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In this paper, we propose a novel energy-aware and density-based clustering and routing protocol (EA-DB-CRP) for gathering data in wireless sensor networks which basically aims at distributing the load among available sensor nodes which in turn balances the energy consumption in the network and consequently elongates the network lifetime. More precisely, we introduce a network model that ends up of having empirical expressions that describe how to partition the network field efficiently into equal-size layers and sub-layers. In each sub-layer, the role of cluster head is pivoted among all cluster individuals, in a round robin fashion, that are sorted in a list in a descending order based on an extremely effective cluster head weight. Additionally, there are a minimum number of cluster members maintained to guarantee the feasibility of clusters being formed and this is through proposing a cluster merge algorithm. Not only to this extent, but rather, we maintain the consideration of network density over created clusters to balance them and subsequently prolong the network lifetime. Lastly, an effective relaying algorithm is proposed in which cluster heads get aware of those sensor nodes located in a layer ahead toward the base station along with their relay-node weights whereas each cluster head picks the relay node that has the highest weight. Our proposed protocol is evaluated through conducting various MATLAB simulations. Strikingly, results demonstrated that our proposed protocol has a momentous change against other related works regarding network lifetime and energy use.

This paper proposes a novel energy-aware and layering-based clustering and routing protocol (EA-CRP) for gathering data in WSNs. The main goal of EA-CRP is to reduce the energy consumption among all sensor nodes in the network. To achieve this goal, EA-CRP employs an innovative multilayered architecture. More specifically, we divide the field into a number of layers where the width of a layer not only decreases towards the base station, but also is composed of a certain number of clusters (sub layers). The proposed design not only shortens the communication distance between nodes, but also decreases the amount of communication overhead required for setting up clusters. Furthermore, a multi-hop routing algorithm for inter-cluster communications is proposed which basically considers the tradeoff between distance and the energy of relaying nodes. The effectiveness of EA-CRP is verified through comparing its results with those obtained from previous relevant protocols. Interestingly, our experimental results show that EA-CRP has superior performance in term of network lifetime, energy efficiency, and scalability.

As the research community is moving toward 5G technology, it is important to keep up this growth by developing new technologies and mechanisms that fulfill its requirements such as spectrum availability, wireless connectivity and coverage. Visible Light Communication (VLC) has been proposed as an efficient way of utilizing the visible wireless spectrum for proving lightning and carrying information utilizing the highly available visible spectrum. In this paper, an experimental evaluation and prototyping are presented utilizing off-the-shelf electronic components and the Telecommunications Instructional Modelling System (TIMS), which is a flexible modelling and prototyping technique widely used for building communication systems. The proposed prototypes are supported by a survey that was conducted among engineering students to get their feedback in regards to VLC, TIMS and 5G technologies. The aim of this paper is to provide the means to pave the way toward educating the students and new technology adopters concerning VLC along with facilitating its deployment.

The current study aimed the syntheses and characterizations of Gold nanoparticles (Au NPs) using a laser ablation Q-switched Nd: YAG laser with a wave-length of 355 nm at a variety of laser pulse energies (E) and deposited on porous silicon (PS). Optical emission spectrometer was used to diagnosed medium air to study gold plasma characteristics and prepared Au nanoparticles. The laser pulse energy influence has been studied on the plasma characteristics in air. The data showed the emergence of the ionic (Au II) spectral emission lines in the gold plasma emission spectrum. XRD has been utilized to examine structural characteristics. Moreover, AFM results 37.2 nm as the mean value of the diameter that is coordinated in a shape similar to the rod that appears for Au NPs, in addition to that, TEM has been an indication of the fact that synthesized Au NPs were spherical with a mean size of particles, ranging from 25 nm to 30 nm. At high laser pulse energy, the intensity of all emission peaks in the air at atmospheric pressure was considerably greater. Finally, variations in the operating temperature associated with the NH3 gas sensor, created from the samples that have been prepared on the sensitivity of the sensor and response time have been evaluated, the maximal sensitivity is nearly 41% concerning Au NPs that have been ablated via laser energy (E) 400 mJ on the porous silicon of the NH3 gas.

The possibility of Internet of Things (IoT) is that a large number of live items (e.g., apparatuses) in the network are available, detected, and interconnected. In any case, the performance of IoT networks may be limited due to several impairments, most importantly, the energy-constrained IoT nodes. In fact, this limitation opens the door to many researchers where using network clustering has proven to be efficient energy saving mechanism. To the best of our knowledge, there are no prior research, in the field of multi-hop clustered IoT networks, which addressed the energy-constrained IoT nodes problem along with the delay in receiving data messages from devices, located far away from the remote users (or control center), in timely basis. Practically, it is significantly challenging to contemplate and clarify this issue. Consequently, in this paper, we make major amendments on the prior work, Improved Energy and Distance Based CH Selection with Balanced Objective Function (IEDB-CHS-BOF), and particularly propose a multi-hop routing (MR) protocol in which the IoT network is divided into a number of virtual sections with lengths held below the cross-over communication distance, thereby ensuring minimal energy depletion. Over those virtual sections, efficient forwarder and cluster head selection algorithms are further proposed. Interestingly, we propose a novel delay-, power-, and interference-aware time slot allocation model in which Time Division Multiple Access (TDMA) and Direct Sequence Spread Spectrum (DSSS) MAC protocols are operated. Furthermore, it is a good representation of the above-mentioned proposals. As a result, our protocols are referred to as MR-IEDB-CHS-TDMA and MR-IEDB-CHS-DSSS, respectively. To this end, numerous simulations have been conducted for evaluating the performance of the proposed protocols in the perspective of IoT network lifetime. In addition, sufficient comparisons have been conducted with the existing state-of-the-art protocols. In overall, the MR-IEDB-CHS-TDMA protocol keeps the IoT network functioning the longest.

Hexamethylene diisocyanate (HDI) is an important industrial chemical that can cause asthma, however pathogenic mechanisms remain unclear. Upon entry into the respiratory tract, HDI's N=C=O groups may undergo nucleophilic addition (conjugate) to host molecules (e.g. proteins), or instead react with water (hydrolyze), releasing CO2 and leaving a primary amine in place of the original N=C=O. We hypothesized that (primary amine groups present on) hydrolyzed or partially hydrolyzed HDI may compete with proteins and water as a reaction target for HDI in solution, resulting in polymers that could be identified and characterized using LC-MS and LC-MS/MS. Analysis of the reaction products formed when HDI was mixed with a pH buffered, isotonic, protein containing solution identified multiple [M+H]+ ions with m/z's and collision-induced dissociation (CID) fragmentation patterns consistent with those expected for dimers (259.25/285.23 m/z), and trimers (401.36/427.35 m/z) of partially hydrolyzed HDI (e.g. ureas/oligoureas). Human peripheral blood mononuclear cells (PBMCs) and monocyte-like U937, but not airway epithelial NCI-H292 cell lines cultured with these HDI ureas contained a novel 260.23 m/z [M+H]+ ion. LC-MS/MS analysis of the 260.23 m/z [M+H]+ ion suggest the formula C13H29N3O2 and a structure containing partially hydrolyzed HDI, however definitive characterization will require further orthogonal analyses.

This paper presents a new decision-gathering scheme that aims at detecting a critical event in an Area of Interests (AoI), where a wireless sensor network is deployed in a group of clusters. The proposed scheme assigns a single time slot for each cluster, where all cluster members simultaneously report their binary decisions to the cluster head on that time slot. As the cluster head is interested in the sum of the binary decisions (not the exact binary decisions), the performance loss due to the concurrent transmission is insignificant compared to the co-channel interference induced from other clusters based on conventional schemes. The main advantage of the proposed scheme is that it avoids the co-channel interference between different clusters and assures minimal delay in detecting the critical event, which is very crucial in many security related applications and scenarios. Both simulation and mathematical analysis of the overall decision-error probability of the proposed scheme are carried out, which demonstrate the effectiveness of the proposed scheme.

The present work investigated the discharge characteristics in the magnetized hollow cathode system. Also, the gas pressure effect on the discharge characteristics has been examined with a gas pressure between (0.08 and 0.4) Torr. The voltage-current curve of magnetized hollow cathode discharges has the voltage become approximately constant with slight increases in current. The normal glow discharge was established with constant voltage and increasing current. When the current is increased even more, then, the discharge turns into a mode comparable to the normal glow discharge between the parallel electrodes. The increasing of the pressure causes compressing of the cathode falls inside the cathode cavity and the negative glow becomes thin and more luminous. The spectroscopic method used depends on analyzing the argon’s emission atomic spectra. The electron temperature has been evaluated with the use of Boltzmann plot approach. The influence of the pressure on electron temperature observed the reduction in electron temperature when the pressure is increased. The electron number density has been calculated with the use of the Stark broadening method. The density curve indicated that the increase in electron number density with increasing of pressure until 0.4 Torr and then reduced with pressure exceeds 0.4 Torr.

This work aim to achieving laser nano-textured Si structures by means of an ultra-fast ultra-violet femtosecond (fs) laser texturing technique. The evidences of the impact of the duration of irradiation of the femtosecond laser pulses on Silicon (Si) have been investigated experimentally. A Ti:Sapphire laser at 800 nm (130 fs pulse duration with 1 kHz rate of repetition) has been employed to create nano-textured surfaces in an n-type (111) Si wafer of 0.015 Ω.cm resistivity and 508 ± 5 μm thickness. The average sizes of diameters were estimated to be in the 25−45 nm. From PL measurements of Si nanostructures, size dependent shifts in the direction of the blue spectral region have been emphasized. A highly symmetrical band shape was recognized from the samples' Raman spectra after the irradiation, the phonon frequency (phonon peak shift) shifted below 520 cm−1. The surface nanostructured Si showed lower reflectance values compared with bulk Si (un-irradiated). The observed enhancement of the fabricated Si nanostructures broad spectral response, which is in the range between the visible to the near infrared (NIR) 400−1150 nm, was attributed to increasing light absorption within sub-nanostructures. Thus, the proposed technique could be a promising approach to enhance the performance of Si-based photo-detector.

Contemporary smart sensing paradigms, that are provided via diverse Internet of Things (IoT) mechanisms, propagate across considerable domains of daily life, such as health, agriculture, transportation, trade sectors to urban environments and smart cities. The new era of revolution in information technology will rely on processing and analyzing big data that are gathered by tremendous numbers of intelligent sensors, which are disseminated in the surrounding regions. However, most of these devices suffer from restrictions on power resources and processing capabilities, which in turn will enforce stringent restrictions on the network operations. In view of this, the development of novel and efficient energy algorithms for IoT paradigm is a challenging issue bearing in mind that the performance of this state-of-the-art network paradigm cannot be handled effectively by the existing techniques or solutions that are utilized in wireless sensor networks. To meet the requirements of maximizing the IoT network lifetime, we address in this work the challenge of IoT networks as of embedding energy-constrained devices by proposing a novel protocol, namely, Life Time Maximizing Based on Analytical Hierarchal Process and Genetic Clustering (LiM-AHP-G-C) protocol. In particular, the proposed protocol presents a novel optimal clustering algorithm for un-rechargeable battery-powered IoT devices, an efficient IoT heads selection algorithm, a heuristic method for optimal hop selection, and a model for avoiding intra- and inter-cluster interferences for IoT networks. The simulation results show that our proposed protocol outperforms the other existing works in terms of network lifetime, resource utilization, and scalability metrics.