Initial Performance Drop Research Articles

Performance analysis of amd ryzen 5 4600h mobile processor undervolting using AMD APU tuning utility on cinebench R23

In an effort to optimize laptop performance for gaming and high-demand applications without costly hardware upgrades, this research investigates the impact of CPU undervoltage using the AMD Ryzen Mobile 4600H processor. Undervolting, the process of reducing the CPU's voltage supply, is proposed as a strategy to enhance performance by lowering operational temperatures, potentially allowing for more efficient processing. This study uses the AMD APU Tuning Utility to adjust voltage settings and assesses performance changes using a series of benchmarks. Initial findings indicate that undervoltage can indeed have beneficial effects. The most significant data point from the research is the comparison of Cinebench R23 scores before and after applying undervolting settings. From a baseline score of 6835 points, system performance increased to 7880 points in the optimal undervolting scenario, an improvement of 1045 points. This shows a noticeable enhancement in processing efficiency. However, the study also reveals some complexities in undervolting, such as an initial drop in performance in the first configuration before gains are realized in subsequent adjustments. Efficiency values varied across different settings, starting with a decrease (-0.41) and culminating in a substantial gain (+1.54) by the fourth configuration. These results suggest that while undervolting can improve performance, the outcomes depend significantly on finding the right voltage balance, highlighting the nuanced nature of CPU voltage manipulation for performance optimization.

The Effect of Histology Examination Format on Medical Student Preparation and Performance: Stand-Alone Versus Integrated Examinations.

Most medical schools have transitioned from discipline-based to integrated curricula. Although the adoption of integrated examinations usually accompanies this change, stand-alone practical examinations are often retained for disciplines such as gross anatomy and histology. Due to a variety of internal and external factors, faculty at the University of Cincinnati College of Medicine recently began to phase out stand-alone histology practical examinations in favor of an integrated approach to testing. The purpose of this study was to evaluate this change by (1) comparing examination performance on histology questions administered as part of stand-alone versus integrated examinations and (2) ascertaining whether students alter their approach to learning histology content based on the examination format. Data from two courses over a period ranging from 2018 to 2022 were used to evaluate these questions. Results indicated histology question performance initially dropped after being included on integrated examinations. Stratification of students by class rank revealed this change had a greater impact on lower-performing students. Longitudinal data showed that performance 2years after the change yielded scores similar to previous standards. Despite the initial performance drop, survey results indicate students overwhelmingly prefer when histology is included on integrated examinations. Additionally, students described alterations in study approaches that align with what is known to promote better long-term retention. The results presented in this study have important implications for those at other institutions who are considering making similar changes in assessment strategies.

Degradation of electrical characteristics in low-bandgap polymer solar cells associated with light-induced aging

Abstract As the efficiency of organic solar cells has been consistently improved, interest is being raised to understand degradation mechanisms inside the solar cells. Among many factors that affect solar cell deterioration, light is the most crucial factor in the degradation mechanism. Here we report degradation under the continuous light-induced conditions for PTB7:PC70BM organic solar cells during the first 24 h with maintaining the temperature at 25 °C. It revealed 30% of initial performance drop after 24 h of light-induced aging, mostly through a decrease in JSC and FF. The morphological and electrical characteristics of the active layer and devices were investigated by atomic force microscopy, impedance spectroscopy, and temperature-dependent current density–voltage characteristics to figure out the origin of the photo-induced degradation. As a result, the light-induced traps were found to be a primary cause of loss. Furthermore, this trap formation was observed with an energy of 78 meV leading to trapped charge limited conduction properties and electrical degradation of solar cells.

Teflon/SiO₂ Bilayer Passivation for Improving the Electrical Reliability of Oxide TFTs Fabricated Using a New Two-Photomask Self-Alignment Process.

This study proposes a two-photomask process for fabricating amorphous indium–gallium–zinc oxide (a-IGZO) thin-film transistors (TFTs) that exhibit a self-aligned structure. The fabricated TFTs, which lack etching-stop (ES) layers, have undamaged a-IGZO active layers that facilitate superior performance. In addition, we demonstrate a bilayer passivation method that uses a polytetrafluoroethylene (Teflon) and SiO2 combination layer for improving the electrical reliability of the fabricated TFTs. Teflon was deposited as a buffer layer through thermal evaporation. The Teflon layer exhibited favorable compatibility with the underlying IGZO channel layer and effectively protected the a-IGZO TFTs from plasma damage during SiO2 deposition, resulting in a negligible initial performance drop in the a-IGZO TFTs. Compared with passivation-free a-IGZO TFTs, passivated TFTs exhibited superior stability even after 168 h of aging under ambient air at 95% relative humidity.

Novel Crosslinked PVA Without Photoinitiator for Organic Passivation Layers of Pentacene Thin-Film Transistors

We report a new polyvinyl alcohol (PVA)-tetraethoxysilane (TEOS) hybrid layer to protect an organic thin-film transistor (OTFT). PVA/TEOS hybrid thin film was successfully fabricated through hydrolysis and condensation mechanism. The surface roughness of PVA/TEOS film was measured by atomic force miscroscophy (AFM) and it showed a good surface roughness with a root-mean-squae value of about 0.23 nm. Thermally crosslinked PVA with TEOS was successfully adaped as a solution processable passivation layer for pentacene TFT. In case of well known photo-crosslinked PVA/ammonium dichromater (ADC) passivation, extremely large initial performance drop (almost 52% mobility drop) was observed after passivation. PVA/TEOS hybrid passiavtion, however, no significant initial performance drop was found after passivation process. In addition, pentacene TFT with PVA/TEOS passivation layer exhibited very stable TFT operation with almost no field mobility drop or threshold voltage shift up to 980 h.

High sensitivity and air stability in an organic transistor-based biosensor by inserting a CuPc layer

The improved label-free DNA sensor based on pentacene organic thin-film transistors (OTFTs) with high sensitivity and air stability was fabricated by inserting a copper phthalocyanine (CuPC) layer between metal electrodes and pentacene active layer. Compared to the electric signals of devices with bare pentacene layer, one can reasonably infer that the single-stranded DNA (ssDNA) molecules may be well immobilized onto the CuPc/pentacene film surface, as well as not degrading the performance of the DNA sensor. Furthermore, the optimized thickness of the CuPc layer for the electrical response to the ssDNA immobilization was also obtained. As a result, the device with a CuPc layer shows that the sensitivity is slightly improved, and there is no significant initial performance drop after exposure to the ambient for 30 days. CuPc is used as the interfacial layer on pentacene film to enhance the sensitivity and air stability of the OFET-based sensors.

Sulfur Poisoning of Ni/Stabilized-Zirconia Anodes – Effect on Long-Term Durability

Sulfur impurities in carbon containing fuels for solid oxide fuel cells (SOFC), e.g. natural gas and biogas, can lead to significant losses in performance due to the sulfur sensitivity of Ni/YSZ SOFC anodes. Full cells having Ni/YSZ and Ni/ScYSZ anodes have been characterized during long-term galvanostatic operation in internal reforming gas mixture (CH4/H2O/H2:30/60/10), with 2 ppm H2S exposure to the anode, at different current densities. The aim was not only to investigate the well-known initial performance drop associated with adsorbed sulfur in the Ni/stabilized-zirconia anodes, but also to focus on the long-term effect over a few hundred of hours. This work describes and correlates the observed evolution of anode performance, over hundreds of hours, with sulfur poisoning with the different operating conditions.

Teflon/SiO2 bilayer passivation for improving the electrical reliability of pentacene-based organic thin-film transistors

We demonstrate a bilayer passivation method using a Teflon and SiO2 combination layer to improve the electrical reliability of pentacene-based organic thin-film transistors (OTFTs). The Teflon was deposited as a buffer layer using a thermal evaporator that exhibited good compatibility with the underlying pentacene channel layer, and can effectively protect the OTFTs from plasma damage during the SiO2 deposition process, resulting in a negligible initial performance drop in OTFTs. Furthermore, because of the excellent moisture barrier ability of SiO2, the OTFTs exhibited good time-dependent electrical performance, even after 168h of aging in ambient air with 60–80% relative humidity.

Thermally Crosslinked Polyvinyl Alcohol (PVA) Layers for the Passivation of Pentacene Thin-Film Transistors

We report a new crosslinked polyvinyl alcohol (PVA) layer to protect organic thin-film transistors (OTFTs) using the glutaraldehyde (GA) as a crosslinking agent. After thermal crosslinking reaction of PVA with GA, the water contact angle was increased from 9.8° to 55.1° as more hydrophobic state. This clearly means that hydroxyl group of PVA surface was disappeared by the crosslinking reaction. Thermally crosslinked PVA/GA was successfully adapted as solution processable passivation layer for pentacene TFT. In case of well known photo-crosslinked PVA/ammonium dichromate (ADC) passivation, extremely large initial performance drop (almost 52% mobility drop) was observed after passivation. PVA/GA passivation, however, only 3.8% initial mobility drop was found after passivation process. In addition, pentacene TFT with PVA/GA passivation layer exhibited very stable TFT operation with almost no field effect mobility drop or threshold voltage shift up to 1100 h.

Extended lifetime of pentacene thin-film transistor with polyvinyl alcohol (PVA)/layered silicate nanocomposite passivation layer

We prepared a novel organic passivation material to protect organic thin-film transistors (OTFTs) from H 2O and O 2 using a polyvinyl alcohol (PVA)/hydrophilic layered silicate (HLS) nanocomposite system. Using up to a 3 wt% layered silicate to PVA weight concentration, a highly homogeneous nanocomposite solution was prepared. In addition, a PVA/HLS nanocomposite solution formed a smooth film layer by the spin-coating method with RMS surface roughness of about 1 nm. An OTFT device with PVA passivation showed a decrease of 23% in field effect mobility after passivation. However, a pentacene TFT device with PVA/HLS nanocomposite passivation showed no significant initial performance drop after passivation, and mobility was even slightly improved. Pentacene TFT-passivated PVA/HLS showed 2860 h of TFT lifetime (the time required to reduce the mobility by one-half of the initial mobility after passivation), which is almost twice the lifetime of pentacene TFT with PVA passivation (1320 h). We propose that a layered silicate containing PVA nanocomposite film can be used as an effective organic passivation layer in an OTFT.

Diagnosing School Decline

WHEN WE run a fever, we suspect that something is wrong with our bodies--a virus perhaps or a bacterial infection. The elevated temperature is a symptom of a deeper problem, though left untreated it can become a cause for additional problems. Such is the case with scores on standardized tests. If test scores start to drop, that may be an indication of deeper problems. Left unaddressed, declining test scores can become the cause of other problems, both for individual students and for entire schools. Researchers know a great deal about how to improve schools, but they have spent less time trying to understand what causes schools to decline in the first place. (1) One probable reason for the scarcity of research is the reluctance of declining schools to place themselves under the microscope. Here I argue that knowing the possible causes of school decline, especially an initial drop in performance, is critical for educators who want to intervene early. Failing to nip student achievement problems in the bud can set into motion a dangerous downward spiral in which every downturn triggers new problems and accelerates the school's rate of decline. (2) Of course, some low-performing schools do not experience decline, because they have never performed well. My focus here is on schools that once were characterized by adequate or even good performance but have begun to slip. A number of these schools have participated over the past four years in the University of Virginia's School Turnaround Specialist Program (STSP). This unique outreach program combines the talents of experienced educators and faculty members from the Curry School of Education and the Darden Graduate School of Business Administration. The goal is to train principals to be school turnaround specialists and to support them in their efforts to reverse a downward trend in school performance. As research director for the STSP, I have spent the past four years working with a team of researchers to understand the circumstances that confront these school turnaround specialists and to discover how they deal with them. This knowledge, combined with what we know from previous investigations of school decline, has led us to identify a number of potential indicators of school decline. By attending to these indicators when they first surface, educators are more likely to prevent a school from slipping into a self-perpetuating downward spiral. The approach I take here may best be characterized as a challenge-and-response analysis. Schools face challenges from time to time. Among the challenges associated with school decline, I want to focus on four that are common: serious budget cuts, new state and federal mandates, the loss of key personnel, and an influx of at-risk students. (3) Strictly speaking, these challenges do not cause schools to decline, but decline is a consequence of failing to address these challenges effectively. In medicine, specialists in iatrogenic medicine study medical problems created or exacerbated by improper medical practice. Education needs an equivalent enterprise devoted to examining the academic problems created or exacerbated by inadequate educational practice. Problems in addressing challenges can be found at the levels of the individual, the group, and the school. Individual teachers may fail to recognize when particular students need help, or they may prescribe a treatment that actually makes matters worse. Groups of educators may invest more energy in diverting blame for low performance than in correcting problems, thereby delaying much-needed reforms. School leaders may fail to recognize systemic issues that undermine a school's ability to raise achievement. In some cases, these failures are ones of omission. Nothing is done to address a challenge. In other cases, the problem is a failure of commission. Actions are taken, but they are inadequate or inappropriate. Here I want to identify 11 early indicators of school decline that are associated with inadequate and inappropriate responses to the aforementioned quartet of challenges. …

Reliability of high strain ionomeric polymer transducers fabricated using the directassembly process

Ionomeric polymer transducers have received considerable attention in the past severalyears. These actuators, sometimes referred to as artificial muscles, have the ability togenerate large bending strain and moderate stress at low applied voltages. As sensors, ionicpolymer transducers generate an electric response due to mechanical strain. Typically, ionicpolymer transducers are composed of Nafion-117 membranes with platinum electrodes andare saturated with water diluents. Recently the authors have developed a novel fabricationtechnique called the direct assembly process (DAP), which allowed improved control of theelectrode morphology and composition. The DAP consists of spraying two highsurface area metal–ionomer electrodes on a Nafion membrane. The benefits ofthe DAP process over previous methods is the ability to control the thickness ofthe electrode, the ability to control the composition of the electrode layer of thetransducer, and the ability for it to be used with a wide variety of diluents. In pastwork we have demonstrated that platinum, ruthenium dioxide, and single-walledcarbon nanotubes can be used as electrode material with diluents such as water,formamide, and ionic liquids. In this work we will present a reliability study oftransducers fabricated using the DAP. Water-hydrated transducers dehydrateand stop moving within 5 min while operating in air under the application of ± 2 V. Ionic liquid based transducers are demonstrated to operate in air for over 400 000 cycleswith little loss in performance, and are reliable up to 1 million cycles with a performanceloss of less than 43%. The main source of degradation is the adhesion of the conductivesurface to the high surface area electrode. This is enhanced in this study by using a PUUlinking polymer that has good adhesion properties to gold. Large voltage and large strainare proven to decrease the life of the transducer. Formamide based samples are stable for 3days under a 1 V actuation signal, while they are only reliable for 3–4 h under a2 V actuation signal. Solvent evaporation is the main reason for degradation informamide samples and it is increased at 2 V, indicating some electrochemicalactivity at such high voltages. Finally the initial drop in performance and thefluctuation in the generated strain are shown to be due to the loss of humidityabsorbed from ambient air and the fluctuation in this ambient humidity, respectively.

The effect of liquid phase on VOC removal in trickle-bed biofilters

The objective of this work was to analyze the effect of water content on the removal of volatile organic compounds (VOCs) in gas phase trickle-bed biofilters. Previous studies revealed that excessive accumulation of biomass in the reactor had a negative effect on contaminant removal efficiency. To solve this problem, periodic backwash was used to remove excess biomass and maintain an effective operation. Results showed that the ether removal efficiency dropped immediately after backwashing and gradually improved to reach the optimal value within about 24 hours. The initial drop in performance can be attributed to biological effects, such as loss of active biomass and the necessity for an adaptation period for the microbial culture. However, mass transfer limitations due to the water retained in the reactor may also be important. To investigate the effect of water content on the biofilter performance, an experiment evaluated the effect of draining after backwashing was conducted. Biofilters were allowed to drain for different periods of time before restarting the reactors. A longer lapse time in draining before the restart resulted in better ether removal efficiency. The improvement of biofilter performance after backwashing was explained with a combination of biological and physical effects. A mathematical model was then used to simulate the performance of the biofilter under these conditions and to support the conclusions obtained. The mathematical model considered a three-phase system (biofilm, water, and gas phase), dunamic processes, non-uniform bacterial population, and one limiting substrate.

The effect of liquid phase on VOC removal in trickle-bed biofilters

The objective of this work was to analyze the effect of water content on the removal of volatile organic compounds (VOCs) in gas phase trickle-bed biofilters. Previous studies revealed that excessive accumulation of biomass in the reactor had a negative effect on contaminant removal efficiency. To solve this problem, periodic backwash was used to remove excess biomass and maintain an effective operation. Results showed that the ether removal efficiency dropped immediately after backwashing and gradually improved to reach the optimal value within about 24 hours. The initial drop in performance can be attributed to biological effects, such as loss of active biomass and the necessity for an adaptation period for the microbial culture. However, mass transfer limitations due to the water retained in the reactor may also be important To investigate the effect of water content on the biofilter performance, an experiment evaluated the effect of draining after backwashing was conducted. Biofilters were allowed to drain for different periods of time before restarting the reactors. A longer lapse time in draining before the restart resulted in better ether removal efficiency. The improvement of biofilter performance after backwashing was explained with a combination of biological and physical effects. A mathematical model was then used to simulate the performance of the biofilter under these conditions and to support the conclusions obtained. The mathematical model considered a three-phase system (biofilm, water, and gas phase), dynamic processes, non-uniform bacterial population, and one limiting substrate.

Target duration effects on iconic memory: the confounding role of changing stimulus dimensions.

Observers’ accuracy in detecting a narrow spatial gap between two brief, luminous rectangles presented successively was determined within a two-alternative, forced-choice procedure. This successive-field task requires iconic memory, because the information (rectangle position) in the two presentations must be combined for successful gap detection. On this task, the effect of varying the duration of the first rectangle was systematically investigated over several target luminance levels and for several ISI conditions between rectangles. At the long ISI conditions (100 and 300 ms), the effects of increasing stimulus duration was to improve performance. However, at the brief ISI condition (20 ms), increasing stimulus duration initially depressed task performance. It was found that, with practice, this initial performance drop largely disappeared, and the beneficial influence of increasing target duration was again obtained. These results are discussed in terms of (a) a proposed retinal locus for the iconic memory involved and (b), at a more general level, the potentially distracting role of changing stimulus dimensions on a task employing transient stimuli as in the present study.

Effects of visual cortex lesions following recovery from monocular deprivation in the cat.

Six monocularly deprived (MD) and four normal cats were trained monocularly on two-choice form and pattern discriminations. MD cats trained through the initially deprived eye were able to learn the discriminations; however, they required many more trials than normals. Retention tests showed that MD cats have nearly perfect retention of the discriminations over periods of up to 4 months. With retention intervals of 6 months or longer, there is a tendency for the MD cats to show an initial drop in performance, particularly on more difficult discriminations. However, criterion performance typically was attained with considerable savings, indicating good retention even over these extended intervals. Following the preoperative training and retention testing, the cats received one of the three types of visual cortex lesions. Two MD cats received total visual cortex removal (areas 17, 18, and 19). This produced a complete postoperative loss of the discriminations with continued chance performance over 800--1000 trials. Two MD cats and two normal cats received removal of the monocular segment of area 17, with the central visual field projection region of area 17 and all of areas 18 and 19 remaining intact. This produced no loss of the discriminations in either normal or MD cats beyond what is expected on the basis of normal forgetting. Two MD cats and two normal cats received removal of areas 18, 19, and the central 5--10 deg. of the visual field projection in area 17. Postoperative retention was somewhat variable for both normal and MD cats. However, subsequent acquisition of the discriminations by both normal and MD cats was in sharp contrast to the prolonged deficits produced by total visual cortex lesions. These results indicate that one or more of visual cortical areas 17, 18, and 19 are involved in the recovery of visual discrimination capacities in MD cats. However, the monocular segment of striate cortex does not appear to be specially involved in this ability, as has been suggested by previous investigations. Possible mechanisms for the recovered visual capacities in MD cats are considered.