bluuebunny/crossref_metadata_2025 huggingface dataset:
The study of spatial autocorrelation for infectious disease epidemiology decision-making: a systematized literature review
Authors: Mergenthaler Christina , Gurp Margo , Rood Ente , Bakker Mirjam
Published: August 2022

In recent years, the global spread of communicable diseases such as Ebola and COVID-19 has stressed the need for clear, geographically targeted, and actionable public health recommendations at appropriate spatial scales. Country-level stakeholders are increasingly utilizing spatial data and spatial decision support systems to optimize resource allocation, and researchers have access to a growing library of spatial data, tools, and software. Application of spatial methods, however, varies widely between researchers, resulting in often unstandardized results, which may be difficult to compare across geographical settings. This literature review aims to compare epidemiological studies, which applies methods including spatial autocorrelation to describe, explain, or predict spatial patterns underlying infectious disease health outcomes, and to describe whether those studies provide clear recommendations. The results of our analysis show an increasing trend in the number of publications applying spatial analysis in epidemiological research per year, with COVID-19, tuberculosis and dengue predominantly studied (43% of n = 98 total articles), and a majority of publication coming from Asia (62%). Spatial autocorrelation was quantified in the majority of studies (72%), and 57 (58%) of articles include some form of statistical modeling of which 11 (19%) accounted for spatial autocorrelation in the model. Most studies (68%) provided some level of recommendation regarding how results should be interpreted for future research or policy development, however often using vague, cautious terms. We recommend the development of standards for spatial epidemiological methods and reporting, and for spatial epidemiological studies to more clearly propose how their findings support or challenge current public health practice.
Suckling strategies in terrestrial ungulates (Artiodactyla, Perissodactyla) and the factors influencing them: the offspring perspective
Authors: Skok Janko
Published: August 2022

In order to survive, ungulate young obtain their mother’s colostrum and milk through a variety of suckling strategies. Here, these strategies and the factors that influence them are reviewed and interpreted primarily from the perspective of the young. Suckling strategies are determined by a variety of factors, some of which play a role even before birth. Neonatal suckling behaviour depends first on the type of placenta and the developmental stage of the young at birth. Ungulates have an epitheliochorial placenta in which transplacental transport of immunoglobulins is impeded. Therefore, they are born in a hypo−/agammaglobulinemic state hence, timely intake of sufficient colostrum is a life-or-death situation and an unsuccessful suckling strategy is likely to result in death. Precociality enables the newborn ungulate to actively participate in the suckling process immediately after birth, which is critically important. After the prenatally defined physiological needs are satisfied, young suckling strategy is influenced by other factors. Continuous milk production requires constant use and stimulation of the mammary gland. Brain lateralization has also been found to play a role in suckling behaviour. Finally, competition between siblings or peers in the social group also influences young suckling strategies. Sibling competition particularly affects polytocous ungulates and leads to suckling order, for example. Similarly, interactions within the social group create the conditions for the emergence of specific strategies, including allosuckling, strategy of suckling a non-filial mother. The young suckling strategies in ungulates basically represent an evolutionary intertwining of offspring selfishness and selection that maximises inclusive fitness.
Sheldon Penman: Visionary of cell form and function
Authors: Pederson Thoru
Published: August 2022

Sheldon Penman made major contributions to the field of RNA synthesis and, more broadly, the nexus between cellular form and gene readout. He will be remembered for his creativity and breadth of expertise, as well as his opposition to what he believed were threatening incursions into science by corporate interests.
Biallelic PAX5 mutations cause hypogammaglobulinemia, sensorimotor deficits, and autism spectrum disorder
Authors: Kaiser Fabian M.P. , Gruenbacher Sarah , Oyaga Maria Roa , Nio Enzo , Jaritz Markus , Sun Qiong , van der Zwaag Wietske , Kreidl Emanuel , Zopf Lydia M. , Dalm Virgil A.S.H. , Pel Johan , Gaiser Carolin , van der Vliet Rick , Wahl Lucas , Rietman André , Hill Louisa , Leca Ines , Driessen Gertjan , Laffeber Charlie , Brooks Alice , Katsikis Peter D. , Lebbink Joyce H.G. , Tachibana Kikuë , van der Burg Mirjam , De Zeeuw Chris I. , Badura Aleksandra , Busslinger Meinrad
Published: August 2022

The genetic causes of primary antibody deficiencies and autism spectrum disorder (ASD) are largely unknown. Here, we report a patient with hypogammaglobulinemia and ASD who carries biallelic mutations in the transcription factor PAX5. A patient-specific Pax5 mutant mouse revealed an early B cell developmental block and impaired immune responses as the cause of hypogammaglobulinemia. Pax5 mutant mice displayed behavioral deficits in all ASD domains. The patient and the mouse model showed aberrant cerebellar foliation and severely impaired sensorimotor learning. PAX5 deficiency also caused profound hypoplasia of the substantia nigra and ventral tegmental area due to loss of GABAergic neurons, thus affecting two midbrain hubs, controlling motor function and reward processing, respectively. Heterozygous Pax5 mutant mice exhibited similar anatomic and behavioral abnormalities. Lineage tracing identified Pax5 as a crucial regulator of cerebellar morphogenesis and midbrain GABAergic neurogenesis. These findings reveal new roles of Pax5 in brain development and unravel the underlying mechanism of a novel immunological and neurodevelopmental syndrome.
Fueling the fire in the gut
Authors: Lin Chia-Hao , Lu Li-Fan
Published: August 2022

Gut dysbiosis has long been associated with the development of Crohn’s disease and other gastrointestinal disorders. Otake-Kasamoto et al. (2022. J. Exp. Med.https://doi.org/10.1084/jem.20211291) report that dysbiotic microbiota-derived bioactive lipids, lysophosphatidylserines, can promote pathological Th1 cell responses through inducing metabolic reprogramming and epigenetic changes.
Nonlinear optical absorption of Co3(PO4)2·4H2O nanosheets in broadband spectra
Authors: Wang Chang , Duan Ran , Xiao Xingcheng , Wang Yingwei , Chen Zhihui , Li Yejun , Xiao Si , He Jun
Published: August 2022

Long hexagonal Co3(PO4)2·4H2O nanosheets were synthesized using a hydrothermal method, where their nonlinearity was probed via a femtosecond Z-scan system. The results show that the Co3(PO4)2·4H2O nanosheets exhibit saturable absorption when the incident photon energy is greater than the forbidden band width, while optical limiting is found when the incident photon energy is smaller than the forbidden band width. In particular, the obtained Co3(PO4)2·4H2O nanosheets demonstrate the best optical limiting properties at 600 nm. The present study suggests the cobalt phosphates nanosheets as a promising candidate for optical limiters.
Power management strategy for unidirectional current pulsed triboelectric nanogenerator
Authors: Zhang Zhihao , Gu Guangqin , Gu Guangxiang , Cheng Gang , Du Zuliang
Published: August 2022

Power management circuit (PMC) can efficiently store the output energy of pulsed triboelectric nanogenerator (Pulsed-TENG). Unidirectional current Pulsed-TENG (UP-TENG) has the advantage of without using rectifier bridge. However, the energy storage efficiency is limited for large capacitors at low capacitor voltage (<10 V). To solve this problem, PMC is optimized here. Firstly, rectifier diode is used to reduce the energy loss. Energy storage efficiency of PMC using rectifier diode (D-PMC) is higher than that of conventional PMC. Then, appropriate inductor is used to further form the optimized PMC (O-PMC), which reduces the energy loss of inductor. Results show that O-PMC using 100 μH inductor has the highest energy storage efficiency. The actual test energy storage efficiency of O-PMC is 30.6%, which 3.4 times higher than that of D-PMC. Finally, an external capacitor is connected to electrodes of UP-TENG to form the EUP-TENG, which improves charging speed and output voltage of O-PMC. O-PMC using EUP-TENG can stably power calculator at low motion frequencies. O-PMC can be widely used in self-powered systems.
Leveraging negative capacitance ferroelectric materials for performance boosting of sub-10 nm graphene nanoribbon field-effect transistors: a quantum simulation study
Authors: Tamersit Khalil , Moaiyeri Mohammad Hossein , Jooq Mohammad Khaleqi Qaleh
Published: August 2022

In this paper, an ultrascaled ballistic graphene nanoribbon field-effect transistor (GNRFET) endowed with a compound double-gate based on metal-ferroelectric-metal (MFM) structure is proposed to overcome the limitations encountered with its conventional counterpart. The ballistic transistor is computationally investigated by solving self-consistently the non-equilibrium Green’s function formalism and the Poisson solver in conjunction with the Landau–Khalatnikov equation. The numerical investigation has included the ferroelectric-induced amplified internal metal voltage, the role of the ferroelectric thickness in boosting the device performance, the assessment of the switching and subthreshold performance, and the analysis of the FE-GNRFET scaling capability. The simulations revealed that the MFM-based gate can significantly boost the performance of GNRFETs, including the switching behavior, the on-current, the off-current, the current ratio, the swing factor, the intrinsic delay, and the scaling capability. More importantly, the proposed MFM GNRFET was found able to provide sub-thermionic subthreshold swing even with sub-10 nm gate lengths, which is very promising for low-power applications. The obtained results indicate that the MFM-based gating approach can give new impulses to the GNRFET technology.
Gravitational wave modes in matter
Authors: Garg Deepen , Dodin I.Y.
Published: August 2022

A general linear gauge-invariant equation for dispersive gravitational waves (GWs) propagating in matter is derived. This equation describes, on the same footing, both the usual tensor modes and the gravitational modes strongly coupled with matter. It is shown that the effect of matter on the former is comparable to diffraction and therefore negligible within the geometrical-optics approximation. However, this approximation is applicable to modes strongly coupled with matter due to their large refractive index. GWs in ideal gas are studied using the kinetic average-Lagrangian approach and the gravitational polarizability of matter that we have introduced earlier. In particular, we show that this formulation subsumes the kinetic Jeans instability as a collective GW mode with a peculiar polarization, which is derived from the dispersion matrix rather than assumed a priori. This forms a foundation for systematically extending GW theory to GW interactions with plasmas, where symmetry considerations alone are insufficient to predict the wave polarization.
Frequency down-conversion of a chirped Ti:sapphire laser pulse with BaWO4 Raman shifter and second-order nonlinear crystal
Authors: Kinyaevskiy I O , Koribut A V , Grudtsyn Ya V , Seleznev L V , Kovalev V I , Pushkarev D V , Dunaeva E E , Ionin A A
Published: August 2022

We experimentally carried out frequency conversion of a chirped and stretched up to 200 ps near-IR 90 fs Ti:Sapphire laser pulse into the mid-IR through difference frequency generation in either GaSe or LiGaS2 crystal. The crystal was pumped by laser radiation that passed through a BaWO4 crystal, where Stokes frequency-shifted radiation (signal wave) was generated through SRS. The generated ∼60 nJ mid-IR pulse had a central wavelength of 11.1 μm and FWHM spectral width of about 0.2 μm, which made it possible to achieve a pulse duration of ∼0.9 ps after its compression. The mid-IR pulse generation efficiency was ∼10−3% at SRS efficiency of 3%. To the best of our knowledge, this all solid-state scheme combining Raman shifting and second-order nonlinear crystals achieves the frequency down-conversion of femtosecond near-IR laser pulses to ∼11 μm radiation for the first time.
Ultrathin gold nanowires as broadband saturable absorbers for ultrashort pulsed lasers
Authors: Li Siqing , Lv Changjian , Luo Hongyu , Cui Linghao , Jia Zhixu , Li Jianfeng , Qin Weiping , Qin Guanshi
Published: August 2022

Ultrathin gold nanowires (UGNWs) with a diameter of ⩽2 nm have attracted much attention because of their high aspect ratios, unusual physical properties and potential applications in nanoelectronics, sensors and photonics. Despite recent advances on UGNWs and the related devices, nonlinear optical properties of UGNWs and their application on photonic devices (e.g. ultrashort pulsed lasers) remain largely unexplored. Here we show that UGNWs can be used as broadband saturable absorbers (SAs) for constructing ultrashort pulsed lasers with an operating wavelength range from near-infrared to mid-infrared (MIR). UGNWs are prepared by using a silane-mediated approach, and then mixed with polyvinyl alcohol to form the UGNWs film. The UGNWs film not only show strong absorption from visible to MIR spectral region (over 25 μm), but also possess the nonlinear saturable absorption properties in the spectral region. As the UGNWs film SA is inserted into an erbium or thulium doped silica fiber laser cavity, stable passively mode-locked lasers at 1562.2 or 1970 nm with a pulse width of a few hundreds of femtoseconds is obtained, respectively. Especially, by inserting the UGNWs film SA into a holmium/praseodymium codoped fluoride fiber laser cavity, stable passively mode-locked laser at 2864 nm is achieved. Our results show that the UGNWs film are promising SAs for constructing broadband ultrashort pulsed lasers.
Real-time observation of dissipative multi-soliton complexes in a net-normal dispersion fiber laser
Authors: Geng Xu , Wang Xude , Pan Jieyu , Li Kaixin , Lu Mengxiang , Sun Mengqiu , Li Suwen
Published: August 2022

Recent progress in real-time measurement technology makes it possible to spectrally characterize multi-soliton complexes. Here, we report on real-time observation to the multi-pulse structures in a net-normal dispersion mode-locked fiber laser. With careful adjustment of cavity parameters, several kinds of multi-soliton complexes, such as the coexistence of soliton singlet and soliton molecule, as well as the coexistence of different types of soliton molecules, are realized in the experiment. Real-time spectral information of each pulse under multi-soliton states can be well resolved with the dispersive Fourier transformation technique, which is markedly different from the results measured by conventional measurement instruments. Note that this is the first reported the simultaneous generation of different types of soliton molecules in a fiber laser to our best knowledge. The findings help to understand the complicated dynamics of the coexisting pattern between different kinds of dissipative solitons.
Nonlinear point-process estimation of neural spiking activity based on variational Bayesian inference
Authors: Xiao Ping , Liu Xinsheng
Published: August 2022

Objective. Understanding neural encoding and decoding processes are crucial to the development of brain-machine interfaces (BMI). Higher decoding speed of neural signals is required for the large-scale neural data and the extremely low detection delay of closed-loop feedback experiment. Approach. To achieve higher neural decoding speed, we proposed a novel adaptive higher-order nonlinear point-process filter based on the variational Bayesian inference (VBI) framework, called the HON-VBI. This algorithm avoids the complex Monte Carlo random sampling in the traditional method. Using the VBI method, it can quickly implement inferences of state posterior distribution and the tuning parameters. Main results. Our result demonstrates the effectiveness and advantages of the HON-VBI by application for decoding the multichannel neural spike trains of the simulation data and real data. Compared with traditional methods, the HON-VBI greatly reduces the decoding time of large-scale neural spike trains. Through capturing the nonlinear evolution of system state and accurate estimating of time-varying tuning parameters, the decoding accuracy is improved. Significance. Our work can be applied to rapidly decode large-scale multichannel neural spike trains in BMIs.
Local and non-local properties of the entanglement Hamiltonian for two disjoint intervals
Authors: Eisler Viktor , Tonni Erik , Peschel Ingo
Published: August 2022

We consider free-fermion chains in the ground state and the entanglement Hamiltonian for a subsystem consisting of two separated intervals. In this case, one has a peculiar long-range hopping between the intervals in addition to the well-known and dominant short-range hopping. We show how the continuum expressions can be recovered from the lattice results for general filling and arbitrary intervals. We also discuss the closely related case of a single interval located at a certain distance from the end of a semi-infinite chain and the continuum limit for this problem. Finally, we show that for the double interval in the continuum a commuting operator exists which can be used to find the eigenstates.
Evaluation of Two-Part rain attenuation model at Ku-band for tropical and equatorial regions
Authors: Yagasena
Published: August 2022

The current ITU rain attenuation model that is used in the design of satellite-earth communication link was derived using data collected predominantly from temperate regions and has limitations when applied to tropical and equatorial regions that are characterized by heavy rainfall. Elevation and frequency scaling was applied to the rain attenuation data obtained from tropical and equatorial regions to validate the linear relationship for rain rates above 90 mm/h in the TPRA model. Analysis of the data from these regions also confirms the linear relationship between the rain attenuation and rain rates above 90 mm/h. The TPRA model can be considered as an alternative model for a reliable satellite-earth link for use in the tropical and equatorial regions.
Performance of Restricted Fault and Bias Differential Protection Against Earth Fault on a Transformer
Authors: Hashim N.H. , Halim N.H. , Arshad S.N.M. , Hussain M.H. , Rahim S.R.A. , Suleiman A.A.
Published: August 2022

In this paper, the effectiveness of restricted earth fault and bias differential protection against earth fault on of transformer winding is presented. Earth fault is one of the failures that occurs on a power transformer winding. Its magnitude depends on how the neutral is connected and the location of fault. For a transformer which is connected to Neutral Earth Resistance (NER), as the fault moves towards its neutral, the magnitude of fault current decreases and the detection of fault diminishes, thus limiting percentage of winding that can be protected. To overcome this problem, restricted earth fault is employed. This paper will show that based on its principles, restricted earth fault protection is more sensitive and provide better coverage for the star winding against earth fault especially resistance earthed.
Design and Implementation of an Automatic Speed Control System of Vehicles for Avoiding Road Accidents in Bangladesh
Authors: Hafsa Umme , Arifin Farhadur
Published: August 2022

Road accident has been a major problem in Bangladesh in recent years. An automatic speed control system is proposed in this paper to reduce road accidents by controlling the speed of the vehicle automatically. The main idea of the proposed system is to design a speed control system where the vehicle can adjust the speed depending upon the speed limit of the road. The designed system includes a sensor unit, a microcontroller unit and a functional unit. In the sensor unit, different sensors are used to perceive information to control the speed of vehicles. In the functional unit, a throttle automation system and brake automation system are introduced. This functional unit is mainly based on an electrical throttle control mechanism. Finally, the microcontroller is applied for taking decisions regarding the speed control of vehicles. This system shows a good prospect for speed control of the vehicles. Thus, it can able to reduce road accidents in Bangladesh.
Real Time Retinal Optic Disc Segmentation via Guided filter and Discrete Wavelet Transform
Authors: Dash Sonali , Satish Rama Chowdary P. , Chakravarthy V.V.S.S.S. , Gopala Raju C.V. , Sahu Gupteswar , Siva Charan KJN , Umamaheshwar Y.
Published: August 2022

In the world, glaucoma is the one of the main causes for loosing vision. Optical Coherence Tomography or fundus camera is utilized to capture the optic disc and optic cup images. For the detection of glaucoma and afterwards monitoring the patients, investigation of the head of optic nerve or cup-to-disc ratio (CDR) is an important factor. For computing the CDR value, segmentation of optic disc and optic cup are utilized for the isolation of the relevant parts of the fundus image. Even though ophthalmologists are computing the CDR value physically, however, it limits the identification of glaucoma at the early stage. The accurate value of CDR is hard to find out if the optic cup and optic disc are not well defined properly. Thus, this paper has suggested a combined model of Guided filter and Discrete Wave Transform (DWT) for the enhancement and OD segmentation. Hysteresis thresholding is utilized for the optic cup segmentation. A set of 50 images of 25 patients are obtained from Visakha Eye Hospital, Visakhapatnam, India, is used to verify the performance of the suggested model. The recommended approach is also verified on the glaucoma subset of High-Resolution Fundus (HRF) database. The experimental results of both the databases demonstrate that the CDR value is computed accurately with low computational time.
Study of Cu-doped silicene nanoribbons in the electric field
Authors: Ngoc Hoang Van
Published: August 2022

This work studies copper doping in silicene nanoribbons. The electric field acting on the system has a constant magnitude of 0.4V/Å. The unit lattice studied here consists of twelve silicon atoms and four hydrogen atoms in one unit cell, hydrogen atoms to modify two edges. There are two doped structures studied, the top stucture and the valley structure, each with one substitution doped Cu atom per unit cell. The theory used to study computation here is density functional theory (DFT). The formation energies, state bands and energy regions of the doped system are calculated and plotted. Thanks to the copper doping process and the influence of the electric magnetic field, the system after doping becomes semi-metallic. The top doped structure shows more optimization and stability. In the quest to find new materials with features that match the requirements of practice, this is a promising study. This study lays the groundwork for future applications in electronic technology.
Series Arc Fault Detection Sensor Based on an ABS Rogowski Coil in Medium Voltage
Authors: Nanyan A.N. , Rohani M.N.K.H. , Hamid H.A. , Bohari Z.H. , Akhmal S
Published: August 2022

Three types of Rogowski coils were designed and constructed by utilising 3D printing technology: RC1, RC2, and RC3, with the sensors having the same geometrical dimensions but varying number of turns: 20, 50, and 100 respectively. To verify the feasibility and effectiveness of the proposed sensors, a series arc fault generator was set up and high voltage of up to 3-kV was injected. The analysis of the Fast Fourier Transform (FFT) was done by using MATLAB to determine frequency and voltage amplitude. From the analysis, it was determined that the higher the number of turns, the greater the sensitivity. The resonance frequency (MHz) dropped significantly as the number of turns increased. Furthermore, sensor features such as frequency bandwidth and sensitivity are affected by the number of turns, which was thoroughly investigated in this study. The Rogowski coil was created to detect the high frequency component of the series arc fault signal. All the designed sensors reliably detect the series arc fault signal, according to the experimental results.
Blockchain-Based Smart Contract for P2P Energy Trading in a Microgrid Environment
Authors: Kajaan Nor Ashbahani Mohamad , Amidi Nurul Hanisa Nor , Salam Zainal , Radzi Raja Zahilah Raja Mohd
Published: August 2022

The purpose of this study is to propose a method of peer-to-peer (P2P) energy trading that allow prosumers with energy deficiency to buy energy from prosumers with excess energy in a microgrid system. The proposed method solves the problems associated with lack of trust in P2P energy trading and utilized the blockchain technology that made it impossible to tamper with data. The data is referred as transaction generated by using blockchain. A blockchain based smart contract execute the trading and payment rules without the intermediaries. Thus, the security and fairness of energy trading are significantly enhanced compared to conventional database technology. Without the third-party intervention, a miner that is selected among the participants in the microgrid environment process all the transaction generated from buying and selling energy. The smart contract consists of two main components; bidding and settlement module, payment module. The smart contract deployed in blockchain test network to test the interaction of smart contract. From the simulation, the proposed method is validated using realistic data with the Ethereum Virtual Machine (EVM). The method will be expected to be useful to designers who need to integrate renewable energy in a microgrid system.
Power loss mitigation and voltage profile improvement by optimizing distributed generation
Authors: Syed Nasir S N , Othman A F , Ayop R , Jamian J J
Published: August 2022

In a developing country, electricity has become the necessity of the growth industries; thus, the distribution system power quality and reliability are crucial. With low carbon initiatives, renewable energy or distributed generation (DG) is a promising source of electricity and leads the complex distribution system. Vital rises in DGs in power grids will significantly impact the system reliability and security, especially in power losses and voltage profiles parameters. This research focuses on an optimization placement and size of DGs in distribution systems to minimize power loss and improve voltage profile using the Modified Lightning Search Algorithm (MLSA). This research has modelled the practical 69-bus radial distribution system. Then MLSA with a weight summation approach is used to identify the suitable location and size for the DGs in the design proposal stage. The optimization objectives are to reduce power losses and improve the voltage profile, especially at the connection point of DGs. Besides that, load profile, DGs constant load and the solar load in distribution system modelled using MATLAB software. The results of the simulation using MLSA indicated that the optimization allocation and sizes of solar DGs applied with current load and load changes can minimize the power losses and improve voltage profile. These results verify the proposed approach’s effectiveness and success in determining the optimal location and sizing of solar DGs to reduce power losses as well as improve voltage profiles.
Investigation of water recovery from sewage using solar thermal technology
Authors: Easwaramoorthi M , Manibarathi B , Mathesan R , Mithiran M , Rajesh R , Sivakumar T.
Published: August 2022

The availability of potable water for human use, agriculture, and industrial usage is a major challenge both in undeveloped and developing countries. Water, like food and air, is considered essential for human survival, and the majority of people rely on untreated water from rivers, lakes, and groundwater reservoirs. Oceans are the only place where enormous amount of water is found and desalination of the water is needed because they consists high levels of salt. But, the increase in population, urbanization and industrialization resulted in higher release of sewage and industrial effluents into water bodies and subsequent water pollution. It results in a scarcity of pure water in many towns and villages, despite their proximity to lakes and rivers. Water scarcity is anticipated to worsen in the next years, with the majority of the world’s population experiencing it in the near future. Potable water is essential not just for survival, but also for industrial and agricultural processes. Physical, chemical, and biological processes are normally used to remove contaminants from wastewater and produce pure water. In this context, an attempt is made in this paper to use the concept of solar still for sewage treatment. The experimental setup was created to examine the performance of a solar still with an evaporator and condenser. The results revealed that combining a heater and a condenser with a pyramid solar system enhanced solar still production by 4 to 8 l/Sq.m/day when using saline water, 4 to 7 l/Sq.m/day when using sewage water, and 3 to 6 l/Sq.m/day when using effluent water.
Optical Efficiency Improvement of Chip-on-Board Design LEDs with TiO2/Silicone Packaging Coating
Authors: Hung Khanh Nguyen , Le Phan Xuan , Lee Hsiao-Yi
Published: August 2022

Since TiO2nanoparticles and silicon composites include a strong scatter influence, they are well-known for improving scattered lighting in LED packets. To improve the optic quality of LEDs packaged with chip-on-board (COB), a thin layer made of high-concentration TiO2and silicon glue is added to the primary packing layer. COB LEDs’ light extraction efficiency (LEE) rises up to 65% when the key encapsulation includes just silicone, according to the findings of experiments. As a coating of TiO2and silicone is added, however, the increase in LEE is dependent on the TiO2concentration. The LEE can be increased from 6% to 24% as the concentration of nanoparticles drops to 0.035 g/cm3. Furthermore, at a mean correlated color temperature (CCT) of around 8500 K, the TiO2/silicone compounds layer will assist in lowering the angular correlated color temperature (CCT) variance between 900 and 470 K within the -90° to 90° observing angle range.
Active High Transmitter-receiver energy model for heterogeneous energy optimisation in a pipeline network
Authors: Subramaniam S K , Feroz F S , Ibrahim A F T , Panessai I Y , Sujatha R
Published: August 2022

A network energy management and optimisation are frequently associated to the network lifetime (maximum operation of nodes in a network) that is contributed by heterogeneous energy consumption pattern among nodes arranged in a pipeline layout. This scenario becomes even more critical in a remote monitoring application of an oil and gas pipeline network where a series of sensing points (commonly battery powered wireless nodes) are needed to communicate the measurements to a centralised monitoring station. This paper introduces the Active High Transmitter-receiver energy model (AHiT) which was designed as an adaptive sleep/wake for sensor nodes to optimise energy consumption in the long run. Implementing AHiT energy model on sensor nodes improves the energy consumption based on data transfer activity in a multi-hop pipeline layout wireless sensor network (WSN). In this research, the proposed AHiT energy model optimises node energy by the demand that is unlike to the conventional sleep and wake energy model that is operated on a predefined scheduling scheme that accommodates the data traffic pattern in a network. Generally, in a pipeline network where sensor nodes connectivity is considered critical among neighbouring nodes to support data transfer from one end to the other end of a network. Simulations results in NS2 has indicated node energy consumption is approximately 60% with extended network lifetime around 30% subjected to the data traffic pattern as compared to the conventional energy model.
Homogenization of Green SiO2 from Rice Husk Burn through Potassium Hydroxide Solid-Liquid Extraction
Authors: Anggraini Lydia , Hendriawan Rivaldo Agung , Anggraina Putri Laila , Hakiki Rijal
Published: August 2022

In the agricultural countries, rice husk is an abundant waste, especially as one of the largest sources of silica (SiO2) production that can be produced. By complete combustion, to about 87% - 97% SiO2 content can be produced from rice husks. Alkaline solution is used as a solvent in the solid-liquid extraction process of rice husk ash. The mass of 10 grams of rice husk ash was weighed for the extraction process added with 80 ml of potassium hydroxide (KOH) solution with 10%, 15% and 20% various concentration for 60 minutes to extract the SiO2 content. The solution was added with 1 N hydrochloric acid (HCl) solution to precipitate the SiO2, after the extraction process was complete. The SiO2 formed is then separated from the rest of the solution by filtration. Next step is the drying process which aims to remove the moisture content of the resulting SiO2. In a systematic study, for 60 minutes the rice husks were soaked and washed using HCl and then heated in a muffle furnace. The results of this study showed that all samples are succeeded in homogenizing SiO2 with a purity close to 90%. Furthermore, through X-Ray Fluorescence (XRF) analysis was proven these results obtained through solid-liquid extraction of KOH from rice husks. Green SiO2, known as biosilica, is useful and has potential in reinforcing compounds, including applications as filler in tires and natural rubber compounds.
Parameter Estimation of DC Motor using Multiparametric Programming
Authors: Ali A N , Che Mid E , Ahamad N B , Ruslan E , Hadi D A
Published: August 2022

Parameter estimation is important in aspects for applied in many process models in control system design, chemistry, and other engineering application for expectation models of statistical observation. The focus of this work is on a nonlinear ordinary differential equation (ODEs) system which is a direct current (DC) motor model to estimate the model parameters using multiparametric programming. In this work, the ODE model is discretized by implementing Euler’s method to obtain the algebraic equation. The model parameters of the DC motor will be derived as an explicit function of measurements to estimate the parameter values. The applicability of the proposed method and accuracy of parameter estimation is demonstrated.
LPG Mass Monitoring Scale with Automatic Gas Leakage Detector System
Authors: Mohd Noor N N , Lee M F
Published: August 2022

A crucial requirement used in everyday human life is the use of liquefied petroleum gas (LPG) or, more generally, cooking gas. However, problems arise for LPG users when the cooking process is disrupted due to running out of cooking gas without them realized that the volume of gas has reached a critical level. In addition, gas leaks may also occur which can cause the house fire. Therefore, this study aims to develop a product that can monitor the remaining volume of cooking gas content in a gas cylinder using a load sensor. The LPG weight value is through LCD display and LED from three different levels, which is green (full), yellow (medium), and red (critical) where it receives programming instructions from Arduino Uno. The product also performs a function of gas leak detector by using the MQ-2 gas sensor and the user will receive a notification warning about the gas leak via buzzer and SMS sent by ESP32. The development process for monitoring scale and gas leakage detector for liquid petroleum gas (LPG) is based on the adapted from the Engineering Design Process Model (EDP), which consists of five phases, namely identify the problem, gather information, select the best solution, develop model, testing and evaluation. The results show that the developed product able to functioning well. However, in terms of product design there is still room for improvement especially for the size of the product and the gas sensor position to make it more user friendly.
Development of Vision Based Smart Gripper for Material Handling Using Internet of Things
Authors: Ali H , Zainur M I , Elshaikh M , Aman AH Mohd
Published: August 2022

Robotic grippers have becoming an emerging trend due to their boundless applications in industrial automation. Nowadays, the deployment of vision based smart gripper for material handling in industrial applications remains challenging and ongoing research. As the Internet of Things (IoT) becomes more commercialized, the various concept of IoT have been integrated with the gripper due to efficient usage. Therefore, this project proposes the development of vision-based sensor of smart gripper for material handling in industrial applications that integrates with the IoT. The rationale of integrating IoT to vision based smart gripper is that it allows authenticated users to log in from any device, anywhere, and view video or images from vision based smart gripper in real-time for critical material handling. This system incorporates a vision sensor camera that acts as an “eye” to automatically detect and recognize the object with different weights and shapes and send the information to the robot for the next task. This smart gripper adopts a force sensor mounted into the fingertip to control the force applied when working with a wide range of objects with different weights. As for the electronic system, power module, communication and control module, sensor and actuator as well as user interface module have been adopted and integrated into the system. In the software development system, user interface configuration was developed through mobile application in which it communicates with Raspberry Pi B+ camera to serve as IoT platform. A series of experiments shows that the vision based gripper using IoT able to detect and recognize the objects and then send the information/command directly to the robot to execute grasping and lifting phase of the object to the desired location that has been assigned.
Digital Tools Approach Based On ‘Gerun’ And Online Partial Discharge Monitoring Project To Resolve Alternator’s Failure
Authors: Rahman Azwanizam b Che Abdul , Tahir Mohd Rahmat , Hamdan Kamarul Bahraini M , Halim Mohd Helmi , Isa Muzamir
Published: August 2022

There is no online monitoring system and digital tools to monitor generator gas turbine healthiness led to generator failure caused un-planned outages resulted power import and penalty chargers. Maintenance program for generator is based on time-based method. Since 2016 to 2020, Asset Team spent millions of ringgit Malaysia for generator rectification and incurred power import cost due to the failure. To overcome the tripping issues, Generator Health Monitoring System was initiated as a research/pilot project as tools to monitor healthiness of Gas Turbine Generator. This project was categorized as digital transformation initiative (Revolution 4.0) as to enable online monitoring & performing diagnostic & prescriptive. The initiative consisted of 2 main pillars which are Generator Rotor Unhealthiness Notification (GERUN) and Online Partial Discharge Monitoring System (PD ONLINE). The aim of this paper is to share the experience in monitoring, economical way, diagnosis, condition evaluation, and possibility of predicting the performance of the generator. The methodology of the Generator Healthiness is to monitor the real time performance of the generator during running condition through rotor thermal losses, ratio of excitation current over the real output power and stator partial discharge pattern. This real time monitoring can improve the maintenance strategy and planning. As a result, plant’s OEE can be increased, reduce the MTBF and more importantly the repair cost. The parameters have been introduced to prevent the generator sudden failure event and bridge the gap condition monitoring especially on the generator part. Arriving to the objective, this project was categorized as digital transformation initiative (Revolution 4.0) as to enable online monitoring & performing diagnostic & prescriptive. The initiative consisted of 2 main pillars which are Generator Rotor Unhealthiness Notification (GERUN) and Online Partial Discharge monitoring system (PD ONLINE) project. Diagnose & prescriptive and provide asset owners with insights on alternator’s health, subsequently prevent unforeseen failure in real time and prescribe operational mitigations to prolong alternator’s life. Recommends targeted test and maintenance (3rd level maintenance predictive) addressing the exact health issue of the alternator value creation & cost saving by eliminating tripping, scope reduction for major inspection, non-dependable on FSR, internal troubleshooting and etc. The system has been implemented across gas processing and utilities Petronas Gas Berhad for 14 units of gas turbine generator. In view of the success implementation, this digital tool will be duplicate to others Petronas Operating Unit.
AC Power Flow Analysis for Inverters in Microgrid Application
Authors: Roslan M A , Azmi S A , Ahmed K H
Published: August 2022

In a microgrid system, proper current distribution and load sharing strategies are essential to achieve reliable parallel operation. Line impedance is an important factor when implementing a control technique for an inverter for microgrid operation, whether it is operating in grid connected or island mode. It is sometime difficult to visualize the impact of different line impedance to the power flow in AC microgrid. In this paper, AC power flow of an inverter-based system connected to a common ac bus through purely resistive, inductive or complex line impedances is investigated. For each line impedance case, the effect of an inverter’s output voltage power angle and amplitude on the active and reactive power flow are studied. Several active and reactive powers plots are generated in 3D surf plots to visualize the impact of line impedance on the power flow in an AC system.
Simulation of Molybdenum Disulfide based MOSFET Device using COMSOL Multiphysics software
Authors: Subramaniyam Sudharsanam , Muthusamy Sasikala , Bharatan Sudhakar K
Published: August 2022

In this work, 2D physical modeling and simulation of Molybdenum disulfide based MOSFET device using COMSOL multiphysics software is carried out. The impact of dielectric materials such as SiO2 and Al2O3 on the performance of FET are investigated. Threshold voltage (VT), sub-threshold swing and on/off ratio are some of the electrical parameters studied in this work. The values of channel doping concentration, choice of metal work function and dielectric material, and the corresponding thickness of the gate material, are systematically varied to arrive at the device threshold voltage. FET device with 50nm thick Al2O3 gate insulator exhibits a threshold voltage of 1V and an on/off ratio of 107, whereas the device with SiO2 as the gate material with the same thickness exhibited higher threshold voltage of 2.8V and lower on/off ratio of 106. The polynomial first order technique in the MATLAB curve fitting tool is utilized to determine the relation between VT and gate oxide thickness.
Comparative Study of Multiphase 5-Level Cascaded H-Bridge Multilevel Inverter System
Authors: Zawawi M N M , Isa Z M , Arshad M H , Ismail B , Talib M H N
Published: August 2022

In terms of cost and structural design, the cascaded H-bridge multilevel inverter (CHBMLI) has a significant advantage over diode clamped and capacitor clamped multilevel inverters. The total harmonic distortion (THD) of a 5-level CHBMLI system for three different phases (single-phase, three-phase, and six-phase system) is studied and compared in this work. As switching angles play a role in lowering THD, the switching angles for a 5-level CHBMLI are evaluated using four specific switching angle methods in the initial section of this paper. In the simulation of single-phase system, these angles are being utilized. The angles with the lowest THD value are chosen for three-phase and six-phase system simulation. Based on the findings, the higher phase of 5-level CHBMLI is more efficient in decreasing harmonics.
VPN–Based WiMAX Network Protection Against Jamming Attacks for VoIP Application
Authors: Nourildean Shayma W , Ameen Siddeeq Y , Mohammed Yousra A
Published: August 2022

WiMAX technology with up to 30 miles of coverage compared to other technologies is more vulnerable to jamming attacks, and therefore, the security issue was a major concern. The jamming attack affected the network by reducing throughput and increasing delay in different applications, several solutions and protocols were introduced for this issue. One of these solutions is a VPN that uses encryption algorithms for securing data transmission. Moreover, the network is integrated with the firewall to protect the server from any unauthorized access. Thus, the paper investigates the impact of VPN with the firewall for securing WiMAX using OPNET Modeler (v14.5) which was chosen as a suitable tool for simulating WiMAX networks. A VoIP application was applied with other applications in terms of sent/received traffic, delay and throughput. After running the OPNET simulation, the collected results showed that the existence of VPN with firewall increased throughput and decreased the delay which was caused by the jamming attack. The inclusion of the firewall will prevent any access to a specific application from the server but the VPN would allow access from a specific source (Base Station1) to access the server. The benefit of integrating VPN in the system is that the unauthorized client cannot access the server from any base station. This will provide more security for the system.
Arcing fault diagnosis using enhanced cross-correlation technique
Authors: Amirruddin Melaty , Adzman Mohd Rafi , Affendi Nur Adyani Mohd , Idris Muhd Hafizi , Abd Halim Syahirah
Published: August 2022

This study explored the potential use of cross-correlation as a technique for detecting arcing faults in a power system distribution network. The cross-correlation technique was employed to investigate the effect of each antenna placement as a detection device, time difference of arrival (TDOA), time delay, and correlation magnitude of arcing signals detected during on-line arcing fault measurement. The arcing fault was detected using four antennas that had been set up around the arc source point in a high voltage (HV) laboratory. The measurements were taken using a digital oscilloscope. For precise results, the Discrete Wavelet Transform (DWT) denoising technique combined with cross-correlation (CC) technique were applied using MATLAB software to identify the arcing signals detected in order to diagnose the differentiation between noisy and real arcing fault signals. Further assessment was carried out by performing a cross-correlation technique on the real arcing signals obtained to find the similarities and arrival time’s delay between single arcing signals’ placement. The outcome shows that all measurements including the time difference of arrival (TDOA), correlation magnitude, time delay, and antennas’ placement towards the arcing source point are valuable in determining the arcing signals detected precisely.