Use Of Performance Research Articles

Simple fabrication of highly sensitive capacitive pressure sensors using a porous dielectric layer with cone-shaped patterns

This study aims to improve the sensitivity of sensors using porous structures and cone-shaped patterns in the composition of a capacitive pressure sensor. A simple and rapid fabrication method for the production of porous structures and cone-shaped patterns using microwave irradiation of emulsions containing polydimethylsiloxane (PDMS) and a sacrificial solvent is introduced in this study. Through this method, a porous PDMS dielectric layer could be simply fabricated within a few minutes. The sensitivity was greatly improved by both enhancing deformability and increasing the dielectric constant under the external pressure. The effect of pattern distance was investigated, and the sensor with the pattern distance of 600 μm showed a remarkably high sensitivity of approximately 5 kPa−1. Moreover, the effect of aspect ratio and sharpness of the patterns were also studied through a finite element analysis. Finally, we demonstrated the performance of the sensor using a sensor array and finger attached sensors, and they showed sufficient performance for use in wearable devices applicable to artificial skin, surgical robots, and pressure monitoring systems, among others.

Predicting Inorganic Photovoltaic Materials with Efficiencies >26% via Structure-Relevant Machine Learning and Density Functional Calculations

Summary Discovering new inorganic photovoltaic materials becomes an efficient way for developing a new generation of solar cells with high efficiency and environmental stability. Using machine learning (ML) and density functional theory calculations, we report four promising inorganic photovoltaic materials—Ba4Te12Ge4, Ba8P8Ge4, Sr8P8Sn4, and Y4Te4Se2—demonstrating notable theoretical photovoltaic performance for use in solar cells. The symmetry-allowed optical transition probability, the large amount of density of states near the conduction band minimum (CBM) and the valence band maximum (VBM), and the strong p-p transition across the band edge contribute to the large optical absorption coefficient, leading to the outstanding theoretical power conversion efficiency (PCE). The separation of the VBM and CBM wave function distributions contribute to the fast separation of the photogenerated electrons and holes and the enhanced carrier lifetimes. Our ML model is an efficient method for fast and atomic-level accuracy prediction of photovoltaic materials with different crystal structures.

Freeze‐assisted Tape Casting of Vertically Aligned MXene Films for High Rate Performance Supercapacitors

Conventional electrode preparation techniques of supercapacitors such as tape casting or vacuum filtration often lead to the restacking or agglomeration of two‐dimensional (2D) materials. As a result, tortuous paths are created for the electrolyte ions and their adsorption onto the surfaces of the active materials can be prevented. Consequently, maintaining high rate performance while increasing the thickness of electrodes has been a challenge. Herein, a facile freeze‐assisted tape‐casting (FaTC) method is reported for the scalable fabrication of flexible MXene (Ti3C2Tx) supercapacitor electrode films of up to 700 μm thickness, exhibiting homogeneous ice‐template microstructure composed of vertically aligned MXene walls within lamellar pores. The efficient ion transport created by the internal morphology allows for fast electrochemical charge–discharge cycles and near thickness‐independent performance at up to 3000 mV s−1 for films of up to 300 μm in thickness. By increasing the scan rate from 20 to 10,000 mV s−1, Ti3C2Tx films of 150 μm in thickness sustain 50% of its specific capacitance (222.9 F g−1). When the film thickness is doubled to 300 μm, its capacitance is still retained by 60 % (at 213.3 F g−1) when the scan rate is increased from 20 to 3000 mV s−1, with a capacitance retention above 97.7% for over 14,000 cycles at 10 A g−1. They also showed a remarkably high gravimetric and areal power density of 150 kW kg−1 at 1000 A g−1 and 667 mW cm−2 at 4444 mA cm−2, respectively. FaTC has the potential to provide industry with a viable way to fabricate electrodes formed from 2D materials on a large scale, while providing promising performance for use in a wide range of applications, such as flexible electronics and wearable energy storage devices.

Revolutions in algal biochar for different applications: State-of-the-art techniques and future scenarios

Algae are potential feedstock for the production of bioenergy and valuable chemicals. After the extraction of specific value-added products, algal residues can be further converted into biogas, biofuel, and biochar through various thermochemical treatments such as conventional pyrolysis, microwave pyrolysis, hydrothermal conversion, and torrefaction. The compositions and physicochemical characteristics of algal biochar that determine the subsequent applications are comprehensively discussed. Algal biochar carbonized at high-temperature showed remarkable performance for use as supercapacitors, CO2 adsorbents, and persulfate activation, due to its graphitic carbon structure, high electron transport, and specific surface area. The algal biochar produced by pyrolysis at moderate-temperature exhibits high performance for adsorption of pollutants due to combination of miscellaneous functional groups and porous structures, whereas coal fuel can be obtained from algae via torrefaction by pyrolysis at relatively low-temperature. The aim of this review is to study the production of algal biochar in a cost-effective and environmental-friendly method and to reduce the environmental pollution associated with bioenergy generation, achieving zero emission energy production.

Advanced Sandwich Composite Cores for Patient Support in Advanced Clinical Imaging and Oncology Treatment.

Ongoing advances in both imaging and treatment for oncology purposes have seen a significant rise in the use of not only the individual imaging modalities, but also their combination in single systems such as Positron Emission Tomography combined with Computed Tomography (PET–CT) and PET–MRI (Magnetic Resonance Imaging) when planning for advanced oncology treatment, the most demanding of which is proton therapy. This has identified issues in the availability of suitable materials upon which to support the patient undergoing imaging and treatment owing to the differing requirements for each of the techniques. Sandwich composites are often selected to solve this issue but there is little information regarding optimum materials for their cores. In this paper, we presented a range of materials which are suitable for such purposes and evaluated the performance for use in terms of PET signal attenuation, proton beam stopping, MRI signal shading and X-Ray CT visibility. We found that Extruded Polystyrene offers the best compromise for patient support and positioning structures across all modalities tested, allowing for significant savings in treatment planning time and delivering more efficient treatment with lower margins.

Microstructure, mechanical and corrosion properties of Mg–Zn–Sr–Ca alloys for use as potential biodegradable implant materials

ABSTRACT Effects of Ca addition on as-cast microstructure, mechanical and corrosion properties of Mg–2Zn–0.3Sr alloy were investigated for biodegradable implant application. First, a comparison between Ca and Sr addition in Mg–2Zn alloy was studied. Mg–2Zn–0.3Sr showed the better corrosion performance, but the worse mechanical property. Then, the results of Ca addition indicated that the dendritic phases dispersed in the Mg matrix. The grains became smaller as Ca content increased. The ultimate tensile strength of Mg–2Zn–0.3Sr–0.3Ca alloy was strengthened to about 170MPa, along with a good ductility of 10%, due to the refinement of grains and homogenous morphology. The ternary alloy had the lowest degradation rate. Mg–2Zn–0.3Sr–0.3Ca still presented a considerable corrosion resistance. 0.5wt% Ca addition brought more and coarser second phases, and worse mechanical and corrosion property. It is suggested that minor addition of Ca (0.1–0.3wt%) in Mg–2Zn–0.3Sr alloy would benefit the practical performance for use in biodegradable implants.

Inter-rater reliability, intra-rater reliability and internal consistency of the Brisbane Evidence-Based Language Test

Purpose To examine the inter-rater reliability, intra-rater reliability, internal consistency and practice effects associated with a new test, the Brisbane Evidence-Based Language Test. Methods Reliability estimates were obtained in a repeated-measures design through analysis of clinician video ratings of stroke participants completing the Brisbane Evidence-Based Language Test. Inter-rater reliability was determined by comparing 15 independent clinicians’ scores of 15 randomly selected videos. Intra-rater reliability was determined by comparing two clinicians’ scores of 35 videos when re-scored after a two-week interval. Results Intraclass correlation coefficient (ICC) analysis demonstrated almost perfect inter-rater reliability (0.995; 95% confidence interval: 0.990–0.998), intra-rater reliability (0.994; 95% confidence interval: 0.989–0.997) and internal consistency (Cronbach’s α = 0.940 (95% confidence interval: 0.920–1.0)). Almost perfect correlations (0.998; 95% confidence interval: 0.995–0.999) between face-to-face and video ratings were obtained. Conclusion The Brisbane Evidence-Based Language Test demonstrates almost perfect inter-rater reliability, intra-rater reliability and internal consistency. High correlation coefficients and narrow confidence intervals demonstrated minimal practice effects with scoring or influence of years of clinical experience on test scores. Almost perfect correlations between face-to-face and video scoring methods indicate these reliability estimates have direct application to everyday practice. The test is available from brisbanetest.org. Implications for Rehabilitation The Brisbane Evidence-Based Language Test is a new measure for the assessment of acquired language disorders. The Brisbane Evidence-Based Language Test demonstrated almost perfect inter-rater reliability, intra-rater reliability and internal consistency. High reliability estimates and narrow confidence intervals indicated that test ratings vary minimally when administered by clinicians of different experience levels, or different levels of familiarity with the new measure. The test is a reliable measure of language performance for use in clinical practice and research.

Delivery of occupant satisfaction in the House of Commons, 1950–2019

The debating chamber of the House of Commons was rebuilt and completed in 1950. It has acted as a learning laboratory for 70 years for occupant satisfaction. Although trials and experiments were undertaken to assess and refine its design empirically, under real-life conditions it did not perform as the design consultants had envisaged. The present study of its history between 1950 and 1954 illustrates that its performance was scrutinised by users, became the subject of scientific investigations, and underwent further physical and operational changes. These critical engagements with performance in use are ongoing. A second period of use is also examined covering the period 1995–2019 using archival research and interviews. This reveals the sociotechnical nature of day-to-day operational procedures, involving collaboration between users and staff as well as between technical and non-technical staff. This process enabled a strong engagement with technical, environmental and human aspects of performance. Insights into the practical reality of building operation are illustrated along with process of continual learning and active stewardship. Practice relevance The post-occupancy history of the House of Commons provides a unique-case, rich study on continual institutional learning about environmental control in public buildings. It sheds a critical light on the nature of facilities management as a practice, and also challenges the traditional boundaries drawn between those responsible for the design, post-occupancy evaluation and routine operation of buildings. Facilities management could not be confined to the technological operations administered by technical staff, but depended on collaboration with occupants and non-technical staff, enabling the integration of social and technological processes. Much understanding was based on ephemeral knowledge that staff had acquired through social interactions and practical experience. The paper illustrates how such practical knowledge of performance was acquired, retained and used in facilities management practice. This expanded approach is also critical for design consultants to gain more appropriate knowledge about the actual use and performance of buildings.

0218 Biomathematical Modeling Predicts Fatigue Risk in General Surgery Residents

Abstract Introduction Fatigue and its effects on performance have long been a concern in medicine. Evidence exists that current duty-hour restrictions for resident trainees have a limited impact on physician wellbeing and patient safety, prompting renewed efforts to address this threat. In this study, sleep patterns of general-surgery residents were used to optimize a biomathematical model of performance for use as a tool for fatigue risk management with residents. Methods General surgery residents based at a multi-hospital, general surgery residency program were approached for participation in this study. Enrolled residents wore actigraph devices for 8 weeks and completed subjective sleep assessments. Sleep data and shift schedules were then input into the Sleep, Activity, Fatigue and Task Effectiveness (SAFTE) Model to assess predicted cognitive performance. Performance was compared to an “effectiveness” level of 77 (equivalent to a blood-alcohol content of 0.05g/dL). Eight hours of sleep debt was considered “below reservoir criteria”. Results Sleep actigraphy data was collected from 22 general surgery residents. Modeling results showed that as shift lengths increased, effectiveness scores generally decreased, and the time spent below criterion (77) increased. Additionally, 11.13% of time on shift was below the effectiveness criterion and 42.7% of shifts included time spent below the reservoir criterion. Adjustments to the sleep prediction were made based on actual sleep, and performance predictions from actual sleep and the adjusted model were significantly correlated (p<.0001). Conclusion Despite adherence to national standards limiting work hours, current surgical resident sleep patterns and shift schedules create concerning levels of fatigue. This study illustrates how biomathematical fatigue models can predict resident physician sleep patterns and performance. Modeling represents a novel and important tool for medical educators seeking to create shift schedules that maintain physician preparedness and minimize fatigue risk. Support N/A

Genomic Selection Using Pedigree and Marker-by-Environment Interaction for Barley Seed Quality Traits From Two Commercial Breeding Programs.

With the current advances in the development of low-cost high-density array-based DNA marker technologies, cereal breeding programs are increasingly relying on genomic selection as a tool to accelerate the rate of genetic gain in seed quality traits. Different sources of genetic information are being explored, with the most prevalent being combined additive information from marker and pedigree-based data, and their interaction with the environment. In this, there has been mixed evidence on the performance of use of these data. This study undertook an extensive analysis of 907 elite winter barley (Hordeum vulgare L.) lines across multiple environments from two breeding companies. Six genomic prediction models were evaluated to demonstrate the effect of using pedigree and marker information individually and in combination, as well their interactions with the environment. Each model was evaluated using three cross-validation schemes that allows the prediction of newly developed lines (lines that have not been evaluated in any environment), prediction of new or unobserved years, and prediction of newly developed lines in unobserved years. The results showed that the best prediction model depends on the cross-validation scheme employed. In predicting newly developed lines in known environments, marker information had no advantage to pedigree information. Predictions in this scenario also benefited from including genotype-by-environment interaction in the models. However, when predicting lines and years not observed previously, marker information was superior to pedigree data. Nonetheless, such scenarios did not benefit from the addition of genotype-by-environment interaction. A combination of pedigree-based and marker-based information produced a similar or only marginal improvement in prediction ability. It was also discovered that combining populations from the different breeding programs to increase training population size had no advantage in prediction.

Evaluating Low Cost Sensor Performance for Use in Industrial Internet-of-Things Platforms: Distributed Sensing Solutions for Urban Area Air Quality Health Monitors

The “Array of Things” project in Chicago, IL (U.S) is a ‘smart-cities’ joint initiative funded by the National Science Foundation and involving a partnership between Argonne National Laboratory, the University of Chicago, and the City of Chicago [1]. Several hundred of these platforms are distributed about the city of Chicago and each incorporates seven low-power electrochemical gas sensors for measuring the air quality health of the city. This collection of nodes is the foundation of an Industrial-Internet-of-Things, managed by a public institution, for the benefit of the surrounding communities. It presents a unique opportunity to develop smart sensor algorithms to calibrate these low-cost sensors, thereby providing meaningful and accurate data to map and identify sources of air pollution or to inform the communities of poor air quality days.To create the numerical calibration methods, ozone (O3), nitrogen dioxide (NO2), and carbon monoxide (CO) gas sensors are compared to reference grade monitors, with data collected between March 2018 and June 2019. The gas sensor sub-assembly board was calibrated in the labs at KWJ Engineering, Inc. (Newark, CA) in October 2017. The AoT node was installed and began operating at the EPA ComEd measurement site in Chicago (7801 S Lawndale Ave, Chicago, IL 60652), with help from Pinaki Banerjee of the Cook County Department of Environment and Sustainability. CO reference instrumentation was provided by Max Berkerlhamer of the University of Illinois – Chicago; NO2 and O3 data were from the EPA instruments run by Cook County. Sensor data is collected at 5-minute intervals, while reference data is reported at 1 hour (NO2/O3) and ½ hour intervals (CO). Over the course of 15 months, the reference data showed peak NO2 and O3 values of about 90 ppb, typically with opposite diurnal cycles. During the four months of CO reference monitoring, the range of recorded values were between 150 and 1,500 ppb. To reach these lower detection limits with low cost sensors, methods to remotely zero and span must be developed to overcome the effects of time, as well as outdoor temperature, humidity, and pressure extremes.The main advantage to EPA or research grade instrumentation is the ability to zero and calibrate the equipment at regular intervals. For instance, an EPA site may report an 8-hour moving average for O3 and/or NO2, and this equipment may be zeroed and calibrated on a weekly or daily schedule. For an air monitor mounted on a telephone pole, or internal to a publicly accessible structure (such as a bus stop), calibration methods requiring gas exposure are not feasible. As an alternative method, numerical zeroing using known or anticipated low values can enable an estimation of a zero. These low points can be timed to a weekly or sometimes a diurnal schedule. EC sensors have a typical baseline exponential sensitivity to temperature, which can change over time. Methods to predict this change for the CO sensor increased the R2 correlation from 0.14 when using a static calibration factor to 0.72 when using a time dependent dynamic factor. For determining the appropriate numerical span values ‘nearest neighbor’ methods can be implemented, using either a publicly available reference station, such as an EPA monitoring site, or similarly timing to a known or expected high point. Also important to the sensor stability are averaging methods that can respond quickly to environmental releases of pollutants. Approaches to these methods depend on the targeted gas as well as the sensors' chemistry including the effects of interference from other gasses typically present in air. For example, in this system the NO2 and O3 co-dependence is also shown to change with time. For the NO2 sensor the baseline (diurnal minimum) should decay over time, similar to the CO sensor. However, with increasing sensitivity to O3, the baseline will start to increase, and this pattern can be used to infer the increasing sensitivity to O3.While improvements to sensor design will mitigate some of the shortcomings of low power sensors, this work highlights important numerical methods, and will provide examples to improve the integrity of low-power sensing nodes for future distributed gas sensing networks, allowing for wider implementation of smart-city platforms at a lower cost to the public for implementation.[1] Catlett CE, Beckman PH, Sankaran R, Galvin KK. Array of things: a scientific research instrument in the public way: platform design and early lessons learned, Proceedings of the 2nd International Workshop on Science of Smart City Operations and Platforms Engineering, 26-33 (2017) Figure 1

Permutation of UTME Multiple-Choice Test Items on Performance in Use of English and Mathematics Among Prospective Higher Education Students

In an attempt to curtail examination malpractice, the Joint Admission and Matriculation Board (JAMB) has been generating different paper types with a different order of test items in the Unified Tertiary Matriculation Examination (UTME). However, the permutation of test items may compromise students’ performance unintentionally because constructive suggestions in theory and practice recommend that test items be sequenced in ascending order of difficulty. This study used data collected from a random sample of 1,226 SSIII students to ascertain whether the permutation of test items has any effect on the performance of students in two different subjects (Use of English and Mathematics). The study adopted the Equivalent Groups Quasi-Experimental Research Design with three independent groups. Findings emerged, amongst others, that there is a significant difference in the performance scores of prospective university students’ in use of English and Mathematics examintaions arranged in three different orders (ED, DE, R). There are no significant gender differences in the performance of students in Use of English and Mathematics based on test item permutation. However female students perform better than male students when test items are arranged in ascending order of difficulty while males perform better when test items are arranged in descending order of difficulty. It was concluded that the permutation of test items in UTME examination tends to affect the performance of students in Use of English and Mathematics. This finding has implications for the future conduct of UTME examinations and enrolment into higher education as the randomization of UTME test items changes the difficulty order of different paper types. It was recommended that other measures of curtailing examination malpractices that would not affect students’ academic performance should be adopted.

Role of substrate temperature and tellurium flux on the electrical and optical properties of MBE grown GeTe and Sb2Te3 thin films on GaAs (100)

Van der Waals layered GeTe/Sb2Te3 chalcogenide superlattices have demonstrated outstanding performance for use in dynamic resistive memories in what is known as interfacial phase change memory devices due to their low power requirement and fast switching. These devices are made from the periodic stacking of nanometer thick crystalline layers of chalcogenide phase change materials. The mechanism for this transition is still debated, though it varies from that of traditional phase change melt-quench transition observed in singular layers of GeTe and Sb2Te3. In order to better understand the mechanism and behavior of this transition, a thorough study on each constituent layer and the parameters for growth via molecular beam epitaxy was performed. In this work, the authors show the effect of tellurium overpressure and substrate temperature on the growth of thin film GeTe and Sb2Te3 on (100) GaAs. The authors demonstrate the significant role during growth that tellurium overpressure plays in the transport properties of both GeTe and Sb2Te3, as well as the negligible impact this has on both the structural and optical properties. The highest mobility recorded was 466 cm2/V s with a p-type bulk carrier concentration of 1.5 × 1019 cm−3 in Sb2Te3. For GeTe, the highest achieved was 55 cm2/V s at a p-type bulk carrier concentration of 8.6 × 1020 cm−3. The authors discuss transport properties, orientation, and crystal structure and the parameters needed to achieve high mobility chalcogenide thin films.

Generation of the Rat Monoclonal Antibody Against the Extracellular Domain of Human CD63 by DNA Immunization.

Human cluster of differentiation 63 (hCD63) is one of the tetraspanin receptors that is abundant on the surface of exosomes. Exosomes are involved in cell-to-cell communication, including from cancer cells to normal cells. It is very important to detect exosomes as a marker for the diagnosis of various diseases. In this study, we report the generation and characterization of a monoclonal antibody (mAb) against the extracellular domain of hCD63 using DNA immunization. This mAb, clone 1C8-2B11, exhibits high performance for use in immunofluorescence and flow cytometry, and it has 10-fold higher affinity than the control antibody that is commercially available. mAb 1C8-2B11 has great potential to be a tool for research and clinical diagnosis.

Enhanced Electrochemical Performance of MWCNT-Intercalated Silica/Sulfur Composite Cathode for Rechargeable Lithium-Sulfur Batteries

Sulfur (S)/silicon dioxide (SiO2)/multiwalled carbon nanotube (MWCNT) ternary composites with potential application in high-performance lithium-sulfur (Li-S) batteries have been prepared by a heat treatment method. The S/SiO2/MWCNT composite with MWCNT content of 20 wt.% exhibited efficient electrochemical performance for use as a cathode in Li-S batteries, with initial discharge capacity of 926 mAh g−1 and coulombic efficiency of 99% at 0.2 C rate. A discharge capacity of 501 mAh g−1 was observed after 300 cycles with a decay rate of 0.15% per cycle. The average capacity retention was found to be 81.7% and 54.1% after 100 cycles and 300 cycles, respectively. These results demonstrate that a high content of MWCNT improved the electronic conductivity while the SiO2/MWCNT matrix represents a strong physical and chemical host for the polysulfides and active material. This study determines the combined effect of silica and MWCNT to improve the performance of the sulfur cathode.

ANALYSIS OF USE OF VARIOUS MATERIALS IN WATER PURIFICATION PROJECT

Availability of clean drinking water is becoming a major issue in the 21st century. The issue is increased because of decreasing water sources and increased population and related agriculture and industrial consumption requirement. There are different methods of cleaning the water but the world is changing to more environmentally friendly methods. Use of solar still is one of the methods which has lower carbon footprints. The present study conducted an experiment and compared the performance of use of four different type of materials including wiry sponge, black volcanic rocks, coated metallic, and uncoated metallic wiry sponge. The experiment continued for 1 week and the performance was monitored on hourly basis. The results show that among the four materials used in the solar still, the coated metallic material had the highest productivity level; followed by the black volcanic rocks.

Validity and Performance of the Patient Health Questionnaire (PHQ-2) for Screening of Depression in a Rural Chilean Cohort.

Validity of PHQ-2 to screen for depression was assessed in an agricultural population in Chile. The sample included 4767 adults enrolled from 2014 to 2017 in a population-based cohort of chronic disease in Maule, Chile. Receiver operating characteristic (ROC) curve analysis was used to find the optimal PHQ-2 cut-off for depression, defined as the highest Youden index, using PHQ-9 as a reference standard. Sensitivity, specificity, and Youden J index were calculated for every cut-off point of PHQ-2. Prevalence of depression measured by PHQ-9 and PHQ-2 was 18% and 18.4%, respectively. Corresponding rates for women were 24.7% and 23.6%, and 8.3% and 10.9 for men. The optimal PHQ-2 cut-off score was 3, achieved with a sensitivity of 74.6%, specificity 93.9%, and Youden index of 0.68. The area under the curve for the ROC analysis ROC curve was 0.92 (95% CI 0.91-0.93). PHQ-2 has good performance for use as a test for depression screening in a rural population of Chile and can be easily applied in areas with low resources.

Synthesis and preparation of branched block polybenzimidazole membranes with high proton conductivity and single-cell performance for use in high temperature proton exchange membrane fuel cells

The application of phosphoric acid (PA)-doped polybenzimidazoles (PBIs) in high-temperature proton exchange membrane fuel cells (HTPEMFCs) requires optimal proton conductivity and fuel cell performance. Recently, we found that branched PBIs could absorb more PA due to their large free volume, and block PBIs could yield obvious nanophase-separated structures, both of which were beneficial to proton transportation. Herein, by constructing a branched PBI core block with another derived PBI structure, a novel membrane with a star-shaped, branched block matrix was prepared for the first time. The dendritic polymer backbone with a phase separation path endows the membranes with high PA doping capacity and high-efficiency proton transmission. Noticeably, a high proton conductivity (0.15 S cm−1, 160 °C) and low activation energy (5.6 kJ mol−1) were obtained under anhydrous conditions, and the peak power density of the single-cell test was as high as 713 mW cm−2 at 160 °C. The results indicate that the combination of branching and a block structure is promising for actual use in HTPEMFCs.

PARENTAL STYLES AND UNDERGRADUATE STUDENTS’ PERFORMANCE IN THE USE OF ENGLISH IN A TERTIARY INSTITUTION IN ONDO STATE, NIGERIA

The study examined how parental styles adopted affect the performance of undergraduate students in Use of English. A descriptive survey design was employed. The population consisted of 840 undergraduate students from two faculties out of the three in the university. Four instruments were used for the study. Two research questions and one hypothesis resulted from the study. Majority of the parents at 401(47.7%) adopted permissive parental style on their undergraduate students while 59(7.0%), 320(38.1%) and 60(7.2%) of the parents utilized authoritarian, uninvolved and authoritative parental styles respectively on their undergraduate students in the study area. The study also indicated that many of the undergraduate students performed moderately in Use of English in the study area 451(53.7%) and parental styles significantly influence undergraduate students’ performance in Use of English at (χ² = 680.101, df = 6, p < 0.05). The study concluded that parental styles play a significant role in determining undergraduate academic performance in Use of English. Article visualizations:

Time-correlated Single Ion Counting Mass Spectrometer with Long and Short Time-of-Flight Tubes and an Evaluation of Its Performance for Use in Trace Analysis of Allergenic Substances.

An analyte molecule was ionized using a femtosecond laser as the ionization source and was measured by a twin-type time-of-flight mass spectrometer with long (42 cm) and short (6.4 cm) flight tubes. The signal was measured using an analog signal digitizer and a time-correlated single ion counting system, and performance was evaluated by comparing data obtained from both instruments. The short mass spectrometer had a mass resolution of 450 and was used in the trace analysis of allergenic substances in a fragrance.