. This objective makes it harder for tourists to decide and plan where to go and what to do. Aside from hiring a local guide, an option which is beyond most travelers’ budgets, the majority of sojourners nowadays use mobile devices to search for or recommend interesting sites on the basis of user reviews. Therefore, this work utilizes the prevalent recommender systems and mobile app technologies to overcome this issue. Accordingly, this study proposes location-aware personalized traveler assistance (LAPTA), a system which integrates user preferences and the global positioning system (GPS) to generate personalized and location-aware recommendations. That integration will enable the enhanced recommendation of the developed scheme relative to those from the traditional recommender systems used in customer ratings. Specifically, LAPTA separates the data obtained from Google locations into name and category tags. After the data separation, the system fetches the keywords from the user’s input according to the user’s past research behavior. The proposed system uses the K-Nearest algorithm to match the name and category tags with the user’s input to generate personalized suggestions. The system also provides suggestions on the basis of nearby popular attractions using the Google point of interest feature to enhance system usability. The experimental results showed that LAPTA could provide more reliable and accurate recommendations compared to the reviewed recommendation applications.     

Nanoscale investigation of charge transport at the grain boundaries and wrinkles in graphene film

The influence of grain boundaries and mechanical deformations in graphene film on the electric charge transport is investigated at nanoscale with conductive atomic force microscopy. Large area monolayer graphene samples were prepared by the chemical vapor deposition technique. Field emission scanning electron microscopy confirmed the formation of grain boundaries and the presence of wrinkles. The presence of the D-band in the Raman spectrum also indicated the existence of sharp defects such as grain boundaries. Extremely low conductivity was found at the grain boundaries and the wrinkled surface was also more resistive in comparison to the plain graphene surface. Many samples were experimented with to justify our findings by selecting different areas on the graphene surface. Uniform conductivity was found on grain boundary and wrinkle free graphene surfaces. We made channels of varied lengths by local anodic oxidation to confine the charge carrier to the smallest dimensions to better confirm the alteration in current due to grain boundaries and wrinkles. The experimental findings are discussed with reference to the implementation of graphene as transparent conductive electrode.     

Performance Evaluation of AOMDV on Realistic and Efficient VANet Simulations

Wireless Personal Communications - The digital transmission amongst vehicles and roadway equipment is necessary for the realization of smart transportation systems. Vehicular ad-hoc network (VANet)...     

A Broadband High Gain Tapered Slot Antenna for Underwater Communication in Microwave Band

Named Data Networking (NDN), an emerging communication model in the content centric networks, has recently presented a solid framework for the future Internet. The NDN exploits content name instead of host name (IP address) and content caching. These features make NDN particularly efficient in networks with intermittent connectivity and dynamic topologies such as mobile ad hoc networks (MANETs). Due to the structure of NDN nodes, design of forwarding strategies has a vital impact on the network performance. In this paper, we propose a new forwarding strategy: redundancy elimination forwarding (REF). In REF, the NDN node structure and the operation of the data structures are modified. These modifications improve network performance in terms of throughput, overhead and resource requirements. REF strategy is simulated in different scenarios based on ndnSIM and the results demonstrate that it provides robust performance for various environments.

     

A novel IoT–fog–cloud-based healthcare system for monitoring and predicting COVID-19 outspread

The Journal of Supercomputing - Rapid communication of viral sicknesses is an arising public medical issue across the globe. Out of these, COVID-19 is viewed as the most critical and novel...     

Adoption of biomass improved cookstoves in a patriarchal society: an example from Sudan

The economic, social, ecological and environmental roles and benefits of forests are obvious and need no emphasis. Inefficient use of fuel wood is considered one of the important causes of deforestation. Use of more efficient improved cookstoves is proposed as one of the measures that can reduce demand for fuel wood and charcoal and help in lowering the annoying deforestation rate in many developing countries. During the 1980s and 1990s several programs aiming at testing and disseminating energy saving technologies were implemented in Sudan. One of these technologies was improved cookstoves, which was intended to increase the efficiency of using energy from biomass sources. This study is carried out to examine the adoption rate and the factors affecting adoption of improved cookstoves in Khartoum State. The study is based on primary data collected through personal interviews with husbands and wives in 300 randomly selected households. Regression analysis was used to analyze the data. The results showed that the device's adoption rate was very low. The improved cookstove's relative advantage, housewife's exposure to messages about improved cookstoves, educational level of the housewife and the average educational level of the female household's members had significant positive effect on the household's innovativeness regarding adoption of improved cookstove. Wife's age and the educational level of the husband had negative significant effects. In the Sudanese patriarchal society all the household domestic tasks, particularly food preparation and related activities, are considered women's responsibilities and all the decisions related to them are taken by women. Therefore, these results could be understood as a reflection of the division of labor, gender relations and decision-making process in the Sudanese household.     

Comparative photocatalytic study of two selected pesticide derivatives, indole-3-acetic acid and indole-3-butyric acid in aqueous suspensions of titanium dioxide

Heterogeneous photocatalysed degradation of two selected pesticide derivatives such as indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) has been investigated in aqueous suspensions of titanium dioxide by monitoring the change in substrate concentration employing UV spectroscopic analysis technique and depletion in total organic carbon (TOC) content as a function of irradiation time. The degradation kinetics was studied under different conditions such as pH, types of TiO_2, substrate and catalyst concentration, and in the presence of electron acceptor such as hydrogen peroxide (H₂O₂) besides molecular oxygen. The degradation rates were found to be strongly influenced by all the above parameters. The photocatalyst Degussa P25 showed comparatively highest photocatalytics. The pesticide derivative, indole-3-acetic acid was found to degrade slightly faster than indole-3-butyric acid.     

Sol-air temperature and daylight illuminance profiles for the UKCP09 data sets

To provide information on climate change, the UK Climate Impacts Programme (UKCIP) provided the latest UKCP09 data to a resolution of 5 km square grids for the UK. Those data sets were used in this study along with the historical measured data for two locations—Bracknell (London) and Edinburgh—to critically analyse the likely changes that may occur in the sol-air temperature and daylight illuminance profiles. These parameters have an important bearing on the design and function of buildings and building services.