Radu RAILIANU

Journal of Experimental and Clinical Surgery • 2020

Introduction. Combined methods of hernioplasty appear to be a promising surgical treatment of inguinal hernias, allowing reducing suture tension due to the contraction and stretching of the abdominal muscles optimized during the operation. This protects the inguinal region from relapse in severe connective tissue dysplasia.The aim of research was to study the influence of the level of connective tissue dysplasia and methods of combined hernioplasty of inguinal hernias on the electroactivity of the abdominal muscles.Methods. The study included 151 patients with inguinal hernias. The electroactivity of the abdominal muscles and the level of severity of connective tissue dysplasia were studied in these patients before and after combined methods of hernioplasty according to Milkovskaya Dmitrova diagnostic scheme; this also includes tension-reducing mechanism.Results. In the preoperative period, the decrease in the parameters of electromyograms compared to the healthy side in the inguinal region was 67.2%, compared to the region over the group of lateral muscles - 55% and compared to the region over the rectus abdominis muscles - 23.6%. The increase in the electrical activity of the rectus muscles against the background of a decrease in the severity of connective tissue dysplasia to the middle and light levels obtained 43.5% and 77.9%, respectively.The average frequency parameters of electromyograms of the abdominal muscles after combined tension-reducing hernioplasty of inguinal hernias seemed to be most significant: in the inguinal regions on the side of the hernia they amounted to 91.95 7.1 vibrations per second, in the region over the group of lateral muscles - 94.61 4.6/s and in the region over the rectus abdominis muscles - 93.7 2.9/s. Moreover, approximately similar rehabilitation of the rectus and lateral abdominal muscles was reported, which allowed balancing oppositely directed tension forces in the abdominal wall.Conclusion. Thus, in patients with inguinal hernias before surgery, the decrease in the electroactivity of the lateral muscle group was more pronounced than the decrease in the electroactivity of the rectus abdominis. The combined tension-reducing hernioplasty of inguinal hernias contributed to the most significant electromyographic rehabilitation of the abdominal muscles.

Iwona Agnieszka Rutkowska, Anna Wadas, Pawel J Kulesza

ECS Meeting Abstracts • 2015

Electrochromism in tungsten oxides and related systems has been recognized for long time and has been still of interest for display applications. Redox transitions and related reversible coloration of thin WO 3 films are believed to be controlled by simultaneous injection or removal of electrons and protons. The dynamics of partial reduction (in acid medium) of transparent tungsten(VI) oxides to blue hydrogen tungsten(VI,V) oxide bronzes or lower tungsten(VI,IV) oxides is largely dependent of the oxide morphology, nanostructuring, degree of hydration, or population of colored W(VI,V) or W(VI,IV) sites. For example, by depositing nanorods of tungsten oxide, rather than conventional tungsten oxide, on the ITO conducting glass (or the inert glassy carbon) substrate, the enhancement in the degree of the system's voltammetric reduction in acid medium (0.5 M H 2 SO 4 ) has been observed. Tungsten oxide nanorods seem to be partially and reversibly reduced not only to nonstoichiometric hydrogen tungsten(VI,V) oxide bronzes (H x WO 3 , 0<x<1) but also substoichiometric lower tungsten (VI,IV) oxides (WO 3-y , 0<y<1). Another important issue is the mobility and availability of protons within the tungsten oxide film. We have found that by controlled admixing of tungsten oxide with zirconia nanoparticles both nanostructured morphology and high mobility of protons can be adjusted. The resulting mixed (hybrid or composite) system is well-behaved: redox reactions (which are characteristics of WO 3 ) are fast and reversible despite the presence of semiconducting zirconia (ZrO­ 2 ). While ZrO 2 is not electroative, WO 3 undergoes redox reactions leading to formation of partially reduced hydrogen bronzes (H x WO 3 ) in which mobility of H + is coupled to electron transfers. The composite material is stabilized through electrostatic attraction between positively charged zirconium oxo cations (ZrO 2+ , ZrOH 3+ , [Zr 3 (OH) 4 ] 3+ ) and anionic tungstates (WO 4 2- in WO 3 *H 2 O or H 2 WO 4 ). Among important issues are: high population of hydroxyl groups and high mobility of protons at surfaces of zirconia (ZrO 2 ) nanostructures in addition to the existence of fast electron transfers coupled to proton displacements in partially reduced tungsten oxides (H x WO 3 ). In a different series of chronocoulometric experiments, diffusion coefficients (for charge propagation) have been determined, and they have been found typically higher for hybrid mixed metal (tungsten(VI)/zirconium(IV) oxide films (close to 10 -7 cm s -1 ). Mechanistic considerations and the results of spectroelectrochemical and diagnostic spectroscopic (e.g. FTIR) experiments will also be provided. We acknowledge collaboration with Christian Perruchot and Mohamed Jouini from ITODYS, Université Paris Diderot, France.

Huajun Tian, Fengxia Xin, Xiaojian Tan et al.

J. Mater. Chem. A • 2014

Highly lithium electroactive hierarchical boron-doped rutile submicrosphere TiO 2 was synthesized by a facile solvothermal method and successfully employed as an anode material for lithium-ion batteries.

Saba Navabzadeh Esmaeely, Srdjan Nesic

ECS Meeting Abstracts • 2017

Iron sulfides, particularly the two most stable polymorphs: pyrite and pyrrhotite, have captured the attention of scholars due to their semi-conductive properties. Their semi-conductive nature allows for the corrosive species to be reduced at their surface while electrons are transported from the steel surface via their network. Thus, as a corrosion product layer, pyrite or pyrrhotite do not offer sufficient protection to the steel underneath in the form of a mass transfer barrier for corrosive species. In addition, these layers could accelerate the corrosion rate via an enhancement of reduction of corrosive species rate on their surface. The electrochemistry of iron sulfide layers as it is related to the field of corrosion is unclear and the reported data in the literature has not reached a conclusion. Most of the available literature about electrochemistry of iron sulfides reports on their anodic, rather than cathodic behavior. However, it is noteworthy that in the mechanism related to a mild steel corrosion under such layers, the mild steel is the anode, and the iron sulfide layers are the cathode. A much higher cathodic surface area emerges due to the porous nature of these layers, which results in a higher corrosion currents of the mild steel. Therefore, in order to understand their main role on mild steel corrosion, it is important to study the rate of reduction of corrosive species such as: hydrogen (H + ), carbonic acid (H 2 CO 3 ) and hydrogen sulfide (H 2 S) on their surface to investigate their electroactivity. This would extend the current understanding of galvanic corrosion of a mild steel under iron sulfide layers. In the current study, pyrite and pyrrhotite electrodes made from geological specimens were polarized negatively and the results were compared with the data obtained from a mild steel electrode. The experiments were conducted in deaerated aqueous solutions with and without H 2 S at different pH at a room temperature. The experimental results revealed the significance of electroactivity of pyrite and pyrrhotite related to H + , H 2 CO 3 and H 2 S reduction rates. A comparison of their polarization data with a bare mild steel data showed a similar level of electroactivity. The measured data were compared with the calculated data from an electrochemical model developed and validated for a mild steel electrode exposed to aqueous environments with and without H 2 S. The experimental results from the pyrrhotite electrode showed an extra wave on the polarization curves with a distinct limiting current, it remains unclear what this wave represents. The nature of this wave is still under investigation. Figure 1

Hyun-Woo Shim, Byoungyong Im, Soyeong Joo et al.

Archives of Metallurgy and Materials • 2024

In this study, cobalt oxide (Co3O4) powder was prepared by simple precipitation and heat-treatment process of cobalt sulfate that is recovered from waste lithium-ion batteries (LIBs), and the effect of heat-treatment on surface properties of as-synthesized Co(OH)2 powder was systematically investigated. With different heat-treatment conditions, a phase of Co(OH)2 is transformed into CoOOH and Co3O4. The result showed that the porous and large BET surface area (ca. 116 m2/g) of Co3O4 powder was prepared at 200°C for 12 h. In addition, the lithium electroactivity of Co3O4 powder was investigated. When evaluated as an anode material for LIB, it exhibited good electrochemical performance with a specific capacity of about 500 mAh g–1 at a current density of C/5 after 50 cycles, which indicates better than those of commercial graphite anode material.

Yu. V. Pleskov, M. D. Кrotova, E. A. Еkimov

Электрохимия • 2023

The diamond electrodes-compacts with extreme high boron-doping level, added with platinum, were prepared at a pressure of 8―9 GPa and temperature ~2500 К from growth mixtures В–С, Pt–C, and Pt–C–B. They are highly electroactive in the reaction of ethylenediaminetetraacetic acid electrooxidation. The oxidation current is a linear function of the ethylenediaminetetraacetic acid concentration over the 0.001–0.05 g-equ/L range. This system can be basic to an electroanalytical method for the ethylenediaminetetraacetic acid determination.

Terdha Narla, Uma Nudurupati, Yangguang Ou

ChemRxiv • 2025

Short-chain fatty acids (SCFAs), specifically acetic acid, propionic acid, and butyric acid, are the most abundant metabolites produced by gut bacteria and play a significant role in brain health and neurochemistry. There is a great deal of interest in measuring how much SCFAs cross into the brain and how they directly affect neurotransmission in a dose-dependent manner. Here we utilize fast scan cyclic voltammetry at carbon fiber microelectrodes to investigate the electroactivity of these SCFAs. Our findings demonstrate that these gut metabolites display a single cathodic and two anodic peaks in the cyclic voltammograms. Two of these peaks (one oxidation, one reduction) respond to changes in scan rate in a manner characteristic of faradaic processes. We varied the holding and switching potentials as well as utilized butyrate analogs to understand the nature of the peaks further. While future optimization will be needed to create SCFA-selective sensors, this work demonstrate the potential for in situ electrochemical detection of these gut metabolites.

A. Gába, Ondřej Kapuš, R. Cuberek et al.

Journal of Human Nutrition and Dietetics • 2015

BACKGROUND Bioelectric impedance analysis (BIA) is commonly used in research to assess body composition. However, studies that validate the accuracy of BIA exclusively in post-menopausal women are lacking. The main purpose of the present study was to evaluate the agreement of multi-frequency (MF)-BIA and single-frequency (SF)-BIA with dual-energy X-ray absorptiometry (DXA) in the estimation of fat mass (FM) and fat-free mass (FFM) among post-menopausal women with variation in body mass index (BMI) and physical activity (PA). METHODS FM and FFM were estimated by BIA and DXA in 146 post-menopausal women with a mean (SD) age of 62.8 (5.2) years. PA was determined by an accelerometer. RESULTS The mean (SD) difference between MF-BIA and DXA was -1.8 (1.8) kg (P = 0.08) and 1.3 (1.8) kg (P = 0.01) for FM and FFM, respectively. SF-BIA provided a significantly lower estimate of FM [-2.0 (2.2) kg; P = 0.04] and a higher estimate of FFM [1.8 (2.4) kg; P < 0.01] compared to DXA. MF-BIA provided significantly better estimates of FM and FFM with narrower limits of agreement than SF-BIA in obese and insufficiently active subjects. In other BMI and PA groups, both BIA devices showed a similar deviation from DXA. CONCLUSIONS BIA tends to underestimate FM and overestimate FFM relative to DXA. MF-BIA appears to be a more appropriate method for the assessment of body composition than SF-BIA in post-menopausal woman with BMI >30 kg/m(2) and in those who are insufficiently active.

D. Petrović, S. Vujkov, B. Petronijević et al.

Vojnosanitetski pregled • 2014

BACKGROUND/AIM The muscles of the orofacial region have great influence on the development of dentition and occlusion formation. It is known that improper function of these muscles is one of the major etiological factors in malocclusion. A correlation between function disorders of orofacial muscle and occlusion disorders has been confirmed, as well as a correlation between the bioelectric activity of the masticatory muscles, recorded by electromyography, and bite force upon maximal voluntary contraction of these muscles. The aim of the study was to analyze the bioelectriacal activity of temporal and masseter muscles. METHODS The sample consisted of 100 subjects of both sexes, divided into the control group (n = 30) with neutral and complete dental arches, and the study group (n = 70) of patients with distal occlusion. Electromyographic measurement of bioelectric potentials in all the subjects was conducted for the examined muscles in the physiologic rest position, central mandible occlusion, and during maximal voluntary contraction of muscles and saliva swallowing, in Angle Class I and II/2 occlusal relationships, prior to treatment, after one year of the orthodontic treatment and after the treatment with an activator. RESULTS Comparing the values of the bioelectrical activity in the control and the study group before the treatment, a decreased muscle activity was established in all the three positions in the study group. After the first year of orthodontic treatment the results showed an elevation in the bioelectrical activity in both muscles. After treatment with an activator, the bioelectrical activity in both muscles in the study group was higher than before the treatment, as it is confirmed by a positive highly significant coefficient of correlation. CONCLUSION In all the three measured positions of the mandible with Angle Class II/2 malocclusion, bioelectrical activity was lowest at baseline and increased during the first year of treatment, and at the end of the treatment it partially reduced close to the approximate values in normal occlusion. Research on electromyographic activity of masticatory muscles is useful in everyday clinical practice, especially in present distinctive skeletal discrepancy before, during and after orthodontic treatment, if on the bases of the results we can evaluate the treatment, but also determine the start and duration of the retention period and retention device type.

T. Halski, Lucyna Słupska, R. Dymarek et al.

BioMed Research International • 2014

Objectives. Evaluation of resting and functional bioelectrical activity of the pelvic floor muscles (PFM) and the synergistic muscles, depending on the orientation of the pelvis, in anterior (P1) and posterior (P2) pelvic tilt. Design. Preliminary, prospective observational study. Setting. Department and Clinic of Urology, University Hospital in Wroclaw, Poland. Participants. Thirty-two menopausal and postmenopausal women with stress urinary incontinence were recruited. Based on inclusion and exclusion criteria, sixteen women aged 55 to 70 years were enrolled in the study. Primary Outcome Measures. Evaluation of resting and functional bioelectrical activity of the pelvic floor muscles by electromyography (sEMG) and vaginal probe. Secondary Outcome Measures. Evaluation of activity of the synergistic muscles by sEMG and surface electrodes. Results. No significant differences between orientations P1 and P2 were found in functional and resting sEMG activity of the PFM. During resting and functional PFM activity, higher electrical activity in P2 than in P1 has been recorded in some of the synergistic muscles. Conclusions. This preliminary study does not provide initial evidence that pelvic tilt influences PFM activation. Although different activity of synergistic muscles occurs in various orientations of the pelvic tilt, it does not have to affect the sEMG activity of the PFM.

D. Chmielewska, M. Stania, G. Sobota et al.

BioMed Research International • 2015

We examined pelvic floor muscles (PFM) activity (%MVC) in twenty nulliparous women by body position during exercise as well as the activation of abdominal muscles and the gluteus maximus during voluntary contractions of the PFMs. Pelvic floor muscle activity was recorded using a vaginal probe during five experimental trials. Activation of transversus abdominis, rectus abdominis, and gluteus maximus during voluntary PFM contractions was also assessed. Significant differences in mean normalized amplitudes of baseline PFM activity were revealed between standing and lying (P < 0.00024) and lying and ball-sitting positions (P < 0.0053). Average peak, average time before peak, and average time after peak did not differ significantly during the voluntary contractions of the PFMs. Baseline PFM activity seemed to depend on the body position and was the highest in standing. Pelvic floor muscles activity during voluntary contractions did not differ by position in continent women. Statistically significant differences between the supine lying and sitting positions were only observed during a sustained 60-second contraction of the PFMs.

Francesco Campa, G. Coratella, Giuseppe Cerullo et al.

Journal of Translational Medicine • 2024

The appropriate use of predictive equations in estimating body composition through bioelectrical impedance analysis (BIA) depends on the device used and the subject’s age, geographical ancestry, healthy status, physical activity level and sex. However, the presence of many isolated predictive equations in the literature makes the correct choice challenging, since the user may not distinguish its appropriateness. Therefore, the present systematic review aimed to classify each predictive equation in accordance with the independent parameters used. Sixty-four studies published between 1988 and 2023 were identified through a systematic search of international electronic databases. We included studies providing predictive equations derived from criterion methods, such as multi-compartment models for fat, fat-free and lean soft mass, dilution techniques for total-body water and extracellular water, total-body potassium for body cell mass, and magnetic resonance imaging or computerized tomography for skeletal muscle mass. The studies were excluded if non-criterion methods were employed or if the developed predictive equations involved mixed populations without specific codes or variables in the regression model. A total of 106 predictive equations were retrieved; 86 predictive equations were based on foot-to-hand and 20 on segmental technology, with no equations used the hand-to-hand and leg-to-leg. Classifying the subject’s characteristics, 19 were for underaged, 26 for adults, 19 for athletes, 26 for elderly and 16 for individuals with diseases, encompassing both sexes. Practitioners now have an updated list of predictive equations for assessing body composition using BIA. Researchers are encouraged to generate novel predictive equations for scenarios not covered by the current literature. Registration code in PROSPERO: CRD42023467894. Supplementary Information The online version contains supplementary material available at 10.1186/s12967-024-05272-x.

N. D. Sorokina, S. Pertsov, G. V. Selitsky

Epilepsia and paroxyzmal conditions • 2018

Recent studies show that the brain gamma activity includes both the gamma rhythm (standard EEG) and high frequency (100-1000 Hz) as well as super-high (>1000 Hz) frequency oscillations, as recorded by electrocorticography. As reported in the literature, the high-frequency oscillations (80-500 Hz) are highly informative markers of an epileptic focus. In this review, we analyze features of high-frequency activity associated with the epileptiform activity, and its relation to the seizure onset range. Further study of high-frequency bioelectric activity of the brain is of interest to researchers and clinicians, and may improve the EEG differential diagnosis of epilepsy.

Wahib Alrofati, Amir Javan-Khoshkholgh, Rui Bao et al.

2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) • 2018

The purpose of this paper is to develop and validate a configurable system that can wirelessly acquire gastric electrical activity called slow waves, and deliver high energy electrical pulses to modulate its activity. The system is composed of a front-end unit, and an external stationary backend unit that is connected to a computer. The front-end unit contains a recording module with four channels, and a stimulating module with two channels. Commercial off-theshelf components were used to develop front- and back-end units. A graphical user interface (GUI) was designed in LabVIEW to process and display the recorded data in realtime, and store the data for off-line analysis. Besides, the gain of the analog conditioning circuit as well as the stimulation pulse configuration is programmable directly through the GUI. The system was successfully validated on bench top. The benchtop studies showed an appropriate frequency response for analog conditioning and digitization resolution to acquire gastric slow waves. Moreover, the system was able to deliver electrical pulses at amplitudes up to ±24 mA and ±12 mA to a load of up to 0.5 k $\Omega $ and 1 $\textbf{k}\Omega $, respectively. This study reports the first high-energy stimulator that can be controlled wirelessly and integrated into a gastric bioelectrical activity monitoring system. The system can be used for treating functional gastrointestinal disorders.

Piotr Gawda, Michał Ginszt, Magdalena Zawadka et al.

Journal of Human Kinetics • 2019

Abstract Patellofemoral pain syndrome (PFPS), the most common source of knee pain among physically active individuals, is defined as anterior knee pain involving the patella and retinaculum that excludes other intraarticular and peri-patellar pathology. Differences in the activation and endurance of the quadriceps components, causing an imbalance in the forces controlling patellar tracking during flexion and extension in the knee joint, appear to be the most commonly reported risk factors for PFPS. The aim of this study was to determine the differences in bioelectric activity of vastus medialis and rectus femoris muscles during half knee bend position in runners with PFPS. The sample comprised 20 recreational runners (15 males, 5 females; aged 27 ± 5 years) reporting knee pain and diagnosed with PFPS. The age- and sex-matched control group consisted of recreational runners who did not report knee pain. The myon electromyographic system was used to determine the changes in the electromyographic median frequency during a half squat position. The decrease in the median frequency of vastus medialis and rectus femoris muscles was significantly greater in runners with PFPS in comparison to the control group (p < 0.01 for right and left vastus medialis and right rectus femoris; p < 0.05 for left rectus femoris). There is a relationship between knee pain related to PFPS and the imbalance of bioelectric activity of vastus medialis and rectus femoris muscles. Achieving the muscular balance within the thigh muscles can be an important factor in the rehabilitation process of PFPS.

Mahtab Roohi-Azizi, L. Azimi, S. Heysieattalab et al.

Medical Journal of the Islamic Republic of Iran • 2017

Background: An electroencephalogram (EEG) is an accepted method in neurophysiology with a wide application. Different types of brain rhythms indicate that simultaneous activity of the brain cortex neurons depend on the person’s mental state. Method: we have focus on reviewing the existing literature pertaining to changes of the brain’s bioelectrical activity that recorded from the scalp in different conditions such as cognition and some mental disorders. Result: The frequency of brain waves may indicate sleep, consciousness, cognition, and some mental disorders. Slow brain waves are seen in some conditions such as sleep, coma, brain death, depression, autism, brain tumors, obsessive–compulsive disorder (OCD), attention deficit hyperactivity disorder (ADHD), and encephalitis, while rapid waves are generally reported in conditions such as epilepsy, anxiety, posttraumatic stress disorder (PTSD), and drug abuse. Conclusion: Increase in the EEG rhythm is a marker of high brain activity that leads to high degrees of consciousness, while slow waves are suggestive of less brain activity. The pattern of EEG rhythm can be an indicator of some mental disorders, too.

I. V. Zolnikova, S. Milash, A. B. Chernyak et al.

Vestnik oftal'mologii • 2019

PURPOSE To assess the changes in photoreceptor retinal layers and the choroid in comparison with bioelectrical activity of the macula in patients with retinitis pigmentosa (RP). MATERIAL AND METHODS The study included 10 patients (20 phakic eyes) with RP. Mean age was 27±18.5 years; mean best corrected visual acuity was 0.38±0.22. In addition to standard ophthalmological examination and fundus photography, each patient underwent an electrophysiological study on an electroretinograph MBN (Russia) recording general electroretinogram (ERG), maximal ERG (cone-rod response), 30 Hz flicker ERG and macular ERG (mERG). Choroidal thickness (CT) measurement and segmentation of the retina with following calculation of the thickness of different retinal layers was performed on SD-OCT RS-3000 Advance 'Nidek', Japan), it included obtainment of the 6-mm-diameter map in accordance with the Early Treatment Diabetic Retinopathy Study (ETDRS). RESULTS The study revealed a decrease in thickness of the choroid, retina, and the photoreceptor layers: 1) the layer with photoreceptor outer segment (OS) and retinal pigment epithelium (RPE) and 2) the layer with photoreceptor inner segment (IS) and outer nuclear layer. Decreased thickness of these layers is associated with the reduction of bioelectric activity of the macula as seen with mERG. CONCLUSION Decreased thickness of the retina, choroid and photoreceptor layers in all segments of the macula according to EDTRS standards is associated with reduced bioelectric activity of the macula recorded with mERG.

P. Marinescu, Lauren A. Miller, R. Young et al.

Obstetrics &amp; Gynecology • 2019

METHODS: This is an observational cohort study of pregnant women at an urban academic medical center from November 2017 to June 2018. Women with short cervical length (CL) ,2.5 cm were compared to women with normal CL ($3 cm). Primary outcome was pattern of bioelectrical activity in both groups. Secondary outcomes were characteristics of identified signals. All subjects had a singleton pregnancy between 16w0d and 22w6d. Up to 4 proprietary uEMG electrode pads (PreTel, Inc., Chattanooga, TN), 4 commercially available ECG pads, a ground electrode, and a tocometer were placed on the lower abdomen. EMG recordings were obtained for 60 minutes using a Porti amplifier (TMSi, Oldenzaal, Netherlands) and analyzed between 0.15 and 1.2 Hz.

Y. Pigareva, O. Grinchuk, A. Gladkov et al.

Journal of Physics: Conference Series • 2020

Synchronization of neuronal subpopulations and spiking pattern propagation are essential features for bioelectrical activity of the brain. In this study, we proposed an engineering method to grow hierarchically connected networks in vitro through the microchannels and investigated the relations of local spiking propagation through the microchannels with integrated bursting events in the chambers.

Łukasz Oleksy, M. Wojciechowska, A. Mika et al.

Medicine • 2020

Abstract The aim of the study was to evaluate pelvic floor muscle bioelectrical activity in healthy, young, and nulliparous women, and to present normative values for all phases and parameters measured with the Glazer Protocol. In this study, 96 healthy, young, nulliparous women (age 22–27 years; 168.6 ± 5.1 cm; 57.1 ± 11.8 kg) were tested. The bioelectrical activity of the pelvic floor muscles was collected using an endovaginal electrode with the Glazer Protocol, which included the following series of muscles contractions and relaxations: pre-baseline rest, phasic contractions, tonic contractions, isometric contractions for muscle endurance evaluation, and post-baseline rest. The following normative values of the bioelectrical signal for all phases of the Glazer Protocol were calculated: mean, minimal, and maximal values, 95% confidence interval, standard deviation, 95% standard deviation confidence interval, variance, coefficient of variation, and standard error of measurement. Average Mean Amplitude (μV) was as follows: pre-baseline rest (6.26 ± 3.33 μV), phasic contractions (49.76 ± 26.44 μV), tonic contractions (37.05 ± 25.99 μV), endurance contraction (16.10 ± 6.68 μV), and post-baseline rest (6.93 ± 3.99 μV). This study was the first in which normative values for all phases of the Glazer Protocol were reported. This protocol is very often used in electromyography devices as a tool for pelvic floor muscle assessment. Due to the fact that the interpretation of the pelvic floor muscle evaluation is complex and difficult, the authors believe that the normative values proposed in this study allow for comprehensive interpretation of this test (both qualitatively and quantitatively) and provide a reference point for parameters measured in women with different pelvic floor dysfunctions.

Renata Kielnar, A. Mika, D. Bylina et al.

PLOS ONE • 2021

Background Coexistence of temporomandibular joint discomfort along with cervical spine disorders is quite common, and is associated with many limitations and adverse symptoms for the patient. Both diagnostics and treatment of these ailments are difficult, and in many cases, the effects of therapy are not satisfactory. This study assessed the impact of a 3-week neck-only rehabilitation programme without direct intervention in the craniofacial area on the bioelectric activity of both the cervical spine and muscles in the craniofacial area among patients with idiopathic neck pain who do not report TMJ pain. Design A parallel group trial with follow-up; Setting: Rehabilitation Clinic. Methods Twenty five patients experiencing idiopathic neck pain underwent the 3-week rehabilitation programme. Thirty five age-matched subjects with no cervical spine and temporomandibular joint (TMJ) dysfunctions were control group. At baseline and after 3 weeks the cervical and craniofacial area muscles’ bioelectrical activity (sEMG) was evaluated. Results In the experimental group during cervical flexion, a significant decrease of sEMG amplitude was noted in the right (mean 25.1 μV; 95% CI: 21.5–28.6 vs mean 16.8 μV; 95% CI: 13.8–19.7) and left (mean 25.9 μV; 95% CI: 21.7–30.0 vs mean 17.2 μV; 95% CI: 13.6–20.7) Sternocleidomastoid as well as a significant increase in sEMG amplitude of the right (mean 11.1 μV; 95% CI: 7.9–14.2 vs mean 15.7 μV; 95% CI: 12.1–19.2) and left (mean 15.3 μV; 95% CI: 11.9–18.6 vs mean 20.2 μV; 95% CI: 15.7–24.2) Upper Trapezius muscles. In the experimental group, after therapy right and left Sternocleidomastoid, Temporalis Anterior and Masseter muscles presented lower fatigue levels. Conclusions Three weeks of rehabilitation without any therapeutic intervention in temporomandibular joint significantly decreased the bioelectrical activity of the neck and craniofacial muscles while improving the muscle pattern of coactivation in participants with idiopathic neck pain who do not report temporomandibular joint pain. These observations could be helpful in the physiotherapeutic treatment of neck and craniofacial area dysfunctions. Trial registration ID ISRCTN14511735—retrospectively registered.

Grzegorz Zieliński, Michał Baszczowski, M. Râpă et al.

Pain Research and Management • 2022

Objective The present study aimed to evaluate the correlation of eye length and bioelectric activity of temporalis, masseter, digastric, and sternocleidomastoid muscles in women with myopia compared to healthy women. Methods Based on the exclusion and inclusion criteria, 42 women aged 24 years (±2 years) were eligible for the study. Two equally sized groups with myopic (n = 21) and emmetropic healthy subjects (n = 21) were formed. An electromyographic study of the examined muscles was performed in four conditions: at rest, during maximal voluntary clenching in the intercuspal position, during maximal voluntary clenching on dental cotton rollers, and during maximal mouth opening using BioEMG III (BioResearch Associates, Inc. Milwaukee, WI, USA). The IOL Master 500 (Carl Zeiss Meditec, Jena, Germany) was used to examine the eyeball length. Statistical analysis showed significant positive correlations during mouth opening in both groups with open and closed eyes. Results A greater number of correlations between the analyzed variables was observed in emmetropic women. In almost all cases, the longer axial eye length was associated with an increase in the bioelectrical activity of the analyzed muscles. Significant correlations were most often observed within the masseter and digastric muscles during the maximum mouth opening and at rest. Conclusion There is a relationship between the bioelectrical activity of the masticatory muscles and the axial length of the eyeball on the same side.

Grzegorz Zieliński, Anna Matysik-Woźniak, Michał Baszczowski et al.

Scientific Reports • 2022

The study aimed to analyze the changes within the bioelectrical activity of the cervical spine and masticatory muscles during the change of visual stimulus—open and closed eyes test. After applying the inclusion criteria, 50 subjects were included in the study, with visual impairment ranging from −0.5 to −5.75 Diopters. Four muscle pairs were analyzed: the anterior part of the temporalis muscle (TA), the superficial part of the masseter muscle (MM), the anterior belly of the digastric muscle (DA), and the middle part of the sternocleidomastoid muscle (SCM) belly during rest, teeth clenching, teeth clenching on dental cotton rollers, and active mouth opening. Statistical analysis showed a significant decrease in the bioelectrical activity during teeth clenching of all analyzed muscles during the closed eyes test. Significant decreases of electromyographic values were also observed during resting activity within TA muscles, during teeth clenching with dental cotton rollers within SCM and DA muscles, and during active mouth opening within the right masseter. Changing the visual stimulus from open eyes to closed eyes in people with myopia affects the bioelectrical activity of the masticatory and cervical spine muscles.

Grzegorz Zieliński, M. Wójcicki, M. Râpă et al.

CRANIO® • 2023

ABSTRACT Objective The aim of this study was to analyze the correlation between the refractive error, muscle thickness, and the bioelectrical activity of selected masticatory and neck muscles in subjects with myopia. Methods For bioelectrical activity analysis within the masticatory muscles, an 8-channel BioEMG III electromyograph was used. An M-Turbo ultrasound machine was used to analyze the masticatory and neck muscle thickness. Results Statistical analysis showed significant positive correlations between masseter muscle thickness at rest on the right side. Statistical analysis showed negative correlations between the digastric muscle and Activity Index within masticatory muscles at rest on the left side when the eyes were closed. Conclusions As refractive error increases in myopic subjects, the resting tension on the temporal muscles increases, an increase in masseter muscle thickness is noted, and a decrease in bioelectrical activity on the digastric muscle at rest.

Grzegorz Zieliński, Anna Matysik-Woźniak, Michał Baszczowski et al.

International Journal of Environmental Research and Public Health • 2023

Background: Myopia is one of the most common eye disorders involving abnormal focusing of light rays. The studies recognize the association between the stomatognathic and visual systems. This compound may have a neurological basis associated with disorders such as central sensitization. The main aim of this study was to evaluate the influence of central sensitization on the bioelectrical activity of selected muscles of the masticatory organ in subjects with myopia. Methods: Selected masticatory and cervical spine muscles were analyzed using an eight-channel BioEMG III electromyograph. Central sensitization was analyzed using the central sensitization inventory. Results: Statistical analysis revealed significantly higher scores on the central sensitization inventory in subjects with axial myopia compared to subjects without refractive error. Repeated positive correlations were observed in the sternocleidomastoid muscle activity and negative correlations in the digastric muscle activity during open and closed eyes in myopic subjects. Conclusions: Subjects with myopia have an increased score in the central sensitization inventory. The increase in the central sensitization inventory score is connected with the changes within the electromyographic activity of the masticatory and neck muscles. The effect of central sensitization on masticatory muscle activity in myopic subjects requires further study.

K. Tsay, Sara Safari, Abdullah Abu-Samra et al.

Visual Neuroscience • 2023

Abstract To compare the baseline signal between two conditions used to generate the photopic negative response (PhNR) of the full-field electroretinogram (ERG): red flash on a blue background (RoB) and white flash on a white background (LA3). The secondary purpose is to identify how the level of pre-stimulus signal affects obtaining an unambiguous PhNR component. A retrospective chart review was conducted on four cohorts of patients undergoing routine ERG testing. In each group, LA3 was recorded the same way while RoB was generated differently using various luminances of red and blue light. The background bioelectrical activity 30 ms before the flash was extracted, and the root mean square (RMS) of the signal was calculated and compared between RoB and LA3 using Wilcoxon test. Pre-stimulus noise was significantly higher under RoB stimulation versus LA3 in all four conditions for both right and left eyes (ratio RoB/LA3 RMS 1.70 and 1.57 respectively, p < 0.033). There was also no significant difference between the RMS of either LA3 or RoB across protocols, indicating that the baseline noise across cohorts were comparable. Additionally, pre-stimulus noise was higher in signals where PhNR was not clearly identifiable as an ERG component versus signals with the presence of unambiguous PhNR component under RoB in all four groups for both eyes (p < 0.05), whereas the difference under LA3 was less pronounced. Our study suggests that LA3 produces less background bioelectrical activity, likely due to decreased facial muscle activity. As it seems that the pre-stimulus signal level affects PhNR recordability, LA3 may also produce a better-quality signal compared to RoB. Therefore, until conditions for a comparable bioelectrical activity under RoB are established, we believe that LA3 should be considered at least as a supplementary method to evaluate retinal ganglion cell function by ERG.

Olena Popazova, Igor Belenichev, Andrii Abramov et al.

Innovative Biosystems and Bioengineering • 2023

Background. Posthypoxic cardiopathy is one of the risk factors for the development of cardiovascular pathology (rhythm disturbances, vascular dystonia, etc.) in subsequent age periods and requires the development of treatment approaches. Objective. to evaluate the cardioprotective effect of modulators of the NO system by the effect on the ECG of rats after intrauterine hypoxia. Methods. Modeling of prenatal hypoxia (PH) by daily intraperitoneal administration of sodium nitrite solution to pregnant female white rats weighing 220–240 g, aged 4.5 months, from the 16th to the 21st day of pregnancy at a dose of 50 mg/kg. The offspring were administered daily from the 1st to the 30th day of life – tiazotic acid (morpholinium 3-methyl-1,2,4-triazolyl-5-thioacetic acid), 50 mg/kg, angiolin ([S]-2,6-diaminohexane acid 3-methyl-1,2,4-triazolyl-5-thioacecate), 50 mg/kg, L-arginine, 200 mg/kg, meldonium (2-(2-carboxyethyl)-1,1,1-trimethylhydrazinium), 100 mg/kg. Аnd then after 2 months of life, an ECG was recorded using the ECG TUNNEL system (without anesthesia). Results. Postponed PG leads to a decrease in heart rate and significant dominance of parasympathetic innervation in regulation of electrical activity of the heart, which can be caused by sinus blockade and may be a reflection of parasympathetic regulation of the heart instead of sympathetic control of electrical activity in the norm. The effectiveness of drugs can be presented in descending order: angiolin &gt; tiazotic acid &gt; meldonium. Angiolin proved to be more effective than tiazotic acidin normalizing the electrical activity of the heart and restoring the neurogenic regulation of the automatism of the function of the sinus node. Сonclusions. The prospects of further study of modulators of the NO system with different mechanisms of action as means of cardioprotection of posthypoxic disorders of the cardiovascular system in newborns are experimentally substantiated.

Olena Severynovska, Viktoriia Babicheva, Alexey Galinskiiy et al.

International Letters of Natural Sciences • 2015

Evaluation of biopotentials in the region of the amygdala of rats in the combined influence of alcohol and drugs, causing an imbalance of nitric oxide is described in this paper. Chronic alcoholism leads to structural morphological changes in the liver. A study of the amplitude of electrical activity showed that the electrical potential in the amygdala after 8 weeks chronic alcoholism was lower compared with normal rats. The frequency spectrum analysis showed decreased in the 2 times or more absolute spectral powers of all components. The relative spectral powers of its components: δ: θ: α: β was as a 2: 2: 2: 4. The use of sodium nitroprusside (donator of NO) together with the chronic consumption of ethanol reduces the effect of ethanol on low and high-frequence portion the performance of the bioelectrical activities spectrum in the amygdala. The use of non-selective blocker of NO-synthase – nitroarginine aggravated by the braking action of alcohol. The important role of nitric oxide in the development of adaptive-compensatory reactions of the damaged body is described. Our results may be useful to assess the contribution of NO in operation amygdala, conditions of chronic pathologies, and treatment of neuropsychiatric conditions, including diseases caused by alcohol abuse.

Anna Mika, Piotr Mika, Łukasz Oleksy et al.

Journal of Clinical Medicine • 2022

Aim: Intermittent claudication is the most common symptomatic manifestation of peripheral arterial disease (PAD), presenting as ischemic leg muscle pain and gait dysfunction. The aim of this study was to evaluate the changes in bioelectrical activity of the lower limb muscles activity in claudicating patients over a 12-week period of supervised treadmill training and to verify the hypothesis as to which muscles of lower limbs are activated by training treatment—the proximal, as compensatory mechanism, or the distal, which are the most ischemic. Methods: The study comprised 45 patients aged 60–70 years (height 168.8 ± 6.8 cm, weight 78.9 ± 9.2 kg) with PAD and unilateral intermittent claudication (Fontaine stage IIa/IIb), who participated in a 12-week supervised treadmill training program. Surface electromyography (sEMG) of the gastrocnemius lateralis (GaL), gastrocnemius medialis (GaM), tibialis anterior (TA), biceps femoris (BF), rectus femoris (RF) and gluteus medius (GM) muscles in the claudicated leg were continuously measured during the treadmill test. The average mean amplitude and mean amplitude range of the sEMG signal were analyzed. Results: During the treadmill test, after 12 weeks of training, the average mean amplitude of the GM (105 ± 43 vs. 74 ± 38%, p = 0.000008, ES = 0.76), BF (41 ± 22 vs. 33 ± 12%, p = 0.006, ES = 0.45) and GaM (134 ± 50 vs. 114 ± 30%, p = 0.007, ES = 0.48) muscles was significantly lower compared with baseline. The mean amplitude range was significantly decreased after 12 weeks of training in the GM (229 ± 64 vs. 181 ± 62%, p = 0.008, ES = 0.77) and BF (110 ± 69 vs. 84 ± 31%, p = 0.0002, ES = 0.48) muscles. After 12 weeks of training, the mean amplitude range of the TA muscle was significantly higher compared with baseline (104 ± 46 vs. 131 ± 53%, p = 0.001, ES = 0.54), but without significant changes in the average mean amplitude value. The most favorable changes, suggesting the lowest muscle fatigue and the highest walking capacity, were found in patients with the longest walking time. Conclusions: The obtained results may suggest that after 12 weeks of treadmill training, beneficial changes occurred in both the proximal and distal muscles. Therefore, greater foot plantar flexion and stronger push-off as well as greater hip extension may be considered the main mechanisms of observed gait pattern improvement. It may also be suggested that the therapy of gait alterations in patients with PAD should be focused not only on calf muscle pump improvement, but also on proximal hip extensor strengthening.

Oleksandr Kozolkіn, Anton Kuznietsov

Ukrains'kyi Visnyk Psykhonevrolohii • 2020

Aim of the study — to detect electroencephalographic criteria of unfavorable vital outcome of spontaneous supratentorial intracerebral hemorrhage (SSICH). Prospective cohort study of 156 patients (mean age 66,7 ± 0.8 years) in acute period of SSICH on the ground of conservative treatment. Diagnosis was made based on clinical neurological and visualization data. Bioelectrical brain activity was done during first 2 days of the onset. Logistic regressive analysis was used for elaboration of prognostic criteria. It was detected, that risk of lethal SSICH outcome is independently associated with the next spectral EEG‑pattern parameters: relative spectral rhythm of δ-band of intact hemisphere (odds ratio (OR) (95 % confidence interval (CI) is equal to 1.12 (1.08—1.17), p &lt; 0.0001), frontal occipital rhythm gradient of α-band of intact hemisphere (ОR (95 % CI) = 5,96 (1.08—33.04), p = 0.0410) and interhemispheric asymmetry of absolute spectral rhythm power of β2-band (OR (95 % CI) = 0.03 (0.001—0.88), p = 0.0419). These predictors were integrated into the mathematic model for individual prognosis of SSICH lethal outcome (AUC (95 % CI) = 0.95 (0.90—0.98), p &lt; 0.0001, predictive accuracy is equal to 89.7 %). Bilateral predominance of electroencephalographic pattern of δ-band rhythm, inversion of negative frontal occipital rhythm gradients of α-band in both hemispheres, formation of negative interhemispheric asymmetry of absolute spectral rhythm power of δ-band, α2-band in frontal region and θ-, β-bands in parietal occipital regions in first 2 days from the SSICH onset are the EEG criteria for unfavorable vital outcome of SSICH.

Vera I. Potievskaya, F. M. Shvetskiy, M. B. Potievskiy

Annals of Critical Care • 2019

Xenon is an inert gas used like inhalational anesthetic during different surgeries, including high-risk operations and for pain treatment caused by different factors. If concentration of the gas is less than 50 %, or the duration of the procedure is very short, no consciousness depression occurs. 20 healthy persons from 22 to 30 years old were undergone xenon/oxygen inhalation with concentration 70/30 % respectively for 3 minutes. Electroencephalography (EEG) was recorded before, during and 30 minutes later the procedure. For the data processing spectral analysis was used. Statistical analysis was performed by Wilcoxon and Page tests. As a result, significant increase in slow wave activity and reduction in alpha-rhythm activity were observed during and after the procedure as well as repartition of activity zones in brain similar to physiological sleep. This fact may be used in conduction of treatment and diagnostics procedures.

Materials International • 2022

The present work evaluated the inactivation efficiency of atmospheric pressure cold plasma (APCP) against three pathogenic microorganisms. We have successfully developed a plasma device that can generate atmospheric pressure cold argon plasma of low temperature (240 - 270C) downstream using a high-voltage power source (6 kV) operating at a frequency of 19.56 kHz, which can be widely used in biomedicine. Therefore, a cost-effective system of generating cold plasma jets at atmospheric pressure with potential applications in biomedical research has been developed. The discharge has been characterized by an optical method. This research aims to investigate the antimicrobial property shown by the atmospheric pressure cold plasma Jet (APCPJ). Three pathogenic bacterial strains (Shigella flexneri, Escherichia coli, and Klebsiella pneumoniae) were used to test the antimicrobial property. The effects of atmospheric pressure cold plasma (APCP) today have been identified worldwide in disinfection, decontamination, and sterilization, as well as oncology applications. This work aims to demonstrate the effect of APCP irradiated media as a promising anticancer tool. Atmospheric pressure cold plasma technology has the efficacy to show anticancer properties with the treatment of cancer cells. To demonstrate the anticancer properties of APCP generated at a high voltage power supply (12 kV) at an operating frequency of 50 Hz. 10% Dulbecco’s Modified Eagle Medium (DMEM) media were treated with cold plasma using argon as a process gas for various time durations (0.5-4 min). The treated media was transferred to Henrietta Lacks (HeLa) and Human Embryonic Kidneys 293(HEK 293) cells, and the viability of cancer cells was observed using MTT assay.

R. R. Dils

CORROSION 1975 • 1975

The national energy program has focused attention on the desirability of converting plentiful resources of low-grade fossil fuels for power generation. Both in the process of fuel conversion and in the combustion of the converted fuel, the structural components of the manufacturing plant and the power generating equipment using the converted fuel will be subjected to severe attack by oxidation and corrosion. In many of the environments, materials surfaces will be exposed to temperatures, pressures, velocities, or compositions which vary significantly and rapidly with time. The oxidation and hot corrosion of the materials can exhibit a pronounced dependence on the local fluid dynamics in an industrial environment. Surface temperature fluctuations induced either from the unmixedness of the fluid streams or by dynamic variations of the fluid boundary layers are a source of cracking or spallation of protective oxide layers. In addition, the fluid dynamics can cause the deposition of non-equilibrium corrosive agents over a range of conditions far in excess of those expected from equilibrium considerations.

J. P. Engle

CORROSION 1975 • 1975

Carbon steel and many different alloys are exposed to varied environments in equipment designed for power generation. The combustion of fuel may give rise to the formation and release of corrosive compounds in the flue gases. Several examples of corrosion from this source are discussed under the heading of Fireside Corrosion Problems.

Furong Zhu

Research Square • 2024

Abstract The photovoltaic performance and artistic perspectives of the translucent color organic solar cells (OSCs), made with the emerging narrowband nonfullerene organic semiconductors are explored. This work reports the effort to develop high-performance translucent color OSCs comprising a Fabry-Pérot microcavity optical coupling layer, with a power conversion efficiency of &gt;15% and a maximum transparency of &gt;20% for the three primary colors. The performance color relationship of the translucent color OSCs was analyzed using a combination of high-throughput optical computing and experimental optimization, allowing light with desired color to pass through, and yet absorbing enough light to generate electricity. A 10×10 cm2-sized replication of Piet Mondrian's artwork "Composition C (1920)" was demonstrated using the translucent OSCs with a wider palette of colors and a high accuracy of hues. The outcome of the work offers an opportunity for translucent color OSCs to serve as both esthetic art and power generating windowpanes for use in our homes, offices, and even greenhouses.

Salahuddeen M. Tahir, Ali M. Sheriff

SPE Nigeria Annual International Conference and Exhibition • 2019

Abstract About 83% of energy used to generate power in Nigeria is currently derived from gas. This is understandable since the country has huge volumes of gas resources which it intends to take advantage of to grow its economy. Nigeria's gas reserves stands at 199 Tcf as at 01/01/2018 (Department of Petroleum Resources Annual Reserves and Production Report). Gas is the preferred source of energy because of the following; Efficiency in energy generationRelatively low per capita costMeans of eliminating gas flaresIncome generation earner for stakeholderOpportunity for additional job creation Several gas development projects have been embarked upon within the Nigerian Oil and Gas industry to deliver gas to the domestic sector. The Nigerian domestic gas sector is classified into the following three (3) sectors as contained in the Nigerian Gas Master Plan (NGMP); Power – Independent Power Plants (IPPs) e.t.cCommercial – Industries utilizing gas as fuel e.g. Cement PlantsGas Based Industry – Industries utilizing gas as feedstock e.g. Fertilizer Plants Presently, twenty five (25) gas fired plants with a combined installed capacity of about 11,500 MW exist in country. The total gas requirement to run all the plants at full capacity is approximately 3.0Bscfd. Between 2018 and 2037, it is expected that fifty five (55) additional thermal plants will come on stream (Transmission Company of Nigeria Transmission Masterplan). These plants will generate an additional combined power of 19,000 MW and will require gas volumes of approximately 5Bscf/d to generate the power equivalent. As the country's gas reserves are growing, gas production has increased over the years. A current total gas volume of about 8Bscfd is being produced in Nigeria out of which 45% is exported (NLNG), 8.5% is flared, 15% is consumed domestically (Power &amp; Industries) while the balance is either re-injected for pressure maintenance or utilized for operational purposes. The gas to power value chain has been bedeviled by issues which have affected the full generation of power based on installed capacity of existing gas fired power plants. Major among the issues are; Lack of sufficient power transmission capacity from the power generating plantsOff Spec gas volumes supplied to power generating plantsLegacy Debt repayment and payment for gas supplyInadequate gas transportation infrastructureWeak payment structure within the power value chainFunding constraints for development of upstream gas supply sourcesDiffering priorities between upstream gas developersAbsence or ineffective contractual terms between stakeholder parties Steps are being taken to address these issues. Alongside the development of Power Plants, Gas Transportation and Power Transmission Infrastructure are also being developed according to laid down Master Plans. To achieve the ultimate objective of power generation to meet the country's domestic needs, there is a need for alignment on existing master plans within the gas and power sector. This paper attempts to evaluate the Country's gas development plans, the Nigerian Gas Master Plan and the Transmission Master Plan in relation to each other. Gaps (if any) will be identified and solutions proffered to ensure that the Federal Government's objectives are realized.

Wayne Allen, David Anderson, Bert Mayer

2003 International Joint Power Generation Conference • 2003

The Ontario Power Generation (OPG) Pickering B Facility consists of four 540 MW nuclear generating units. Each unit is furnished with a once-through Condenser Cooling Water (CCW) System that uses Lake Ontario water. Zebra mussels (Dreissena polymorpha) are infesting the condenser cooling water intakes at Pickering. The mature mussels and their shells become entrained in the CCW, are deposited in the condenser inlet water boxes, and become lodged in the condenser tube sheets and within the tubes. As a result, the flow through the condenser is reduced, and the existing Condenser Tube Cleaning System (CTCS) performance is degraded. This reduces the Turbine-Generator generating capability that results in a loss of electric generation revenues for OPG, and increased maintenance costs to manually remove the zebra mussels from the condenser. OPG decided to install Debris Filters in the six 72-inch diameter inlets of each of the four Pickering B units to automatically remove the zebra mussels before they enter the condensers and discharge them back into the lake. The Debris Filters for Unit 8 were installed during a scheduled outage in the winter of 2001/2002. The Unit 5 installation was completed at the end of 2002 and the Unit 6 &amp; 7 installations are scheduled for 2003. The installed equipment is performing as expected. The zebra mussels are intercepted by the Debris Filter, and are automatically discharged into the condenser bypass and returned to the lake. The CTCS system can again perform its intended function to prevent bio-fouling buildup inside the condenser tubes. As a result, generation capacity increased and maintenance expenditures decreased with a net result of increased revenues for OPG.

, Thomas Adriaan de Bruin

• 2024

INTRODUCTION In the future, more and more people will live in cities, while the space for renewable energy in urban areas is scarce. As a result, there is a strong need for renewable energy generation technologies that double as a building element to sustainably supply our future cities. A promising technology is the luminescent solar concentrator (LSC), which is a type of transparent solar panel. The LSC can function as a window while at the same time generating renewable electricity. The LSC uses luminescent particles to absorb and emit sunlight, which is guided through the window glass to solar cells attached at the sides. This leads to a trade-off between the transmitted light necessary for functioning as a window and the absorbed light necessary to generate electricity. RESEARCH QUESTIONS The main question research question is: "Is it possible to develop efficient, transparent, and durable luminescent solar concentrators to replace conventional windows?" For LSCs to function as a window, they need to be sufficiently transparent while being efficient enough to generate a significant amount of electricity. Furthermore, they need to be able to maintain this power output for a long period of time in an outdoor environment. In this thesis, these requirements are investigated in six chapters that broadly cover the following three topics. Chapter 2 and 3: The viability of tandem configurations is explored, i.e., the stacking of two different LSCs, and the maximum theoretical efficiency of LSCs is researched. Chapter 4 and 5: A novel algorithm that is much quicker than previous algorithms is introduced. The algorithm calculates the maximum efficiency based on existing LSC data from the scientific literature. Chapter 6 and 7: The performance of LSCs during and after two years in an outdoor environment is presented. The results from chapters two to seven provide the answer to the main research question. RESULTS The results based on the six chapters: Chapters 2 and 3: Tandem configurations are feasible but do not lead to significantly better performances for the tested luminophores. The maximum theoretical power conversion efficiency for a luminescent solar concentrator that functions as a window is around 10%. Chapters 4 and 5: The maximum power conversion efficiency for window-appropriate LSCs based on currently existing luminophores is around 1%. Chapters 6 and 7: LSCs in an outdoor environment perform well over a full day, showing consistent performance for sunny and cloudy days and can remain stable after two years. CONCLUSION AND DISCUSSION Based on chapters two and three and chapters six and seven, the LSC can theoretically have an efficiency of 10%, and it can remain stable for more than two years in an outdoor environment. However, based on chapters four and five, the currently feasible efficiency for an LSC that can function as a window is around 1%. As a result, the answer to the research question is that durable and transparent LSCs are feasible but with a maximum efficiency of 1%. Future research should focus on improved LSCs and alternative applications, e.g., in agriculture.

Elis Nycander, Lennart Söder

• 2021

&lt;pre&gt;Efficient integration of variable renewable energy (VRE) such as wind power into power systems requires methods for power system operation planning that account for VRE uncertainty and variability. This has motivated extensive research into unit commitment (UC) and optimal power flow (OPF) formulations with VRE uncertainty. However, these formulations are often tested using significantly simplified representations of VRE production. We seek to address this issue by providing a model for generating realistic wind power scenarios using real production and forecast data. The scenarios are generated using 5-min production and 30-min forecast data for real wind farms from Australia. The model captures the empirical distribution of the forecast errors and the covariance between different wind farms. The high time resolution of the production data also allows the recreation of the high-frequency (5-min) component of wind power production. The resulting model is openly available, and can be used to generate wind power scenarios for use in formulations for operation planning of power systems (UC/OPF) considering wind uncertainty and intra-hour variability. The scenarios can be tailored according to preferences for, e.g., the number of wind farms and their geographical dispersion.&lt;/pre&gt;

Lama Fayad, Rania Amer, Ali Hammoud et al.

BAU Journal - Science and Technology • 2022

Global warming and the accumulation of organic waste constitute a serious environmental problem. Therefore, microbial fuel cells (MFC) are an eco-friendly device that have significant capability for the production of electricity using biodegradable waste as fuel. Microorganisms used as catalysts in the anode compartment, execute a principal function in operating MFCs. The present study was conducted to isolate and to screen potential bioelectricity generating microorganisms from dumpsite soil samples and also to construct a domestic dual-chambered microbial fuel cell (MFC). Streptomyces fimicarius was found to be the best isolate for the degradation of cellulose and the production of bioelectricity. The bacterial isolate was identified based on morphological characteristics, biochemical characteristics and molecular identification using 16S rRNA. Double-chambered MFC was constructed by using two polypropylene plastic containers of 1.4 L volume each. The two chambers were joined by using an agar salt bridge and carbon rods were utilized as electrodes. The generation of electricity by the isolate was compared using glucose and cellulose as sole carbon source in a minimal medium. The maximum voltage was found to be 322 mV in the presence of cellulose used as substrate after 5 days of incubation at room temperature and last for 10 days.