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Fulltext Reconfigurable ring filter with controllable frequency response

Ab Wahab N, Mohd Salleh MK, Ismail Khan Z, Abd Rashid NE

ScientificWorldJournal, 2014;2014:671369.
PMID: 25121132 DOI: 10.1155/2014/671369

Reconfigurable ring filter based on single-side-access ring topology is presented. Using capacitive tuning elements, the electrical length of the ring can be manipulated to shift the nominal center frequency to a desired position. A synthesis is developed to determine the values of the capacitive elements. To show the advantage of the synthesis, it is applied to the reconfigurable filter design using RF lumped capacitors. The concept is further explored by introducing varactor-diodes to continuously tune the center frequency of the ring filter. For demonstration, two prototypes of reconfigurable ring filters are realized using microstrip technology, simulated, and measured to validate the proposed concept. The reconfigured filter using lumped elements is successfully reconfigured from 2 GHz to 984.4 MHz and miniaturized by 71% compared to the filter directly designed at the same reconfigured frequency, while, for the filter using varactor-diodes, the frequency is chosen from 1.10 GHz to 1.38 GHz spreading over 280 MHz frequency range. Both designs are found to be compact with acceptable insertion loss and high selectivity.

Matched MeSH terms: Electronics/instrumentation*
Fulltext Supramolecular Nested Microbeads as Building Blocks for Macroscopic Self-Healing Scaffolds

Yu Z, Liu J, Tan CSY, Scherman OA, Abell C

Angew Chem Int Ed Engl, 2018 03 12;57(12):3079-3083.
PMID: 29377541 DOI: 10.1002/anie.201711522

The ability to construct self-healing scaffolds that are injectable and capable of forming a designed morphology offers the possibility to engineer sustainable materials. Herein, we introduce supramolecular nested microbeads that can be used as building blocks to construct macroscopic self-healing scaffolds. The core-shell microbeads remain in an "inert" state owing to the isolation of a pair of complementary polymers in a form that can be stored as an aqueous suspension. An annealing process after injection effectively induces the re-construction of the microbead units, leading to supramolecular gelation in a preconfigured shape. The resulting macroscopic scaffold is dynamically stable, displaying self-recovery in a self-healing electronic conductor. This strategy of using the supramolecular assembled nested microbeads as building blocks represents an alternative to injectable hydrogel systems, and shows promise in the field of structural biomaterials and flexible electronics.

Matched MeSH terms: Electronics
Fulltext A longitudinal analysis of injury characteristics among elite and amateur tennis players at different tournaments from electronic newspaper reports

Musa RM, Hassan I, Abdullah MR, Latiff Azmi MN, Abdul Majeed APP, Abu Osman NA

Front Public Health, 2022;10:835119.
PMID: 36033746 DOI: 10.3389/fpubh.2022.835119

The non-complexity of tennis, coupled with its health benefits, renders it appealing and encourages varying competitions at different levels of age, gender, and expertise. However, the rapid increase in the participation rates witnesses a surge in injury occurrences, prompting the need for in-depth analysis to facilitate immediate intervention. We employed a media content analysis technique in which tennis-associated articles published in the last 5 years were examined. A total of 207 news reports were gathered and screened for analysis. Subsequently, 71 articles were excluded from the study due to content duplications or summary updates of existing news articles, while 23 news articles were also excluded from the study due to inappropriateness. Finally, 113 news reports directly related to injury in tennis were coded and analyzed. We examined various types of injuries reported from the screened articles with respect to their status (fresh, recurrent, and recovery) across expertise levels i.e., elite, or amateur. Similarly, the incidence of injury occurrences based on the types of tournaments the players engage in was also investigated. A chi-square analysis was employed to achieve the objectives of the study. Occurrences of tennis-associated injuries are disseminated across expertise levels [ χ ( 18 ) 2 = 16.542; p = 0.555], with knee, hip, elbow, and shoulder injuries being highly prevalent in both elite and amateur players. Nevertheless, it was noted that elite players suffered a staggering 72.60% of injury-related problems, while amateur players sustained 27.40% of injuries. Moreover, the status of injury spreads based on types of tournaments [ χ ( 4 ) 2 = 3.374; p = 0.497], with higher occurrences of fresh and recurrent injuries, while low recovery rates were observed. The findings further demonstrated that injuries are sustained regardless of tournament types [ χ ( 36 ) 2 = 39.393; p = 0.321]. However, most of the injuries occurred at international tournaments (85%). Whereas, only 5.30% of the injuries occurred at national/regional tournaments while 9.70% were unidentified. It could be deduced from the findings of this investigation that elite players are more prone to injuries compared with amateur players. Furthermore, the most common tennis-related injuries affect the lower, trunk, and upper regions of the body, respectively. A large number of the reported tennis injuries are fresh and recurrent, with a few recoveries. The international tennis tournaments are highly attributed to injury occurrences as opposed to the national/regional tournaments. The application of the media-based data mining technique is non-trivial in projecting injury-related problems that could be used to facilitate the development of an injury index peculiar to the tennis sport for prompt intervention.

Matched MeSH terms: Electronics
Driving sustainable circular economy in electronics: A comprehensive review on environmental life cycle assessment of e-waste recycling

He Y, Kiehbadroudinezhad M, Hosseinzadeh-Bandbafha H, Gupta VK, Peng W, Lam SS, et al.

Environ Pollut, 2024 Feb 01;342:123081.
PMID: 38072018 DOI: 10.1016/j.envpol.2023.123081

E-waste, encompassing discarded materials from outdated electronic equipment, often ends up intermixed with municipal solid waste, leading to improper disposal through burial and incineration. This improper handling releases hazardous substances into water, soil, and air, posing significant risks to ecosystems and human health, ultimately entering the food chain and water supply. Formal e-waste recycling, guided by circular economy models and zero-discharge principles, offers potential solutions to this critical challenge. However, implementing a circular economy for e-waste management due to chemical and energy consumption may cause environmental impacts. Consequently, advanced sustainability assessment tools, such as Life Cycle Assessment (LCA), have been applied to investigate e-waste management strategies. While LCA is a standardized methodology, researchers have employed various routes for environmental assessment of different e-waste management methods. However, to the authors' knowledge, there lacks a comprehensive study focusing on LCA studies to discern the opportunities and limitations of this method in formal e-waste management strategies. Hence, this review aims to survey the existing literature on the LCA of e-waste management under a circular economy, shedding light on the current state of research, identifying research gaps, and proposing future research directions. It first explains various methods of managing e-waste in the circular economy. This review then evaluates and scrutinizes the LCA approach in implementing the circular bioeconomy for e-waste management. Finally, it proposes frameworks and procedures to enhance the applicability of the LCA method to future e-waste management research. The literature on the LCA of e-waste management reveals a wide variation in implementing LCA in formal e-waste management, resulting in diverse results and findings in this field. This paper underscores that LCA can pinpoint the environmental hotspots for various pathways of formal e-waste recycling, particularly focusing on metals. It can help address these concerns and achieve greater sustainability in e-waste recycling, especially in pyrometallurgical and hydrometallurgical pathways. The recovery of high-value metals is more environmentally justified compared to other metals. However, biometallurgical pathways remain limited in terms of environmental studies. Despite the potential for recycling e-waste into plastic or glass, there is a dearth of robust background in LCA studies within this sector. This review concludes that LCA can offer valuable insights for decision-making and policy processes on e-waste management, promoting environmentally sound e-waste recycling practices. However, the accuracy of LCA results in e-waste recycling, owing to data requirements, subjectivity, impact category weighting, and other factors, remains debatable, emphasizing the need for more uncertainty analysis in this field.

Matched MeSH terms: Electronics
Fulltext Free-Radical Photopolymerization of Acrylonitrile Grafted onto Epoxidized Natural Rubber

Whba R, Su'ait MS, Tian Khoon L, Ibrahim S, Mohamed NS, Ahmad A

Polymers (Basel), 2021 Feb 23;13(4).
PMID: 33672185 DOI: 10.3390/polym13040660

The exploitation of epoxidized natural rubber (ENR) in electrochemical applications is approaching its limits because of its poor thermo-mechanical properties. These properties could be improved by chemical and/or physical modification, including grafting and/or crosslinking techniques. In this work, acrylonitrile (ACN) has been successfully grafted onto ENR- 25 by a radical photopolymerization technique. The effect of (ACN to ENR) mole ratios on chemical structure and interaction, thermo-mechanical behaviour and that related to the viscoelastic properties of the polymer was investigated. The existence of the -C≡N functional group at the end-product of ACN-g-ENR is confirmed by infrared (FT-IR) and nuclear magnetic resonance (NMR) analyses. An enhanced grafting efficiency (~57%) was obtained after ACN was grafted onto the isoprene unit of ENR- 25 and showing a significant improvement in thermal stability and dielectric properties. The viscoelastic behaviour of the sample analysis showed an increase of storage modulus up to 150 × 103 MPa and the temperature of glass transition (Tg) was between -40 and 10 °C. The loss modulus, relaxation process, and tan delta were also described. Overall, the ACN-g-ENR shows a distinctive improvement in characteristics compared to ENR and can be widely used in many applications where natural rubber is used but improved thermal and mechanical properties are required. Likewise, it may also be used in electronic applications, for example, as a polymer electrolyte in batteries or supercapacitor.

Matched MeSH terms: Electronics
Fulltext Prevalence of occupational diseases among small and medium industry workers in Malaysia: a systematic review

Muhammad Zubir Yusof, Nik Ahmad Kamal Nik Mahmod, Nor Azlina A. Rahman, Ailin Razali, Niza Samsuddin, Nik Mohamed Nizan Nik Mohamed, et al.

Journal of Clinical and Health Sciences, 2019;4(2):4-30.
MyJurnal

Occupational diseases are one of the major health problems related to workplace hazards.
However, the epidemiological data for this problem is scarce especially among Small and
Medium Industry (SMI) workers. These workers are vulnerable to occupational health problem
due to lack of knowledge and implementation of health and safety in the workplace. In Malaysia,
most of the SMI workers have limited coverage for basic occupational health services which
may worsen their health. Thus, this article aims to provide a review on the burden of
occupational health problems among them. The electronic and library searches were used to
extract the information from both published and unpublished articles that were not limited to any
year of publication until 2017. One hundred and ninety-six published articles and 198
unpublished articles were retrieved from the database. Only 19 published articles and 25
unpublished articles met the eligibility criteria. Prevalence data of occupational
diseases/poisoning, including overall and body specific (musculoskeletal disorders) was
extracted in raw data from the eligible studies. Prevalent statistics on occupational
musculoskeletal diseases (1.3% - 97.6%), noise-induced hearing loss (29.4% - 73.3%),
occupational skin diseases (10.5% - 84.3%), respiratory (1.9% - 92.2%) and occupational
poisoning (14.9% - 17.7%) among the working population is different within published papers
compared to unpublished ones. In Malaysia, there are no specific statistic that give a true picture
of the burden of occupational diseases in the SMI. However, this review concludes that
musculoskeletal diseases are significant occupational problems among SMI workers.

Matched MeSH terms: Electronics
Fulltext WS2: A New Window Layer Material for Solar Cell Application

Bin Rafiq MKS, Amin N, Alharbi HF, Luqman M, Ayob A, Alharthi YS, et al.

Sci Rep, 2020 Jan 21;10(1):771.
PMID: 31964954 DOI: 10.1038/s41598-020-57596-5

Radio frequency (RF) magnetron sputtering was used to deposit tungsten disulfide (WS2) thin films on top of soda lime glass substrates. The deposition power of RF magnetron sputtering varied at 50, 100, 150, 200, and 250 W to investigate the impact on film characteristics and determine the optimized conditions for suitable application in thin-film solar cells. Morphological, structural, and opto-electronic properties of as-grown films were investigated and analyzed for different deposition powers. All the WS2 films exhibited granular morphology and consisted of a rhombohedral phase with a strong preferential orientation toward the (101) crystal plane. Polycrystalline ultra-thin WS2 films with bandgap of 2.2 eV, carrier concentration of 1.01 × 1019 cm-3, and resistivity of 0.135 Ω-cm were successfully achieved at RF deposition power of 200 W. The optimized WS2 thin film was successfully incorporated as a window layer for the first time in CdTe/WS2 solar cell. Initial investigations revealed that the newly incorporated WS2 window layer in CdTe solar cell demonstrated photovoltaic conversion efficiency of 1.2% with Voc of 379 mV, Jsc of 11.5 mA/cm2, and FF of 27.1%. This study paves the way for WS2 thin film as a potential window layer to be used in thin-film solar cells.

Matched MeSH terms: Electronics
Electronic structure and optical properties of the dialkali metal monotelluride compounds: Ab initio study

Souadia Z, Bouhemadou A, Bin-Omran S, Khenata R, Al-Douri Y, Al Essa S

J Mol Graph Model, 2019 07;90:77-86.
PMID: 31031219 DOI: 10.1016/j.jmgm.2019.04.008

Structural parameters, electronic structure and optical properties of the dialkali metal monotelluride M2Te (M = Li, Na, K and Rb) compounds in the cubic antifluorite structure were investigated via ab initio calculations using the all electron linearized augmented plane wave approach based on density functional theory with and without including spin-orbit coupling (SOC). The exchange-correlation interactions were described within the PBEsol version of the generalized gradient approximation and Tran-Blaha modified Becke-Johnson potential (TB-mBJ). Optimized equilibrium lattice parameters are in excellent accordance with existing measured ones. Computed energy band dispersions show that the studied compounds are large band gap materials. Inclusion of SOC reduces the band gap value compared to the corresponding one calculated without including SOC. Determination of the energy band character and interatomic bonding nature are performed using the densities of states diagrams and charge density distribution map. Linear optical function spectra are predicted for a wide energy range and the origin of the dielectric function spectrum peaks are determined.

Matched MeSH terms: Electronics/methods
Fulltext Development and implementation of a potential coronavirus disease 2019 (COVID-19) vaccine: A systematic review and meta-analysis of vaccine clinical trials

Sathian B, Asim M, Banerjee I, Roy B, Pizarro AB, Mancha MA, et al.

Nepal J Epidemiol, 2021 Mar;11(1):959-982.
PMID: 33868742 DOI: 10.3126/nje.v11i1.36163

Background: To date, there is no comprehensive systematic review and meta-analysis to assess the suitability of COVID-19 vaccines for mass immunization. The current systematic review and meta-analysis was conducted to evaluate the safety and immunogenicity of novel COVID-19 vaccine candidates under clinical trial evaluation and present a contemporary update on the development and implementation of a potential vaccines.
Methods: For this study PubMed, MEDLINE, and Embase electronic databases were used to search for eligible studies on the interface between novel coronavirus and vaccine design until December 31, 2020.
Results: We have included fourteen non-randomized and randomized controlled phase I-III trials. Implementation of a universal vaccination program with proven safety and efficacy through robust clinical evaluation is the long-term goal for preventing COVID-19. The immunization program must be cost-effective for mass production and accessibility. Despite pioneering techniques for the fast-track development of the vaccine in the current global emergency, mass production and availability of an effective COVID-19 vaccine could take some more time.
Conclusion: Our findings suggest a revisiting of the reported solicited and unsolicited systemic adverse events for COVID-19 candidate vaccines. Hence, it is alarming to judiciously expose thousands of participants to COVID-19 candidate vaccines at Phase-3 trials that have adverse events and insufficient evidence on safety and effectiveness that necessitates further justification.

Matched MeSH terms: Electronics
Fulltext Synergistic enhancement in the microelectronic properties of poly-(dioctylfluorene) based Schottky devices by CdSe quantum dots

Muhammad F, Tahir M, Zeb M, Kalasad MN, Mohd Said S, Sarker MR, et al.

Sci Rep, 2020 Mar 16;10(1):4828.
PMID: 32179797 DOI: 10.1038/s41598-020-61602-1

This paper reports the potential application of cadmium selenide (CdSe) quantum dots (QDs) in improving the microelectronic characteristics of Schottky barrier diode (SBD) prepared from a semiconducting material poly-(9,9-dioctylfluorene) (F8). Two SBDs, Ag/F8/P3HT/ITO and Ag/F8-CdSe QDs/P3HT/ITO, are fabricated by spin coating a 10 wt% solution of F8 in chloroform and 10:1 wt% solution of F8:CdSe QDs, respectively, on a pre-deposited poly(3-hexylthiophene) (P3HT) on indium tin oxide (ITO) substrate. To study the electronic properties of the fabricated devices, current-voltage (I-V) measurements are carried out at 25 °C in dark conditions. The I-V curves of Ag/F8/P3HT/ITO and Ag/F8-CdSe QDs/P3HT/ITO SBDs demonstrate asymmetrical behavior with forward bias current rectification ratio (RR) of 7.42 ± 0.02 and 142 ± 0.02, respectively, at ± 3.5 V which confirm the formation of depletion region. Other key parameters which govern microelectronic properties of the fabricated devices such as charge carrier mobility (µ), barrier height (ϕb), series resistance (Rs) and quality factor (n) are extracted from their corresponding I-V characteristics. Norde's and Cheung functions are also applied to characterize the devices to study consistency in various parameters. Significant improvement is found in the values of Rs, n, and RR by 3, 1.7, and 19 times, respectively, for Ag/F8-CdSe QDs/P3HT/ITO SBD as compared to Ag/F8/P3HT/ITO. This enhancement is due to the incorporation of CdSe QDs having 3-dimensional quantum confinement and large surface-to-volume area. Poole-Frenkle and Richardson-Schottky conduction mechanisms are also discussed for both of the devices. Morphology, optical bandgap (1.88 ± 0.5 eV) and photoluminescence (PL) spectrum of CdSe QDs with a peak intensity at 556 nm are also reported and discussed.

Matched MeSH terms: Electronics
Fulltext Electronic Properties of DNA-Based Schottky Barrier Diodes in Response to Alpha Particles

Al-Ta'ii HM, Periasamy V, Amin YM

Sensors (Basel), 2015;15(5):11836-53.
PMID: 26007733 DOI: 10.3390/s150511836

Detection of nuclear radiation such as alpha particles has become an important field of research in recent history due to nuclear threats and accidents. In this context; deoxyribonucleic acid (DNA) acting as an organic semiconducting material could be utilized in a metal/semiconductor Schottky junction for detecting alpha particles. In this work we demonstrate for the first time the effect of alpha irradiation on an Al/DNA/p-Si/Al Schottky diode by investigating its current-voltage characteristics. The diodes were exposed for different periods (0-20 min) of irradiation. Various diode parameters such as ideality factor, barrier height, series resistance, Richardson constant and saturation current were then determined using conventional, Cheung and Cheung's and Norde methods. Generally, ideality factor or n values were observed to be greater than unity, which indicates the influence of some other current transport mechanism besides thermionic processes. Results indicated ideality factor variation between 9.97 and 9.57 for irradiation times between the ranges 0 to 20 min. Increase in the series resistance with increase in irradiation time was also observed when calculated using conventional and Cheung and Cheung's methods. These responses demonstrate that changes in the electrical characteristics of the metal-semiconductor-metal diode could be further utilized as sensing elements to detect alpha particles.

Matched MeSH terms: Electronics/instrumentation*
Evaluation of Interference of Cellular Phones on Electronic Apex Locators: An In Vitro Study

Sidhu P, Shankargouda S, Dicksit DD, Mahdey HM, Muzaffar D, Arora S

J Endod, 2016 Apr;42(4):622-5.
PMID: 26850688 DOI: 10.1016/j.joen.2015.12.027

INTRODUCTION: Use of mobile phone has been prohibited in many hospitals to prevent interference with medical devices. Electromagnetic radiation emitted from cellular phones might interfere with electronic working length determination. The purpose of this in vitro study was to evaluate the effect of a smart phone (Samsung Galaxy Note Edge) on working length determination of electronic apex locators (EALs) Propex II and Rootor.
METHODS: Fifteen intact, non-carious single-rooted teeth were decoronated at the cementoenamel junction. Visually, working length was determined by using a #15 K-file under stereomicroscope (×20). The effect of cellular phones on electronic working length (EWL) was determined under 2 experimental settings: (1) in a closed room with poor signal strength and (2) in a polyclinic set up with good signal strength and 5 conditions: (1) electronically, without cellular phone in room; (2) electronically, with cellular phone in physical contact with EAL; (3) electronically, with mobile phone in physical contact with EAL and in calling mode for a period of 25 seconds; (4) electronically, mobile phone placed at a distance of 40 cm from the EAL; and (5) electronically, mobile phone placed at a distance of 40 cm and in calling mode for a period of 25 seconds. The EWL was measured 3 times per tooth under each condition. Stability of the readings was scored from 1 to 3: (1) good stability, (2) stable reading after 1 attempt, and (3) stable reading after 2 attempts. The data were compared by using analysis of variance.
RESULTS: The EWL measurements were not influenced by the presence of cellular phone and could be determined under all experimental conditions.
CONCLUSIONS: Within the limitations of this study, it can be concluded that mobile phones do not interfere with the EWL determination.

Matched MeSH terms: Electronics, Medical/instrumentation*
Photonics-powered augmented reality skin electronics for proactive healthcare: multifaceted opportunities

Taha BA, Addie AJ, Kadhim AC, Azzahran AS, Haider AJ, Chaudhary V, et al.

Mikrochim Acta, 2024 Apr 08;191(5):250.
PMID: 38587660 DOI: 10.1007/s00604-024-06314-3

Rapid technological advancements have created opportunities for new solutions in various industries, including healthcare. One exciting new direction in this field of innovation is the combination of skin-based technologies and augmented reality (AR). These dermatological devices allow for the continuous and non-invasive measurement of vital signs and biomarkers, enabling the real-time diagnosis of anomalies, which have applications in telemedicine, oncology, dermatology, and early diagnostics. Despite its many potential benefits, there is a substantial information vacuum regarding using flexible photonics in conjunction with augmented reality for medical purposes. This review explores the current state of dermal augmented reality and flexible optics in skin-conforming sensing platforms by examining the obstacles faced thus far, including technical hurdles, demanding clinical validation standards, and problems with user acceptance. Our main areas of interest are skills, chiroptical properties, and health platform applications, such as optogenetic pixels, spectroscopic imagers, and optical biosensors. My skin-enhanced spherical dichroism and powerful spherically polarized light enable thorough physical inspection with these augmented reality devices: diabetic tracking, skin cancer diagnosis, and cardiovascular illness: preventative medicine, namely blood pressure screening. We demonstrate how to accomplish early prevention using case studies and emergency detection. Finally, it addresses real-world obstacles that hinder fully realizing these materials' extraordinary potential in advancing proactive and preventative personalized medicine, including technical constraints, clinical validation gaps, and barriers to widespread adoption.

Matched MeSH terms: Electronics
Fulltext One-year outcomes of two-week double-dose clopidogrel treatment following percutaneous coronary intervention in a state general hospital in Malaysia

Doris George, Chang Chee Tao, Kumutha Kumarasamy, Asri Ranga

Malaysian Journal of Medicine and Health Sciences, 2020;16(2):187-192.
MyJurnal

Introduction: Previous studies reported that a two-week double-dose clopidogrel treatment following percutaneous coronary intervention has no difference in safety compared to standard therapy. This study aimed to determine the all-cause readmission rate and survival after a year of percutaneous coronary intervention (PCI) in patients who were treated with two-week double-dose clopidogrel regimen. Methods: This was a retrospective study on patients who underwent PCI in a state general hospital in Malaysia in 2014. Patients’ one month and one-year survival status were retrieved using the hospital electronic patient management system. Patients who received a two-week course of 150mg clopidogrel and subsequently a one-year course of standard double antiplatelet therapy were included. Results: A total of 381 out of 563 patients who underwent PCI were included in the analysis, while those who were switched to ticagrelor and transferred to other hospitals post-PCI excluded. Patients had a mean age of 56.9 (SD 10.7), with majority male (331, 86.9%) and Malay (144, 37.8%). The PCI was mainly indicated for ST-elevated myocardial infarction (188, 49.3%), non-STEMI (114, 29.9%) and unstable angina (36, 9.4%). A total of 107 (28.1%) patients were readmitted within the one year post-PCI period. Readmissions were mainly due to ACS (55.5%) and bleeding events (2.4%). The 30-day and 1-year all-cause mortality was 33 cases and 43 cases, respectively. Conclu- sion: The low readmission and bleeding related readmission suggested that the two-week double-dose clopidogrel regimen was safe for the post PCI patients. Future randomised trial to establish the efficacy of this dosing regimen is therefore warranted.

Matched MeSH terms: Electronics
Fulltext Characterization of the Fat Channel for Intra-Body Communication at R-Band Frequencies

Asan NB, Hassan E, Shah JVSRM, Noreland D, Blokhuis TJ, Wadbro E, et al.

Sensors (Basel), 2018 Aug 21;18(9).
PMID: 30134629 DOI: 10.3390/s18092752

In this paper, we investigate the use of fat tissue as a communication channel between in-body, implanted devices at R-band frequencies (1.7⁻2.6 GHz). The proposed fat channel is based on an anatomical model of the human body. We propose a novel probe that is optimized to efficiently radiate the R-band frequencies into the fat tissue. We use our probe to evaluate the path loss of the fat channel by studying the channel transmission coefficient over the R-band frequencies. We conduct extensive simulation studies and validate our results by experimentation on phantom and ex-vivo porcine tissue, with good agreement between simulations and experiments. We demonstrate a performance comparison between the fat channel and similar waveguide structures. Our characterization of the fat channel reveals propagation path loss of ∼0.7 dB and ∼1.9 dB per cm for phantom and ex-vivo porcine tissue, respectively. These results demonstrate that fat tissue can be used as a communication channel for high data rate intra-body networks.

Matched MeSH terms: Electronics/methods*
Fulltext Investigations on physical characteristics of three-dimensional coil structure for MEMS magnetometer

N. Sulaiman, B. Y. Majlis

ASM Science Journal, 2013;7(1):27-36.
MyJurnal

Measurement of low magnetic field has played an important role in many electronics applications such as navigation, military, non-destructive test, traffic detection as well as medical diagnosis and treatment. The presence of magnetic field, particularly its strength and direction, can be measured using magnetometer. There are many types of magnetometers being investigated through the years and one of the prominent types is fluxgate magnetometer. The main components of fluxgate magnetometer consisting of driving coils, sensing coils and magnetic core are developed by MEMS silicon processing technology. In this paper, an investigation on physical characteristics of the three-dimensional coil structure for a micro-scaled fluxgate magnetometer is presented. The physical characteristics such as width of the coil, distance between successive coils, and gap between the top and bottom coils which would influence the magnetic energy in magnetometer is discussed. In this work, finite-element method simulations to investigate the physical characteristics of the sensing coils were carried out, where the parameter of interest is the coils’ inductance as well as the magnetic flux density. Based on the simulation results, the varying of physical characteristics of the coils had its effects particularly in coil inductance, magnetic flux density, and magnetic energy. It could also be seen that the simulated results agreed with the theoretical aspects of magnetism in a coil. From the investigations, suitable coil dimensions were proposed.

Matched MeSH terms: Electronics
Fulltext Temperature and magnetic field driven modifications in the I-V features of gold-DNA-gold structure I-V

Khatir NM, Abdul-Malek Z, Banihashemian SM

Sensors (Basel), 2014;14(10):19229-41.
PMID: 25320908 DOI: 10.3390/s141019229

The fabrication of Metal-DNA-Metal (MDM) structure-based high sensitivity sensors from DNA micro-and nanoarray strands is a key issue in their development. The tunable semiconducting response of DNA in the presence of external electromagnetic and thermal fields is a gift for molecular electronics. The impact of temperatures (25-55 °C) and magnetic fields (0-1200 mT) on the current-voltage (I-V) features of Au-DNA-Au (GDG) structures with an optimum gap of 10 μm is reported. The I-V characteristics acquired in the presence and absence of magnetic fields demonstrated the semiconducting diode nature of DNA in GDG structures with high temperature sensitivity. The saturation current in the absence of magnetic field was found to increase sharply with the increase of temperature up to 45 °C and decrease rapidly thereafter. This increase was attributed to the temperature-assisted conversion of double bonds into single bond in DNA structures. Furthermore, the potential barrier height and Richardson constant for all the structures increased steadily with the increase of external magnetic field irrespective of temperature variations. Our observation on magnetic field and temperature sensitivity of I-V response in GDG sandwiches may contribute towards the development of DNA-based magnetic sensors.

Matched MeSH terms: Electronics
Electronic Transport and Possible Superconductivity at Van Hove Singularities in Carbon Nanotubes

Yang Y, Fedorov G, Shafranjuk SE, Klapwijk TM, Cooper BK, Lewis RM, et al.

Nano Lett., 2015 Dec 09;15(12):7859-66.
PMID: 26506109 DOI: 10.1021/acs.nanolett.5b02564

Van Hove singularities (VHSs) are a hallmark of reduced dimensionality, leading to a divergent density of states in one and two dimensions and predictions of new electronic properties when the Fermi energy is close to these divergences. In carbon nanotubes, VHSs mark the onset of new subbands. They are elusive in standard electronic transport characterization measurements because they do not typically appear as notable features and therefore their effect on the nanotube conductance is largely unexplored. Here we report conductance measurements of carbon nanotubes where VHSs are clearly revealed by interference patterns of the electronic wave functions, showing both a sharp increase of quantum capacitance, and a sharp reduction of energy level spacing, consistent with an upsurge of density of states. At VHSs, we also measure an anomalous increase of conductance below a temperature of about 30 K. We argue that this transport feature is consistent with the formation of Cooper pairs in the nanotube.

Matched MeSH terms: Electronics
Fulltext An 8.72 µW Low-Noise and Wide Bandwidth FEE Design for High-Throughput Pixel-Strip (PS) Sensors

Jérôme FK, Evariste WT, Bernard EZ, Crespo ML, Cicuttin A, Reaz MBI, et al.

Sensors (Basel), 2021 Mar 04;21(5).
PMID: 33806350 DOI: 10.3390/s21051760

The front-end electronics (FEE) of the Compact Muon Solenoid (CMS) is needed very low power consumption and higher readout bandwidth to match the low power requirement of its Short Strip application-specific integrated circuits (ASIC) (SSA) and to handle a large number of pileup events in the High-Luminosity Large Hadron Collider (LHC). A low-noise, wide bandwidth, and ultra-low power FEE for the pixel-strip sensor of the CMS has been designed and simulated in a 0.35 µm Complementary Metal Oxide Semiconductor (CMOS) process. The design comprises a Charge Sensitive Amplifier (CSA) and a fast Capacitor-Resistor-Resistor-Capacitor (CR-RC) pulse shaper (PS). A compact structure of the CSA circuit has been analyzed and designed for high throughput purposes. Analytical calculations were performed to achieve at least 998 MHz gain bandwidth, and then overcome pileup issue in the High-Luminosity LHC. The spice simulations prove that the circuit can achieve 88 dB dc-gain while exhibiting up to 1 GHz gain-bandwidth product (GBP). The stability of the design was guaranteed with an 82-degree phase margin while 214 ns optimal shaping time was extracted for low-power purposes. The robustness of the design against radiations was performed and the amplitude resolution of the proposed front-end was controlled at 1.87% FWHM (full width half maximum). The circuit has been designed to handle up to 280 fC input charge pulses with 2 pF maximum sensor capacitance. In good agreement with the analytical calculations, simulations outcomes were validated by post-layout simulations results, which provided a baseline gain of 546.56 mV/MeV and 920.66 mV/MeV, respectively, for the CSA and the shaping module while the ENC (Equivalent Noise Charge) of the device was controlled at 37.6 e- at 0 pF with a noise slope of 16.32 e-/pF. Moreover, the proposed circuit dissipates very low power which is only 8.72 µW from a 3.3 V supply and the compact layout occupied just 0.0205 mm2 die area.

Matched MeSH terms: Electronics
Differential cross sections for intermediate-energy electron scattering from α-tetrahydrofurfuryl alcohol: excitation of electronic-states

Chiari L, Duque HV, Jones DB, Thorn PA, Pettifer Z, da Silva GB, et al.

J Chem Phys, 2014 Jul 14;141(2):024301.
PMID: 25028013 DOI: 10.1063/1.4885856

We report on measurements of differential cross sections (DCSs) for electron impact excitation of a series of Rydberg electronic-states in α-tetrahydrofurfuryl alcohol (THFA). The energy range of these experiments was 20-50 eV, while the scattered electron was detected in the 10°-90° angular range. There are currently no other experimental data or theoretical computations against which we can directly compare the present measured results. Nonetheless, we are able to compare our THFA DCSs with earlier cross section measurements for Rydberg-state electronic excitation for tetrahydrofuran, a similar cyclic ether, from Do et al. [J. Chem. Phys. 134, 144302 (2011)]. In addition, "rotationally averaged" elastic DCSs, calculated using our independent atom model with screened additivity rule correction approach are also reported. Those latter results give integral cross sections consistent with the optical theorem, and supercede those from the only previous study of Milosavljević et al. [Eur. Phys. J. D 40, 107 (2006)].

Matched MeSH terms: Electronics*

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