Reduction Potential

Although UASB systems treating municipal wastewater generally remove fecal coliform (FC) by ~ one order of magnitude, the effl uent still contains concentrations higher than the WHO standard for unrestricted irrigation. In this study, the effect of continuous diffused aeration on the removal of FC was examined. The diffused aeration system was operated at different hydraulic retention times (60, 30 and 15 min) and dissolved oxygen (DO) concentrations (5-6 and 1-2 mg/l). The removal of FC was affected by the applied HRT and DO. Optimum results were obtained at HRT and DO equal to 60 min and 5-6 mg/l respectively, with FC removal of approximately 2 log (97%). The mechanisms responsible for FC die-off were the pH and oxidation reduction potential (ORP) of the medium.

The nitritation-anaerobic ammonium oxidation (anammox) process was studied for the first time using an oxidation-reduction potential (ORP) decrease rate control in the anammox sequencing batch reactor (SBR). SBR was inoculated and fed with high-strength N-rich real reject wastewater (containing an average of 740 mg NH 4 + -N/L) coming from a biogas plant. Start-up with total nitrogen removal rates (TNRRs) of 90 g N/[m 3 $day] (87 mg N/g VSS/day) was achieved shortly at 25°C within a 132-day operation period. However, during a further 470-day operation with ORP control using aeration ''switch off'' values in the aerobic and ''switch on'' values in the anoxic phase, much higher TNRRs of 220 g N/[m 3 $day] were achieved with maximum total nitrogen removal efficiency at 95%. The ORP decrease rate as a novel anammox treatment step shortening the control parameter was gradually decreased at values of 1.65, 0.9, and 0.4 mV/min ensuring a high TNRR and low accumulation of ammonium and nitrate. Batch testing showed the highest specific anammox activities of 4.4 (-1.8) mg N/g VSS/h at ORP decrease rates of 0.4 mV/min. Low optimum dissolved oxygen concentrations of up to 0.5 mg O 2 /L could reduce treatment costs in anammox full-scale systems in combination with ORP control. Among other microorganisms determined by pyrosequencing, anammox bacteria, Candidatus Brocadia fulgida and uncultured Planctomycetales bacterium clone P4 were determined and the latter bacterium's increase in quantities from 2.8 • 10 4 up to 1.6 • 10 6 copies/g TSS during ORP-controlled conditions were examined using a quantitative polymerase chain reaction.

Although redox potential is very rarely taken into account in food fermentation it could be as influential as pH on bacterial activities. Lactococcus lactis is already known to exhibit a powerful reducing activity in milk but its reduction activity was shown to occur prior to its acidification activity with a potential interaction between these two lactococcal activities. Therefore, acidification lag-type phase could be shortened by decreasing the redox potential of milk before inoculation. As the redox potential is highly dependent on the dissolved oxygen level, our objective was to study their separate and combined influences on acidification and growth kinetics of pure L. lactis strains in milk. Results showed that high level of dissolved oxygen is significantly more influential on growth, and even more on acidification kinetics, than initial decreased redox potential of milk. Reduction of milk was drastic and mostly due to bacterial activity. The redox potential of milk only dropped when dissolved oxygen was entirely consumed. When there was no dissolved oxygen from the beginning, L. lactis immediately decreased the redox potential of milk and acidified afterwards. When the level of dissolved oxygen was initially high, acidification and reduction of milk occurred at the same time. Acidification kinetics was then biphasic with a slower rate during the aerobic stage and a faster rate during the anaerobic stage. The seven strains tested demonstrated diversity in both their acidification kinetics and their adaptation to high level of dissolved oxygen, independent of their growth kinetics. To conclude, we have shown that the level of dissolved oxygen in milk has a dramatic influence on acidification kinetics and could be used to control acidification kinetics in dairy industries.

Raw fish is prone to the risk of microbial outbreaks due to contamination by pathogenic microorganisms, such as Escherichia coli O157:H7 and Listeria monocytogenes. Therefore, it is essential to treat raw fish to inactivate pathogenic microorganisms. Electrolyzed Oxidizing Water (EO) is a novel antimicrobial agent containing acidic solution with a pH of 2.6, Oxidation Reduction Potential (ORP) of 1150 mV, and 70-90 ppm free chlorine, and alkaline solution with a pH of 11.4 and ORP of À795 mV. This study was undertaken to evaluate the efficacy of acidic EO water treatment and alkaline EO water treatment followed by acidic EO water treatment at various temperatures for the inactivation of E. coli O157:H7 and L. monocytogenes Scott A on the muscle and skin surfaces of inoculated salmon fillets. Inoculated salmon fillets were treated with acidic EO water at 22 and 35 °C and 90 ppm free-chlorine solution as control at 22 °C for 2, 4, 8, 16, 32, and 64 min. The acidic EO water treatments resulted in a reduction of L. monocytogenes Scott A population in the range of 0.40 log 10 CFU/g (60%) at 22 °C to 1.12 log 10 CFU/g (92.3%) at 35 °C. Treatment of inoculated salmon fillets with acidic EO water reduced E. coli O157:H7 populations by 0.49 log 10 CFU/g (67%) at 22 °C and 1.07 log 10 CFU/g (91.1%) at 35 °C. The maximum reduction with chlorine solution (control) was 1.46 log 10 CFU/g (96.3%) for E. coli O157:H7 and 1.3 log 10 CFU/g (95.3%) for L. monocytogenes Scott A at 64 min. A response surface model was developed for alkaline treatment followed by acidic EO water treatment to predict treatment times in the range of 5-30 min and temperatures in the range of 22-35 °C for effective treatment with alkaline EO water followed by acidic water, alkaline and acidic water treatments. Response surface analysis demonstrated maximum log reductions of 1.33 log 10 CFU/g (95.3%) for E. coli O157:H7 and 1.09 log 10 CFU/g (91.9%) for L. monocytogenes Scott A. Data collected from the treatments was used to develop empirical models as a function of treatment times and temperature for prediction of population of E. coli O157:H7 and L. monocytogenes Scott A. Correlations (R 2 ) of 0.52 and 0.77 were obtained between model predicted and experimental log 10 reduction for E. coli O157:H7 and L. monocytogenes Scott A reductions, respectively. These results clearly indicated that EO water has a potential to be used for decontamination of raw fish.

In this paper we obtain the analytical solution for the reverse Werential pulse O P ) technique for a slow electronic transfer process, starting fkom expressions obtained previously for the faradaic response to a triple potential pulse. The solutions are valid for the planar approximations of a static mercury drop electrode and of a dropping mercury electrode. An irreversible reduction process gives rise i n the RDP technique to the appearance of two peaks, one at more negative potentials than the normal reduction potential, E", and the other at more positive potentials than E". From half-width peak and peak potential measurements, it is possible to evaluate approximately the kinetic and thermodynamic parameters corresponding to the electronic transfer, such as the transfer coefficient, a, the normal reduction potential, E", and the apparent heterogeneous rate constant, k,. The solutions are checked against experimental examples of well-known processes. Among double-pulse electrochemical techniques, the reverse pulse (RP) technique is, undoubtedly, the most powerful from the kinetic point of view, due to the information that it provides on the degree of reversibility of electrode processes. This informa-

of organic matter in the soil. Under equilibrium conditions, a theoretically well-defined sequence of reduction The objective of this study was to compare three methods of evaluof electron acceptors should take place when the soil ating redox status, i.e., conventional redox potential (E H) measurement, terminal electron-accepting processes (TEAPs) and oxidative goes from oxic to suboxic to anoxic conditions (Sposito, capacity (OXC) in pore waters of a paddy soil during the rice-growing 1989). The principal redox couples in sequence are O 2 / season. The redox potential can be measured readily which can moni-H 2 O, NO Ϫ 3 /N 2 , Mn(IV, III)/Mn(II), Fe(III)/Fe(II), SO 2Ϫ 4 / tor progressive development of reducing conditions and distinguish H 2 S, and CO 2 /CH 4. The reduced conditions in suboxic from anoxic conditions but with little information on specific merged paddy soils may be readily measured by measurredox processes under anoxic conditions. Identifying dominant TEAPs ing E H of the pore water, but E H is a difficult soil paramerequires intensive data collection and analysis. The sequence of TEAPs ter to interpret. Bartlett (1999) described thoroughly development basically followed theoretical predictions but overlapthe redox behavior in soils, providing an important base ping, typically among Mn, Fe, SO 2Ϫ 4-S reductions and methane producto our understanding of equilibrium and dynamic redox tion, was featured throughout the season. The measured dissolved H 2 conditions. He pointed out that a Pt electrode may not gas as the intermediate product, reflected the overlap among electron acceptors. Oxidative capacity integrated all the major oxidized and reflect changes in some species involved in redox reacreduced species to a single conservative parameter and showed clearly tions, such as partial pressure of O 2 and neither Mn or the progressive redox status from oxic to postoxic and then to sulfidic Fe oxides nor nitrate had the expected quantitative efconditions in the paddies with no apparent methanic condition during fect on the Pt electrode measurement. Methane, bicarthis particular growing season. In OXC computations, a more reliable bonate, N 2 gas, nitrate, and sulfate are not electroactive, method to estimate Mn and Fe oxyhydroxide concentrations as eleci.e., they do not readily take up or give off electrons at tron acceptors needs further testing. The measured E H showed a the surface of the Pt electrode used to measure E H higher correlation to redox species Mn(II), Fe(II) and methane con-(Berner, 1981). Since it is a measurement of potential, centrations (r 2 ϭ 0.76, 0.73, and 0.76, respectively) than to dissolved the Pt electrode also responds to changes in pH and O 2 (DO), NO Ϫ 3-N, and SO 2Ϫ 4-S (r 2 ϭ 0.53, 0.37, and 0.16, respectively). other potentials. Thus, measured E H usually reflects a Measured E H was also highly correlated to OXC for low sulfate solutions. The three methods for evaluating redox status all indicated Description of Redox Parameters considers simultaneously the consumption of electron acceptors (DO, NO Ϫ 3-N, Fe(III), SO 2Ϫ 4-S, and CO 2); in-Redox Potential termediate product (dissolved hydrogen gas, H 2) con-Microbes that utilize oxidized species in the soil as centration, and the concentrations of final products terminal electron acceptors mediate the decomposition

of organic matter in the soil. Under equilibrium conditions, a theoretically well-defined sequence of reduction The objective of this study was to compare three methods of evaluof electron acceptors should take place when the soil ating redox status, i.e., conventional redox potential (E H) measurement, terminal electron-accepting processes (TEAPs) and oxidative goes from oxic to suboxic to anoxic conditions (Sposito, capacity (OXC) in pore waters of a paddy soil during the rice-growing 1989). The principal redox couples in sequence are O 2 / season. The redox potential can be measured readily which can moni-H 2 O, NO Ϫ 3 /N 2 , Mn(IV, III)/Mn(II), Fe(III)/Fe(II), SO 2Ϫ 4 / tor progressive development of reducing conditions and distinguish H 2 S, and CO 2 /CH 4. The reduced conditions in suboxic from anoxic conditions but with little information on specific merged paddy soils may be readily measured by measurredox processes under anoxic conditions. Identifying dominant TEAPs ing E H of the pore water, but E H is a difficult soil paramerequires intensive data collection and analysis. The sequence of TEAPs ter to interpret. Bartlett (1999) described thoroughly development basically followed theoretical predictions but overlapthe redox behavior in soils, providing an important base ping, typically among Mn, Fe, SO 2Ϫ 4-S reductions and methane producto our understanding of equilibrium and dynamic redox tion, was featured throughout the season. The measured dissolved H 2 conditions. He pointed out that a Pt electrode may not gas as the intermediate product, reflected the overlap among electron acceptors. Oxidative capacity integrated all the major oxidized and reflect changes in some species involved in redox reacreduced species to a single conservative parameter and showed clearly tions, such as partial pressure of O 2 and neither Mn or the progressive redox status from oxic to postoxic and then to sulfidic Fe oxides nor nitrate had the expected quantitative efconditions in the paddies with no apparent methanic condition during fect on the Pt electrode measurement. Methane, bicarthis particular growing season. In OXC computations, a more reliable bonate, N 2 gas, nitrate, and sulfate are not electroactive, method to estimate Mn and Fe oxyhydroxide concentrations as eleci.e., they do not readily take up or give off electrons at tron acceptors needs further testing. The measured E H showed a the surface of the Pt electrode used to measure E H higher correlation to redox species Mn(II), Fe(II) and methane con-(Berner, 1981). Since it is a measurement of potential, centrations (r 2 ϭ 0.76, 0.73, and 0.76, respectively) than to dissolved the Pt electrode also responds to changes in pH and O 2 (DO), NO Ϫ 3-N, and SO 2Ϫ 4-S (r 2 ϭ 0.53, 0.37, and 0.16, respectively). other potentials. Thus, measured E H usually reflects a Measured E H was also highly correlated to OXC for low sulfate solutions. The three methods for evaluating redox status all indicated Description of Redox Parameters considers simultaneously the consumption of electron acceptors (DO, NO Ϫ 3-N, Fe(III), SO 2Ϫ 4-S, and CO 2); in-Redox Potential termediate product (dissolved hydrogen gas, H 2) con-Microbes that utilize oxidized species in the soil as centration, and the concentrations of final products terminal electron acceptors mediate the decomposition

The present study was conducted to carry out bioleaching of waste mobile phone printed circuit board (WMPPCB) in a high redox potential-controlled fed-batch process compared to the low redox potential batch process. Concomitant additions of WMPPCB achieved high redox potential bioleaching of WMPPCB. The pH of the bioleaching slurry was maintained at 1.50 for both high and low redox potential experiment. High redox potential was controlled to allow more Fe-oxidizing activity compared to sulfur oxidation process. The primary element in the WMPPCB was Cu (26.3%) along with Ni, Zn, Al, etc., analyzed by XRF, while XRD revealed the presence of metal sulfide/oxides. Both experiments were carried out in a 2-L stirred tank reactor and regular measurement of pH, redox potential, planktonic viable cell count, Fe 2+ , Fe 3+ , Fe (total), SO 4 2− , Cu 2+ concentration. The change in pH and controlling with acid addition showed that fed-batch bioleaching consumes 1.35 times lower sulfuric acid per ton WMPPCB than the batch process. Both the batch and fed-batch bioleaching supported first-order reaction and also followed as similar type of intermediate leaching kinetics, which is neither chemically controlled nor diffusion-controlled type. The leaching yield of copper was found to be best (98-97%) in both leach residue and leach liquor analysis. The acid requirement/ton WMPPCB and the bio-residue weight loss state a better fed-batch process. The fed-batch bioleaching was comparatively better than batch process, when compared all bioprocess dynamics parameters and leaching yield of various metals.

This paper deals with the synthesis and characterization of new ternary [Ni(diimine)(thiolate) 2 ] complexes where diimine is 2,2'-bypiridine (bpy) or its 4,4'-derivates: 4,4'-dimethyl-2,2'-bypiridine (dmbpy) and 4,4'-dinitro-2,2'bypiridine (dnbpy) and thiolate is thioaminoacid cysteine (Cys) or its methylic ester (CysMe) in which Ni lies in a square planar N 2 S 2 environment. The investigation on the presence of ligand-ligand electron transfer processes in these complex compounds and of the factors these processes depends on are also studied. The complex compounds are suitable for being metalloenzyme simple in vitro models.

Oxidative stress (OS) is an important contributing factor to male infertility. While previous methods to measure seminal OS are time-consuming and limited to the use of freshly produced semen, oxidation reduction potential (ORP) is easier and quicker to perform and can also be used in frozen semen. Therefore, this study evaluated the clinical utility of ORP as a potential marker of male infertility. ORP was measured in semen samples from 293 patients and 15 fertile controls and categorised according to WHO criteria as normozoospermic, oligozoospermic, asthenozoospermic, teratozoospermic and oligoasthenoteratozoospermic. Receiver operating characteristic (ROC) curves were generated to differentiate these categories. Semen parameters were significantly different when subjects were grouped as control and patients or between the patient and normozoospermic group for concentration and morphology. ORP levels were significantly different between the control and normozoospermic group. When ...

 Se presenta la caracterización electroquímica para evaluar la resistencia a la corrosión de un recubrimiento metálico Zn-Fe por vía electrolítica sobre sustratos de lámina de acero cold-rolled. Los recubrimientos se depositaron mediante un generador de funciones, un osciloscopio y una celda electrolítica de 50 ml, provista de un ánodo soluble de zinc puro. Los reactivos utilizados son de grado analítico, y las pruebas se realizaron a temperatura de 25oC. No se utilizaron agentes acomplejantes ni abrillantadores; para que el proceso sea ambientalmente limpio. La caracterización electroquímica se realizó con mediciones de potencial de circuito abierto, resistencia a la polarización lineal y Espectroscopia de Impedancia Electroquímica, los cuales muestran que dentro del rango de ciclo de trabajo desde el 87,5% al 97,5%; y con variación de frecuencias entre 40 Hz y 100 Hz, el efecto de la corriente pulsante inversa favorece la resistencia a la corrosión del recubrimiento para valores d...

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Globally, infertility remains a prevalent and escalating health con dition with the male factor contributing partially or wholly to ap proximately half of the infertile couples (Inhorn & Patrizio, 2015), of which oxidative stress (OS) is a major contributor. OS is defined as an excessive amount of reactive oxygen species (ROS) as compared to the available amount of seminal antioxidants (Agarwal, Panner Selvam, et al., 2019; Henkel et al., 2003). Consequently, the physio logical mechanisms in maintaining the redox equilibrium, which play a crucial role for sperm functions and the fertilisation process (Henkel et al., 2003), are totally overwhelmed. As a result, OS may lead to male infertility due to the reaction between oxidants and any cellular components, hence causing an increased rate of lipid peroxi dation, loss of protein function and sperm DNA damage. Currently, it is estimated that OS is the causative factor in 30%-80% of the male

The electrochemical properties of 24 quinoxaline 1,4-diN oxide -2-ketone derivatives with varying degrees of anti-chagas activity were investigated in the aprotic solvent dimethylformamide (DMF) using cyclic voltammetry and first derivative cyclic voltammetry. For this group of compounds, the first reduction in DMF was either reversible or quasireversible and consistent with reduction of the N-oxide functionality to form the radical anion. The second reduction process for these compounds was found to be irreversible under the conditions used. The reduction potentials correlated well with molecular structure. Substitution in the 3-, 6-, and 7-positions of the quinoxaline ring by electron-withdrawing substituents directly affects the ease of reduction and improves the biological activities of these compounds, whereas substitution by electrondonating groups has the opposite effect. The results of this study when combined with previous work into their mechanism of action against chagas disease suggest that charge transfer might play a role in the mechanism of action for these compounds.

As a continuation of our research and with the aim of obtaining new agents against Chagas disease, an extremely neglected disease which threatens 100 million people, eighteen new quinoxaline 1,4-diN oxide derivatives have been synthesized following the Beirut reaction. The synthesis of the new derivatives was optimized through the use of a new and more efficient microwave-assisted organic synthetic method. The new derivatives showed excellent in vitro biological activity against Trypanosoma cruzi. Compound 17, which was substituted with fluoro groups at the 6-and 7-positions of the quinoxaline ring, was the most active and selective in the cytotoxicity assay. The electrochemical study showed that the most active compounds, which were substituted by electron-withdrawing groups, possessed a greater ease of reduction of the N-oxide groups.

The oxidation-reduction potential (ORP) is highly related to Hg re-emission in wet flue gas desulfurization (WFGD) systems in coal-fired power plants. Developing an accurate model that describes the ORP characteristics is beneficial to achieve the operation optimization of the WFGD system and Hg re-emission reduction. In this paper, steady and dynamic ORP models were reported based on the least squares support vector machine (LSSVM) technique and using operating data acquired from a coal-fired power plant. For the steady model, input parameters consisted of flue gas flow, flue gas temperature, inlet SO 2 concentration, oxidation air flow, recycle pump currents, and slurry feed flow. For the dynamic model, in addition to the parameters listed above, time delays of these parameters were also considered in the modeling scheme. Both models achieved high accurate predictions. Model sensitivity analysis was conducted to investigate the influence of the input parameters and time delays on ORP. Results show that the parameters are adequate to describe the characteristics of the ORP. In addition, parametric time delays play an important role to represent the dynamic characteristics of the ORP. These models can be extended to design process control strategy and conduct the ORP operation optimization of the WFGD system in power plants to mitigate Hg re-emission from the scrubber.

Standard postharvest unit operations that rely on copious water contact, such as fruit unloading and washing, approach the criteria for a true critical control point in fresh tomato production. Performance data for approved sanitizers that reflect commercial systems are needed to set standards for audit compliance. This study was conducted to evaluate the efficacy of chlorine dioxide (ClO2) for water disinfection as an objective assessment of recent industry-adopted standards for dump tank and flume management in fresh tomato packing operations. On-site assessments were conducted during eight temporally distinct shifts in two Florida packinghouses and one California packinghouse. Microbiological analyses of incoming and washed fruit and dump and flume system water were evaluated. Water temperature, pH, turbidity, conductivity, and oxidation-reduction potential (ORP) were monitored. Reduction in populations of mesophilic and coliform bacteria on fruit was not significant, and populat...

Uma série de seis derivados de ferroceno contendo uma cadeia lateral de semicarbazona ou tiossemicarbazona foi investigada por voltametria cíclica e estudos utilizando medidas de tempo de vida de pósitrons. Ambos os fenômenos, tanto o processo redox como o de captura de elétrons, ocorreram no átomo de ferro. Foram propostas correlações entre os dois métodos, levando em conta os substituintes na cadeia lateral dos compostos, os potenciais redox e as probabilidades de formação de o-positrônio (o-Ps). A series of six ferrocene derivatives containing a semicarbazone or thiosemicarbazone side chain was investigated by cyclic voltammetry and positron annihilation lifetime measurements. Both the redox and the electron capture processes took place on the Fe atom. Correlations between the two methods were proposed, taking into account the substituents on the side chain of the compounds, their redox potentials and the probabilities of o-positronium (o-Ps).formation.

ÐThe electronic effect of some meta-or para-substituents on the reduction of the title compounds has been investigated. The reversible reduction potential values of these compounds have been evaluated by cyclic voltammetry at a mercury electrode in 0.1 M tetraethylammoniumtetra¯uoroborate, dimethylsulfoxide solutions. The substituent effect depends on both its nature and its position. The reduction potential values of the derivatives studied have been correlated with the Hammett substituent constants.

ÐThe electronic effect of some meta-or para-substituents on the reduction of the title compounds has been investigated. The reversible reduction potential values of these compounds have been evaluated by cyclic voltammetry at a mercury electrode in 0.1 M tetraethylammoniumtetra¯uoroborate, dimethylsulfoxide solutions. The substituent effect depends on both its nature and its position. The reduction potential values of the derivatives studied have been correlated with the Hammett substituent constants.

with higher precision. This application also highlights its ability to be used in other haploid samples such as second polar bodies or in vitro-generated gametes. In addition, our data supports the fact that aneuploidy rates in human sperm are low.

The role of oxidative stress in male infertility has been broadly recognised, and the search for a new marker to determine the redox environment in semen has gained considerable interest. Oxidation-reduction potential (ORP) or redox potential, is a measure of the electron transfer from antioxidants to oxidants and provides information on the redox balance. In this review, the benefits of ORP as a new oxidative stress marker, the protocol for its evaluation and the importance of its measurement in the context of male infertility are discussed. In association with the standard semen analysis, seminal ORP has been analysed to evaluate semen quality and male fertility status. However, further studies are required to establish its use in assisted reproductive techniques (ART) practice.

Oxidation-reduction potential describes the balance between the oxidants and antioxidants in fluids including semen. Various artificial culture media are used in andrology and IVF laboratories for sperm preparation and to support the development of fertilized oocytes under in vitro conditions. The composition and conditions of these media are vital for optimal functioning of the gametes. Currently, there are no data on the status of redox potential of sperm processing and assisted reproduction media. The purpose of this study was to compare the oxidation-reduction potential values of the different media and to calibrate the oxidation-reduction potential values of the sperm wash medium using oxidative stress inducer cumene hydroperoxide and antioxidant ascorbic acid. Redox potential was measured in 10 different media ranging from sperm wash media, freezing media and assisted reproductive technology one-step medium to sequential media. Oxidation-reduction potential values of the sequential culture medium and one-step culture medium were lower and significantly different (p < 0.05) from the sperm wash media. Calibration of the sperm wash media using the oxidant cumene hydroperoxide and antioxidant ascorbic acid demonstrated that oxidation-reduction potential and the concentration of oxidant or antioxidant are logarithmically dependent. This study highlights the importance of calibrating the oxidation-reduction potential levels of the sperm wash media in order to utilize it as a reference value to identify the physiological range of oxidation oxidation-reduction potential that does not have any adverse effect on normal physiological sperm function.

Oxidative stress (OS) is an important contributing factor to male infertility. While previous methods to measure seminal OS are time-consuming and limited to the use of freshly produced semen, oxidation reduction potential (ORP) is easier and quicker to perform and can also be used in frozen semen. Therefore, this study evaluated the clinical utility of ORP as a potential marker of male infertility. ORP was measured in semen samples from 293 patients and 15 fertile controls and categorised according to WHO criteria as normozoospermic, oligozoospermic, asthenozoospermic, teratozoospermic and oligoasthenoteratozoospermic. Receiver operating characteristic (ROC) curves were generated to differentiate these categories. Semen parameters were significantly different when subjects were grouped as control and patients or between the patient and normozoospermic group for concentration and morphology. ORP levels were significantly different between the control and normozoospermic group. When subjects were grouped based on concentration, motility, morphology or a combination of these, the area under the ROC curve, sensitivity, specificity, positive predictive value and cutoff values were significantly different. These differences were significant when combined with ORP and grouped with any two sperm abnormalities. In conclusion, ORP is a quick, easy, costeffective and reliable marker of semen quality as well as oxidative stress for use in a clinical setting.

Sperm cryopreservation has revolutionised the field of assisted reproduction, particularly when the infertile men are presenting with azoospermia (Anger, Gilbert, & Goldstein, 2003). It allows those azoospermic men to avoid the need for repeated sperm retrieval surgeries. Sperm cryopreservation is also essential for fertility preservation in cancer patients who undergo chemotherapy, radiotherapy or radical pelvic surgery (Sharma, Kattoor, Ghulmiyyah, & Agarwal, 2015). Despite recent advances in the tools and techniques of cryopreservation, the quality of post-thaw spermatozoa is still suboptimal due to the inevitable cell injury of the freezing process (Medeiros, Forell, Oliveira, & Rodrigues, 2002). Several factors had been proposed to explain the cryo-damage to human spermatozoa such as cold shock, osmotic stress and oxidative stress (OS; Amidi, Pazhohan, Shabani, Khodarahmian, & Nekoonam, 2016). The post-thaw sperm quality is critically affected by the OS status that accompanies the cryopreservation process (Bucak et al., 2010; Kumar et al., 2018). Freezing and thawing result in the generation of reactive oxygen species (ROS) in semen samples due to cold shock and dilution of seminal plasma (Watson, 2000). The susceptibility of spermatozoa to ROS-induced damage is due to the large content of polyunsaturated fatty acids (PUFA) in their plasma membranes (Alvarez & Storey, 1995) and the small amount of scavenging antioxidants in their cytoplasm (Sharma & Agarwal, 1996). Sperm damage due to excess ROS is mediated via reduction of motility and fertilising potential;

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Globally, infertility remains a prevalent and escalating health con dition with the male factor contributing partially or wholly to ap proximately half of the infertile couples (Inhorn & Patrizio, 2015), of which oxidative stress (OS) is a major contributor. OS is defined as an excessive amount of reactive oxygen species (ROS) as compared to the available amount of seminal antioxidants (Agarwal, Panner Selvam, et al., 2019; Henkel et al., 2003). Consequently, the physio logical mechanisms in maintaining the redox equilibrium, which play a crucial role for sperm functions and the fertilisation process (Henkel et al., 2003), are totally overwhelmed. As a result, OS may lead to male infertility due to the reaction between oxidants and any cellular components, hence causing an increased rate of lipid peroxi dation, loss of protein function and sperm DNA damage. Currently, it is estimated that OS is the causative factor in 30%-80% of the male

Oxidation-reduction potential (ORP) is a newer integrated measure of the balance between total oxidants (reactive oxygen species-ROS) and reductants (antioxidants) that reflects oxidative stress in a biological system. This study measures ORP and evaluates the effect of exogenous induction of oxidative stress by cumene hydroperoxide (CH) on ORP in fresh and frozen semen using the MiOXSYS Analyzer. Semen samples from healthy donors (n = 20) were collected and evaluated for sperm parameters. All samples were then flash-frozen at -80°C. Oxidative stress was induced by CH (5 and 50 μmoles/ml). Static ORP (sORP-(mV/10(6) sperm/ml) and capacity ORP (cORP-μC/10(6) sperm/ml) were measured in all samples before and after freezing. All values are reported as mean ± SEM. Both 5 and 50 μmoles/ml of CH resulted in a significant decline in per cent motility compared to control in pre-freeze semen samples. The increase in both pre-freeze and post-thaw semen samples for sORP was higher in the contr...

A series containing twelve substituted styryl 2-phenothiazenyl ketones have been synthesized. The electrochemical potentials of carbonyl and vinyl groups were measured. These potentials are correlated with Hammett substituent constants, F and R parameters. From the results of statistical analyses, the effects of substituent on the group reduction potentials have been discussed. The insect antifeedant activities of these chalcones have been studied using 4th instar larvae Achoea Janata L with castor leaf discs.

The anaerobic degradation pathway of hexachlorobenzene starts with a series of reductive dehalogenatlon steps. In the present paper it was evaluated whether the dehalogenation pathway observed m microbial ecosystems could be predicted by the redox potential and/or the reduction potential (the latter determined in dimethylsulforade) of the various potential intermediates. It was found that these two parameters suggest different pathways. The redox potential correctly predicts the dominant pathway observed m microbial systems, while the reduction potential does not. The redox potential of the various redox couples showed no correlation with the kinetic constants for the various dechlorination steps as determined with a quantitative structure-actwlty relationship developed for the environmental reductive dehalogenation of chlorinated aromatic compounds, even though both approaches predicted the same pathway

A new series of ruthenium(II) polypyridyl sensitizers with strongly electron donating dithiolate ligands Ru(dcbpy) 2 (L) and Ru(dcphen) 2 (L) where L is quinoxaline-2,3-dithiolate (qdt) or ethyl-2-cyano-3,3-dimercaptoacrylate (ecda) or 1,2-benzenedithiolate (bdt) or 3,4-toluenedithiolate (tdt), dcbpy is 4,4-dicarboxy-2,2-bipyridine, and dcphen is 4,7-dicarboxy-1,10-phenanthroline have been prepared for sensitization of nanocrystalline TiO 2 electrodes. All the complexes exhibit a broad metal-to-ligand charge transfer absorption band over the whole visible range. The low-energy absorption bands and the Ru(II)/(III) oxidation potentials in these complexes could be tuned to about 150 nm and 600 mV, respectively, by choosing appropriate dithiolate ligands. When anchored to nanocrystalline titanium dioxide electrodes for light to electrical energy conversion in regenerative photoelectrochemical cells with I − /I 3 − acetonitrile electrolyte, these complexes show different sensitization to TiO 2 electrodes with increasing activity in the sequence L = tdt, bdt, ecda, qdt. Both Ru(dcbpy) 2 (qdt) and Ru(dcphen) 2 (qdt) show overall cell efficiency (η) of about 3-4%, due to incident photon to current conversion efficiency of around 40-45% at 500 nm. The low cell efficiency of ecda complexes may be due to slow regeneration of the dye by electron donation from iodide following charge injection into TiO 2 .

Wooden construction constitutes a specific branch of the building industry that focuses on high-quality materials, a developed sense of aesthetics connected with comfort and functionality, and concern for ecology and durability. This type of construction has a positive effect on human quality of life. This article focuses on modular frame construction and technological aspects of wooden houses built according to Canadian or Scandinavian technologies. Taking weather conditions of Scandinavian countries into consideration, timber is a popular building material, which, when preserving certain parameters such as density of rings, may provide durability of a modular wooden building even up to 200–300 years. This article is a review and presents the possibility of producing frame buildings in Europe (Poland) in accordance with the applicable standards, including a heat transfer coefficient U = 2 [W/(m²·K]. In Poland, wooden frame buildings can be traced back to the 14th century. Wooden fr...

This paper investigates the reduction of COD of dairy industry waste water by individual and combined process of acoustic cavitation, H2O2, Fenton and Photo Fenton process. All experiments were performed on a laboratory scale setup. The effect various parameters such as sonication power, duty cycle, initial pH, hydrogen peroxide concentrations and Fenton reagents on the reduction of COD of dairy waste water have been assessed. Effective system conditions were found to be sonication power of 800W, duty cycle of 60 %, pH of 3, 200 μl/L of hydrogen peroxide concentration and 78 mg/L of Fenton reagents. The results show that the % of COD reduction of dairy industry waste water after 180 min reaction time follows the decreasing order: Acoustic Cavitation + Photo Fenton Process (88.78 %) &gt; Acoustic Cavitation + Fenton Process (66.22 %) &gt; Acoustic Cavitation + H2O2 (40.02 %) &gt; Acoustic Cavitation (13.53 %).

The textile and dye industries require ahuge amount of water for processing and produce a large volume of wastewater. Generated wastewater had potential hazards and a threat to the aquatic life.In the present study, reduction of chemical oxygen demand (COD) of textile industry waste water has been carried out using acoustic cavitation, acoustic cavitation + H 2 O 2 , acoustic cavitation + Fenton process and acoustic cavitation + Photo Fenton process. The process parameters such as sonication power, duty cycle, solution pH, loading of H 2 O 2 and loading of FeSO 4 .7H 2 O were investigated in detail to evaluate their effects on the reduction of COD of textile industry waste water. Effective optimum conditions were found to be 800W of sonication power, 60 % duty cycle, pH of 3, loading of H 2 O 2 , 75 µl/Land loading of FeSO 4 .7 H 2 O, 65 mg/L. The results showed that the percentage of COD reduction of textile industry waste water was maximumfor Acoustic cavitation + Photo Fenton process as compared to Acoustic cavitation + Fenton process, acoustic cavitation + H 2 O 2 and the conventional processes. It was also observed that percentage of COD reduction of textile industry waste water was more effective in acoustic cavitation based combined techniques as compared to individual process.

Reactions H 1000 Reduction of O2 to Superoxide Anion (O2 •-) in Water by Heteropolytungstate Cluster-Anions.-The kinetics of the electron transfer from α-[X n+ W 12 O 40 ] (9-n)-(X n+ : Al 3+ , Si 4+ , P 5+) to O2, and the effect of donor-ion charge on reduction of O2 to O2 •are monitored by UV/VIS spectroscopy. The data indicate that protonated HO2 • forms in two steps, electron transfer followed by proton transfer, rather than via simultaneous proton-coupled electron transfer. Electron transfer from reduced Keggin heteropolytungstates to O 2 occurs via outersphere electron transfer. An inherent limitation to the use of heteropolytungstate charge and reduction potential to control rates of electron transfer to O2 under turnover conditions in catalysis is revealed.-(GELETII, Y. V.;

In this study, a new organophosphorus acid-based solvent (KMC-P) from KMC Co., Ltd. was used for the recovery of the iron chloride etching waste solution. In order to increase the extraction efficiency for the new solvent in the solvent extraction process, we selected the process variables and conducted the optimization experiment according to the DOE to investigate the correlation between the variables. Solvent concentration, pH, and O/A ratio were found to be factors affecting extraction and stripping efficiency. The optimum stripping efficiency was 69.7% when the solvent concentration was 29.4 wt%, the HCl addition amount was 0 mL, and the O/A ratio was 7, and the reliability was more than 86%.

The role and importance of the redox potential phenomena in submerged citric acid production are discussed. The redox potential of the fermentation broth is the result of oxydo-reduction processes where the metabolic activity of the microorganism Aspergillus niger plays the most significant role. The course of the redox curve for a good yielding citric acid production is presented and interpreted. The experiments of submerged citric acid production were carried out on beet molasses treated with potassiurn hexacyanoferrate and inoculated with A. niger spores.

Heme c is characterized by its covalent attachment to a polypeptide. The attachment is typically to a CXXCH motif in which the two Cys form thioether bonds with the heme, "X" can be any amino acid other than Cys, and the His serves as a heme axial ligand. Some cytochromes c, however, contain heme attachment motifs with three or four intervening residues in a CX 3 CH or CX 4 CH motif. Here, the impacts of these variations in the heme attachment motif on heme ruffling and electronic structure are investigated by spectroscopically characterizing CX 3 CH and CX 4 CH variants of Hydrogenobacter thermophilus cytochrome c 552. In addition, a novel CXCH variant is studied. 1 H and 13 C NMR, EPR, and resonance Raman spectra of the protein variants are analyzed to deduce the extent of ruffling using previously reported relationships between these spectral data and heme ruffling. In addition, the reduction potentials of these protein variants are measured using protein film voltammetry. The CXCH and CX 4 CH variants are found to have enhanced heme ruffling and lower reduction potentials. Implications of these results for the use of these noncanonical motifs in nature, and for the engineering of novel heme peptide structures, are discussed.

Heme c is characterized by its covalent attachment to a polypeptide. The attachment is typically to a CXXCH motif in which the two Cys form thioether bonds with the heme, "X" can be any amino acid other than Cys, and the His serves as a heme axial ligand. Some cytochromes c, however, contain heme attachment motifs with three or four intervening residues in a CX 3 CH or CX 4 CH motif. Here, the impacts of these variations in the heme attachment motif on heme ruffling and electronic structure are investigated by spectroscopically characterizing CX 3 CH and CX 4 CH variants of Hydrogenobacter thermophilus cytochrome c 552. In addition, a novel CXCH variant is studied. 1 H and 13 C NMR, EPR, and resonance Raman spectra of the protein variants are analyzed to deduce the extent of ruffling using previously reported relationships between these spectral data and heme ruffling. In addition, the reduction potentials of these protein variants are measured using protein film voltammetry. The CXCH and CX 4 CH variants are found to have enhanced heme ruffling and lower reduction potentials. Implications of these results for the use of these noncanonical motifs in nature, and for the engineering of novel heme peptide structures, are discussed.

Effect of treatment with zinc (2.0% owm), ferrous sulphate (2.0% owm), zinc + hydrose (1.0% + 1.0% owm) and ferrous sulphate + hydrose (1.0% + 1.0% owm) reducing agents on dyeing properties of cotton fabric dyed with vat dye has been studied and the results are compared with those of the treatment with conventional hydrose (2.0% owm) in terms of reduction potential, depth of shade, and SEM analysis. The appreciable results are observed for the combination ferrous sulphate + hydrose as reducing agent, showing 99.17% colour strength with uniform dyeing and good reduction potential.

The synthesis and characterization, spectroscopic, and biological studies of 2-acetylferrocenyl-4phenylthiosemicarbazone, 2-acetylferrocenyl-4-methylthiosemicarbazone, 2-acetylpyridine-2thiophenecarboxylsemicarbazone and 2-acetylferrocenyl-2-thiophenecarboxylsemicarbazone with copper(II) chloride are reported here. The ligands were synthesized by condensation reaction of appropriate carbonyl and amine compounds. The reactions were carried out in the presence of acetic acid. The complexes were characterized by means of Elemental Analysis (EA), Fourier Transform Infrared (FT-IR) spectroscopy, Nuclear Magnetic Resonance (1 HNMR and 13 CNMR) spectroscopy. The metal complexes and their corresponding ligands were tested against malaria parasites. It was found that the copper complexes synthesized are more biologically active then their corresponding ligands.

Water is an essential element for every plant to survive, absorb nutrients, and perform photosynthesis and respiration. If water is polluted, plant growth can be truncated. The aim of this research is to develop a water quality monitoring system for agriculture purposes based on integration of sensing framework with a smart decision support method. This research consists of three stages: (1) the first stage: developing sensing framework which has four different water quality parameter sensors such as potential hydrogen (pH), electrical conductivity (EC), temperature, and oxidation-reduction potential (ORP), (2) the second stage: developing a hardware platform that uses an Arduino for sensor array of data processing and acquisition, and finally (3) the third stage: developing soft computing framework for decision support which uses python applications and fuzzy logic. The system was tested using water from many sources such as rivers, lakes, tap water, and filtered machine. Filtered ...

There is increasing interest to improve the functionality and performance of pit latrines in low income urban areas. This study aimed at assessing the ambient and pit environmental conditions and their implications on the performance (smell and fly nuisance) of pit latrines. Forty-two pit latrines were investigated in urban slums of Kampala, Uganda, through field observation and measurements of ambient and pit environmental conditions. The implications were assessed using oxygen-reduction potential (ORP) and its association with smell/insect nuisances. The pit temperature (21 to 30.7 °C), pH (5.0–11.8) and ORP (−247 to 65.9 mV) were consistently, significantly different (p &lt; 0.001) between the surface and 0.5 m depth of pit content. The conditions in most (95%) pit latrines were anoxic (ORP &lt; +50 mV), and mainly within the acid formation range (ORP −199 to −51 mV). Most smelling pit latrines and flies were within the acid formation ORP range, with a significant association (ga...

The performance of the Li-mediated ammonia synthesis has progressed dramatically since its recent reintroduction. However, fundamental understanding of this reaction is slower paced, due to the many uncontrolled variables influencing it. To address this, we developed a true non-aqueous LiFePO4 reference electrode, providing both a redox anchor from which to measure potentials against, and estimates of energy efficiency loss sources. We demonstrate its stable electrochemical potential in operation using different N2- and H2-saturated electrolytes. Using this reference, we uncover the relation between partial current density and potentials. Whilst the counter electrode potential increases linearly with current, the working electrode remains stable at lithium plating, suggesting it to be the only electrochemical step involved in this process. We also use the LiFePO4/Li+ equilibrium as a tool to probe Li-ion activity changes in situ. We hope to drive the field towards more defined syste...

The ligand electrochemical series, &(L), has been developed for many hundreds of ligands, and provides an accurate prediction of metal-centered redox potentials for coordination complexes. Semiempirical methods are used in conjunction with second-order perturbation theory to provide a new method to factorize the EL(L) parameter and extract a new and general measure of the uand n-donating and n-accepting properties of a ligand.

A series of mixed-ligand diimine–halide and diimine–dithiolene clusters based on the Mo3S7 core have been synthesized. Their optical limiting behavior was assessed by Z-scan techniques, and compared to that of a dithiolene Mo2O2S2-based cluster.

ÐThe electronic effect of some meta-or para-substituents on the reduction of the title compounds has been investigated. The reversible reduction potential values of these compounds have been evaluated by cyclic voltammetry at a mercury electrode in 0.1 M tetraethylammoniumtetra¯uoroborate, dimethylsulfoxide solutions. The substituent effect depends on both its nature and its position. The reduction potential values of the derivatives studied have been correlated with the Hammett substituent constants.

A new aqueous-compatible photoinduced electron transfer based photolabile protecting group has been developed for the release of carboxylic acids. The reduction potential of this group is more positive than previous systems, thereby allowing the use of sensitizers with modest oxidation potentials. Release of several carboxylic acids has been demonstrated using tris(bipyridyl)ruthenium(II) as both a direct sensitizer and a mediator for electron transfer between a good donor and the protecting group.