Minimum Rate Research Articles

Tick infestation in spur-thighed tortoise population: a pilot study for unraveling epidemiological patterns and demographic consequences

Ectoparasites, such as ticks, modulate host population dynamics by impacting demographic traits. They transmit infectious agents among their hosts, posing a critical threat to animal and public health. This study aimed to characterize and analyze the Hyalomma aegyptium infestation on one of its main hosts, the spur-thighed tortoise, its effects on demographic traits, and to determine the diversity of infectious agents present in both ticks and tortoises in the Maamora forest (northwestern Morocco). Our results show that 100% of the tortoises were parasitized by adult ticks in spring, an infestation intensity of 4 ticks/tortoise (5.1 and 3.6 ticks/tortoise in males and females, respectively; 4.2 and 3.3 ticks/tortoise in gravid and non-gravid females, respectively) and an abundance ranging from 1 to 12. Although without significant differences, male tortoises had higher tick abundances than females. The interaction of tortoise sex and body condition was significantly related to tick abundance, male body condition decreased with higher tick abundance in contrast to females. Nevertheless, the interaction of body condition and reproductive stage of females was not significantly related to tick abundance. Gravid females were significantly associated with tick abundance, showing a slightly higher infestation than non-gravid females. Molecular analysis of pooled tick samples revealed the presence of Ehrlichia ewingii, Candidatus Midichloria mitochondrii, and Rickettsia africae, with a minimum infection rate of 0.61 to 1.84%. However, blood sample analysis of the tortoises was infectious agent-free, pinpointing a lack of significant health problems. Given the possible effect on the transmission of zoonotic diseases by spur-thighed tortoises associated with their frequent collection as pets, it should be surveyed to control possible human health problems. In conservation terms, as a long-lived species, the role of tick infestation in demographic traits might be included in the management and conservation programs of spur-thighed tortoises.

On the effect of tempering temperature on the long-term creep behavior of a 10% Cr steel with low nitrogen and high boron contents

The effect of a decrease in the tempering temperature from 770 to 750 °C on the long-term creep behavior of a 10% Cr martensitic steel with 0.008 wt % B and 0.003 wt % N was studied. The evolution of microstructure and precipitation distribution during creep was examined using the interrupted tests under an applied stress of 120 MPa at 650 °C. It was found that a higher dislocation density, a finer lath structure and finer carbides after tempering at 750 °C did not provide higher long-term creep strength than after tempering at 770 °C. The creep rupture time was about 30% shorter. Effect of changes in the dislocation density, lath width, sizes of M23C6 carbides and Laves phase particles, and precipitation of V-rich MX phase on the strengthening contribution at the onset of creep and at the transient, apparent steady-state and tertiary stages was analyzed. The higher dislocation density formed by the tempering at a lower temperature provided a higher climb velocity at the transient creep stage. The higher driving force for recovery was not fully compensated by the higher strength exerted by smaller M23C6 carbides. This led to faster annihilation of the lath boundaries and a decrease in internal stress and, consequently, to an order of magnitude higher minimum creep rate of the steel after tempering at 750 °C as compared to tempering at 770 °C.

RIS-Assisted Covert Transmission in Satellite–Terrestrial Communication Systems

With the development of the sixth-generation wireless communication technology, the difficulty of covert communication in the satellite communications system (SCS) is further increased. In this paper, a satellite covert communication system based on reconfigurable intelligent surface (RIS) is studied, which consists of a satellite, a terrestrial receiver, RIS, and a warden. Specifically, the ground terminal simultaneously receives the signal transmitted by the satellite and the signal reflected by RIS, while the warden wants to overhear the transmitted signal from the satellite and that reflected by the RIS. The main target of this wort is to maximize the minimum covert rate to improve signal quality while considering the limited onboard resources, the hardware constraints of RIS, and the requirement to implement covert communication. To address the non-convex problem, we propose an effective alternating optimization scheme by jointly optimizing transmitter precoding and RIS to improve the covert communication performance of the considered system. In addition to ideal RIS, we also consider the non-ideal RIS, the angle of which is discrete in the actual case. In addition, several simplified methods are proposed to decrease the computational complexity of the covert communication optimal problem under multiple terminals. Finally, simulation results are provided to verify the superiority of the proposed scheme compared with the benchmark scheme, which suggests that the considered RIS-based satellite-terrestrial covert communication system can significantly improve the achievable masking.

Incidence Trends of Type 2 Diabetes Mellitus, Medication-Induced Diabetes, and Monogenic Diabetes in Canadian Children, Then (2006–2008) and Now (2017–2019)

Introduction. The landscape of childhood diabetes has evolved and addressing the knowledge gaps in non-Type 1 diabetes mellitus are key to accurate diagnosis. Objectives. A national surveillance study was completed between 2006 and 2008 and then repeated between 2017 and 2019 to describe Canadian incidence trends and clinical characteristics of non-Type 1 diabetes mellitus. Methods. We prospectively tracked new cases of non-Type 1 diabetes mellitus in children <18 years of age between June 1, 2017 and May 31, 2019. For each reported new case, a detailed questionnaire was completed, and cases were classified as Type 2 diabetes mellitus, medication-induced diabetes (MID), monogenic diabetes, or “indeterminate.” Minimum incidence rates and 10-year incidence trends of non-Type 1 diabetes mellitus and its subtypes were calculated. Results. 441 cases of non-Type 1 diabetes mellitus were included (Type 2 diabetes mellitus = 332; MID = 52; monogenic diabetes = 30; indeterminate = 27). Compared to 10 years ago, the incidence of MID and monogenic diabetes remained stable, while Type 2 diabetes mellitus increased by 60% ( p < 0.001 ) overall and by 37% ( p = 0.005 ) and 50% ( p = 0.001 ) in females and males, respectively. Type 2 diabetes mellitus incidence increased by 1.5 times in Indigenous ( p < 0.001 ) and doubled in Asian ( p = 0.003 ) children. Conclusions. Canadian incidence rates of childhood-onset Type 2 diabetes mellitus have significantly increased. Further research, policy, and prevention efforts are needed to curb rising rates of youth onset Type 2 diabetes mellitus.

Corrosion Studies of Temperature-Resistant Zinc Alloy Sacrificial Anodes and Casing Pipe at Different Temperatures.

In order to solve the problem of external corrosion of deep well casing in oil and gas fields, a new type of high-temperature-resistant zinc alloy sacrificial anode material was used. The temperature and corrosion resistance of the new anode material and TP140 casing were investigated by simulating the high-temperature working conditions of a deep well in an oil field using high-temperature and high-pressure corrosion tests and electrochemical tests. The results showed that at 100-120 °C, the corrosion rate of TP140 protected by a sacrificial anode was only one-tenth of that under unprotected conditions, and the minimum corrosion rate of TP140 protected by a sacrificial anode at 100 °C was 0.0089 mm/a. The results of the dynamic potential polarization curve showed that the corresponding corrosion current density of TP140 first increased and then decreased with the increase in temperature. The self-corrosion potential in sacrificial anode materials first increased and then decreased with the increase in temperature, and the potential difference with TP140 gradually decreased.

Development of a P91 uniaxial creep model for a wide stress range with an artificial neural network

ABSTRACT A uniaxial creep model that describes creep over a wide stress range was developed for P91 steel using an artificial neural network (ANN). The training dataset was based on measurements from uniaxial creep tests and information derived from a combination of the logistic creep strain prediction and the Wilshire models. The ANN model reproduces the training dataset with high accuracy (R 2 = 0.975; RMSE (Root Mean Square Error) = 0.19). The model can be easily implemented in finite element analysis (FEA) codes since it provides an analytical expression of the true creep rate as a function of temperature, true stress and true creep strain. In FEA simulations under the same conditions as the training dataset, the model provides times to rupture and minimum creep rates very close to those in the training dataset. The model can be adapted for heats with different properties from the average behaviour of the training dataset by means of a stress-scaling factor.

Surface rupturing earthquakes along the eastern Rhine Graben Boundary Fault near Ettlingen-Oberweier (Germany)

The eastern Rhine Graben Boundary Fault (eastern RGBF) forms the eastern margin of the Upper Rhine Graben (URG), the most seismically active area in the plate interiors of Europe. Despite seismic activity posing a significant threat to the densely populated URG and critical facilities therein, only a few studies have documented the paleoearthquake history and associated seismic hazard, focusing mainly on the western margin. We present the results of the first paleoseismological trenching ever conducted on the central section of the eastern RGBF. Following high-resolution near-surface geophysical studies, we excavated six trenches near Ettlingen-Oberweier (south of Karlsruhe, Germany) on one of its secondary fault strands. The nearly-vertical fault is transtensional left-lateral and splits into several NNW-SSE en échelon branches, forming a negative flower structure. Stratigraphic and structural relationships along with radiocarbon and Optically Stimulated Luminescence dating reveal a minimum of three surface-rupturing paleoearthquakes with a Mw of potentially 6.5 ± 0.5, occurring from old to young, >56 ka (EX), between 54 and 19 ka (EY), and between 15 and 1 ka (EZ). The events are poorly constrained in age due to erosional unconformities. Based on the cumulative vertical separation of 1.2 ± 0.3 m, we calculate an average vertical slip rate of 0.02 ± 0.005 mm/yr. From a horizontally offset alluvial channel, we infer a cumulative left-lateral slip of 5.9 ± 0.7 m and derive an average horizontal slip rate of 0.1 ± 0.01 mm/yr. The average net slip rate is 0.1 ± 0.02 mm/yr for the past 59.5 ± 3.8 ka. This value represents a minimum slip rate for the eastern RGBF, considering slip distribution within the different fault strands of the fault system. Our findings highlight the seismic potential of the eastern RGBF, providing new evidence of the Late Pleistocene and Holocene tectonic activity of its central section.

Energy Efficiency Optimization for a V2X Network with NOMA-CoMP Enabled

With the increase in user density, it is a challenging problem to achieve higher energy efficiency in vehicle-to-everything (V2X) networks, where frequent handovers occur as users continuously pass through dense cell boundaries. In this paper, we investigate this energy efficiency problem in a highly dense V2X network. To alleviate inter-cell interference and reduce unnecessary handovers, we propose a user-centric network architecture and utilize the coordinated multiple point (CoMP) transmission scheme to enable multiple roadside access points (APs) simultaneously to service one mobile vehicle. Moreover, non-orthogonal multiple access (NOMA) is adopted to enable multiple users to multiplex within one sub-channel and improve system spectrum reuse. Accordingly, the energy efficiency optimization problem is formulated as system achievable rate per joule, with the constraints of the AP transmit power budget, vehicle minimum rate requirements, and the maximum number of CoMP APs serving each vehicle. To solve the optimization problem, a semi-dynamic CoMP AP clustering algorithm is proposed to select a group of CoMP APs to serve a vehicle user by considering the vehicle–AP channel coefficients and the vehicle user’s achievable energy efficiency. Then, with the selected CoMP AP clusters, a bidirectional selection algorithm is applied via NOMA to select multiple vehicle users multiplexing within one sub-channel and perform sub-channel power allocation. Numerical simulations are presented to verify the effectiveness of the proposed algorithms, and the results show the improvements offered by the proposed algorithms compared to current benchmarks.

Detection of supraventricular arrhythmias with apple watch

Abstract Introduction With the recent developments in wearable technology, detecting arrhythmias has become much easier. Although smartwatches are commonly used to detect patients with atrial fibrillation, there is no consensus on their efficiency in detecting supraventricular tachycardias (SVT). Methods & Results Electrophysiological procedures were performed on 47 patients that have been previously documented to have SVT by a 12-lead ECG. All patients had sinus rhythm before the procedure. A narrow complex SVT which patients had at least once was induced by electrophysiological methods. Induced SVTs were recorded with a 6th-generation Apple Watch as one rhythm strip. Among the induced tachycardias, 27 typical AVNRT, 11 AVRT and 9 AT/AFLwere diagnosed. These records obtained from the smartwatch were evaluated by 3 cardiology residents and 3 attending cardiologists. Evaluated records were predicted among attending physicians with a minimum sensitivity of 66.0% and maximum sensitivity of 76.6%. Among residents, minimum and maximum sensitivity rates were 68.1% and 74.5%, respectively. The reliability between residents and attendings was assessed separately using Fleiss’s kappa method. The interrater reliability was found to be Kappa=0.465 (p<0.001), 95% CI (0.30-0.63) within the group of residents and Kappa=0.519, (p<0.001), 95% CI (0.35-0.68) within the group of attendings. Overall Kappa value was 0.417 (p<0.001), 95% CI (0.34-0.49), indicating a significantly important moderate level of agreement (p<0.001). Conclusion To the best of our knowledge, this is the first study showing how accurately clinicians can interpret the recording of SVTs with wearable devices such as smart watches, whose definitive diagnosis was made invasively by electrophysiological study. As presented in our study, induced, and subsequently recorded SVTs were predicted with high sensitivity and a moderate reliability rate. Adoption of smartwatches could significantly limit the delays in diagnosis and treatment of patients admitted to the hospitals with complaints of palpitations that cannot be documented.Statistics

Kinetic constraints for the formation of microniches for microaerophilic Fe(II) oxidation

Oxidation of Fe(II) by oxygen (O2) at circumneutral pH occurs abiotically or is mediated by microaerophilic Fe(II)-oxidizing bacteria. Abiotic Fe(II) oxidation(s) compete with microbial processes and the relative contribution of abiotic reactions depend on the chemical conditions, e.g. PO2, pH and the presence and identity of ferric (oxyhydr)oxide mineral surfaces, catalyzing the heterogeneous reaction. At circumneutral pH, abiotic Fe(II) oxidation proceeds rapidly, which raises the question how and to which extent neutrophilic microaerophilic Fe(II)-oxidizing bacteria can compete with chemical reactions and gain metabolic energy from microbial Fe(II) oxidation. In this study, we have investigated the environmental constraints for microaerophilic Fe(II) oxidation in a film layer characterized by diffusive supply of both atmospheric O2 (from the top) and dissolved Fe(II) (from the bottom) by use of a numerical model. A coupled diffusion–reaction model was tested at different chemical (pH and alkalinity gradients) and physical (film layer thickness) parameters to investigate their effects on the relative contributions of different reactions (abiotic homogeneous, heterogeneous and biological Fe(II) oxidation) to the overall (net) Fe(II) oxidation. A first order rate constant for biological oxidation was derived from experimental data from simplifcation of a Monod rate law to be 0.06 h−1. The simulations demonstrate distinct spatial oxidation rate patterns for all of the considered reactions. Microaerophilic Fe(II) oxidation is predominant at a uniform pH 6 and a film thickness z of 1 mm with minor importance at pH 7. Maximum biological rates were on the order of 7∙10-10 mol L−1 s−1 and are in the range of experimentally observed values. Minimum rates were close to the thermodynamic limit. In the presence of a pH gradient and z ≤ 1 mm, two distinct zones were observed: an upper zone dominated by abiotic Fe(II) oxidation (pH ∼ 7) and a lower zone dominated by microaerophilic Fe(II) oxidation (pH < 6.3), while the position and extent of the zones depend on the alkalinity. Such separation is strongly amplified for thinner films (z = 0.2 mm). The importance of heterogenous oxidation depends both on the pH and the amount of ferric (oxyhydr)oxides formed which increases with decreasing diffusive O2 supply at z > 1 mm. In combination with high resolution imaging of pH values in a biofilm, our simulations underpin the importance of pH gradients in allowing for the formation of microniches. The conditions suitable for microaerophilic Fe(II) oxidation can be predicted based on reaction time scales and three factors were identified to be especially important: i) a pH low enough (<6.3) to outcompete abiotic processes; ii) sufficiently fast diffusive supply of Fe(II) (e.g. by Fe(III)-reducing bacteria or chemical processes) with O2 concentrations below 150 μmol L−1; iii) sufficient energy gain from Fe(II) oxidation reaction considering the thermodynamic factor FT. We end by discussing strategies that Fe(II)-oxidizing microorganisms can employ to enhance their competitiveness against abiotic reactions.

Detection of Wuchereria bancrofti in human blood samples and mosquitoes in Matayos, Busia County-Kenya

Lymphatic filariasis is a mosquito borne disease which leads to abnormal painful enlarged body parts, severe disability and social stigma. We screened Wuchereria bancrofti in Matayos constituency in Busia County. Blood samples were collected from 23 villages selected purposively based on clinical case reports. Finger prick and/or venous blood sampling and mosquito collections was carried out. Antigenaemia and filarial DNA prevalence were determined. Infection rates on mosquito pools were estimated and SPSS version 26 was used for descriptive statistics analysis. A total of 262 participants were recruited, 73.3% (n = 192) of the participants had no symptoms, 14.1% (n = 5.3) had swollen legs, 5.3% (n = 14) had painful legs and 3.8% (n = 10) with scrotal swellings. Average antigenemia prevalence was 35.9% (n = 94) and DNA prevalence was at 8.0% (n = 21). A total of 1305 mosquitoes were collected and pooled into 2–20 mosquitoes of the same species and from the same village. Two pools out of 78 were positive for filarial DNA with a minimum infection rate of 0.15%. From this study, antigenaemia and infected mosquitoes are an indication of active transmission. The clinical signs are evidence that filarial infections have been in circulation for over 10 years. The global climate change phenomenon currently happening has been shown to adversely affect the transmission of vector borne diseases and is likely to increase lymphatic filariasis transmission in the area. This study therefore recommends further screening before Mass Drug Administration, morbidity management and enhanced mosquito control Programmes are recommended in the study area.

Abstract 12825: Comparison of Workout Heart Rates in Obese and Non-Obese Individuals Using Wearable Devices

Introduction: The impact of exercise on the body is influenced by various factors, including obesity. Existing research on how exercise affects heart rates of obese individuals, especially in a real-world, unsupervised setting, is limited. Our study aims to address this gap by comparing heart rates recorded during workouts in both obese and non-obese individuals using Fitbit data from the All of Us database. Methods: This study analyzed data from the "All of Us" Dataset v6, which included data from 258,188 individuals. ICD codes were used to identify people with obesity. A control group was generated using propensity score matching, accounting for age, gender, race, ethnicity, cigarette exposure, drug use, and Charlson Comorbidity Score. The heart rates during Fitbit-recorded workouts were analyzed for both the obesity cohort and the control group. The maximum and minimum heart rates for each workout session were averaged per individual, and the mean of these averages was compared between the two groups. Results: A total of 63,704 obese and 63,704 matched non-obese individuals were analyzed. Demographics for the two groups were not significantly different for variables used for matching. By recruiting available Fitbit workout data and after discarding erroneous data points, 160,248 workout records from 1,092 obese individuals and 142,065 records from 967 non-obese individuals were included in the study. The mean and the standard deviation (SD) of the average minimum and maximum heart rate for the non-obese group were 99.98 (SD=12.24) and 127.53 (SD=13.06), respectively, and for the obese group were 101.05 (SD=11.61) and 128.55 (SD=12.53), respectively (Figure 1). Conclusion: The heart rates, both maximum and minimum, during workouts were found to be higher in the obese group compared to the non-obese control group. This difference was statistically significant but small, and further research is warranted regarding the less-than-expected difference in heart rates.

Injection Flow Rate Threshold Preventing Atypical In-Cavity Pressure during Low-Pressure Powder Injection Molding

Controlling injection parameters is paramount when it comes to producing high-quality green parts using powder injection molding. This work combines experimental and numerical approaches to study the impact of injection parameters on mold in-cavity pressure and on the overall quality of green parts produced by low-pressure powder injection molding. The properties of two low-viscosity feedstocks (formulated from a water-atomized stainless-steel powder and wax-based binder system) were measured and implemented in an Autodesk Moldflow numerical model to quantify the molding pressures, which were finally validated using experimental real-scale injections. The results confirmed that an increase in mold temperature, an increase in feedstock temperature, and a decrease in solid loading decrease the mold in-cavity pressure, which was correlated with the feedstock viscosity. As a key result, real-scale injections confirmed that a minimum flow rate was required to avoid atypical high in-cavity pressure leading to several visual defects such as weld lines, flow marks, cracks, sinks, and incomplete filling. Due to differences in its thermal transfer properties, this flow rate threshold value decreases as the feedstock solid loading increases. For injection speeds higher than this value, the injection pressure measured experimentally was linearly correlated with the injection flow rate.

Modified Furlow palatoplasty using small double-opposing Z-plasty: Long-term outcome and comparison with two-flap palatoplasty.

The post-palatoplasty velopharyngeal function needs to be evaluated through long-term follow-up, but such reports are limited in the literature and there has been no consensus as to which surgical technique yields optimal velopharyngeal function with minimum complication rate. This study aimed to evaluate the long-term outcome of the modified Furlow palatoplasty using small double-opposing Z-plasty (small-DOZ). A retrospective review of consecutive patients who received palatoplasty performed by the senior author between January 2000 and March 2014 was conducted. Non-syndromic patients who underwent palatoplasty before the age of 18 months and followed-up until at least 9 years of age were included. Comparisons between the small-DOZ and two-flap methods for soft palate repair were made. A total of 196 small-DOZ and 167 two-flap palatoplasty patients were eligible in the study. Among the small-DOZ palatoplasty patients, 1 patient (0.5%) developed oronasal fistula, and 18 patients (9.2%) received velopharyngeal insufficiency (VPI) surgery (10 patients at preschool age and 8 at nine years of age). Compared with the small-DOZ palatoplasty, the oronasal fistula rate, VPI surgery rate, and the need for myringotomy tube insertion were significantly higher in the two-flap group (p =0.01, <0.01, <0.01, respectively). Patients who developed oronasal fistula had significantly higher likelihood of having velopharyngeal insufficiency (p < 0.01). The small-DOZ provided successful palatal repair with low rates of oronasal fistula and VPI in the long-term. Wound closure under minimal tension facilitated to avoid oronasal fistula. Reconstruction of the functional muscle sling enabled to achieve normal velopharyngeal function with favorable speech outcome and middle ear function.

THE SHORT-TERM EFFECTS OF WHEAT STRAW CELLULOSE ON SOIL CARBON MINERALIZATION

Cellulosic wastes constitute the majority of agricultural fields. The purpose of this study was to utilize these cellulosic wastes such as wheat straw and wheat straw cellulose on soil carbon mineralization in a sandy loam soils. Two different doses (100 and 1000 mg) of wheat straw cellulose were used to determine the carbon mineralization using CO2 respiration method. The cumulative carbon mineralization was found to be highest at the minumum doses of wheat straw cellulose with nitrogen (W-CL-N, 19.65 mg) and the lowest at the maximum doses of wheat straw (W-Straw, 14.32 mg). The results showed that the application of wheat straw cellulose at minumum doses resulted in higher carbon mineralization rate. The maximum carbon mineralization rate was observed in soil with minimum wheat straw cellulose and nitrogen source were added (1.41%). Whereas, the minimum carbon mineralization rate was determined in the soil mixed maximum wheat straw (1.03 %). The soil mixed maximum wheat straw was determined the lowest carbon mineralization rate due to its complex structure. The use of nitrogen source and organic matter with cellulose have positive effect on soil carbon mineralization. It might be said that these results describe an effective way for disposal of organic wastes.

Renewable Energy Integration on a High Inflation Economic Scenario by Means of Firework Algorithm, Genetic Algorithm and Monte Carlo Simulation

This paper presents a solution to the Renewable Energy Integration Problem (REIP) by finding the Optimal Configuration of components required in a hybrid microgrid located in Kuwait, such that the cost of energy (COE) is minimized when considering several components such as: solar panels, wind turbines, electric batteries, converters, inverters, diesel generators and connection to the power grid. The optimal configuration is found by evaluating the interaction and effects of several combinations of components via Monte-Carlo simulation, and such configurations are in turn optimized by means of 2 alternative stochastic algorithms: The Genetic Algorithm and the Fireworks Algorithm. The two approaches are compared, concluding that the Fireworks Algorithm provides more variety of configurations along the iterations before reaching convergence. The evaluation by Monte-Carlo simulation is calculated, by means of Present Worth (PW) with a minimum attractive rate of return (MARR) set to 7 percent to represent a high inflation rate-scenario, concluding that both methods can be safely used to optimize the design of hybrid micro-grids under high economical stress.&#x0D; &#x0D; Received: 18 August 2023 / Accepted: 25 October 2023 / Published: 5 November 2023

Smoothing of Binary Codes, Uniform Distributions, and Applications.

The action of a noise operator on a code transforms it into a distribution on the respective space. Some common examples from information theory include Bernoulli noise acting on a code in the Hamming space and Gaussian noise acting on a lattice in the Euclidean space. We aim to characterize the cases when the output distribution is close to the uniform distribution on the space, as measured by the Rényi divergence of order α∈(1,∞]. A version of this question is known as the channel resolvability problem in information theory, and it has implications for security guarantees in wiretap channels, error correction, discrepancy, worst-to-average case complexity reductions, and many other problems. Our work quantifies the requirements for asymptotic uniformity (perfect smoothing) and identifies explicit code families that achieve it under the action of the Bernoulli and ball noise operators on the code. We derive expressions for the minimum rate of codes required to attain asymptotically perfect smoothing. In proving our results, we leverage recent results from harmonic analysis of functions on the Hamming space. Another result pertains to the use of code families in Wyner's transmission scheme on the binary wiretap channel. We identify explicit families that guarantee strong secrecy when applied in this scheme, showing that nested Reed-Muller codes can transmit messages reliably and securely over a binary symmetric wiretap channel with a positive rate. Finally, we establish a connection between smoothing and error correction in the binary symmetric channel.

Influence of Artificially Altered Engine Oil on Tribofilm Formation and Wear Behaviour of Grey Cast Cylinder Liners

This work investigates the influence of altered engine oil on the tribological performance, focusing in particular on wear and interconnected tribofilm formation. For this purpose, Zinc dialkyldithiophosphate (ZDDP) additivated engine oils of different degradation levels, produced in an artificial oil alteration process, were used in tribometer tests with a nitride steel piston ring against a grey cast iron cylinder liner model contact. Parameters were chosen to simulate the boundary and mixed lubrication regime typical for the top dead centre conditions of an internal combustion engine of a passenger car. Wear of the cylinder liner specimens was continuously monitored during the tribometer tests by the radio-isotope concentration (RIC) method, and tribofilms were posteriorly investigated by X-ray photoelectron spectroscopy (XPS). The results clearly show that the steady-state wear rates for experiments with altered lubricants were significantly lower than for the experiments with fresh lubricants. XPS analysis on the formed tribofilms revealed a decrease in sulphide and an increase in sulphate states for altered oils evaluated at 120 °C oil temperature, correlating with a decrease in steady-state wear rate. This finding emphasizes the role of sulphate species in the tribofilm formation process and its anti-wear capabilities, in contrast to the sulphide species and the (poly-)phosphate species, as outlined in most of the ZDDP literature. Moreover, the RIC signal that represents the amount of wear in the engine oil showed a decrease over time for specific altered lubricants and test conditions. These “negative” trends in the wear signal are remarkable and have been identified as an incorporation of wear particles from the lubricant into the tribofilm. This finding is supported by XPS results that detected an iron-oxide layer with a remarkably similar quantity within the tribofilm on the surface. Based on these findings, an assessment of the minimum film formation rate and particle incorporation rate was achieved, which is an important basis for adequate tribofilm formation and wear models.

Multi-objective optimization of cortical bone grinding parameters based on particle swarm optimization.

Grinding is a fundamental operation in craniotomy. Suitable grinding parameters will not only reduce force damage, but also ensure grinding efficiency. In this study, the regression equations of material removal rate and grinding force were obtained based on the theory of cortical bone grinding and full factorial test results, a multi-objective optimization based on the particle swarm algorithm was proposed for optimizing the grinding parameters: spindle speed, feed speed, and grinding depth in the grinding process. Two conflicting objectives, minimum grinding force and maximum material removal rate, were optimized simultaneously. The results revealed that the optimal grinding parameter combination and optimization results were as follows: spindle speed of 5000 rpm, feed rate of 60 mm/min, grinding depth of 0.6 mm, grinding force of 15.1 N, and material removal rate of 113.8 mm3/min. The parameter optimization result can provide theoretical guidance for selecting cortical bone grinding parameters in actual craniotomy.

Predictions of the behavior of a single droplet and blends composed of Newtonian/viscoelastic minor phase and viscous major phase subjected to oscillatory shear flow

The oscillatory behavior of Newtonian and viscoelastic droplets in a Newtonian phase and blends composed of viscoelastic minor phase in a Newtonian major phase are theoretically investigated in this work. The non-Newtonian constrained volume model predictions are compared to experimental oscillatory shearing flow data of droplet and blends that are available in the literature. For a Newtonian droplet in a Newtonian phase, the model describes experimental droplet behavior well at high viscosity ratio and high strain amplitude. For viscoelastic droplet in a Newtonian phase, the model predicts less deformation for viscoelastic droplet than a comparable Newtonian droplet. For large amplitude oscillatory shear rheological data of blends composed of Boger fluid minor phase in a Newtonian major phase, the model shows improvement in prediction of the elastic modulus at high viscosity ratio, compared to the Newtonian model. The model also shows good agreement with large and minimum strain elastic moduli and large and minimum rate dynamic viscosities for small and large viscosity ratio viscoelastic polymer blends. For the blend of Boger fluid minor phase in a Newtonian major phase at viscosity ratio larger than one, we find that elasticity contributes to total stress from small to large strain amplitude values. For the blend of Boger fluid minor phase in a Newtonian major phase at viscosity ratio smaller than one, we find that elasticity is important only at large values of strain amplitude. Moreover, for the aforementioned blend at viscosity ratio larger than one, the predicted Lissajous Bowditch plots of excess stress do not reflect droplet shape/droplet orientation, and the opposite is true for the small viscosity ratio blend. Investigation of droplet long semi axis for the large viscosity ratio blend at LAOS conditions reveals oscillations at two to three times the imposed frequency.